Support view mapping mode in projective texture painting. Disable
[blender.git] / source / blender / editors / sculpt_paint / paint_image.c
1 /*
2  * ***** BEGIN GPL LICENSE BLOCK *****
3  *
4  * This program is free software; you can redistribute it and/or
5  * modify it under the terms of the GNU General Public License
6  * as published by the Free Software Foundation; either version 2
7  * of the License, or (at your option) any later version.
8  *
9  * This program is distributed in the hope that it will be useful,
10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
12  * GNU General Public License for more details.
13  *
14  * along with this program; if not, write to the Free Software Foundation,
15  * Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
16  *
17  * The Original Code is Copyright (C) 2001-2002 by NaN Holding BV.
18  * All rights reserved.
19  *
20  * The Original Code is: some of this file.
21  *
22  * Contributor(s): Jens Ole Wund (bjornmose), Campbell Barton (ideasman42)
23  *
24  * ***** END GPL LICENSE BLOCK *****
25  */
26
27 /** \file blender/editors/sculpt_paint/paint_image.c
28  *  \ingroup edsculpt
29  *  \brief Functions to paint images in 2D and 3D.
30  */
31
32 #include <float.h>
33 #include <string.h>
34 #include <stdio.h>
35 #include <math.h>
36
37 #include "MEM_guardedalloc.h"
38
39 #ifdef WIN32
40 #  include "BLI_winstuff.h"
41 #endif
42
43 #include "BLI_math.h"
44 #include "BLI_blenlib.h"
45 #include "BLI_linklist.h"
46 #include "BLI_memarena.h"
47 #include "BLI_threads.h"
48 #include "BLI_utildefines.h"
49
50 #include "PIL_time.h"
51
52 #include "IMB_imbuf.h"
53 #include "IMB_imbuf_types.h"
54
55 #include "DNA_brush_types.h"
56 #include "DNA_mesh_types.h"
57 #include "DNA_node_types.h"
58 #include "DNA_object_types.h"
59
60 #include "BKE_camera.h"
61 #include "BKE_context.h"
62 #include "BKE_depsgraph.h"
63 #include "BKE_DerivedMesh.h"
64 #include "BKE_idprop.h"
65 #include "BKE_brush.h"
66 #include "BKE_image.h"
67 #include "BKE_library.h"
68 #include "BKE_main.h"
69 #include "BKE_mesh.h"
70 #include "BKE_node.h"
71 #include "BKE_object.h"
72 #include "BKE_paint.h"
73 #include "BKE_report.h"
74 #include "BKE_scene.h"
75 #include "BKE_colortools.h"
76
77 #include "BKE_tessmesh.h"
78
79 #include "BIF_gl.h"
80 #include "BIF_glutil.h"
81
82 #include "UI_view2d.h"
83
84 #include "ED_image.h"
85 #include "ED_screen.h"
86 #include "ED_sculpt.h"
87 #include "ED_uvedit.h"
88 #include "ED_view3d.h"
89 #include "ED_mesh.h"
90
91 #include "WM_api.h"
92 #include "WM_types.h"
93
94 #include "RNA_access.h"
95 #include "RNA_define.h"
96 #include "RNA_enum_types.h"
97
98 #include "GPU_draw.h"
99
100 #include "IMB_colormanagement.h"
101
102 #include "paint_intern.h"
103
104 /* Defines and Structs */
105 /* FTOCHAR as inline function */
106 BLI_INLINE unsigned char f_to_char(const float val)
107 {
108         return FTOCHAR(val);
109 }
110
111
112 #define IMAPAINT_CHAR_TO_FLOAT(c) ((c) / 255.0f)
113
114 #define IMAPAINT_FLOAT_RGB_TO_CHAR(c, f)  {                                   \
115         (c)[0] = f_to_char((f)[0]);                                               \
116         (c)[1] = f_to_char((f)[1]);                                               \
117         (c)[2] = f_to_char((f)[2]);                                               \
118 } (void)0
119 #define IMAPAINT_FLOAT_RGBA_TO_CHAR(c, f)  {                                  \
120         (c)[0] = f_to_char((f)[0]);                                               \
121         (c)[1] = f_to_char((f)[1]);                                               \
122         (c)[2] = f_to_char((f)[2]);                                               \
123         (c)[3] = f_to_char((f)[3]);                                               \
124 } (void)0
125 #define IMAPAINT_CHAR_RGB_TO_FLOAT(f, c)  {                                   \
126         (f)[0] = IMAPAINT_CHAR_TO_FLOAT((c)[0]);                                   \
127         (f)[1] = IMAPAINT_CHAR_TO_FLOAT((c)[1]);                                   \
128         (f)[2] = IMAPAINT_CHAR_TO_FLOAT((c)[2]);                                   \
129 } (void)0
130 #define IMAPAINT_CHAR_RGBA_TO_FLOAT(f, c)  {                                  \
131         (f)[0] = IMAPAINT_CHAR_TO_FLOAT((c)[0]);                                   \
132         (f)[1] = IMAPAINT_CHAR_TO_FLOAT((c)[1]);                                   \
133         (f)[2] = IMAPAINT_CHAR_TO_FLOAT((c)[2]);                                   \
134         (f)[3] = IMAPAINT_CHAR_TO_FLOAT((c)[3]);                                   \
135 } (void)0
136
137 #define IMAPAINT_FLOAT_RGB_COPY(a, b) copy_v3_v3(a, b)
138
139 #define IMAPAINT_TILE_BITS          6
140 #define IMAPAINT_TILE_SIZE          (1 << IMAPAINT_TILE_BITS)
141 #define IMAPAINT_TILE_NUMBER(size)  (((size) + IMAPAINT_TILE_SIZE - 1) >> IMAPAINT_TILE_BITS)
142
143 static void imapaint_image_update(Scene *scene, SpaceImage *sima, Image *image, ImBuf *ibuf, short texpaint);
144
145
146 typedef struct ImagePaintState {
147         SpaceImage *sima;
148         View2D *v2d;
149         Scene *scene;
150         bScreen *screen;
151
152         Brush *brush;
153         short tool, blend;
154         Image *image;
155         ImBuf *canvas;
156         ImBuf *clonecanvas;
157         char *warnpackedfile;
158         char *warnmultifile;
159
160         /* viewport texture paint only, but _not_ project paint */
161         Object *ob;
162         int faceindex;
163         float uv[2];
164         int do_facesel;
165
166         DerivedMesh    *dm;
167         int             dm_totface;
168         int             dm_release;
169
170         MFace          *dm_mface;
171         MTFace         *dm_mtface;
172 } ImagePaintState;
173
174 typedef struct ImagePaintPartialRedraw {
175         int x1, y1, x2, y2;  /* XXX, could use 'rcti' */
176         int enabled;
177 } ImagePaintPartialRedraw;
178
179 typedef struct ImagePaintRegion {
180         int destx, desty;
181         int srcx, srcy;
182         int width, height;
183 } ImagePaintRegion;
184
185 /* ProjectionPaint defines */
186
187 /* approx the number of buckets to have under the brush,
188  * used with the brush size to set the ps->buckets_x and ps->buckets_y value.
189  * 
190  * When 3 - a brush should have ~9 buckets under it at once
191  * ...this helps for threading while painting as well as
192  * avoiding initializing pixels that wont touch the brush */
193 #define PROJ_BUCKET_BRUSH_DIV 4
194
195 #define PROJ_BUCKET_RECT_MIN 4
196 #define PROJ_BUCKET_RECT_MAX 256
197
198 #define PROJ_BOUNDBOX_DIV 8
199 #define PROJ_BOUNDBOX_SQUARED  (PROJ_BOUNDBOX_DIV * PROJ_BOUNDBOX_DIV)
200
201 //#define PROJ_DEBUG_PAINT 1
202 //#define PROJ_DEBUG_NOSEAMBLEED 1
203 //#define PROJ_DEBUG_PRINT_CLIP 1
204 #define PROJ_DEBUG_WINCLIP 1
205
206 /* projectFaceSeamFlags options */
207 //#define PROJ_FACE_IGNORE      (1<<0)  /* When the face is hidden, backfacing or occluded */
208 //#define PROJ_FACE_INIT        (1<<1)  /* When we have initialized the faces data */
209 #define PROJ_FACE_SEAM1 (1 << 0)  /* If this face has a seam on any of its edges */
210 #define PROJ_FACE_SEAM2 (1 << 1)
211 #define PROJ_FACE_SEAM3 (1 << 2)
212 #define PROJ_FACE_SEAM4 (1 << 3)
213
214 #define PROJ_FACE_NOSEAM1   (1 << 4)
215 #define PROJ_FACE_NOSEAM2   (1 << 5)
216 #define PROJ_FACE_NOSEAM3   (1 << 6)
217 #define PROJ_FACE_NOSEAM4   (1 << 7)
218
219 #define PROJ_SRC_VIEW       1
220 #define PROJ_SRC_IMAGE_CAM  2
221 #define PROJ_SRC_IMAGE_VIEW 3
222
223 #define PROJ_VIEW_DATA_ID "view_data"
224 #define PROJ_VIEW_DATA_SIZE (4 * 4 + 4 * 4 + 3) /* viewmat + winmat + clipsta + clipend + is_ortho */
225
226
227 /* a slightly scaled down face is used to get fake 3D location for edge pixels in the seams
228  * as this number approaches  1.0f the likelihood increases of float precision errors where
229  * it is occluded by an adjacent face */
230 #define PROJ_FACE_SCALE_SEAM    0.99f
231
232 #define PROJ_BUCKET_NULL        0
233 #define PROJ_BUCKET_INIT        (1 << 0)
234 // #define PROJ_BUCKET_CLONE_INIT       (1<<1)
235
236 /* used for testing doubles, if a point is on a line etc */
237 #define PROJ_GEOM_TOLERANCE 0.00075f
238
239 /* vert flags */
240 #define PROJ_VERT_CULL 1
241
242 /* This is mainly a convenience struct used so we can keep an array of images we use
243  * Thir imbufs, etc, in 1 array, When using threads this array is copied for each thread
244  * because 'partRedrawRect' and 'touch' values would not be thread safe */
245 typedef struct ProjPaintImage {
246         Image *ima;
247         ImBuf *ibuf;
248         ImagePaintPartialRedraw *partRedrawRect;
249         void **undoRect; /* only used to build undo tiles after painting */
250         int touch;
251 } ProjPaintImage;
252
253 /* Main projection painting struct passed to all projection painting functions */
254 typedef struct ProjPaintState {
255         View3D *v3d;
256         RegionView3D *rv3d;
257         ARegion *ar;
258         Scene *scene;
259         int source; /* PROJ_SRC_**** */
260
261         Brush *brush;
262         short tool, blend;
263         Object *ob;
264         /* end similarities with ImagePaintState */
265         
266         DerivedMesh    *dm;
267         int dm_totface;
268         int dm_totvert;
269         int dm_release;
270
271         MVert          *dm_mvert;
272         MFace          *dm_mface;
273         MTFace         *dm_mtface;
274         MTFace         *dm_mtface_clone;    /* other UV map, use for cloning between layers */
275         MTFace         *dm_mtface_stencil;
276         
277         /* projection painting only */
278         MemArena *arena_mt[BLENDER_MAX_THREADS]; /* for multithreading, the first item is sometimes used for non threaded cases too */
279         LinkNode **bucketRect;              /* screen sized 2D array, each pixel has a linked list of ProjPixel's */
280         LinkNode **bucketFaces;             /* bucketRect aligned array linkList of faces overlapping each bucket */
281         unsigned char *bucketFlags;         /* store if the bucks have been initialized  */
282 #ifndef PROJ_DEBUG_NOSEAMBLEED
283         char *faceSeamFlags;                /* store info about faces, if they are initialized etc*/
284         float (*faceSeamUVs)[4][2];         /* expanded UVs for faces to use as seams */
285         LinkNode **vertFaces;               /* Only needed for when seam_bleed_px is enabled, use to find UV seams */
286 #endif
287         char *vertFlags;                    /* store options per vert, now only store if the vert is pointing away from the view */
288         int buckets_x;                      /* The size of the bucket grid, the grid span's screenMin/screenMax so you can paint outsize the screen or with 2 brushes at once */
289         int buckets_y;
290
291         ProjPaintImage *projImages;
292         
293         int pixel_sizeof;           /* result of project_paint_pixel_sizeof(), constant per stroke */
294
295         int image_tot;              /* size of projectImages array */
296         
297         float (*screenCoords)[4];   /* verts projected into floating point screen space */
298         
299         float screenMin[2];         /* 2D bounds for mesh verts on the screen's plane (screenspace) */
300         float screenMax[2]; 
301         float screen_width;         /* Calculated from screenMin & screenMax */
302         float screen_height;
303         int winx, winy;             /* from the carea or from the projection render */
304         
305         /* options for projection painting */
306         int do_layer_clone;
307         int do_layer_stencil;
308         int do_layer_stencil_inv;
309         
310         short do_occlude;               /* Use raytraced occlusion? - ortherwise will paint right through to the back*/
311         short do_backfacecull;          /* ignore faces with normals pointing away, skips a lot of raycasts if your normals are correctly flipped */
312         short do_mask_normal;           /* mask out pixels based on their normals */
313         short do_new_shading_nodes;     /* cache BKE_scene_use_new_shading_nodes value */
314         float normal_angle;             /* what angle to mask at*/
315         float normal_angle_inner;
316         float normal_angle_range;       /* difference between normal_angle and normal_angle_inner, for easy access */
317         
318         short is_ortho;
319         bool do_masking;              /* use masking during painting. Some operations such as airbrush may disable */
320         short is_texbrush;              /* only to avoid running  */
321 #ifndef PROJ_DEBUG_NOSEAMBLEED
322         float seam_bleed_px;
323 #endif
324         /* clone vars */
325         float cloneOffset[2];
326         
327         float projectMat[4][4];     /* Projection matrix, use for getting screen coords */
328         float viewDir[3];           /* View vector, use for do_backfacecull and for ray casting with an ortho viewport  */
329         float viewPos[3];           /* View location in object relative 3D space, so can compare to verts  */
330         float clipsta, clipend;
331         
332         /* reproject vars */
333         Image *reproject_image;
334         ImBuf *reproject_ibuf;
335
336
337         /* threads */
338         int thread_tot;
339         int bucketMin[2];
340         int bucketMax[2];
341         int context_bucket_x, context_bucket_y; /* must lock threads while accessing these */
342 } ProjPaintState;
343
344 typedef union pixelPointer {
345         float *f_pt;            /* float buffer */
346         unsigned int *uint_pt; /* 2 ways to access a char buffer */
347         unsigned char *ch_pt;
348 } PixelPointer;
349
350 typedef union pixelStore {
351         unsigned char ch[4];
352         unsigned int uint;
353         float f[4];
354 } PixelStore;
355
356 typedef struct ProjPixel {
357         float projCoSS[2]; /* the floating point screen projection of this pixel */
358         
359         /* Only used when the airbrush is disabled.
360          * Store the max mask value to avoid painting over an area with a lower opacity
361          * with an advantage that we can avoid touching the pixel at all, if the 
362          * new mask value is lower then mask_max */
363         unsigned short mask_max;
364         
365         /* for various reasons we may want to mask out painting onto this pixel */
366         unsigned short mask;
367         
368         short x_px, y_px;
369         
370         PixelStore origColor;
371         PixelStore newColor;
372         PixelPointer pixel;
373         
374         short image_index; /* if anyone wants to paint onto more then 32768 images they can bite me */
375         unsigned char bb_cell_index;
376 } ProjPixel;
377
378 typedef struct ProjPixelClone {
379         struct ProjPixel __pp;
380         PixelStore clonepx;
381 } ProjPixelClone;
382
383 /* blur, store surrounding colors */
384 #define PROJ_PIXEL_SOFTEN_TOT 4
385 /* blur picking offset (in screenspace) */
386 #define PROJ_PIXEL_SOFTEN_OFS_PX 1.0f
387
388 static const float proj_pixel_soften_v2[PROJ_PIXEL_SOFTEN_TOT][2] = {
389         {-PROJ_PIXEL_SOFTEN_OFS_PX,                         0.0f},
390         { 0.0f,                        -PROJ_PIXEL_SOFTEN_OFS_PX},
391         { 0.0f,                         PROJ_PIXEL_SOFTEN_OFS_PX},
392         { PROJ_PIXEL_SOFTEN_OFS_PX,                         0.0f},
393 };
394
395 /* Finish projection painting structs */
396
397 typedef struct UndoImageTile {
398         struct UndoImageTile *next, *prev;
399
400         char idname[MAX_ID_NAME];  /* name instead of pointer*/
401         char ibufname[IB_FILENAME_SIZE];
402
403         union {
404                 float        *fp;
405                 unsigned int *uint;
406                 void         *pt;
407         } rect;
408         int x, y;
409
410         short source, use_float;
411         char gen_type;
412 } UndoImageTile;
413
414 static ImagePaintPartialRedraw imapaintpartial = {0, 0, 0, 0, 0};
415
416 /* UNDO */
417
418 static void undo_copy_tile(UndoImageTile *tile, ImBuf *tmpibuf, ImBuf *ibuf, int restore)
419 {
420         /* copy or swap contents of tile->rect and region in ibuf->rect */
421         IMB_rectcpy(tmpibuf, ibuf, 0, 0, tile->x * IMAPAINT_TILE_SIZE,
422                     tile->y * IMAPAINT_TILE_SIZE, IMAPAINT_TILE_SIZE, IMAPAINT_TILE_SIZE);
423
424         if (ibuf->rect_float) {
425                 SWAP(float *, tmpibuf->rect_float, tile->rect.fp);
426         }
427         else {
428                 SWAP(unsigned int *, tmpibuf->rect, tile->rect.uint);
429         }
430         
431         if (restore)
432                 IMB_rectcpy(ibuf, tmpibuf, tile->x * IMAPAINT_TILE_SIZE,
433                             tile->y * IMAPAINT_TILE_SIZE, 0, 0, IMAPAINT_TILE_SIZE, IMAPAINT_TILE_SIZE);
434 }
435
436 static void *image_undo_push_tile(Image *ima, ImBuf *ibuf, ImBuf **tmpibuf, int x_tile, int y_tile)
437 {
438         ListBase *lb = undo_paint_push_get_list(UNDO_PAINT_IMAGE);
439         UndoImageTile *tile;
440         int allocsize;
441         short use_float = ibuf->rect_float ? 1 : 0;
442
443         for (tile = lb->first; tile; tile = tile->next)
444                 if (tile->x == x_tile && tile->y == y_tile && ima->gen_type == tile->gen_type && ima->source == tile->source)
445                         if (tile->use_float == use_float)
446                                 if (strcmp(tile->idname, ima->id.name) == 0 && strcmp(tile->ibufname, ibuf->name) == 0)
447                                         return tile->rect.pt;
448         
449         if (*tmpibuf == NULL)
450                 *tmpibuf = IMB_allocImBuf(IMAPAINT_TILE_SIZE, IMAPAINT_TILE_SIZE, 32, IB_rectfloat | IB_rect);
451         
452         tile = MEM_callocN(sizeof(UndoImageTile), "UndoImageTile");
453         BLI_strncpy(tile->idname, ima->id.name, sizeof(tile->idname));
454         tile->x = x_tile;
455         tile->y = y_tile;
456
457         allocsize = IMAPAINT_TILE_SIZE * IMAPAINT_TILE_SIZE * 4;
458         allocsize *= (ibuf->rect_float) ? sizeof(float) : sizeof(char);
459         tile->rect.pt = MEM_mapallocN(allocsize, "UndeImageTile.rect");
460
461         BLI_strncpy(tile->ibufname, ibuf->name, sizeof(tile->ibufname));
462
463         tile->gen_type = ima->gen_type;
464         tile->source = ima->source;
465         tile->use_float = use_float;
466
467         undo_copy_tile(tile, *tmpibuf, ibuf, 0);
468         undo_paint_push_count_alloc(UNDO_PAINT_IMAGE, allocsize);
469
470         BLI_addtail(lb, tile);
471         
472         return tile->rect.pt;
473 }
474
475 static void image_undo_restore(bContext *C, ListBase *lb)
476 {
477         Main *bmain = CTX_data_main(C);
478         Image *ima = NULL;
479         ImBuf *ibuf, *tmpibuf;
480         UndoImageTile *tile;
481
482         tmpibuf = IMB_allocImBuf(IMAPAINT_TILE_SIZE, IMAPAINT_TILE_SIZE, 32,
483                                  IB_rectfloat | IB_rect);
484         
485         for (tile = lb->first; tile; tile = tile->next) {
486                 short use_float;
487
488                 /* find image based on name, pointer becomes invalid with global undo */
489                 if (ima && strcmp(tile->idname, ima->id.name) == 0) {
490                         /* ima is valid */
491                 }
492                 else {
493                         ima = BLI_findstring(&bmain->image, tile->idname, offsetof(ID, name));
494                 }
495
496                 ibuf = BKE_image_acquire_ibuf(ima, NULL, NULL);
497
498                 if (ima && ibuf && strcmp(tile->ibufname, ibuf->name) != 0) {
499                         /* current ImBuf filename was changed, probably current frame
500                          * was changed when paiting on image sequence, rather than storing
501                          * full image user (which isn't so obvious, btw) try to find ImBuf with
502                          * matched file name in list of already loaded images */
503
504                         BKE_image_release_ibuf(ima, ibuf, NULL);
505
506                         ibuf = BLI_findstring(&ima->ibufs, tile->ibufname, offsetof(ImBuf, name));
507                 }
508
509                 if (!ima || !ibuf || !(ibuf->rect || ibuf->rect_float)) {
510                         BKE_image_release_ibuf(ima, ibuf, NULL);
511                         continue;
512                 }
513
514                 if (ima->gen_type != tile->gen_type || ima->source != tile->source) {
515                         BKE_image_release_ibuf(ima, ibuf, NULL);
516                         continue;
517                 }
518
519                 use_float = ibuf->rect_float ? 1 : 0;
520
521                 if (use_float != tile->use_float) {
522                         BKE_image_release_ibuf(ima, ibuf, NULL);
523                         continue;
524                 }
525
526                 undo_copy_tile(tile, tmpibuf, ibuf, 1);
527
528                 GPU_free_image(ima); /* force OpenGL reload */
529                 if (ibuf->rect_float)
530                         ibuf->userflags |= IB_RECT_INVALID; /* force recreate of char rect */
531                 if (ibuf->mipmap[0])
532                         ibuf->userflags |= IB_MIPMAP_INVALID;  /* force mipmap recreatiom */
533                 ibuf->userflags |= IB_DISPLAY_BUFFER_INVALID;
534
535                 BKE_image_release_ibuf(ima, ibuf, NULL);
536         }
537
538         IMB_freeImBuf(tmpibuf);
539 }
540
541 static void image_undo_free(ListBase *lb)
542 {
543         UndoImageTile *tile;
544
545         for (tile = lb->first; tile; tile = tile->next)
546                 MEM_freeN(tile->rect.pt);
547 }
548
549 /* get active image for face depending on old/new shading system */
550
551 static Image *imapaint_face_image(const ImagePaintState *s, int face_index)
552 {
553         Image *ima;
554
555         if (BKE_scene_use_new_shading_nodes(s->scene)) {
556                 MFace *mf = &s->dm_mface[face_index];
557                 ED_object_get_active_image(s->ob, mf->mat_nr + 1, &ima, NULL, NULL);
558         }
559         else {
560                 MTFace *tf = &s->dm_mtface[face_index];
561                 ima = tf->tpage;
562         }
563
564         return ima;
565 }
566
567 static Image *project_paint_face_image(const ProjPaintState *ps, MTFace *dm_mtface, int face_index)
568 {
569         Image *ima;
570
571         if (ps->do_new_shading_nodes) { /* cached BKE_scene_use_new_shading_nodes result */
572                 MFace *mf = ps->dm_mface + face_index;
573                 ED_object_get_active_image(ps->ob, mf->mat_nr + 1, &ima, NULL, NULL);
574         }
575         else {
576                 ima = dm_mtface[face_index].tpage;
577         }
578
579         return ima;
580 }
581
582 /* fast projection bucket array lookup, use the safe version for bound checking  */
583 static int project_bucket_offset(const ProjPaintState *ps, const float projCoSS[2])
584 {
585         /* If we were not dealing with screenspace 2D coords we could simple do...
586          * ps->bucketRect[x + (y*ps->buckets_y)] */
587         
588         /* please explain?
589          * projCoSS[0] - ps->screenMin[0]   : zero origin
590          * ... / ps->screen_width           : range from 0.0 to 1.0
591          * ... * ps->buckets_x              : use as a bucket index
592          *
593          * Second multiplication does similar but for vertical offset
594          */
595         return ( (int)(((projCoSS[0] - ps->screenMin[0]) / ps->screen_width)  * ps->buckets_x)) +
596                (((int)(((projCoSS[1] - ps->screenMin[1]) / ps->screen_height) * ps->buckets_y)) * ps->buckets_x);
597 }
598
599 static int project_bucket_offset_safe(const ProjPaintState *ps, const float projCoSS[2])
600 {
601         int bucket_index = project_bucket_offset(ps, projCoSS);
602         
603         if (bucket_index < 0 || bucket_index >= ps->buckets_x * ps->buckets_y) {
604                 return -1;
605         }
606         else {
607                 return bucket_index;
608         }
609 }
610
611 /* still use 2D X,Y space but this works for verts transformed by a perspective matrix, using their 4th component as a weight */
612 static void barycentric_weights_v2_persp(const float v1[4], const float v2[4], const float v3[4], const float co[2], float w[3])
613 {
614         float wtot_inv, wtot;
615
616         w[0] = area_tri_signed_v2(v2, v3, co) / v1[3];
617         w[1] = area_tri_signed_v2(v3, v1, co) / v2[3];
618         w[2] = area_tri_signed_v2(v1, v2, co) / v3[3];
619         wtot = w[0] + w[1] + w[2];
620
621         if (wtot != 0.0f) {
622                 wtot_inv = 1.0f / wtot;
623
624                 w[0] = w[0] * wtot_inv;
625                 w[1] = w[1] * wtot_inv;
626                 w[2] = w[2] * wtot_inv;
627         }
628         else /* dummy values for zero area face */
629                 w[0] = w[1] = w[2] = 1.0f / 3.0f;
630 }
631
632 static float VecZDepthOrtho(const float pt[2],
633                             const float v1[3], const float v2[3], const float v3[3],
634                             float w[3])
635 {
636         barycentric_weights_v2(v1, v2, v3, pt, w);
637         return (v1[2] * w[0]) + (v2[2] * w[1]) + (v3[2] * w[2]);
638 }
639
640 static float VecZDepthPersp(const float pt[2],
641                             const float v1[4], const float v2[4], const float v3[4],
642                             float w[3])
643 {
644         float wtot_inv, wtot;
645         float w_tmp[3];
646
647         barycentric_weights_v2_persp(v1, v2, v3, pt, w);
648         /* for the depth we need the weights to match what
649          * barycentric_weights_v2 would return, in this case its easiest just to
650          * undo the 4th axis division and make it unit-sum
651          *
652          * don't call barycentric_weights_v2() because our callers expect 'w'
653          * to be weighted from the perspective */
654         w_tmp[0] = w[0] * v1[3];
655         w_tmp[1] = w[1] * v2[3];
656         w_tmp[2] = w[2] * v3[3];
657
658         wtot = w_tmp[0] + w_tmp[1] + w_tmp[2];
659
660         if (wtot != 0.0f) {
661                 wtot_inv = 1.0f / wtot;
662
663                 w_tmp[0] = w_tmp[0] * wtot_inv;
664                 w_tmp[1] = w_tmp[1] * wtot_inv;
665                 w_tmp[2] = w_tmp[2] * wtot_inv;
666         }
667         else /* dummy values for zero area face */
668                 w_tmp[0] = w_tmp[1] = w_tmp[2] = 1.0f / 3.0f;
669         /* done mimicing barycentric_weights_v2() */
670
671         return (v1[2] * w_tmp[0]) + (v2[2] * w_tmp[1]) + (v3[2] * w_tmp[2]);
672 }
673
674
675 /* Return the top-most face index that the screen space coord 'pt' touches (or -1) */
676 static int project_paint_PickFace(const ProjPaintState *ps, float pt[2], float w[3], int *side)
677 {
678         LinkNode *node;
679         float w_tmp[3];
680         float *v1, *v2, *v3, *v4;
681         int bucket_index;
682         int face_index;
683         int best_side = -1;
684         int best_face_index = -1;
685         float z_depth_best = FLT_MAX, z_depth;
686         MFace *mf;
687         
688         bucket_index = project_bucket_offset_safe(ps, pt);
689         if (bucket_index == -1)
690                 return -1;
691         
692         
693         
694         /* we could return 0 for 1 face buckets, as long as this function assumes
695          * that the point its testing is only every originated from an existing face */
696         
697         for (node = ps->bucketFaces[bucket_index]; node; node = node->next) {
698                 face_index = GET_INT_FROM_POINTER(node->link);
699                 mf = ps->dm_mface + face_index;
700                 
701                 v1 = ps->screenCoords[mf->v1];
702                 v2 = ps->screenCoords[mf->v2];
703                 v3 = ps->screenCoords[mf->v3];
704                 
705                 if (isect_point_tri_v2(pt, v1, v2, v3)) {
706                         if (ps->is_ortho) z_depth = VecZDepthOrtho(pt, v1, v2, v3, w_tmp);
707                         else z_depth = VecZDepthPersp(pt, v1, v2, v3, w_tmp);
708                         
709                         if (z_depth < z_depth_best) {
710                                 best_face_index = face_index;
711                                 best_side = 0;
712                                 z_depth_best = z_depth;
713                                 copy_v3_v3(w, w_tmp);
714                         }
715                 }
716                 else if (mf->v4) {
717                         v4 = ps->screenCoords[mf->v4];
718                         
719                         if (isect_point_tri_v2(pt, v1, v3, v4)) {
720                                 if (ps->is_ortho) z_depth = VecZDepthOrtho(pt, v1, v3, v4, w_tmp);
721                                 else z_depth = VecZDepthPersp(pt, v1, v3, v4, w_tmp);
722
723                                 if (z_depth < z_depth_best) {
724                                         best_face_index = face_index;
725                                         best_side = 1;
726                                         z_depth_best = z_depth;
727                                         copy_v3_v3(w, w_tmp);
728                                 }
729                         }
730                 }
731         }
732         
733         *side = best_side;
734         return best_face_index; /* will be -1 or a valid face */
735 }
736
737 /* Converts a uv coord into a pixel location wrapping if the uv is outside 0-1 range */
738 static void uvco_to_wrapped_pxco(float uv[2], int ibuf_x, int ibuf_y, float *x, float *y)
739 {
740         /* use */
741         *x = (float)fmodf(uv[0], 1.0f);
742         *y = (float)fmodf(uv[1], 1.0f);
743         
744         if (*x < 0.0f) *x += 1.0f;
745         if (*y < 0.0f) *y += 1.0f;
746         
747         *x = *x * ibuf_x - 0.5f;
748         *y = *y * ibuf_y - 0.5f;
749 }
750
751 /* Set the top-most face color that the screen space coord 'pt' touches (or return 0 if none touch) */
752 static int project_paint_PickColor(const ProjPaintState *ps, float pt[2], float *rgba_fp, unsigned char *rgba, const int interp)
753 {
754         float w[3], uv[2];
755         int side;
756         int face_index;
757         MTFace *tf;
758         Image *ima;
759         ImBuf *ibuf;
760         int xi, yi;
761         
762         
763         face_index = project_paint_PickFace(ps, pt, w, &side);
764         
765         if (face_index == -1)
766                 return 0;
767         
768         tf = ps->dm_mtface + face_index;
769         
770         if (side == 0) {
771                 interp_v2_v2v2v2(uv, tf->uv[0], tf->uv[1], tf->uv[2], w);
772         }
773         else { /* QUAD */
774                 interp_v2_v2v2v2(uv, tf->uv[0], tf->uv[2], tf->uv[3], w);
775         }
776
777         ima = project_paint_face_image(ps, ps->dm_mtface, face_index);
778         ibuf = ima->ibufs.first; /* we must have got the imbuf before getting here */
779         if (!ibuf) return 0;
780         
781         if (interp) {
782                 float x, y;
783                 uvco_to_wrapped_pxco(uv, ibuf->x, ibuf->y, &x, &y);
784                 
785                 if (ibuf->rect_float) {
786                         if (rgba_fp) {
787                                 bilinear_interpolation_color_wrap(ibuf, NULL, rgba_fp, x, y);
788                         }
789                         else {
790                                 float rgba_tmp_f[4];
791                                 bilinear_interpolation_color_wrap(ibuf, NULL, rgba_tmp_f, x, y);
792                                 IMAPAINT_FLOAT_RGBA_TO_CHAR(rgba, rgba_tmp_f);
793                         }
794                 }
795                 else {
796                         if (rgba) {
797                                 bilinear_interpolation_color_wrap(ibuf, rgba, NULL, x, y);
798                         }
799                         else {
800                                 unsigned char rgba_tmp[4];
801                                 bilinear_interpolation_color_wrap(ibuf, rgba_tmp, NULL, x, y);
802                                 IMAPAINT_CHAR_RGBA_TO_FLOAT(rgba_fp, rgba_tmp);
803                         }
804                 }
805         }
806         else {
807                 //xi = (int)((uv[0]*ibuf->x) + 0.5f);
808                 //yi = (int)((uv[1]*ibuf->y) + 0.5f);
809                 //if (xi < 0 || xi >= ibuf->x  ||  yi < 0 || yi >= ibuf->y) return 0;
810                 
811                 /* wrap */
812                 xi = ((int)(uv[0] * ibuf->x)) % ibuf->x;
813                 if (xi < 0) xi += ibuf->x;
814                 yi = ((int)(uv[1] * ibuf->y)) % ibuf->y;
815                 if (yi < 0) yi += ibuf->y;
816                 
817                 
818                 if (rgba) {
819                         if (ibuf->rect_float) {
820                                 float *rgba_tmp_fp = ibuf->rect_float + (xi + yi * ibuf->x * 4);
821                                 IMAPAINT_FLOAT_RGBA_TO_CHAR(rgba, rgba_tmp_fp);
822                         }
823                         else {
824                                 *((unsigned int *)rgba) = *(unsigned int *)(((char *)ibuf->rect) + ((xi + yi * ibuf->x) * 4));
825                         }
826                 }
827                 
828                 if (rgba_fp) {
829                         if (ibuf->rect_float) {
830                                 copy_v4_v4(rgba_fp, (ibuf->rect_float + ((xi + yi * ibuf->x) * 4)));
831                         }
832                         else {
833                                 char *tmp_ch = ((char *)ibuf->rect) + ((xi + yi * ibuf->x) * 4);
834                                 IMAPAINT_CHAR_RGBA_TO_FLOAT(rgba_fp, tmp_ch);
835                         }
836                 }
837         }
838         return 1;
839 }
840
841 /* Check if 'pt' is infront of the 3 verts on the Z axis (used for screenspace occlusuion test)
842  * return...
843  *  0   : no occlusion
844  * -1   : no occlusion but 2D intersection is true (avoid testing the other half of a quad)
845  *  1   : occluded
846  *  2   : occluded with w[3] weights set (need to know in some cases) */
847
848 static int project_paint_occlude_ptv(float pt[3], float v1[4], float v2[4], float v3[4], float w[3], int is_ortho)
849 {
850         /* if all are behind us, return false */
851         if (v1[2] > pt[2] && v2[2] > pt[2] && v3[2] > pt[2])
852                 return 0;
853                 
854         /* do a 2D point in try intersection */
855         if (!isect_point_tri_v2(pt, v1, v2, v3))
856                 return 0;  /* we know there is  */
857         
858
859         /* From here on we know there IS an intersection */
860         /* if ALL of the verts are infront of us then we know it intersects ? */
861         if (v1[2] < pt[2] && v2[2] < pt[2] && v3[2] < pt[2]) {
862                 return 1;
863         }
864         else {
865                 /* we intersect? - find the exact depth at the point of intersection */
866                 /* Is this point is occluded by another face? */
867                 if (is_ortho) {
868                         if (VecZDepthOrtho(pt, v1, v2, v3, w) < pt[2]) return 2;
869                 }
870                 else {
871                         if (VecZDepthPersp(pt, v1, v2, v3, w) < pt[2]) return 2;
872                 }
873         }
874         return -1;
875 }
876
877
878 static int project_paint_occlude_ptv_clip(const ProjPaintState *ps, const MFace *mf,
879                                           float pt[3], float v1[4], float v2[4], float v3[4],
880                                           const int side)
881 {
882         float w[3], wco[3];
883         int ret = project_paint_occlude_ptv(pt, v1, v2, v3, w, ps->is_ortho);
884
885         if (ret <= 0)
886                 return ret;
887
888         if (ret == 1) { /* weights not calculated */
889                 if (ps->is_ortho) barycentric_weights_v2(v1, v2, v3, pt, w);
890                 else barycentric_weights_v2_persp(v1, v2, v3, pt, w);
891         }
892
893         /* Test if we're in the clipped area, */
894         if (side) interp_v3_v3v3v3(wco, ps->dm_mvert[mf->v1].co, ps->dm_mvert[mf->v3].co, ps->dm_mvert[mf->v4].co, w);
895         else interp_v3_v3v3v3(wco, ps->dm_mvert[mf->v1].co, ps->dm_mvert[mf->v2].co, ps->dm_mvert[mf->v3].co, w);
896         
897         if (!ED_view3d_clipping_test(ps->rv3d, wco, TRUE)) {
898                 return 1;
899         }
900         
901         return -1;
902 }
903
904
905 /* Check if a screenspace location is occluded by any other faces
906  * check, pixelScreenCo must be in screenspace, its Z-Depth only needs to be used for comparison
907  * and dosn't need to be correct in relation to X and Y coords (this is the case in perspective view) */
908 static int project_bucket_point_occluded(const ProjPaintState *ps, LinkNode *bucketFace, const int orig_face, float pixelScreenCo[4])
909 {
910         MFace *mf;
911         int face_index;
912         int isect_ret;
913         float w[3]; /* not needed when clipping */
914         const short do_clip = ps->rv3d ? ps->rv3d->rflag & RV3D_CLIPPING : 0;
915         
916         /* we could return 0 for 1 face buckets, as long as this function assumes
917          * that the point its testing is only every originated from an existing face */
918
919         for (; bucketFace; bucketFace = bucketFace->next) {
920                 face_index = GET_INT_FROM_POINTER(bucketFace->link);
921
922                 if (orig_face != face_index) {
923                         mf = ps->dm_mface + face_index;
924                         if (do_clip)
925                                 isect_ret = project_paint_occlude_ptv_clip(ps, mf, pixelScreenCo, ps->screenCoords[mf->v1], ps->screenCoords[mf->v2], ps->screenCoords[mf->v3], 0);
926                         else
927                                 isect_ret = project_paint_occlude_ptv(pixelScreenCo, ps->screenCoords[mf->v1], ps->screenCoords[mf->v2], ps->screenCoords[mf->v3], w, ps->is_ortho);
928
929                         /* Note, if (isect_ret == -1) then we don't want to test the other side of the quad */
930                         if (isect_ret == 0 && mf->v4) {
931                                 if (do_clip)
932                                         isect_ret = project_paint_occlude_ptv_clip(ps, mf, pixelScreenCo, ps->screenCoords[mf->v1], ps->screenCoords[mf->v3], ps->screenCoords[mf->v4], 1);
933                                 else
934                                         isect_ret = project_paint_occlude_ptv(pixelScreenCo, ps->screenCoords[mf->v1], ps->screenCoords[mf->v3], ps->screenCoords[mf->v4], w, ps->is_ortho);
935                         }
936                         if (isect_ret >= 1) {
937                                 /* TODO - we may want to cache the first hit,
938                                  * it is not possible to swap the face order in the list anymore */
939                                 return 1;
940                         }
941                 }
942         }
943         return 0;
944 }
945
946 /* basic line intersection, could move to math_geom.c, 2 points with a horiz line
947  * 1 for an intersection, 2 if the first point is aligned, 3 if the second point is aligned */
948 #define ISECT_TRUE 1
949 #define ISECT_TRUE_P1 2
950 #define ISECT_TRUE_P2 3
951 static int line_isect_y(const float p1[2], const float p2[2], const float y_level, float *x_isect)
952 {
953         float y_diff;
954         
955         if (y_level == p1[1]) { /* are we touching the first point? - no interpolation needed */
956                 *x_isect = p1[0];
957                 return ISECT_TRUE_P1;
958         }
959         if (y_level == p2[1]) { /* are we touching the second point? - no interpolation needed */
960                 *x_isect = p2[0];
961                 return ISECT_TRUE_P2;
962         }
963         
964         y_diff = fabsf(p1[1] - p2[1]); /* yuck, horizontal line, we cant do much here */
965         
966         if (y_diff < 0.000001f) {
967                 *x_isect = (p1[0] + p2[0]) * 0.5f;
968                 return ISECT_TRUE;
969         }
970         
971         if (p1[1] > y_level && p2[1] < y_level) {
972                 *x_isect = (p2[0] * (p1[1] - y_level) + p1[0] * (y_level - p2[1])) / y_diff;  /*(p1[1]-p2[1]);*/
973                 return ISECT_TRUE;
974         }
975         else if (p1[1] < y_level && p2[1] > y_level) {
976                 *x_isect = (p2[0] * (y_level - p1[1]) + p1[0] * (p2[1] - y_level)) / y_diff;  /*(p2[1]-p1[1]);*/
977                 return ISECT_TRUE;
978         }
979         else {
980                 return 0;
981         }
982 }
983
984 static int line_isect_x(const float p1[2], const float p2[2], const float x_level, float *y_isect)
985 {
986         float x_diff;
987         
988         if (x_level == p1[0]) { /* are we touching the first point? - no interpolation needed */
989                 *y_isect = p1[1];
990                 return ISECT_TRUE_P1;
991         }
992         if (x_level == p2[0]) { /* are we touching the second point? - no interpolation needed */
993                 *y_isect = p2[1];
994                 return ISECT_TRUE_P2;
995         }
996         
997         x_diff = fabsf(p1[0] - p2[0]); /* yuck, horizontal line, we cant do much here */
998         
999         if (x_diff < 0.000001f) { /* yuck, vertical line, we cant do much here */
1000                 *y_isect = (p1[0] + p2[0]) * 0.5f;
1001                 return ISECT_TRUE;
1002         }
1003         
1004         if (p1[0] > x_level && p2[0] < x_level) {
1005                 *y_isect = (p2[1] * (p1[0] - x_level) + p1[1] * (x_level - p2[0])) / x_diff; /*(p1[0]-p2[0]);*/
1006                 return ISECT_TRUE;
1007         }
1008         else if (p1[0] < x_level && p2[0] > x_level) {
1009                 *y_isect = (p2[1] * (x_level - p1[0]) + p1[1] * (p2[0] - x_level)) / x_diff; /*(p2[0]-p1[0]);*/
1010                 return ISECT_TRUE;
1011         }
1012         else {
1013                 return 0;
1014         }
1015 }
1016
1017 /* simple func use for comparing UV locations to check if there are seams.
1018  * Its possible this gives incorrect results, when the UVs for 1 face go into the next 
1019  * tile, but do not do this for the adjacent face, it could return a false positive.
1020  * This is so unlikely that Id not worry about it. */
1021 #ifndef PROJ_DEBUG_NOSEAMBLEED
1022 static int cmp_uv(const float vec2a[2], const float vec2b[2])
1023 {
1024         /* if the UV's are not between 0.0 and 1.0 */
1025         float xa = (float)fmodf(vec2a[0], 1.0f);
1026         float ya = (float)fmodf(vec2a[1], 1.0f);
1027         
1028         float xb = (float)fmodf(vec2b[0], 1.0f);
1029         float yb = (float)fmodf(vec2b[1], 1.0f);
1030         
1031         if (xa < 0.0f) xa += 1.0f;
1032         if (ya < 0.0f) ya += 1.0f;
1033         
1034         if (xb < 0.0f) xb += 1.0f;
1035         if (yb < 0.0f) yb += 1.0f;
1036         
1037         return ((fabsf(xa - xb) < PROJ_GEOM_TOLERANCE) && (fabsf(ya - yb) < PROJ_GEOM_TOLERANCE)) ? 1 : 0;
1038 }
1039 #endif
1040
1041 /* set min_px and max_px to the image space bounds of the UV coords 
1042  * return zero if there is no area in the returned rectangle */
1043 #ifndef PROJ_DEBUG_NOSEAMBLEED
1044 static int pixel_bounds_uv(
1045         const float uv1[2], const float uv2[2], const float uv3[2], const float uv4[2],
1046         rcti *bounds_px,
1047         const int ibuf_x, const int ibuf_y,
1048         int is_quad
1049         )
1050 {
1051         float min_uv[2], max_uv[2]; /* UV bounds */
1052         
1053         INIT_MINMAX2(min_uv, max_uv);
1054         
1055         minmax_v2v2_v2(min_uv, max_uv, uv1);
1056         minmax_v2v2_v2(min_uv, max_uv, uv2);
1057         minmax_v2v2_v2(min_uv, max_uv, uv3);
1058         if (is_quad)
1059                 minmax_v2v2_v2(min_uv, max_uv, uv4);
1060         
1061         bounds_px->xmin = (int)(ibuf_x * min_uv[0]);
1062         bounds_px->ymin = (int)(ibuf_y * min_uv[1]);
1063         
1064         bounds_px->xmax = (int)(ibuf_x * max_uv[0]) + 1;
1065         bounds_px->ymax = (int)(ibuf_y * max_uv[1]) + 1;
1066         
1067         /*printf("%d %d %d %d\n", min_px[0], min_px[1], max_px[0], max_px[1]);*/
1068         
1069         /* face uses no UV area when quantized to pixels? */
1070         return (bounds_px->xmin == bounds_px->xmax || bounds_px->ymin == bounds_px->ymax) ? 0 : 1;
1071 }
1072 #endif
1073
1074 static int pixel_bounds_array(float (*uv)[2], rcti *bounds_px, const int ibuf_x, const int ibuf_y, int tot)
1075 {
1076         float min_uv[2], max_uv[2]; /* UV bounds */
1077         
1078         if (tot == 0) {
1079                 return 0;
1080         }
1081         
1082         INIT_MINMAX2(min_uv, max_uv);
1083         
1084         while (tot--) {
1085                 minmax_v2v2_v2(min_uv, max_uv, (*uv));
1086                 uv++;
1087         }
1088         
1089         bounds_px->xmin = (int)(ibuf_x * min_uv[0]);
1090         bounds_px->ymin = (int)(ibuf_y * min_uv[1]);
1091         
1092         bounds_px->xmax = (int)(ibuf_x * max_uv[0]) + 1;
1093         bounds_px->ymax = (int)(ibuf_y * max_uv[1]) + 1;
1094         
1095         /*printf("%d %d %d %d\n", min_px[0], min_px[1], max_px[0], max_px[1]);*/
1096         
1097         /* face uses no UV area when quantized to pixels? */
1098         return (bounds_px->xmin == bounds_px->xmax || bounds_px->ymin == bounds_px->ymax) ? 0 : 1;
1099 }
1100
1101 #ifndef PROJ_DEBUG_NOSEAMBLEED
1102
1103 /* This function returns 1 if this face has a seam along the 2 face-vert indices
1104  * 'orig_i1_fidx' and 'orig_i2_fidx' */
1105 static int check_seam(const ProjPaintState *ps, const int orig_face, const int orig_i1_fidx, const int orig_i2_fidx, int *other_face, int *orig_fidx)
1106 {
1107         LinkNode *node;
1108         int face_index;
1109         unsigned int i1, i2;
1110         int i1_fidx = -1, i2_fidx = -1; /* index in face */
1111         MFace *mf;
1112         MTFace *tf;
1113         const MFace *orig_mf = ps->dm_mface + orig_face;  
1114         const MTFace *orig_tf = ps->dm_mtface + orig_face;
1115         
1116         /* vert indices from face vert order indices */
1117         i1 = (*(&orig_mf->v1 + orig_i1_fidx));
1118         i2 = (*(&orig_mf->v1 + orig_i2_fidx));
1119         
1120         for (node = ps->vertFaces[i1]; node; node = node->next) {
1121                 face_index = GET_INT_FROM_POINTER(node->link);
1122
1123                 if (face_index != orig_face) {
1124                         mf = ps->dm_mface + face_index;
1125                         /* could check if the 2 faces images match here,
1126                          * but then there wouldn't be a way to return the opposite face's info */
1127                         
1128                         
1129                         /* We need to know the order of the verts in the adjacent face 
1130                          * set the i1_fidx and i2_fidx to (0,1,2,3) */
1131                         if      (mf->v1 == i1) i1_fidx = 0;
1132                         else if (mf->v2 == i1) i1_fidx = 1;
1133                         else if (mf->v3 == i1) i1_fidx = 2;
1134                         else if (mf->v4 && mf->v4 == i1) i1_fidx = 3;
1135
1136                         if      (mf->v1 == i2) i2_fidx = 0;
1137                         else if (mf->v2 == i2) i2_fidx = 1;
1138                         else if (mf->v3 == i2) i2_fidx = 2;
1139                         else if (mf->v4 && mf->v4 == i2) i2_fidx = 3;
1140                         
1141                         /* Only need to check if 'i2_fidx' is valid because we know i1_fidx is the same vert on both faces */
1142                         if (i2_fidx != -1) {
1143                                 Image *tpage = project_paint_face_image(ps, ps->dm_mtface, face_index);
1144                                 Image *orig_tpage = project_paint_face_image(ps, ps->dm_mtface, orig_face);
1145
1146                                 /* This IS an adjacent face!, now lets check if the UVs are ok */
1147                                 tf = ps->dm_mtface + face_index;
1148                                 
1149                                 /* set up the other face */
1150                                 *other_face = face_index;
1151                                 *orig_fidx = (i1_fidx < i2_fidx) ? i1_fidx : i2_fidx;
1152                                 
1153                                 /* first test if they have the same image */
1154                                 if ((orig_tpage == tpage) &&
1155                                     cmp_uv(orig_tf->uv[orig_i1_fidx], tf->uv[i1_fidx]) &&
1156                                     cmp_uv(orig_tf->uv[orig_i2_fidx], tf->uv[i2_fidx]) )
1157                                 {
1158                                         // printf("SEAM (NONE)\n");
1159                                         return 0;
1160                                         
1161                                 }
1162                                 else {
1163                                         // printf("SEAM (UV GAP)\n");
1164                                         return 1;
1165                                 }
1166                         }
1167                 }
1168         }
1169         // printf("SEAM (NO FACE)\n");
1170         *other_face = -1;
1171         return 1;
1172 }
1173
1174 /* Calculate outset UV's, this is not the same as simply scaling the UVs,
1175  * since the outset coords are a margin that keep an even distance from the original UV's,
1176  * note that the image aspect is taken into account */
1177 static void uv_image_outset(float (*orig_uv)[2], float (*outset_uv)[2], const float scaler, const int ibuf_x, const int ibuf_y, const int is_quad)
1178 {
1179         float a1, a2, a3, a4 = 0.0f;
1180         float puv[4][2]; /* pixelspace uv's */
1181         float no1[2], no2[2], no3[2], no4[2]; /* normals */
1182         float dir1[2], dir2[2], dir3[2], dir4[2];
1183         float ibuf_inv[2];
1184
1185         ibuf_inv[0] = 1.0f / (float)ibuf_x;
1186         ibuf_inv[1] = 1.0f / (float)ibuf_y;
1187
1188         /* make UV's in pixel space so we can */
1189         puv[0][0] = orig_uv[0][0] * ibuf_x;
1190         puv[0][1] = orig_uv[0][1] * ibuf_y;
1191         
1192         puv[1][0] = orig_uv[1][0] * ibuf_x;
1193         puv[1][1] = orig_uv[1][1] * ibuf_y;
1194         
1195         puv[2][0] = orig_uv[2][0] * ibuf_x;
1196         puv[2][1] = orig_uv[2][1] * ibuf_y;
1197         
1198         if (is_quad) {
1199                 puv[3][0] = orig_uv[3][0] * ibuf_x;
1200                 puv[3][1] = orig_uv[3][1] * ibuf_y;
1201         }
1202         
1203         /* face edge directions */
1204         sub_v2_v2v2(dir1, puv[1], puv[0]);
1205         sub_v2_v2v2(dir2, puv[2], puv[1]);
1206         normalize_v2(dir1);
1207         normalize_v2(dir2);
1208         
1209         if (is_quad) {
1210                 sub_v2_v2v2(dir3, puv[3], puv[2]);
1211                 sub_v2_v2v2(dir4, puv[0], puv[3]);
1212                 normalize_v2(dir3);
1213                 normalize_v2(dir4);
1214         }
1215         else {
1216                 sub_v2_v2v2(dir3, puv[0], puv[2]);
1217                 normalize_v2(dir3);
1218         }
1219
1220         /* TODO - angle_normalized_v2v2(...) * (M_PI/180.0f)
1221          * This is incorrect. Its already given radians but without it wont work.
1222          * need to look into a fix - campbell */
1223         if (is_quad) {
1224                 a1 = shell_angle_to_dist(angle_normalized_v2v2(dir4, dir1) * ((float)M_PI / 180.0f));
1225                 a2 = shell_angle_to_dist(angle_normalized_v2v2(dir1, dir2) * ((float)M_PI / 180.0f));
1226                 a3 = shell_angle_to_dist(angle_normalized_v2v2(dir2, dir3) * ((float)M_PI / 180.0f));
1227                 a4 = shell_angle_to_dist(angle_normalized_v2v2(dir3, dir4) * ((float)M_PI / 180.0f));
1228         }
1229         else {
1230                 a1 = shell_angle_to_dist(angle_normalized_v2v2(dir3, dir1) * ((float)M_PI / 180.0f));
1231                 a2 = shell_angle_to_dist(angle_normalized_v2v2(dir1, dir2) * ((float)M_PI / 180.0f));
1232                 a3 = shell_angle_to_dist(angle_normalized_v2v2(dir2, dir3) * ((float)M_PI / 180.0f));
1233         }
1234         
1235         if (is_quad) {
1236                 sub_v2_v2v2(no1, dir4, dir1);
1237                 sub_v2_v2v2(no2, dir1, dir2);
1238                 sub_v2_v2v2(no3, dir2, dir3);
1239                 sub_v2_v2v2(no4, dir3, dir4);
1240                 normalize_v2(no1);
1241                 normalize_v2(no2);
1242                 normalize_v2(no3);
1243                 normalize_v2(no4);
1244                 mul_v2_fl(no1, a1 * scaler);
1245                 mul_v2_fl(no2, a2 * scaler);
1246                 mul_v2_fl(no3, a3 * scaler);
1247                 mul_v2_fl(no4, a4 * scaler);
1248                 add_v2_v2v2(outset_uv[0], puv[0], no1);
1249                 add_v2_v2v2(outset_uv[1], puv[1], no2);
1250                 add_v2_v2v2(outset_uv[2], puv[2], no3);
1251                 add_v2_v2v2(outset_uv[3], puv[3], no4);
1252                 mul_v2_v2(outset_uv[0], ibuf_inv);
1253                 mul_v2_v2(outset_uv[1], ibuf_inv);
1254                 mul_v2_v2(outset_uv[2], ibuf_inv);
1255                 mul_v2_v2(outset_uv[3], ibuf_inv);
1256         }
1257         else {
1258                 sub_v2_v2v2(no1, dir3, dir1);
1259                 sub_v2_v2v2(no2, dir1, dir2);
1260                 sub_v2_v2v2(no3, dir2, dir3);
1261                 normalize_v2(no1);
1262                 normalize_v2(no2);
1263                 normalize_v2(no3);
1264                 mul_v2_fl(no1, a1 * scaler);
1265                 mul_v2_fl(no2, a2 * scaler);
1266                 mul_v2_fl(no3, a3 * scaler);
1267                 add_v2_v2v2(outset_uv[0], puv[0], no1);
1268                 add_v2_v2v2(outset_uv[1], puv[1], no2);
1269                 add_v2_v2v2(outset_uv[2], puv[2], no3);
1270
1271                 mul_v2_v2(outset_uv[0], ibuf_inv);
1272                 mul_v2_v2(outset_uv[1], ibuf_inv);
1273                 mul_v2_v2(outset_uv[2], ibuf_inv);
1274         }
1275 }
1276
1277 /* 
1278  * Be tricky with flags, first 4 bits are PROJ_FACE_SEAM1 to 4, last 4 bits are PROJ_FACE_NOSEAM1 to 4
1279  * 1<<i - where i is (0-3) 
1280  * 
1281  * If we're multithreadng, make sure threads are locked when this is called
1282  */
1283 static void project_face_seams_init(const ProjPaintState *ps, const int face_index, const int is_quad)
1284 {
1285         int other_face, other_fidx; /* vars for the other face, we also set its flag */
1286         int fidx1 = is_quad ? 3 : 2;
1287         int fidx2 = 0; /* next fidx in the face (0,1,2,3) -> (1,2,3,0) or (0,1,2) -> (1,2,0) for a tri */
1288         
1289         do {
1290                 if ((ps->faceSeamFlags[face_index] & (1 << fidx1 | 16 << fidx1)) == 0) {
1291                         if (check_seam(ps, face_index, fidx1, fidx2, &other_face, &other_fidx)) {
1292                                 ps->faceSeamFlags[face_index] |= 1 << fidx1;
1293                                 if (other_face != -1)
1294                                         ps->faceSeamFlags[other_face] |= 1 << other_fidx;
1295                         }
1296                         else {
1297                                 ps->faceSeamFlags[face_index] |= 16 << fidx1;
1298                                 if (other_face != -1)
1299                                         ps->faceSeamFlags[other_face] |= 16 << other_fidx;  /* second 4 bits for disabled */
1300                         }
1301                 }
1302                 
1303                 fidx2 = fidx1;
1304         } while (fidx1--);
1305 }
1306 #endif // PROJ_DEBUG_NOSEAMBLEED
1307
1308
1309 /* Converts a UV location to a 3D screenspace location
1310  * Takes a 'uv' and 3 UV coords, and sets the values of pixelScreenCo
1311  * 
1312  * This is used for finding a pixels location in screenspace for painting */
1313 static void screen_px_from_ortho(
1314         float uv[2],
1315         float v1co[3], float v2co[3], float v3co[3],  /* Screenspace coords */
1316         float uv1co[2], float uv2co[2], float uv3co[2],
1317         float pixelScreenCo[4],
1318         float w[3])
1319 {
1320         barycentric_weights_v2(uv1co, uv2co, uv3co, uv, w);
1321         interp_v3_v3v3v3(pixelScreenCo, v1co, v2co, v3co, w);
1322 }
1323
1324 /* same as screen_px_from_ortho except we need to take into account
1325  * the perspective W coord for each vert */
1326 static void screen_px_from_persp(
1327         float uv[2],
1328         float v1co[4], float v2co[4], float v3co[4],  /* screenspace coords */
1329         float uv1co[2], float uv2co[2], float uv3co[2],
1330         float pixelScreenCo[4],
1331         float w[3])
1332 {
1333
1334         float wtot_inv, wtot;
1335         barycentric_weights_v2(uv1co, uv2co, uv3co, uv, w);
1336         
1337         /* re-weight from the 4th coord of each screen vert */
1338         w[0] *= v1co[3];
1339         w[1] *= v2co[3];
1340         w[2] *= v3co[3];
1341         
1342         wtot = w[0] + w[1] + w[2];
1343         
1344         if (wtot > 0.0f) {
1345                 wtot_inv = 1.0f / wtot;
1346                 w[0] *= wtot_inv;
1347                 w[1] *= wtot_inv;
1348                 w[2] *= wtot_inv;
1349         }
1350         else {
1351                 w[0] = w[1] = w[2] = 1.0f / 3.0f;  /* dummy values for zero area face */
1352         }
1353         /* done re-weighting */
1354         
1355         interp_v3_v3v3v3(pixelScreenCo, v1co, v2co, v3co, w);
1356 }
1357
1358 static void project_face_pixel(const MTFace *tf_other, ImBuf *ibuf_other, const float w[3], int side, unsigned char rgba_ub[4], float rgba_f[4])
1359 {
1360         float *uvCo1, *uvCo2, *uvCo3;
1361         float uv_other[2], x, y;
1362         
1363         uvCo1 =  (float *)tf_other->uv[0];
1364         if (side == 1) {
1365                 uvCo2 =  (float *)tf_other->uv[2];
1366                 uvCo3 =  (float *)tf_other->uv[3];
1367         }
1368         else {
1369                 uvCo2 =  (float *)tf_other->uv[1];
1370                 uvCo3 =  (float *)tf_other->uv[2];
1371         }
1372         
1373         interp_v2_v2v2v2(uv_other, uvCo1, uvCo2, uvCo3, (float *)w);
1374         
1375         /* use */
1376         uvco_to_wrapped_pxco(uv_other, ibuf_other->x, ibuf_other->y, &x, &y);
1377         
1378         
1379         if (ibuf_other->rect_float) { /* from float to float */
1380                 bilinear_interpolation_color_wrap(ibuf_other, NULL, rgba_f, x, y);
1381         }
1382         else { /* from char to float */
1383                 bilinear_interpolation_color_wrap(ibuf_other, rgba_ub, NULL, x, y);
1384         }
1385                 
1386 }
1387
1388 /* run this outside project_paint_uvpixel_init since pixels with mask 0 don't need init */
1389 static float project_paint_uvpixel_mask(
1390         const ProjPaintState *ps,
1391         const int face_index,
1392         const int side,
1393         const float w[3])
1394 {
1395         float mask;
1396         
1397         /* Image Mask */
1398         if (ps->do_layer_stencil) {
1399                 /* another UV maps image is masking this one's */
1400                 ImBuf *ibuf_other;
1401                 Image *other_tpage = project_paint_face_image(ps, ps->dm_mtface_stencil, face_index);
1402                 const MTFace *tf_other = ps->dm_mtface_stencil + face_index;
1403                 
1404                 if (other_tpage && (ibuf_other = BKE_image_acquire_ibuf(other_tpage, NULL, NULL))) {
1405                         /* BKE_image_acquire_ibuf - TODO - this may be slow */
1406                         unsigned char rgba_ub[4];
1407                         float rgba_f[4];
1408                         
1409                         project_face_pixel(tf_other, ibuf_other, w, side, rgba_ub, rgba_f);
1410                         
1411                         if (ibuf_other->rect_float) { /* from float to float */
1412                                 mask = ((rgba_f[0] + rgba_f[1] + rgba_f[2]) / 3.0f) * rgba_f[3];
1413                         }
1414                         else { /* from char to float */
1415                                 mask = ((rgba_ub[0] + rgba_ub[1] + rgba_ub[2]) / (256 * 3.0f)) * (rgba_ub[3] / 256.0f);
1416                         }
1417
1418                         BKE_image_release_ibuf(other_tpage, ibuf_other, NULL);
1419
1420                         if (!ps->do_layer_stencil_inv) /* matching the gimps layer mask black/white rules, white==full opacity */
1421                                 mask = (1.0f - mask);
1422
1423                         if (mask == 0.0f) {
1424                                 return 0.0f;
1425                         }
1426                 }
1427                 else {
1428                         return 0.0f;
1429                 }
1430         }
1431         else {
1432                 mask = 1.0f;
1433         }
1434         
1435         /* calculate mask */
1436         if (ps->do_mask_normal) {
1437                 MFace *mf = &ps->dm_mface[face_index];
1438                 float no[3], angle;
1439                 if (mf->flag & ME_SMOOTH) {
1440                         short *no1, *no2, *no3;
1441                         no1 = ps->dm_mvert[mf->v1].no;
1442                         if (side == 1) {
1443                                 no2 = ps->dm_mvert[mf->v3].no;
1444                                 no3 = ps->dm_mvert[mf->v4].no;
1445                         }
1446                         else {
1447                                 no2 = ps->dm_mvert[mf->v2].no;
1448                                 no3 = ps->dm_mvert[mf->v3].no;
1449                         }
1450
1451                         no[0] = w[0] * no1[0] + w[1] * no2[0] + w[2] * no3[0];
1452                         no[1] = w[0] * no1[1] + w[1] * no2[1] + w[2] * no3[1];
1453                         no[2] = w[0] * no1[2] + w[1] * no2[2] + w[2] * no3[2];
1454                         normalize_v3(no);
1455                 }
1456                 else {
1457                         /* incase the */
1458 #if 1
1459                         /* normalizing per pixel isn't optimal, we could cache or check ps->*/
1460                         if (mf->v4)
1461                                 normal_quad_v3(no,
1462                                                ps->dm_mvert[mf->v1].co,
1463                                                ps->dm_mvert[mf->v2].co,
1464                                                ps->dm_mvert[mf->v3].co,
1465                                                ps->dm_mvert[mf->v4].co);
1466                         else
1467                                 normal_tri_v3(no,
1468                                               ps->dm_mvert[mf->v1].co,
1469                                               ps->dm_mvert[mf->v2].co,
1470                                               ps->dm_mvert[mf->v3].co);
1471 #else
1472                         /* don't use because some modifiers dont have normal data (subsurf for eg) */
1473                         copy_v3_v3(no, (float *)ps->dm->getTessFaceData(ps->dm, face_index, CD_NORMAL));
1474 #endif
1475                 }
1476                 
1477                 /* now we can use the normal as a mask */
1478                 if (ps->is_ortho) {
1479                         angle = angle_normalized_v3v3((float *)ps->viewDir, no);
1480                 }
1481                 else {
1482                         /* Annoying but for the perspective view we need to get the pixels location in 3D space :/ */
1483                         float viewDirPersp[3];
1484                         float *co1, *co2, *co3;
1485                         co1 = ps->dm_mvert[mf->v1].co;
1486                         if (side == 1) {
1487                                 co2 = ps->dm_mvert[mf->v3].co;
1488                                 co3 = ps->dm_mvert[mf->v4].co;
1489                         }
1490                         else {
1491                                 co2 = ps->dm_mvert[mf->v2].co;
1492                                 co3 = ps->dm_mvert[mf->v3].co;
1493                         }
1494
1495                         /* Get the direction from the viewPoint to the pixel and normalize */
1496                         viewDirPersp[0] = (ps->viewPos[0] - (w[0] * co1[0] + w[1] * co2[0] + w[2] * co3[0]));
1497                         viewDirPersp[1] = (ps->viewPos[1] - (w[0] * co1[1] + w[1] * co2[1] + w[2] * co3[1]));
1498                         viewDirPersp[2] = (ps->viewPos[2] - (w[0] * co1[2] + w[1] * co2[2] + w[2] * co3[2]));
1499                         normalize_v3(viewDirPersp);
1500                         
1501                         angle = angle_normalized_v3v3(viewDirPersp, no);
1502                 }
1503                 
1504                 if (angle >= ps->normal_angle) {
1505                         return 0.0f; /* outsize the normal limit*/
1506                 }
1507                 else if (angle > ps->normal_angle_inner) {
1508                         mask *= (ps->normal_angle - angle) / ps->normal_angle_range;
1509                 } /* otherwise no mask normal is needed, were within the limit */
1510         }
1511         
1512         /* This only works when the opacity dosnt change while painting, stylus pressure messes with this
1513          * so don't use it. */
1514         // if (ps->is_airbrush == 0) mask *= BKE_brush_alpha_get(ps->brush);
1515         
1516         return mask;
1517 }
1518
1519 static int project_paint_pixel_sizeof(const short tool)
1520 {
1521         if ((tool == PAINT_TOOL_CLONE) || (tool == PAINT_TOOL_SMEAR)) {
1522                 return sizeof(ProjPixelClone);
1523         }
1524         else {
1525                 return sizeof(ProjPixel);
1526         }
1527 }
1528
1529 /* run this function when we know a bucket's, face's pixel can be initialized,
1530  * return the ProjPixel which is added to 'ps->bucketRect[bucket_index]' */
1531 static ProjPixel *project_paint_uvpixel_init(
1532         const ProjPaintState *ps,
1533         MemArena *arena,
1534         const ImBuf *ibuf,
1535         short x_px, short y_px,
1536         const float mask,
1537         const int face_index,
1538         const int image_index,
1539         const float pixelScreenCo[4],
1540         const int side,
1541         const float w[3])
1542 {
1543         ProjPixel *projPixel;
1544
1545         /* wrap pixel location */
1546         x_px = x_px % ibuf->x;
1547         if (x_px < 0) x_px += ibuf->x;
1548         y_px = y_px % ibuf->y;
1549         if (y_px < 0) y_px += ibuf->y;
1550
1551         BLI_assert(ps->pixel_sizeof == project_paint_pixel_sizeof(ps->tool));
1552         projPixel = (ProjPixel *)BLI_memarena_alloc(arena, ps->pixel_sizeof);
1553         //memset(projPixel, 0, size);
1554         
1555         if (ibuf->rect_float) {
1556                 projPixel->pixel.f_pt = ibuf->rect_float + ((x_px + y_px * ibuf->x) * 4);
1557                 projPixel->origColor.f[0] = projPixel->newColor.f[0] = projPixel->pixel.f_pt[0];
1558                 projPixel->origColor.f[1] = projPixel->newColor.f[1] = projPixel->pixel.f_pt[1];
1559                 projPixel->origColor.f[2] = projPixel->newColor.f[2] = projPixel->pixel.f_pt[2];
1560                 projPixel->origColor.f[3] = projPixel->newColor.f[3] = projPixel->pixel.f_pt[3];
1561         }
1562         else {
1563                 projPixel->pixel.ch_pt = ((unsigned char *)ibuf->rect + ((x_px + y_px * ibuf->x) * 4));
1564                 projPixel->origColor.uint = projPixel->newColor.uint = *projPixel->pixel.uint_pt;
1565         }
1566         
1567         /* screenspace unclamped, we could keep its z and w values but don't need them at the moment */
1568         copy_v2_v2(projPixel->projCoSS, pixelScreenCo);
1569         
1570         projPixel->x_px = x_px;
1571         projPixel->y_px = y_px;
1572         
1573         projPixel->mask = (unsigned short)(mask * 65535);
1574         projPixel->mask_max = 0;
1575         
1576         /* which bounding box cell are we in?, needed for undo */
1577         projPixel->bb_cell_index = ((int)(((float)x_px / (float)ibuf->x) * PROJ_BOUNDBOX_DIV)) +
1578                                    ((int)(((float)y_px / (float)ibuf->y) * PROJ_BOUNDBOX_DIV)) * PROJ_BOUNDBOX_DIV;
1579         
1580         /* done with view3d_project_float inline */
1581         if (ps->tool == PAINT_TOOL_CLONE) {
1582                 if (ps->dm_mtface_clone) {
1583                         ImBuf *ibuf_other;
1584                         Image *other_tpage = project_paint_face_image(ps, ps->dm_mtface_clone, face_index);
1585                         const MTFace *tf_other = ps->dm_mtface_clone + face_index;
1586                         
1587                         if (other_tpage && (ibuf_other = BKE_image_acquire_ibuf(other_tpage, NULL, NULL))) {
1588                                 /* BKE_image_acquire_ibuf - TODO - this may be slow */
1589                                 
1590                                 if (ibuf->rect_float) {
1591                                         if (ibuf_other->rect_float) { /* from float to float */
1592                                                 project_face_pixel(tf_other, ibuf_other, w, side, NULL, ((ProjPixelClone *)projPixel)->clonepx.f);
1593                                         }
1594                                         else { /* from char to float */
1595                                                 unsigned char rgba_ub[4];
1596                                                 project_face_pixel(tf_other, ibuf_other, w, side, rgba_ub, NULL);
1597                                                 IMAPAINT_CHAR_RGBA_TO_FLOAT(((ProjPixelClone *)projPixel)->clonepx.f, rgba_ub);
1598                                         }
1599                                 }
1600                                 else {
1601                                         if (ibuf_other->rect_float) { /* float to char */
1602                                                 float rgba[4];
1603                                                 project_face_pixel(tf_other, ibuf_other, w, side, NULL, rgba);
1604                                                 IMAPAINT_FLOAT_RGBA_TO_CHAR(((ProjPixelClone *)projPixel)->clonepx.ch, rgba);
1605                                         }
1606                                         else { /* char to char */
1607                                                 project_face_pixel(tf_other, ibuf_other, w, side, ((ProjPixelClone *)projPixel)->clonepx.ch, NULL);
1608                                         }
1609                                 }
1610
1611                                 BKE_image_release_ibuf(other_tpage, ibuf_other, NULL);
1612                         }
1613                         else {
1614                                 if (ibuf->rect_float) {
1615                                         ((ProjPixelClone *)projPixel)->clonepx.f[3] = 0;
1616                                 }
1617                                 else {
1618                                         ((ProjPixelClone *)projPixel)->clonepx.ch[3] = 0;
1619                                 }
1620                         }
1621                         
1622                 }
1623                 else {
1624                         float co[2];
1625                         sub_v2_v2v2(co, projPixel->projCoSS, (float *)ps->cloneOffset);
1626                         
1627                         /* no need to initialize the bucket, we're only checking buckets faces and for this
1628                          * the faces are already initialized in project_paint_delayed_face_init(...) */
1629                         if (ibuf->rect_float) {
1630                                 if (!project_paint_PickColor(ps, co, ((ProjPixelClone *)projPixel)->clonepx.f, NULL, 1)) {
1631                                         ((ProjPixelClone *)projPixel)->clonepx.f[3] = 0; /* zero alpha - ignore */
1632                                 }
1633                         }
1634                         else {
1635                                 if (!project_paint_PickColor(ps, co, NULL, ((ProjPixelClone *)projPixel)->clonepx.ch, 1)) {
1636                                         ((ProjPixelClone *)projPixel)->clonepx.ch[3] = 0; /* zero alpha - ignore */
1637                                 }
1638                         }
1639                 }
1640         }
1641         
1642 #ifdef PROJ_DEBUG_PAINT
1643         if (ibuf->rect_float) projPixel->pixel.f_pt[0] = 0;
1644         else                  projPixel->pixel.ch_pt[0] = 0;
1645 #endif
1646         projPixel->image_index = image_index;
1647         
1648         return projPixel;
1649 }
1650
1651 static int line_clip_rect2f(
1652         rctf *rect,
1653         const float l1[2], const float l2[2],
1654         float l1_clip[2], float l2_clip[2])
1655 {
1656         /* first account for horizontal, then vertical lines */
1657         /* horiz */
1658         if (fabsf(l1[1] - l2[1]) < PROJ_GEOM_TOLERANCE) {
1659                 /* is the line out of range on its Y axis? */
1660                 if (l1[1] < rect->ymin || l1[1] > rect->ymax) {
1661                         return 0;
1662                 }
1663                 /* line is out of range on its X axis */
1664                 if ((l1[0] < rect->xmin && l2[0] < rect->xmin) || (l1[0] > rect->xmax && l2[0] > rect->xmax)) {
1665                         return 0;
1666                 }
1667                 
1668                 
1669                 if (fabsf(l1[0] - l2[0]) < PROJ_GEOM_TOLERANCE) { /* this is a single point  (or close to)*/
1670                         if (BLI_rctf_isect_pt_v(rect, l1)) {
1671                                 copy_v2_v2(l1_clip, l1);
1672                                 copy_v2_v2(l2_clip, l2);
1673                                 return 1;
1674                         }
1675                         else {
1676                                 return 0;
1677                         }
1678                 }
1679                 
1680                 copy_v2_v2(l1_clip, l1);
1681                 copy_v2_v2(l2_clip, l2);
1682                 CLAMP(l1_clip[0], rect->xmin, rect->xmax);
1683                 CLAMP(l2_clip[0], rect->xmin, rect->xmax);
1684                 return 1;
1685         }
1686         else if (fabsf(l1[0] - l2[0]) < PROJ_GEOM_TOLERANCE) {
1687                 /* is the line out of range on its X axis? */
1688                 if (l1[0] < rect->xmin || l1[0] > rect->xmax) {
1689                         return 0;
1690                 }
1691                 
1692                 /* line is out of range on its Y axis */
1693                 if ((l1[1] < rect->ymin && l2[1] < rect->ymin) || (l1[1] > rect->ymax && l2[1] > rect->ymax)) {
1694                         return 0;
1695                 }
1696                 
1697                 if (fabsf(l1[1] - l2[1]) < PROJ_GEOM_TOLERANCE) { /* this is a single point  (or close to)*/
1698                         if (BLI_rctf_isect_pt_v(rect, l1)) {
1699                                 copy_v2_v2(l1_clip, l1);
1700                                 copy_v2_v2(l2_clip, l2);
1701                                 return 1;
1702                         }
1703                         else {
1704                                 return 0;
1705                         }
1706                 }
1707                 
1708                 copy_v2_v2(l1_clip, l1);
1709                 copy_v2_v2(l2_clip, l2);
1710                 CLAMP(l1_clip[1], rect->ymin, rect->ymax);
1711                 CLAMP(l2_clip[1], rect->ymin, rect->ymax);
1712                 return 1;
1713         }
1714         else {
1715                 float isect;
1716                 short ok1 = 0;
1717                 short ok2 = 0;
1718                 
1719                 /* Done with vertical lines */
1720                 
1721                 /* are either of the points inside the rectangle ? */
1722                 if (BLI_rctf_isect_pt_v(rect, l1)) {
1723                         copy_v2_v2(l1_clip, l1);
1724                         ok1 = 1;
1725                 }
1726                 
1727                 if (BLI_rctf_isect_pt_v(rect, l2)) {
1728                         copy_v2_v2(l2_clip, l2);
1729                         ok2 = 1;
1730                 }
1731                 
1732                 /* line inside rect */
1733                 if (ok1 && ok2) return 1;
1734                 
1735                 /* top/bottom */
1736                 if (line_isect_y(l1, l2, rect->ymin, &isect) && (isect >= rect->xmin) && (isect <= rect->xmax)) {
1737                         if (l1[1] < l2[1]) { /* line 1 is outside */
1738                                 l1_clip[0] = isect;
1739                                 l1_clip[1] = rect->ymin;
1740                                 ok1 = 1;
1741                         }
1742                         else {
1743                                 l2_clip[0] = isect;
1744                                 l2_clip[1] = rect->ymin;
1745                                 ok2 = 2;
1746                         }
1747                 }
1748                 
1749                 if (ok1 && ok2) return 1;
1750                 
1751                 if (line_isect_y(l1, l2, rect->ymax, &isect) && (isect >= rect->xmin) && (isect <= rect->xmax)) {
1752                         if (l1[1] > l2[1]) { /* line 1 is outside */
1753                                 l1_clip[0] = isect;
1754                                 l1_clip[1] = rect->ymax;
1755                                 ok1 = 1;
1756                         }
1757                         else {
1758                                 l2_clip[0] = isect;
1759                                 l2_clip[1] = rect->ymax;
1760                                 ok2 = 2;
1761                         }
1762                 }
1763                 
1764                 if (ok1 && ok2) return 1;
1765                 
1766                 /* left/right */
1767                 if (line_isect_x(l1, l2, rect->xmin, &isect) && (isect >= rect->ymin) && (isect <= rect->ymax)) {
1768                         if (l1[0] < l2[0]) { /* line 1 is outside */
1769                                 l1_clip[0] = rect->xmin;
1770                                 l1_clip[1] = isect;
1771                                 ok1 = 1;
1772                         }
1773                         else {
1774                                 l2_clip[0] = rect->xmin;
1775                                 l2_clip[1] = isect;
1776                                 ok2 = 2;
1777                         }
1778                 }
1779         
1780                 if (ok1 && ok2) return 1;
1781                 
1782                 if (line_isect_x(l1, l2, rect->xmax, &isect) && (isect >= rect->ymin) && (isect <= rect->ymax)) {
1783                         if (l1[0] > l2[0]) { /* line 1 is outside */
1784                                 l1_clip[0] = rect->xmax;
1785                                 l1_clip[1] = isect;
1786                                 ok1 = 1;
1787                         }
1788                         else {
1789                                 l2_clip[0] = rect->xmax;
1790                                 l2_clip[1] = isect;
1791                                 ok2 = 2;
1792                         }
1793                 }
1794                 
1795                 if (ok1 && ok2) {
1796                         return 1;
1797                 }
1798                 else {
1799                         return 0;
1800                 }
1801         }
1802 }
1803
1804
1805
1806 /* scale the quad & tri about its center
1807  * scaling by PROJ_FACE_SCALE_SEAM (0.99x) is used for getting fake UV pixel coords that are on the
1808  * edge of the face but slightly inside it occlusion tests don't return hits on adjacent faces */
1809 #ifndef PROJ_DEBUG_NOSEAMBLEED
1810 static void scale_quad(float insetCos[4][3], float *origCos[4], const float inset)
1811 {
1812         float cent[3];
1813         cent[0] = (origCos[0][0] + origCos[1][0] + origCos[2][0] + origCos[3][0]) / 4.0f;
1814         cent[1] = (origCos[0][1] + origCos[1][1] + origCos[2][1] + origCos[3][1]) / 4.0f;
1815         cent[2] = (origCos[0][2] + origCos[1][2] + origCos[2][2] + origCos[3][2]) / 4.0f;
1816         
1817         sub_v3_v3v3(insetCos[0], origCos[0], cent);
1818         sub_v3_v3v3(insetCos[1], origCos[1], cent);
1819         sub_v3_v3v3(insetCos[2], origCos[2], cent);
1820         sub_v3_v3v3(insetCos[3], origCos[3], cent);
1821         
1822         mul_v3_fl(insetCos[0], inset);
1823         mul_v3_fl(insetCos[1], inset);
1824         mul_v3_fl(insetCos[2], inset);
1825         mul_v3_fl(insetCos[3], inset);
1826         
1827         add_v3_v3(insetCos[0], cent);
1828         add_v3_v3(insetCos[1], cent);
1829         add_v3_v3(insetCos[2], cent);
1830         add_v3_v3(insetCos[3], cent);
1831 }
1832
1833
1834 static void scale_tri(float insetCos[4][3], float *origCos[4], const float inset)
1835 {
1836         float cent[3];
1837         cent[0] = (origCos[0][0] + origCos[1][0] + origCos[2][0]) / 3.0f;
1838         cent[1] = (origCos[0][1] + origCos[1][1] + origCos[2][1]) / 3.0f;
1839         cent[2] = (origCos[0][2] + origCos[1][2] + origCos[2][2]) / 3.0f;
1840         
1841         sub_v3_v3v3(insetCos[0], origCos[0], cent);
1842         sub_v3_v3v3(insetCos[1], origCos[1], cent);
1843         sub_v3_v3v3(insetCos[2], origCos[2], cent);
1844         
1845         mul_v3_fl(insetCos[0], inset);
1846         mul_v3_fl(insetCos[1], inset);
1847         mul_v3_fl(insetCos[2], inset);
1848         
1849         add_v3_v3(insetCos[0], cent);
1850         add_v3_v3(insetCos[1], cent);
1851         add_v3_v3(insetCos[2], cent);
1852 }
1853 #endif //PROJ_DEBUG_NOSEAMBLEED
1854
1855 static float len_squared_v2v2_alt(const float *v1, const float v2_1, const float v2_2)
1856 {
1857         float x, y;
1858
1859         x = v1[0] - v2_1;
1860         y = v1[1] - v2_2;
1861         return x * x + y * y;
1862 }
1863
1864 /* note, use a squared value so we can use len_squared_v2v2
1865  * be sure that you have done a bounds check first or this may fail */
1866 /* only give bucket_bounds as an arg because we need it elsewhere */
1867 static int project_bucket_isect_circle(const float cent[2], const float radius_squared, rctf *bucket_bounds)
1868 {
1869          
1870         /* Would normally to a simple intersection test, however we know the bounds of these 2 already intersect 
1871          * so we only need to test if the center is inside the vertical or horizontal bounds on either axis,
1872          * this is even less work then an intersection test
1873          */
1874 #if 0
1875         if (BLI_rctf_isect_pt_v(bucket_bounds, cent))
1876                 return 1;
1877 #endif
1878         
1879         if ((bucket_bounds->xmin <= cent[0] && bucket_bounds->xmax >= cent[0]) ||
1880             (bucket_bounds->ymin <= cent[1] && bucket_bounds->ymax >= cent[1]))
1881         {
1882                 return 1;
1883         }
1884         
1885         /* out of bounds left */
1886         if (cent[0] < bucket_bounds->xmin) {
1887                 /* lower left out of radius test */
1888                 if (cent[1] < bucket_bounds->ymin) {
1889                         return (len_squared_v2v2_alt(cent, bucket_bounds->xmin, bucket_bounds->ymin) < radius_squared) ? 1 : 0;
1890                 }
1891                 /* top left test */
1892                 else if (cent[1] > bucket_bounds->ymax) {
1893                         return (len_squared_v2v2_alt(cent, bucket_bounds->xmin, bucket_bounds->ymax) < radius_squared) ? 1 : 0;
1894                 }
1895         }
1896         else if (cent[0] > bucket_bounds->xmax) {
1897                 /* lower right out of radius test */
1898                 if (cent[1] < bucket_bounds->ymin) {
1899                         return (len_squared_v2v2_alt(cent, bucket_bounds->xmax, bucket_bounds->ymin) < radius_squared) ? 1 : 0;
1900                 }
1901                 /* top right test */
1902                 else if (cent[1] > bucket_bounds->ymax) {
1903                         return (len_squared_v2v2_alt(cent, bucket_bounds->xmax, bucket_bounds->ymax) < radius_squared) ? 1 : 0;
1904                 }
1905         }
1906         
1907         return 0;
1908 }
1909
1910
1911
1912 /* Note for rect_to_uvspace_ortho() and rect_to_uvspace_persp()
1913  * in ortho view this function gives good results when bucket_bounds are outside the triangle
1914  * however in some cases, perspective view will mess up with faces that have minimal screenspace area
1915  * (viewed from the side)
1916  * 
1917  * for this reason its not reliable in this case so we'll use the Simple Barycentric'
1918  * funcs that only account for points inside the triangle.
1919  * however switching back to this for ortho is always an option */
1920
1921 static void rect_to_uvspace_ortho(
1922         rctf *bucket_bounds,
1923         float *v1coSS, float *v2coSS, float *v3coSS,
1924         float *uv1co, float *uv2co, float *uv3co,
1925         float bucket_bounds_uv[4][2],
1926         const int flip)
1927 {
1928         float uv[2];
1929         float w[3];
1930         
1931         /* get the UV space bounding box */
1932         uv[0] = bucket_bounds->xmax;
1933         uv[1] = bucket_bounds->ymin;
1934         barycentric_weights_v2(v1coSS, v2coSS, v3coSS, uv, w);
1935         interp_v2_v2v2v2(bucket_bounds_uv[flip ? 3 : 0], uv1co, uv2co, uv3co, w);
1936
1937         //uv[0] = bucket_bounds->xmax; // set above
1938         uv[1] = bucket_bounds->ymax;
1939         barycentric_weights_v2(v1coSS, v2coSS, v3coSS, uv, w);
1940         interp_v2_v2v2v2(bucket_bounds_uv[flip ? 2 : 1], uv1co, uv2co, uv3co, w);
1941
1942         uv[0] = bucket_bounds->xmin;
1943         //uv[1] = bucket_bounds->ymax; // set above
1944         barycentric_weights_v2(v1coSS, v2coSS, v3coSS, uv, w);
1945         interp_v2_v2v2v2(bucket_bounds_uv[flip ? 1 : 2], uv1co, uv2co, uv3co, w);
1946
1947         //uv[0] = bucket_bounds->xmin; // set above
1948         uv[1] = bucket_bounds->ymin;
1949         barycentric_weights_v2(v1coSS, v2coSS, v3coSS, uv, w);
1950         interp_v2_v2v2v2(bucket_bounds_uv[flip ? 0 : 3], uv1co, uv2co, uv3co, w);
1951 }
1952
1953 /* same as above but use barycentric_weights_v2_persp */
1954 static void rect_to_uvspace_persp(
1955         rctf *bucket_bounds,
1956         float *v1coSS, float *v2coSS, float *v3coSS,
1957         float *uv1co, float *uv2co, float *uv3co,
1958         float bucket_bounds_uv[4][2],
1959         const int flip
1960         )
1961 {
1962         float uv[2];
1963         float w[3];
1964         
1965         /* get the UV space bounding box */
1966         uv[0] = bucket_bounds->xmax;
1967         uv[1] = bucket_bounds->ymin;
1968         barycentric_weights_v2_persp(v1coSS, v2coSS, v3coSS, uv, w);
1969         interp_v2_v2v2v2(bucket_bounds_uv[flip ? 3 : 0], uv1co, uv2co, uv3co, w);
1970
1971         //uv[0] = bucket_bounds->xmax; // set above
1972         uv[1] = bucket_bounds->ymax;
1973         barycentric_weights_v2_persp(v1coSS, v2coSS, v3coSS, uv, w);
1974         interp_v2_v2v2v2(bucket_bounds_uv[flip ? 2 : 1], uv1co, uv2co, uv3co, w);
1975
1976         uv[0] = bucket_bounds->xmin;
1977         //uv[1] = bucket_bounds->ymax; // set above
1978         barycentric_weights_v2_persp(v1coSS, v2coSS, v3coSS, uv, w);
1979         interp_v2_v2v2v2(bucket_bounds_uv[flip ? 1 : 2], uv1co, uv2co, uv3co, w);
1980
1981         //uv[0] = bucket_bounds->xmin; // set above
1982         uv[1] = bucket_bounds->ymin;
1983         barycentric_weights_v2_persp(v1coSS, v2coSS, v3coSS, uv, w);
1984         interp_v2_v2v2v2(bucket_bounds_uv[flip ? 0 : 3], uv1co, uv2co, uv3co, w);
1985 }
1986
1987 /* This works as we need it to but we can save a few steps and not use it */
1988
1989 #if 0
1990 static float angle_2d_clockwise(const float p1[2], const float p2[2], const float p3[2])
1991 {
1992         float v1[2], v2[2];
1993         
1994         v1[0] = p1[0] - p2[0];    v1[1] = p1[1] - p2[1];
1995         v2[0] = p3[0] - p2[0];    v2[1] = p3[1] - p2[1];
1996         
1997         return -atan2(v1[0] * v2[1] - v1[1] * v2[0], v1[0] * v2[0] + v1[1] * v2[1]);
1998 }
1999 #endif
2000
2001 #define ISECT_1 (1)
2002 #define ISECT_2 (1 << 1)
2003 #define ISECT_3 (1 << 2)
2004 #define ISECT_4 (1 << 3)
2005 #define ISECT_ALL3 ((1 << 3) - 1)
2006 #define ISECT_ALL4 ((1 << 4) - 1)
2007
2008 /* limit must be a fraction over 1.0f */
2009 static int IsectPT2Df_limit(float pt[2], float v1[2], float v2[2], float v3[2], float limit)
2010 {
2011         return ((area_tri_v2(pt, v1, v2) + area_tri_v2(pt, v2, v3) + area_tri_v2(pt, v3, v1)) / (area_tri_v2(v1, v2, v3))) < limit;
2012 }
2013
2014 /* Clip the face by a bucket and set the uv-space bucket_bounds_uv
2015  * so we have the clipped UV's to do pixel intersection tests with 
2016  * */
2017 static int float_z_sort_flip(const void *p1, const void *p2)
2018 {
2019         return (((float *)p1)[2] < ((float *)p2)[2] ? 1 : -1);
2020 }
2021
2022 static int float_z_sort(const void *p1, const void *p2)
2023 {
2024         return (((float *)p1)[2] < ((float *)p2)[2] ? -1 : 1);
2025 }
2026
2027 static void project_bucket_clip_face(
2028         const int is_ortho,
2029         rctf *bucket_bounds,
2030         float *v1coSS, float *v2coSS, float *v3coSS,
2031         float *uv1co, float *uv2co, float *uv3co,
2032         float bucket_bounds_uv[8][2],
2033         int *tot)
2034 {
2035         int inside_bucket_flag = 0;
2036         int inside_face_flag = 0;
2037         const int flip = ((line_point_side_v2(v1coSS, v2coSS, v3coSS) > 0.0f) != (line_point_side_v2(uv1co, uv2co, uv3co) > 0.0f));
2038         
2039         float bucket_bounds_ss[4][2];
2040
2041         /* get the UV space bounding box */
2042         inside_bucket_flag |= BLI_rctf_isect_pt_v(bucket_bounds, v1coSS);
2043         inside_bucket_flag |= BLI_rctf_isect_pt_v(bucket_bounds, v2coSS) << 1;
2044         inside_bucket_flag |= BLI_rctf_isect_pt_v(bucket_bounds, v3coSS) << 2;
2045         
2046         if (inside_bucket_flag == ISECT_ALL3) {
2047                 /* all screenspace points are inside the bucket bounding box, this means we don't need to clip and can simply return the UVs */
2048                 if (flip) { /* facing the back? */
2049                         copy_v2_v2(bucket_bounds_uv[0], uv3co);
2050                         copy_v2_v2(bucket_bounds_uv[1], uv2co);
2051                         copy_v2_v2(bucket_bounds_uv[2], uv1co);
2052                 }
2053                 else {
2054                         copy_v2_v2(bucket_bounds_uv[0], uv1co);
2055                         copy_v2_v2(bucket_bounds_uv[1], uv2co);
2056                         copy_v2_v2(bucket_bounds_uv[2], uv3co);
2057                 }
2058                 
2059                 *tot = 3; 
2060                 return;
2061         }
2062         
2063         /* get the UV space bounding box */
2064         /* use IsectPT2Df_limit here so we catch points are are touching the tri edge (or a small fraction over) */
2065         bucket_bounds_ss[0][0] = bucket_bounds->xmax;
2066         bucket_bounds_ss[0][1] = bucket_bounds->ymin;
2067         inside_face_flag |= (IsectPT2Df_limit(bucket_bounds_ss[0], v1coSS, v2coSS, v3coSS, 1 + PROJ_GEOM_TOLERANCE) ? ISECT_1 : 0);
2068         
2069         bucket_bounds_ss[1][0] = bucket_bounds->xmax;
2070         bucket_bounds_ss[1][1] = bucket_bounds->ymax;
2071         inside_face_flag |= (IsectPT2Df_limit(bucket_bounds_ss[1], v1coSS, v2coSS, v3coSS, 1 + PROJ_GEOM_TOLERANCE) ? ISECT_2 : 0);
2072
2073         bucket_bounds_ss[2][0] = bucket_bounds->xmin;
2074         bucket_bounds_ss[2][1] = bucket_bounds->ymax;
2075         inside_face_flag |= (IsectPT2Df_limit(bucket_bounds_ss[2], v1coSS, v2coSS, v3coSS, 1 + PROJ_GEOM_TOLERANCE) ? ISECT_3 : 0);
2076
2077         bucket_bounds_ss[3][0] = bucket_bounds->xmin;
2078         bucket_bounds_ss[3][1] = bucket_bounds->ymin;
2079         inside_face_flag |= (IsectPT2Df_limit(bucket_bounds_ss[3], v1coSS, v2coSS, v3coSS, 1 + PROJ_GEOM_TOLERANCE) ? ISECT_4 : 0);
2080         
2081         if (inside_face_flag == ISECT_ALL4) {
2082                 /* bucket is totally inside the screenspace face, we can safely use weights */
2083                 
2084                 if (is_ortho) rect_to_uvspace_ortho(bucket_bounds, v1coSS, v2coSS, v3coSS, uv1co, uv2co, uv3co, bucket_bounds_uv, flip);
2085                 else rect_to_uvspace_persp(bucket_bounds, v1coSS, v2coSS, v3coSS, uv1co, uv2co, uv3co, bucket_bounds_uv, flip);
2086                 
2087                 *tot = 4;
2088                 return;
2089         }
2090         else {
2091                 /* The Complicated Case! 
2092                  * 
2093                  * The 2 cases above are where the face is inside the bucket or the bucket is inside the face.
2094                  * 
2095                  * we need to make a convex polyline from the intersection between the screenspace face
2096                  * and the bucket bounds.
2097                  * 
2098                  * There are a number of ways this could be done, currently it just collects all intersecting verts,
2099                  * and line intersections,  then sorts them clockwise, this is a lot easier then evaluating the geometry to
2100                  * do a correct clipping on both shapes. */
2101                 
2102                 
2103                 /* add a bunch of points, we know must make up the convex hull which is the clipped rect and triangle */
2104                 
2105                 
2106                 
2107                 /* Maximum possible 6 intersections when using a rectangle and triangle */
2108                 float isectVCosSS[8][3]; /* The 3rd float is used to store angle for qsort(), NOT as a Z location */
2109                 float v1_clipSS[2], v2_clipSS[2];
2110                 float w[3];
2111                 
2112                 /* calc center */
2113                 float cent[2] = {0.0f, 0.0f};
2114                 /*float up[2] = {0.0f, 1.0f};*/
2115                 int i;
2116                 short doubles;
2117                 
2118                 (*tot) = 0;
2119                 
2120                 if (inside_face_flag & ISECT_1) { copy_v2_v2(isectVCosSS[*tot], bucket_bounds_ss[0]); (*tot)++; }
2121                 if (inside_face_flag & ISECT_2) { copy_v2_v2(isectVCosSS[*tot], bucket_bounds_ss[1]); (*tot)++; }
2122                 if (inside_face_flag & ISECT_3) { copy_v2_v2(isectVCosSS[*tot], bucket_bounds_ss[2]); (*tot)++; }
2123                 if (inside_face_flag & ISECT_4) { copy_v2_v2(isectVCosSS[*tot], bucket_bounds_ss[3]); (*tot)++; }
2124
2125                 if (inside_bucket_flag & ISECT_1) { copy_v2_v2(isectVCosSS[*tot], v1coSS); (*tot)++; }
2126                 if (inside_bucket_flag & ISECT_2) { copy_v2_v2(isectVCosSS[*tot], v2coSS); (*tot)++; }
2127                 if (inside_bucket_flag & ISECT_3) { copy_v2_v2(isectVCosSS[*tot], v3coSS); (*tot)++; }
2128                 
2129                 if ((inside_bucket_flag & (ISECT_1 | ISECT_2)) != (ISECT_1 | ISECT_2)) {
2130                         if (line_clip_rect2f(bucket_bounds, v1coSS, v2coSS, v1_clipSS, v2_clipSS)) {
2131                                 if ((inside_bucket_flag & ISECT_1) == 0) { copy_v2_v2(isectVCosSS[*tot], v1_clipSS); (*tot)++; }
2132                                 if ((inside_bucket_flag & ISECT_2) == 0) { copy_v2_v2(isectVCosSS[*tot], v2_clipSS); (*tot)++; }
2133                         }
2134                 }
2135                 
2136                 if ((inside_bucket_flag & (ISECT_2 | ISECT_3)) != (ISECT_2 | ISECT_3)) {
2137                         if (line_clip_rect2f(bucket_bounds, v2coSS, v3coSS, v1_clipSS, v2_clipSS)) {
2138                                 if ((inside_bucket_flag & ISECT_2) == 0) { copy_v2_v2(isectVCosSS[*tot], v1_clipSS); (*tot)++; }
2139                                 if ((inside_bucket_flag & ISECT_3) == 0) { copy_v2_v2(isectVCosSS[*tot], v2_clipSS); (*tot)++; }
2140                         }
2141                 }
2142                 
2143                 if ((inside_bucket_flag & (ISECT_3 | ISECT_1)) != (ISECT_3 | ISECT_1)) {
2144                         if (line_clip_rect2f(bucket_bounds, v3coSS, v1coSS, v1_clipSS, v2_clipSS)) {
2145                                 if ((inside_bucket_flag & ISECT_3) == 0) { copy_v2_v2(isectVCosSS[*tot], v1_clipSS); (*tot)++; }
2146                                 if ((inside_bucket_flag & ISECT_1) == 0) { copy_v2_v2(isectVCosSS[*tot], v2_clipSS); (*tot)++; }
2147                         }
2148                 }
2149                 
2150                 
2151                 if ((*tot) < 3) { /* no intersections to speak of */
2152                         *tot = 0;
2153                         return;
2154                 }
2155         
2156                 /* now we have all points we need, collect their angles and sort them clockwise */
2157                 
2158                 for (i = 0; i < (*tot); i++) {
2159                         cent[0] += isectVCosSS[i][0];
2160                         cent[1] += isectVCosSS[i][1];
2161                 }
2162                 cent[0] = cent[0] / (float)(*tot);
2163                 cent[1] = cent[1] / (float)(*tot);
2164                 
2165                 
2166                 
2167                 /* Collect angles for every point around the center point */
2168
2169                 
2170 #if 0   /* uses a few more cycles then the above loop */
2171                 for (i = 0; i < (*tot); i++) {
2172                         isectVCosSS[i][2] = angle_2d_clockwise(up, cent, isectVCosSS[i]);
2173                 }
2174 #endif
2175
2176                 v1_clipSS[0] = cent[0]; /* Abuse this var for the loop below */
2177                 v1_clipSS[1] = cent[1] + 1.0f;
2178                 
2179                 for (i = 0; i < (*tot); i++) {
2180                         v2_clipSS[0] = isectVCosSS[i][0] - cent[0];
2181                         v2_clipSS[1] = isectVCosSS[i][1] - cent[1];
2182                         isectVCosSS[i][2] = atan2f(v1_clipSS[0] * v2_clipSS[1] - v1_clipSS[1] * v2_clipSS[0], v1_clipSS[0] * v2_clipSS[0] + v1_clipSS[1] * v2_clipSS[1]);
2183                 }
2184                 
2185                 if (flip) qsort(isectVCosSS, *tot, sizeof(float) * 3, float_z_sort_flip);
2186                 else      qsort(isectVCosSS, *tot, sizeof(float) * 3, float_z_sort);
2187                 
2188                 /* remove doubles */
2189                 /* first/last check */
2190                 if (fabsf(isectVCosSS[0][0] - isectVCosSS[(*tot) - 1][0]) < PROJ_GEOM_TOLERANCE &&
2191                     fabsf(isectVCosSS[0][1] - isectVCosSS[(*tot) - 1][1]) < PROJ_GEOM_TOLERANCE)
2192                 {
2193                         (*tot)--;
2194                 }
2195                 
2196                 /* its possible there is only a few left after remove doubles */
2197                 if ((*tot) < 3) {
2198                         // printf("removed too many doubles A\n");
2199                         *tot = 0;
2200                         return;
2201                 }
2202                 
2203                 doubles = TRUE;
2204                 while (doubles == TRUE) {
2205                         doubles = FALSE;
2206                         for (i = 1; i < (*tot); i++) {
2207                                 if (fabsf(isectVCosSS[i - 1][0] - isectVCosSS[i][0]) < PROJ_GEOM_TOLERANCE &&
2208                                     fabsf(isectVCosSS[i - 1][1] - isectVCosSS[i][1]) < PROJ_GEOM_TOLERANCE)
2209                                 {
2210                                         int j;
2211                                         for (j = i + 1; j < (*tot); j++) {
2212                                                 isectVCosSS[j - 1][0] = isectVCosSS[j][0];
2213                                                 isectVCosSS[j - 1][1] = isectVCosSS[j][1];
2214                                         }
2215                                         doubles = TRUE; /* keep looking for more doubles */
2216                                         (*tot)--;
2217                                 }
2218                         }
2219                 }
2220                 
2221                 /* its possible there is only a few left after remove doubles */
2222                 if ((*tot) < 3) {
2223                         // printf("removed too many doubles B\n");
2224                         *tot = 0;
2225                         return;
2226                 }
2227                 
2228                 
2229                 if (is_ortho) {
2230                         for (i = 0; i < (*tot); i++) {
2231                                 barycentric_weights_v2(v1coSS, v2coSS, v3coSS, isectVCosSS[i], w);
2232                                 interp_v2_v2v2v2(bucket_bounds_uv[i], uv1co, uv2co, uv3co, w);
2233                         }
2234                 }
2235                 else {
2236                         for (i = 0; i < (*tot); i++) {
2237                                 barycentric_weights_v2_persp(v1coSS, v2coSS, v3coSS, isectVCosSS[i], w);
2238                                 interp_v2_v2v2v2(bucket_bounds_uv[i], uv1co, uv2co, uv3co, w);
2239                         }
2240                 }
2241         }
2242
2243 #ifdef PROJ_DEBUG_PRINT_CLIP
2244         /* include this at the bottom of the above function to debug the output */
2245
2246         {
2247                 /* If there are ever any problems, */
2248                 float test_uv[4][2];
2249                 int i;
2250                 if (is_ortho) rect_to_uvspace_ortho(bucket_bounds, v1coSS, v2coSS, v3coSS, uv1co, uv2co, uv3co, test_uv, flip);
2251                 else          rect_to_uvspace_persp(bucket_bounds, v1coSS, v2coSS, v3coSS, uv1co, uv2co, uv3co, test_uv, flip);
2252                 printf("(  [(%f,%f), (%f,%f), (%f,%f), (%f,%f)], ", test_uv[0][0], test_uv[0][1],   test_uv[1][0], test_uv[1][1],    test_uv[2][0], test_uv[2][1],    test_uv[3][0], test_uv[3][1]);
2253                 
2254                 printf("  [(%f,%f), (%f,%f), (%f,%f)], ", uv1co[0], uv1co[1],   uv2co[0], uv2co[1],    uv3co[0], uv3co[1]);
2255                 
2256                 printf("[");
2257                 for (i = 0; i < (*tot); i++) {
2258                         printf("(%f, %f),", bucket_bounds_uv[i][0], bucket_bounds_uv[i][1]);
2259                 }
2260                 printf("]),\\\n");
2261         }
2262 #endif
2263 }
2264
2265 /*
2266  * # This script creates faces in a blender scene from printed data above.
2267  *
2268  * project_ls = [
2269  * ...(output from above block)...
2270  * ]
2271  *
2272  * from Blender import Scene, Mesh, Window, sys, Mathutils
2273  *
2274  * import bpy
2275  *
2276  * V = Mathutils.Vector
2277  *
2278  * def main():
2279  *     sce = bpy.data.scenes.active
2280  *     
2281  *     for item in project_ls:
2282  *         bb = item[0]
2283  *         uv = item[1]
2284  *         poly = item[2]
2285  *         
2286  *         me = bpy.data.meshes.new()
2287  *         ob = sce.objects.new(me)
2288  *         
2289  *         me.verts.extend([V(bb[0]).xyz, V(bb[1]).xyz, V(bb[2]).xyz, V(bb[3]).xyz])
2290  *         me.faces.extend([(0,1,2,3),])
2291  *         me.verts.extend([V(uv[0]).xyz, V(uv[1]).xyz, V(uv[2]).xyz])
2292  *         me.faces.extend([(4,5,6),])
2293  *         
2294  *         vs = [V(p).xyz for p in poly]
2295  *         print len(vs)
2296  *         l = len(me.verts)
2297  *         me.verts.extend(vs)
2298  *         
2299  *         i = l
2300  *         while i < len(me.verts):
2301  *             ii = i + 1
2302  *             if ii == len(me.verts):
2303  *                 ii = l
2304  *             me.edges.extend([i, ii])
2305  *             i += 1
2306  * 
2307  * if __name__ == '__main__':
2308  *     main()
2309  */
2310
2311
2312 #undef ISECT_1
2313 #undef ISECT_2
2314 #undef ISECT_3
2315 #undef ISECT_4
2316 #undef ISECT_ALL3
2317 #undef ISECT_ALL4
2318
2319         
2320 /* checks if pt is inside a convex 2D polyline, the polyline must be ordered rotating clockwise
2321  * otherwise it would have to test for mixed (line_point_side_v2 > 0.0f) cases */
2322 static int IsectPoly2Df(const float pt[2], float uv[][2], const int tot)
2323 {
2324         int i;
2325         if (line_point_side_v2(uv[tot - 1], uv[0], pt) < 0.0f)
2326                 return 0;
2327         
2328         for (i = 1; i < tot; i++) {
2329                 if (line_point_side_v2(uv[i - 1], uv[i], pt) < 0.0f)
2330                         return 0;
2331                 
2332         }
2333         
2334         return 1;
2335 }
2336 static int IsectPoly2Df_twoside(const float pt[2], float uv[][2], const int tot)
2337 {
2338         int i;
2339         int side = (line_point_side_v2(uv[tot - 1], uv[0], pt) > 0.0f);
2340         
2341         for (i = 1; i < tot; i++) {
2342                 if ((line_point_side_v2(uv[i - 1], uv[i], pt) > 0.0f) != side)
2343                         return 0;
2344                 
2345         }
2346         
2347         return 1;
2348 }
2349
2350 /* One of the most important function for projection painting, since it selects the pixels to be added into each bucket.
2351  * initialize pixels from this face where it intersects with the bucket_index, optionally initialize pixels for removing seams */
2352 static void project_paint_face_init(const ProjPaintState *ps, const int thread_index, const int bucket_index, const int face_index, const int image_index, rctf *bucket_bounds, const ImBuf *ibuf, const short clamp_u, const short clamp_v)
2353 {
2354         /* Projection vars, to get the 3D locations into screen space  */
2355         MemArena *arena = ps->arena_mt[thread_index];
2356         LinkNode **bucketPixelNodes = ps->bucketRect + bucket_index;
2357         LinkNode *bucketFaceNodes = ps->bucketFaces[bucket_index];
2358         
2359         const MFace *mf = ps->dm_mface + face_index;
2360         const MTFace *tf = ps->dm_mtface + face_index;
2361         
2362         /* UV/pixel seeking data */
2363         int x; /* Image X-Pixel */
2364         int y; /* Image Y-Pixel */
2365         float mask;
2366         float uv[2]; /* Image floating point UV - same as x, y but from 0.0-1.0 */
2367         
2368         int side;
2369         float *v1coSS, *v2coSS, *v3coSS; /* vert co screen-space, these will be assigned to mf->v1,2,3 or mf->v1,3,4 */
2370         
2371         float *vCo[4]; /* vertex screenspace coords */
2372         
2373         float w[3], wco[3];
2374         
2375         float *uv1co, *uv2co, *uv3co; /* for convenience only, these will be assigned to tf->uv[0],1,2 or tf->uv[0],2,3 */
2376         float pixelScreenCo[4];
2377         
2378         rcti bounds_px; /* ispace bounds */
2379         /* vars for getting uvspace bounds */
2380         
2381         float tf_uv_pxoffset[4][2]; /* bucket bounds in UV space so we can init pixels only for this face,  */
2382         float xhalfpx, yhalfpx;
2383         const float ibuf_xf = (float)ibuf->x, ibuf_yf = (float)ibuf->y;
2384         
2385         int has_x_isect = 0, has_isect = 0; /* for early loop exit */
2386         
2387         int i1, i2, i3;
2388         
2389         float uv_clip[8][2];
2390         int uv_clip_tot;
2391         const short is_ortho = ps->is_ortho;
2392         const short do_backfacecull = ps->do_backfacecull;
2393         const short do_clip = ps->rv3d ? ps->rv3d->rflag & RV3D_CLIPPING : 0;
2394         
2395         vCo[0] = ps->dm_mvert[mf->v1].co;
2396         vCo[1] = ps->dm_mvert[mf->v2].co;
2397         vCo[2] = ps->dm_mvert[mf->v3].co;
2398         
2399         
2400         /* Use tf_uv_pxoffset instead of tf->uv so we can offset the UV half a pixel
2401          * this is done so we can avoid offsetting all the pixels by 0.5 which causes
2402          * problems when wrapping negative coords */
2403         xhalfpx = (0.5f + (PROJ_GEOM_TOLERANCE / 3.0f)) / ibuf_xf;
2404         yhalfpx = (0.5f + (PROJ_GEOM_TOLERANCE / 4.0f)) / ibuf_yf;
2405         
2406         /* Note about (PROJ_GEOM_TOLERANCE/x) above...
2407          * Needed to add this offset since UV coords are often quads aligned to pixels.
2408          * In this case pixels can be exactly between 2 triangles causing nasty
2409          * artifacts.
2410          * 
2411          * This workaround can be removed and painting will still work on most cases
2412          * but since the first thing most people try is painting onto a quad- better make it work.
2413          */
2414
2415
2416
2417         tf_uv_pxoffset[0][0] = tf->uv[0][0] - xhalfpx;
2418         tf_uv_pxoffset[0][1] = tf->uv[0][1] - yhalfpx;
2419
2420         tf_uv_pxoffset[1][0] = tf->uv[1][0] - xhalfpx;
2421         tf_uv_pxoffset[1][1] = tf->uv[1][1] - yhalfpx;
2422         
2423         tf_uv_pxoffset[2][0] = tf->uv[2][0] - xhalfpx;
2424         tf_uv_pxoffset[2][1] = tf->uv[2][1] - yhalfpx;
2425         
2426         if (mf->v4) {
2427                 vCo[3] = ps->dm_mvert[mf->v4].co;
2428                 
2429                 tf_uv_pxoffset[3][0] = tf->uv[3][0] - xhalfpx;
2430                 tf_uv_pxoffset[3][1] = tf->uv[3][1] - yhalfpx;
2431                 side = 1;
2432         }
2433         else {
2434                 side = 0;
2435         }
2436         
2437         do {
2438                 if (side == 1) {
2439                         i1 = 0; i2 = 2; i3 = 3;
2440                 }
2441                 else {
2442                         i1 = 0; i2 = 1; i3 = 2;
2443                 }
2444                 
2445                 uv1co = tf_uv_pxoffset[i1]; // was tf->uv[i1];
2446                 uv2co = tf_uv_pxoffset[i2]; // was tf->uv[i2];
2447                 uv3co = tf_uv_pxoffset[i3]; // was tf->uv[i3];
2448
2449                 v1coSS = ps->screenCoords[(*(&mf->v1 + i1))];
2450                 v2coSS = ps->screenCoords[(*(&mf->v1 + i2))];
2451                 v3coSS = ps->screenCoords[(*(&mf->v1 + i3))];
2452                 
2453                 /* This funtion gives is a concave polyline in UV space from the clipped quad and tri*/
2454                 project_bucket_clip_face(
2455                         is_ortho, bucket_bounds,
2456                         v1coSS, v2coSS, v3coSS,
2457                         uv1co, uv2co, uv3co,
2458                         uv_clip, &uv_clip_tot
2459                         );
2460
2461                 /* sometimes this happens, better just allow for 8 intersectiosn even though there should be max 6 */
2462 #if 0
2463                 if (uv_clip_tot > 6) {
2464                         printf("this should never happen! %d\n", uv_clip_tot);
2465                 }
2466 #endif
2467
2468                 if (pixel_bounds_array(uv_clip, &bounds_px, ibuf->x, ibuf->y, uv_clip_tot)) {
2469
2470                         if (clamp_u) {
2471                                 CLAMP(bounds_px.xmin, 0, ibuf->x);
2472                                 CLAMP(bounds_px.xmax, 0, ibuf->x);
2473                         }
2474
2475                         if (clamp_v) {
2476                                 CLAMP(bounds_px.ymin, 0, ibuf->y);
2477                                 CLAMP(bounds_px.ymax, 0, ibuf->y);
2478                         }
2479
2480                         /* clip face and */
2481                         
2482                         has_isect = 0;
2483                         for (y = bounds_px.ymin; y < bounds_px.ymax; y++) {
2484                                 //uv[1] = (((float)y) + 0.5f) / (float)ibuf->y;
2485                                 uv[1] = (float)y / ibuf_yf; /* use pixel offset UV coords instead */
2486
2487                                 has_x_isect = 0;
2488                                 for (x = bounds_px.xmin; x < bounds_px.xmax; x++) {
2489                                         //uv[0] = (((float)x) + 0.5f) / ibuf->x;
2490                                         uv[0] = (float)x / ibuf_xf; /* use pixel offset UV coords instead */
2491                                         
2492                                         /* Note about IsectPoly2Df_twoside, checking the face or uv flipping doesnt work,
2493                                          * could check the poly direction but better to do this */
2494                                         if ((do_backfacecull == TRUE  && IsectPoly2Df(uv, uv_clip, uv_clip_tot)) ||
2495                                             (do_backfacecull == FALSE && IsectPoly2Df_twoside(uv, uv_clip, uv_clip_tot)))
2496                                         {
2497                                                 
2498                                                 has_x_isect = has_isect = 1;
2499                                                 
2500                                                 if (is_ortho) screen_px_from_ortho(uv, v1coSS, v2coSS, v3coSS, uv1co, uv2co, uv3co, pixelScreenCo, w);
2501                                                 else          screen_px_from_persp(uv, v1coSS, v2coSS, v3coSS, uv1co, uv2co, uv3co, pixelScreenCo, w);
2502                                                 
2503                                                 /* a pity we need to get the worldspace pixel location here */
2504                                                 if (do_clip) {
2505                                                         interp_v3_v3v3v3(wco, ps->dm_mvert[(*(&mf->v1 + i1))].co, ps->dm_mvert[(*(&mf->v1 + i2))].co, ps->dm_mvert[(*(&mf->v1 + i3))].co, w);
2506                                                         if (ED_view3d_clipping_test(ps->rv3d, wco, TRUE)) {
2507                                                                 continue; /* Watch out that no code below this needs to run */
2508                                                         }
2509                                                 }
2510                                                 
2511                                                 /* Is this UV visible from the view? - raytrace */
2512                                                 /* project_paint_PickFace is less complex, use for testing */
2513                                                 //if (project_paint_PickFace(ps, pixelScreenCo, w, &side) == face_index) {
2514                                                 if ((ps->do_occlude == FALSE) ||
2515                                                     !project_bucket_point_occluded(ps, bucketFaceNodes, face_index, pixelScreenCo))
2516                                                 {
2517                                                         
2518                                                         mask = project_paint_uvpixel_mask(ps, face_index, side, w);
2519                                                         
2520                                                         if (mask > 0.0f) {
2521                                                                 BLI_linklist_prepend_arena(
2522                                                                         bucketPixelNodes,
2523                                                                         project_paint_uvpixel_init(ps, arena, ibuf, x, y, mask, face_index, image_index, pixelScreenCo, side, w),
2524                                                                         arena
2525                                                                         );
2526                                                         }
2527                                                 }
2528                                                 
2529                                         }
2530 //#if 0
2531                                         else if (has_x_isect) {
2532                                                 /* assuming the face is not a bow-tie - we know we cant intersect again on the X */
2533                                                 break;
2534                                         }
2535 //#endif
2536                                 }
2537                                 
2538                                 
2539 #if 0           /* TODO - investigate why this dosnt work sometimes! it should! */
2540                                 /* no intersection for this entire row, after some intersection above means we can quit now */
2541                                 if (has_x_isect == 0 && has_isect) {
2542                                         break;
2543                                 }
2544 #endif
2545                         }
2546                 }
2547         } while (side--);
2548
2549         
2550         
2551 #ifndef PROJ_DEBUG_NOSEAMBLEED
2552         if (ps->seam_bleed_px > 0.0f) {
2553                 int face_seam_flag;
2554                 
2555                 if (ps->thread_tot > 1)
2556                         BLI_lock_thread(LOCK_CUSTOM1);  /* Other threads could be modifying these vars */
2557                 
2558                 face_seam_flag = ps->faceSeamFlags[face_index];
2559                 
2560                 /* are any of our edges un-initialized? */
2561                 if ((face_seam_flag & (PROJ_FACE_SEAM1 | PROJ_FACE_NOSEAM1)) == 0 ||
2562                     (face_seam_flag & (PROJ_FACE_SEAM2 | PROJ_FACE_NOSEAM2)) == 0 ||
2563                     (face_seam_flag & (PROJ_FACE_SEAM3 | PROJ_FACE_NOSEAM3)) == 0 ||
2564                     (face_seam_flag & (PROJ_FACE_SEAM4 | PROJ_FACE_NOSEAM4)) == 0)
2565                 {
2566                         project_face_seams_init(ps, face_index, mf->v4);
2567                         face_seam_flag = ps->faceSeamFlags[face_index];
2568                         //printf("seams - %d %d %d %d\n", flag&PROJ_FACE_SEAM1, flag&PROJ_FACE_SEAM2, flag&PROJ_FACE_SEAM3, flag&PROJ_FACE_SEAM4);
2569                 }
2570                 
2571                 if ((face_seam_flag & (PROJ_FACE_SEAM1 | PROJ_FACE_SEAM2 | PROJ_FACE_SEAM3 | PROJ_FACE_SEAM4)) == 0) {
2572                         
2573                         if (ps->thread_tot > 1)
2574                                 BLI_unlock_thread(LOCK_CUSTOM1);  /* Other threads could be modifying these vars */
2575                         
2576                 }
2577                 else {
2578                         /* we have a seam - deal with it! */
2579                         
2580                         /* Now create new UV's for the seam face */
2581                         float (*outset_uv)[2] = ps->faceSeamUVs[face_index];
2582                         float insetCos[4][3]; /* inset face coords.  NOTE!!! ScreenSace for ortho, Worldspace in prespective view */
2583
2584                         float *vCoSS[4]; /* vertex screenspace coords */
2585                         
2586                         float bucket_clip_edges[2][2]; /* store the screenspace coords of the face, clipped by the bucket's screen aligned rectangle */
2587                         float edge_verts_inset_clip[2][3];
2588                         int fidx1, fidx2; /* face edge pairs - loop throuh these ((0,1), (1,2), (2,3), (3,0)) or ((0,1), (1,2), (2,0)) for a tri */
2589                         
2590                         float seam_subsection[4][2];
2591                         float fac1, fac2, ftot;
2592                         
2593                         
2594                         if (outset_uv[0][0] == FLT_MAX) /* first time initialize */
2595                                 uv_image_outset(tf_uv_pxoffset, outset_uv, ps->seam_bleed_px, ibuf->x, ibuf->y, mf->v4);
2596                         
2597                         /* ps->faceSeamUVs cant be modified when threading, now this is done we can unlock */
2598                         if (ps->thread_tot > 1)
2599                                 BLI_unlock_thread(LOCK_CUSTOM1);  /* Other threads could be modifying these vars */
2600                         
2601                         vCoSS[0] = ps->screenCoords[mf->v1];
2602                         vCoSS[1] = ps->screenCoords[mf->v2];
2603                         vCoSS[2] = ps->screenCoords[mf->v3];
2604                         if (mf->v4)
2605                                 vCoSS[3] = ps->screenCoords[mf->v4];
2606                         
2607                         /* PROJ_FACE_SCALE_SEAM must be slightly less then 1.0f */
2608                         if (is_ortho) {
2609                                 if (mf->v4) scale_quad(insetCos, vCoSS, PROJ_FACE_SCALE_SEAM);
2610                                 else        scale_tri(insetCos, vCoSS, PROJ_FACE_SCALE_SEAM);
2611                         }
2612                         else {
2613                                 if (mf->v4) scale_quad(insetCos, vCo, PROJ_FACE_SCALE_SEAM);
2614                                 else        scale_tri(insetCos, vCo, PROJ_FACE_SCALE_SEAM);
2615                         }
2616                         
2617                         side = 0; /* for triangles this wont need to change */
2618                         
2619                         for (fidx1 = 0; fidx1 < (mf->v4 ? 4 : 3); fidx1++) {
2620                                 if (mf->v4) fidx2 = (fidx1 == 3) ? 0 : fidx1 + 1;  /* next fidx in the face (0,1,2,3) -> (1,2,3,0) */
2621                                 else        fidx2 = (fidx1 == 2) ? 0 : fidx1 + 1;  /* next fidx in the face (0,1,2) -> (1,2,0) */
2622                                 
2623                                 if ((face_seam_flag & (1 << fidx1)) && /* 1<<fidx1 -> PROJ_FACE_SEAM# */
2624                                     line_clip_rect2f(bucket_bounds, vCoSS[fidx1], vCoSS[fidx2], bucket_clip_edges[0], bucket_clip_edges[1]))
2625                                 {
2626
2627                                         ftot = len_v2v2(vCoSS[fidx1], vCoSS[fidx2]); /* screenspace edge length */
2628                                         
2629                                         if (ftot > 0.0f) { /* avoid div by zero */
2630                                                 if (mf->v4) {
2631                                                         if (fidx1 == 2 || fidx2 == 2) side = 1;
2632                                                         else side = 0;
2633                                                 }
2634                                                 
2635                                                 fac1 = len_v2v2(vCoSS[fidx1], bucket_clip_edges[0]) / ftot;
2636                                                 fac2 = len_v2v2(vCoSS[fidx1], bucket_clip_edges[1]) / ftot;
2637                                                 
2638                                                 interp_v2_v2v2(seam_subsection[0], tf_uv_pxoffset[fidx1], tf_uv_pxoffset[fidx2], fac1);
2639                                                 interp_v2_v2v2(seam_subsection[1], tf_uv_pxoffset[fidx1], tf_uv_pxoffset[fidx2], fac2);
2640
2641                                                 interp_v2_v2v2(seam_subsection[2], outset_uv[fidx1], outset_uv[fidx2], fac2);
2642                                                 interp_v2_v2v2(seam_subsection[3], outset_uv[fidx1], outset_uv[fidx2], fac1);
2643                                                 
2644                                                 /* if the bucket_clip_edges values Z values was kept we could avoid this
2645                                                  * Inset needs to be added so occlusion tests wont hit adjacent faces */
2646                                                 interp_v3_v3v3(edge_verts_inset_clip[0], insetCos[fidx1], insetCos[fidx2], fac1);
2647                                                 interp_v3_v3v3(edge_verts_inset_clip[1], insetCos[fidx1], insetCos[fidx2], fac2);
2648                                                 
2649
2650                                                 if (pixel_bounds_uv(seam_subsection[0], seam_subsection[1], seam_subsection[2], seam_subsection[3], &bounds_px, ibuf->x, ibuf->y, 1)) {
2651                                                         /* bounds between the seam rect and the uvspace bucket pixels */
2652                                                         
2653                                                         has_isect = 0;
2654                                                         for (y = bounds_px.ymin; y < bounds_px.ymax; y++) {
2655                                                                 // uv[1] = (((float)y) + 0.5f) / (float)ibuf->y;
2656                                                                 uv[1] = (float)y / ibuf_yf; /* use offset uvs instead */
2657                                                                 
2658                                                                 has_x_isect = 0;
2659                                                                 for (x = bounds_px.xmin; x < bounds_px.xmax; x++) {
2660                                                                         //uv[0] = (((float)x) + 0.5f) / (float)ibuf->x;
2661                                                                         uv[0] = (float)x / ibuf_xf; /* use offset uvs instead */
2662                                                                         
2663                                                                         /* test we're inside uvspace bucket and triangle bounds */
2664                                                                         if (isect_point_quad_v2(uv, seam_subsection[0], seam_subsection[1], seam_subsection[2], seam_subsection[3])) {
2665                                                                                 float fac;
2666                                                                                 
2667                                                                                 /* We need to find the closest point along the face edge,
2668                                                                                  * getting the screen_px_from_*** wont work because our actual location
2669                                                                                  * is not relevant, since we are outside the face, Use VecLerpf to find
2670                                                                                  * our location on the side of the face's UV */
2671 #if 0
2672                                                                                 if (is_ortho) screen_px_from_ortho(ps, uv, v1co, v2co, v3co, uv1co, uv2co, uv3co, pixelScreenCo);
2673                                                                                 else          screen_px_from_persp(ps, uv, v1co, v2co, v3co, uv1co, uv2co, uv3co, pixelScreenCo);
2674 #endif
2675                                                                                 
2676                                                                                 /* Since this is a seam we need to work out where on the line this pixel is */
2677                                                                                 //fac = line_point_factor_v2(uv, uv_seam_quad[0], uv_seam_quad[1]);
2678                                                                                 
2679                                                                                 fac = line_point_factor_v2(uv, seam_subsection[0], seam_subsection[1]);
2680                                                                                 if      (fac < 0.0f) { copy_v3_v3(pixelScreenCo, edge_verts_inset_clip[0]); }
2681                                                                                 else if (fac > 1.0f) { copy_v3_v3(pixelScreenCo, edge_verts_inset_clip[1]); }
2682                                                                                 else                 { interp_v3_v3v3(pixelScreenCo, edge_verts_inset_clip[0], edge_verts_inset_clip[1], fac); }
2683                                                                                 
2684                                                                                 if (!is_ortho) {
2685                                                                                         pixelScreenCo[3] = 1.0f;
2686                                                                                         mul_m4_v4((float(*)[4])ps->projectMat, pixelScreenCo); /* cast because of const */
2687                                                                                         pixelScreenCo[0] = (float)(ps->winx / 2.0f) + (ps->winx / 2.0f) * pixelScreenCo[0] / pixelScreenCo[3];
2688                                                                                         pixelScreenCo[1] = (float)(ps->winy / 2.0f) + (ps->winy / 2.0f) * pixelScreenCo[1] / pixelScreenCo[3];
2689                                                                                         pixelScreenCo[2] = pixelScreenCo[2] / pixelScreenCo[3]; /* Use the depth for bucket point occlusion */
2690                                                                                 }
2691                                                                                 
2692                                                                                 if ((ps->do_occlude == FALSE) ||
2693                                                                                     !project_bucket_point_occluded(ps, bucketFaceNodes, face_index, pixelScreenCo))
2694                                                                                 {
2695                                                                                         /* Only bother calculating the weights if we intersect */
2696                                                                                         if (ps->do_mask_normal || ps->dm_mtface_clone) {
2697 #if 1
2698                                                                                                 /* get the UV on the line since we want to copy the pixels from there for bleeding */
2699                                                                                                 float uv_close[2];
2700                                                                                                 float uv_fac = closest_to_line_v2(uv_close, uv, tf_uv_pxoffset[fidx1], tf_uv_pxoffset[fidx2]);
2701                                                                                                 if      (uv_fac < 0.0f) copy_v2_v2(uv_close, tf_uv_pxoffset[fidx1]);
2702                                                                                                 else if (uv_fac > 1.0f) copy_v2_v2(uv_close, tf_uv_pxoffset[fidx2]);
2703
2704                                                                                                 if (side) {
2705                                                                                                         barycentric_weights_v2(tf_uv_pxoffset[0], tf_uv_pxoffset[2], tf_uv_pxoffset[3], uv_close, w);
2706                                                                                                 }
2707                                                                                                 else {
2708                                                                                                         barycentric_weights_v2(tf_uv_pxoffset[0], tf_uv_pxoffset[1], tf_uv_pxoffset[2], uv_close, w);
2709                                                                                                 }
2710 #else                                                                                   /* this is buggy with quads, don't use for now */
2711
2712                                                                                                 /* Cheat, we know where we are along the edge so work out the weights from that */
2713                                                                                                 uv_fac = fac1 + (uv_fac * (fac2 - fac1));
2714
2715                                                                                                 w[0] = w[1] = w[2] = 0.0;
2716                                                                                                 if (side) {
2717                                                                                                         w[fidx1 ? fidx1 - 1 : 0] = 1.0f - uv_fac;
2718                                                                                                         w[fidx2 ? fidx2 - 1 : 0] = uv_fac;
2719                                                                                                 }
2720                                                                                                 else {
2721                                                                                                         w[fidx1] = 1.0f - uv_fac;
2722                                                                                                         w[fidx2] = uv_fac;
2723                                                                                                 }
2724 #endif
2725                                                                                         }
2726                                                                                         
2727                                                                                         /* a pity we need to get the worldspace pixel location here */
2728                                                                                         if (do_clip) {
2729                                                                                                 if (side) interp_v3_v3v3v3(wco, ps->dm_mvert[mf->v1].co, ps->dm_mvert[mf->v3].co, ps->dm_mvert[mf->v4].co, w);
2730                                                                                                 else      interp_v3_v3v3v3(wco, ps->dm_mvert[mf->v1].co, ps->dm_mvert[mf->v2].co, ps->dm_mvert[mf->v3].co, w);
2731
2732                                                                                                 if (ED_view3d_clipping_test(ps->rv3d, wco, TRUE)) {
2733                                                                                                         continue; /* Watch out that no code below this needs to run */
2734                                                                                                 }
2735                                                                                         }
2736                                                                                         
2737                                                                                         mask = project_paint_uvpixel_mask(ps, face_index, side, w);
2738                                                                                         
2739                                                                                         if (mask > 0.0f) {
2740                                                                                                 BLI_linklist_prepend_arena(
2741                                                                                                         bucketPixelNodes,
2742                                                                                                         project_paint_uvpixel_init(ps, arena, ibuf, x, y, mask, face_index, image_index, pixelScreenCo, side, w),
2743                                                                                                         arena
2744                                                                                                         );
2745                                                                                         }
2746                                                                                         
2747                                                                                 }
2748                                                                         }
2749                                                                         else if (has_x_isect) {
2750                                                                                 /* assuming the face is not a bow-tie - we know we cant intersect again on the X */
2751                                                                                 break;
2752                                                                         }
2753                                                                 }
2754                                                                 
2755 #if 0                           /* TODO - investigate why this dosnt work sometimes! it should! */
2756                                                                 /* no intersection for this entire row, after some intersection above means we can quit now */
2757                                                                 if (has_x_isect == 0 && has_isect) {
2758                                                                         break;
2759                                                                 }
2760 #endif
2761                                                         }
2762                                                 }
2763                                         }
2764                                 }
2765                         }
2766                 }
2767         }
2768 #endif // PROJ_DEBUG_NOSEAMBLEED
2769 }
2770
2771
2772 /* takes floating point screenspace min/max and returns int min/max to be used as indices for ps->bucketRect, ps->bucketFlags */
2773 static void project_paint_bucket_bounds(const ProjPaintState *ps, const float min[2], const float max[2], int bucketMin[2], int bucketMax[2])
2774 {
2775         /* divide by bucketWidth & bucketHeight so the bounds are offset in bucket grid units */
2776         /* XXX: the offset of 0.5 is always truncated to zero and the offset of 1.5f is always truncated to 1, is this really correct?? - jwilkins */
2777         bucketMin[0] = (int)((int)(((float)(min[0] - ps->screenMin[0]) / ps->screen_width) * ps->buckets_x) + 0.5f); /* these offsets of 0.5 and 1.5 seem odd but they are correct */
2778         bucketMin[1] = (int)((int)(((float)(min[1] - ps->screenMin[1]) / ps->screen_height) * ps->buckets_y) + 0.5f);
2779         
2780         bucketMax[0] = (int)((int)(((float)(max[0] - ps->screenMin[0]) / ps->screen_width) * ps->buckets_x) + 1.5f);
2781         bucketMax[1] = (int)((int)(((float)(max[1] - ps->screenMin[1]) / ps->screen_height) * ps->buckets_y) + 1.5f);
2782         
2783         /* in case the rect is outside the mesh 2d bounds */
2784         CLAMP(bucketMin[0], 0, ps->buckets_x);
2785         CLAMP(bucketMin[1], 0, ps->buckets_y);
2786         
2787         CLAMP(bucketMax[0], 0, ps->buckets_x);
2788         CLAMP(bucketMax[1], 0, ps->buckets_y);
2789 }
2790
2791 /* set bucket_bounds to a screen space-aligned floating point bound-box */
2792 static void project_bucket_bounds(const ProjPaintState *ps, const int bucket_x, const int bucket_y, rctf *bucket_bounds)
2793 {
2794         bucket_bounds->xmin = ps->screenMin[0] + ((bucket_x) * (ps->screen_width / ps->buckets_x));     /* left */
2795         bucket_bounds->xmax = ps->screenMin[0] + ((bucket_x + 1) * (ps->screen_width / ps->buckets_x)); /* right */
2796         
2797         bucket_bounds->ymin = ps->screenMin[1] + ((bucket_y) * (ps->screen_height / ps->buckets_y));      /* bottom */
2798         bucket_bounds->ymax = ps->screenMin[1] + ((bucket_y + 1) * (ps->screen_height  / ps->buckets_y)); /* top */
2799 }
2800
2801 /* Fill this bucket with pixels from the faces that intersect it.
2802  * 
2803  * have bucket_bounds as an argument so we don't need to give bucket_x/y the rect function needs */
2804 static void project_bucket_init(const ProjPaintState *ps, const int thread_index, const int bucket_index, rctf *bucket_bounds)
2805 {
2806         LinkNode *node;
2807         int face_index, image_index = 0;
2808         ImBuf *ibuf = NULL;
2809         Image *tpage_last = NULL, *tpage;
2810         Image *ima = NULL;
2811
2812         if (ps->image_tot == 1) {
2813                 /* Simple loop, no context switching */
2814                 ibuf = ps->projImages[0].ibuf;
2815                 ima = ps->projImages[0].ima;
2816
2817                 for (node = ps->bucketFaces[bucket_index]; node; node = node->next) {
2818                         project_paint_face_init(ps, thread_index, bucket_index, GET_INT_FROM_POINTER(node->link), 0, bucket_bounds, ibuf, ima->tpageflag & IMA_CLAMP_U, ima->tpageflag & IMA_CLAMP_V);
2819                 }
2820         }
2821         else {
2822                 
2823                 /* More complicated loop, switch between images */
2824                 for (node = ps->bucketFaces[bucket_index]; node; node = node->next) {
2825                         face_index = GET_INT_FROM_POINTER(node->link);
2826                                 
2827                         /* Image context switching */
2828                         tpage = project_paint_face_image(ps, ps->dm_mtface, face_index);
2829                         if (tpage_last != tpage) {
2830                                 tpage_last = tpage;
2831
2832                                 for (image_index = 0; image_index < ps->image_tot; image_index++) {
2833                                         if (ps->projImages[image_index].ima == tpage_last) {
2834                                                 ibuf = ps->projImages[image_index].ibuf;
2835                                                 ima = ps->projImages[image_index].ima;
2836                                                 break;
2837                                         }
2838                                 }
2839                         }
2840                         /* context switching done */
2841                         
2842                         project_paint_face_init(ps, thread_index, bucket_index, face_index, image_index, bucket_bounds, ibuf, ima->tpageflag & IMA_CLAMP_U, ima->tpageflag & IMA_CLAMP_V);
2843                 }
2844         }
2845         
2846         ps->bucketFlags[bucket_index] |= PROJ_BUCKET_INIT;
2847 }
2848
2849
2850 /* We want to know if a bucket and a face overlap in screen-space
2851  * 
2852  * Note, if this ever returns false positives its not that bad, since a face in the bounding area will have its pixels