3db25800a0660f82cfb448287e073224ce9179f8
[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 typedef struct ImagePaintState {
144         SpaceImage *sima;
145         View2D *v2d;
146         Scene *scene;
147         bScreen *screen;
148
149         Brush *brush;
150         short tool, blend;
151         Image *image;
152         ImBuf *canvas;
153         ImBuf *clonecanvas;
154         char *warnpackedfile;
155         char *warnmultifile;
156
157         /* viewport texture paint only, but _not_ project paint */
158         Object *ob;
159         int faceindex;
160         float uv[2];
161         int do_facesel;
162
163         DerivedMesh    *dm;
164         int             dm_totface;
165         int             dm_release;
166
167         MFace          *dm_mface;
168         MTFace         *dm_mtface;
169 } ImagePaintState;
170
171 typedef struct ImagePaintRegion {
172         int destx, desty;
173         int srcx, srcy;
174         int width, height;
175 } ImagePaintRegion;
176
177 /* ProjectionPaint defines */
178
179 /* approx the number of buckets to have under the brush,
180  * used with the brush size to set the ps->buckets_x and ps->buckets_y value.
181  * 
182  * When 3 - a brush should have ~9 buckets under it at once
183  * ...this helps for threading while painting as well as
184  * avoiding initializing pixels that wont touch the brush */
185 #define PROJ_BUCKET_BRUSH_DIV 4
186
187 #define PROJ_BUCKET_RECT_MIN 4
188 #define PROJ_BUCKET_RECT_MAX 256
189
190 #define PROJ_BOUNDBOX_DIV 8
191 #define PROJ_BOUNDBOX_SQUARED  (PROJ_BOUNDBOX_DIV * PROJ_BOUNDBOX_DIV)
192
193 //#define PROJ_DEBUG_PAINT 1
194 //#define PROJ_DEBUG_NOSEAMBLEED 1
195 //#define PROJ_DEBUG_PRINT_CLIP 1
196 #define PROJ_DEBUG_WINCLIP 1
197
198 /* projectFaceSeamFlags options */
199 //#define PROJ_FACE_IGNORE      (1<<0)  /* When the face is hidden, backfacing or occluded */
200 //#define PROJ_FACE_INIT        (1<<1)  /* When we have initialized the faces data */
201 #define PROJ_FACE_SEAM1 (1 << 0)  /* If this face has a seam on any of its edges */
202 #define PROJ_FACE_SEAM2 (1 << 1)
203 #define PROJ_FACE_SEAM3 (1 << 2)
204 #define PROJ_FACE_SEAM4 (1 << 3)
205
206 #define PROJ_FACE_NOSEAM1   (1 << 4)
207 #define PROJ_FACE_NOSEAM2   (1 << 5)
208 #define PROJ_FACE_NOSEAM3   (1 << 6)
209 #define PROJ_FACE_NOSEAM4   (1 << 7)
210
211 #define PROJ_SRC_VIEW       1
212 #define PROJ_SRC_IMAGE_CAM  2
213 #define PROJ_SRC_IMAGE_VIEW 3
214
215 #define PROJ_VIEW_DATA_ID "view_data"
216 #define PROJ_VIEW_DATA_SIZE (4 * 4 + 4 * 4 + 3) /* viewmat + winmat + clipsta + clipend + is_ortho */
217
218
219 /* a slightly scaled down face is used to get fake 3D location for edge pixels in the seams
220  * as this number approaches  1.0f the likelihood increases of float precision errors where
221  * it is occluded by an adjacent face */
222 #define PROJ_FACE_SCALE_SEAM    0.99f
223
224 #define PROJ_BUCKET_NULL        0
225 #define PROJ_BUCKET_INIT        (1 << 0)
226 // #define PROJ_BUCKET_CLONE_INIT       (1<<1)
227
228 /* used for testing doubles, if a point is on a line etc */
229 #define PROJ_GEOM_TOLERANCE 0.00075f
230
231 /* vert flags */
232 #define PROJ_VERT_CULL 1
233
234 /* This is mainly a convenience struct used so we can keep an array of images we use
235  * Thir imbufs, etc, in 1 array, When using threads this array is copied for each thread
236  * because 'partRedrawRect' and 'touch' values would not be thread safe */
237 typedef struct ProjPaintImage {
238         Image *ima;
239         ImBuf *ibuf;
240         ImagePaintPartialRedraw *partRedrawRect;
241         void **undoRect; /* only used to build undo tiles after painting */
242         int touch;
243 } ProjPaintImage;
244
245 /* Main projection painting struct passed to all projection painting functions */
246 typedef struct ProjPaintState {
247         View3D *v3d;
248         RegionView3D *rv3d;
249         ARegion *ar;
250         Scene *scene;
251         int source; /* PROJ_SRC_**** */
252
253         Brush *brush;
254         short tool, blend;
255         Object *ob;
256         /* end similarities with ImagePaintState */
257         
258         DerivedMesh    *dm;
259         int dm_totface;
260         int dm_totvert;
261         int dm_release;
262
263         MVert          *dm_mvert;
264         MFace          *dm_mface;
265         MTFace         *dm_mtface;
266         MTFace         *dm_mtface_clone;    /* other UV map, use for cloning between layers */
267         MTFace         *dm_mtface_stencil;
268         
269         /* projection painting only */
270         MemArena *arena_mt[BLENDER_MAX_THREADS]; /* for multithreading, the first item is sometimes used for non threaded cases too */
271         LinkNode **bucketRect;              /* screen sized 2D array, each pixel has a linked list of ProjPixel's */
272         LinkNode **bucketFaces;             /* bucketRect aligned array linkList of faces overlapping each bucket */
273         unsigned char *bucketFlags;         /* store if the bucks have been initialized  */
274 #ifndef PROJ_DEBUG_NOSEAMBLEED
275         char *faceSeamFlags;                /* store info about faces, if they are initialized etc*/
276         float (*faceSeamUVs)[4][2];         /* expanded UVs for faces to use as seams */
277         LinkNode **vertFaces;               /* Only needed for when seam_bleed_px is enabled, use to find UV seams */
278 #endif
279         char *vertFlags;                    /* store options per vert, now only store if the vert is pointing away from the view */
280         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 */
281         int buckets_y;
282
283         ProjPaintImage *projImages;
284         
285         int pixel_sizeof;           /* result of project_paint_pixel_sizeof(), constant per stroke */
286
287         int image_tot;              /* size of projectImages array */
288         
289         float (*screenCoords)[4];   /* verts projected into floating point screen space */
290         
291         float screenMin[2];         /* 2D bounds for mesh verts on the screen's plane (screenspace) */
292         float screenMax[2]; 
293         float screen_width;         /* Calculated from screenMin & screenMax */
294         float screen_height;
295         int winx, winy;             /* from the carea or from the projection render */
296         
297         /* options for projection painting */
298         int do_layer_clone;
299         int do_layer_stencil;
300         int do_layer_stencil_inv;
301         
302         short do_occlude;               /* Use raytraced occlusion? - ortherwise will paint right through to the back*/
303         short do_backfacecull;          /* ignore faces with normals pointing away, skips a lot of raycasts if your normals are correctly flipped */
304         short do_mask_normal;           /* mask out pixels based on their normals */
305         short do_new_shading_nodes;     /* cache BKE_scene_use_new_shading_nodes value */
306         float normal_angle;             /* what angle to mask at*/
307         float normal_angle_inner;
308         float normal_angle_range;       /* difference between normal_angle and normal_angle_inner, for easy access */
309         
310         short is_ortho;
311         bool do_masking;              /* use masking during painting. Some operations such as airbrush may disable */
312         short is_texbrush;              /* only to avoid running  */
313 #ifndef PROJ_DEBUG_NOSEAMBLEED
314         float seam_bleed_px;
315 #endif
316         /* clone vars */
317         float cloneOffset[2];
318         
319         float projectMat[4][4];     /* Projection matrix, use for getting screen coords */
320         float viewDir[3];           /* View vector, use for do_backfacecull and for ray casting with an ortho viewport  */
321         float viewPos[3];           /* View location in object relative 3D space, so can compare to verts  */
322         float clipsta, clipend;
323         
324         /* reproject vars */
325         Image *reproject_image;
326         ImBuf *reproject_ibuf;
327
328
329         /* threads */
330         int thread_tot;
331         int bucketMin[2];
332         int bucketMax[2];
333         int context_bucket_x, context_bucket_y; /* must lock threads while accessing these */
334 } ProjPaintState;
335
336 typedef union pixelPointer {
337         float *f_pt;            /* float buffer */
338         unsigned int *uint_pt; /* 2 ways to access a char buffer */
339         unsigned char *ch_pt;
340 } PixelPointer;
341
342 typedef union pixelStore {
343         unsigned char ch[4];
344         unsigned int uint;
345         float f[4];
346 } PixelStore;
347
348 typedef struct ProjPixel {
349         float projCoSS[2]; /* the floating point screen projection of this pixel */
350         float worldCoSS[3];
351         /* Only used when the airbrush is disabled.
352          * Store the max mask value to avoid painting over an area with a lower opacity
353          * with an advantage that we can avoid touching the pixel at all, if the 
354          * new mask value is lower then mask_max */
355         unsigned short mask_max;
356         
357         /* for various reasons we may want to mask out painting onto this pixel */
358         unsigned short mask;
359         
360         short x_px, y_px;
361         
362         PixelStore origColor;
363         PixelStore newColor;
364         PixelPointer pixel;
365         
366         short image_index; /* if anyone wants to paint onto more then 32768 images they can bite me */
367         unsigned char bb_cell_index;
368 } ProjPixel;
369
370 typedef struct ProjPixelClone {
371         struct ProjPixel __pp;
372         PixelStore clonepx;
373 } ProjPixelClone;
374
375 /* blur, store surrounding colors */
376 #define PROJ_PIXEL_SOFTEN_TOT 4
377 /* blur picking offset (in screenspace) */
378 #define PROJ_PIXEL_SOFTEN_OFS_PX 1.0f
379
380 static const float proj_pixel_soften_v2[PROJ_PIXEL_SOFTEN_TOT][2] = {
381         {-PROJ_PIXEL_SOFTEN_OFS_PX,                         0.0f},
382         { 0.0f,                        -PROJ_PIXEL_SOFTEN_OFS_PX},
383         { 0.0f,                         PROJ_PIXEL_SOFTEN_OFS_PX},
384         { PROJ_PIXEL_SOFTEN_OFS_PX,                         0.0f},
385 };
386
387 /* Finish projection painting structs */
388
389 typedef struct UndoImageTile {
390         struct UndoImageTile *next, *prev;
391
392         char idname[MAX_ID_NAME];  /* name instead of pointer*/
393         char ibufname[IB_FILENAME_SIZE];
394
395         union {
396                 float        *fp;
397                 unsigned int *uint;
398                 void         *pt;
399         } rect;
400         int x, y;
401
402         short source, use_float;
403         char gen_type;
404 } UndoImageTile;
405
406 /* this is a static resource for non-globality,
407  * Maybe it should be exposed as part of the
408  * paint operation, but for now just give a public interface */
409 static ImagePaintPartialRedraw imapaintpartial = {0, 0, 0, 0, 0};
410
411 ImagePaintPartialRedraw *get_imapaintpartial(void)
412 {
413         return &imapaintpartial;
414 }
415
416 void set_imapaintpartial(struct ImagePaintPartialRedraw *ippr)
417 {
418         imapaintpartial = *ippr;
419 }
420
421 /* UNDO */
422
423 static void undo_copy_tile(UndoImageTile *tile, ImBuf *tmpibuf, ImBuf *ibuf, int restore)
424 {
425         /* copy or swap contents of tile->rect and region in ibuf->rect */
426         IMB_rectcpy(tmpibuf, ibuf, 0, 0, tile->x * IMAPAINT_TILE_SIZE,
427                     tile->y * IMAPAINT_TILE_SIZE, IMAPAINT_TILE_SIZE, IMAPAINT_TILE_SIZE);
428
429         if (ibuf->rect_float) {
430                 SWAP(float *, tmpibuf->rect_float, tile->rect.fp);
431         }
432         else {
433                 SWAP(unsigned int *, tmpibuf->rect, tile->rect.uint);
434         }
435         
436         if (restore)
437                 IMB_rectcpy(ibuf, tmpibuf, tile->x * IMAPAINT_TILE_SIZE,
438                             tile->y * IMAPAINT_TILE_SIZE, 0, 0, IMAPAINT_TILE_SIZE, IMAPAINT_TILE_SIZE);
439 }
440
441 void *image_undo_push_tile(Image *ima, ImBuf *ibuf, ImBuf **tmpibuf, int x_tile, int y_tile)
442 {
443         ListBase *lb = undo_paint_push_get_list(UNDO_PAINT_IMAGE);
444         UndoImageTile *tile;
445         int allocsize;
446         short use_float = ibuf->rect_float ? 1 : 0;
447
448         for (tile = lb->first; tile; tile = tile->next)
449                 if (tile->x == x_tile && tile->y == y_tile && ima->gen_type == tile->gen_type && ima->source == tile->source)
450                         if (tile->use_float == use_float)
451                                 if (strcmp(tile->idname, ima->id.name) == 0 && strcmp(tile->ibufname, ibuf->name) == 0)
452                                         return tile->rect.pt;
453         
454         if (*tmpibuf == NULL)
455                 *tmpibuf = IMB_allocImBuf(IMAPAINT_TILE_SIZE, IMAPAINT_TILE_SIZE, 32, IB_rectfloat | IB_rect);
456         
457         tile = MEM_callocN(sizeof(UndoImageTile), "UndoImageTile");
458         BLI_strncpy(tile->idname, ima->id.name, sizeof(tile->idname));
459         tile->x = x_tile;
460         tile->y = y_tile;
461
462         allocsize = IMAPAINT_TILE_SIZE * IMAPAINT_TILE_SIZE * 4;
463         allocsize *= (ibuf->rect_float) ? sizeof(float) : sizeof(char);
464         tile->rect.pt = MEM_mapallocN(allocsize, "UndeImageTile.rect");
465
466         BLI_strncpy(tile->ibufname, ibuf->name, sizeof(tile->ibufname));
467
468         tile->gen_type = ima->gen_type;
469         tile->source = ima->source;
470         tile->use_float = use_float;
471
472         undo_copy_tile(tile, *tmpibuf, ibuf, 0);
473         undo_paint_push_count_alloc(UNDO_PAINT_IMAGE, allocsize);
474
475         BLI_addtail(lb, tile);
476         
477         return tile->rect.pt;
478 }
479
480 static void image_undo_restore(bContext *C, ListBase *lb)
481 {
482         Main *bmain = CTX_data_main(C);
483         Image *ima = NULL;
484         ImBuf *ibuf, *tmpibuf;
485         UndoImageTile *tile;
486
487         tmpibuf = IMB_allocImBuf(IMAPAINT_TILE_SIZE, IMAPAINT_TILE_SIZE, 32,
488                                  IB_rectfloat | IB_rect);
489         
490         for (tile = lb->first; tile; tile = tile->next) {
491                 short use_float;
492
493                 /* find image based on name, pointer becomes invalid with global undo */
494                 if (ima && strcmp(tile->idname, ima->id.name) == 0) {
495                         /* ima is valid */
496                 }
497                 else {
498                         ima = BLI_findstring(&bmain->image, tile->idname, offsetof(ID, name));
499                 }
500
501                 ibuf = BKE_image_acquire_ibuf(ima, NULL, NULL);
502
503                 if (ima && ibuf && strcmp(tile->ibufname, ibuf->name) != 0) {
504                         /* current ImBuf filename was changed, probably current frame
505                          * was changed when paiting on image sequence, rather than storing
506                          * full image user (which isn't so obvious, btw) try to find ImBuf with
507                          * matched file name in list of already loaded images */
508
509                         BKE_image_release_ibuf(ima, ibuf, NULL);
510
511                         ibuf = BLI_findstring(&ima->ibufs, tile->ibufname, offsetof(ImBuf, name));
512                 }
513
514                 if (!ima || !ibuf || !(ibuf->rect || ibuf->rect_float)) {
515                         BKE_image_release_ibuf(ima, ibuf, NULL);
516                         continue;
517                 }
518
519                 if (ima->gen_type != tile->gen_type || ima->source != tile->source) {
520                         BKE_image_release_ibuf(ima, ibuf, NULL);
521                         continue;
522                 }
523
524                 use_float = ibuf->rect_float ? 1 : 0;
525
526                 if (use_float != tile->use_float) {
527                         BKE_image_release_ibuf(ima, ibuf, NULL);
528                         continue;
529                 }
530
531                 undo_copy_tile(tile, tmpibuf, ibuf, 1);
532
533                 GPU_free_image(ima); /* force OpenGL reload */
534                 if (ibuf->rect_float)
535                         ibuf->userflags |= IB_RECT_INVALID; /* force recreate of char rect */
536                 if (ibuf->mipmap[0])
537                         ibuf->userflags |= IB_MIPMAP_INVALID;  /* force mipmap recreatiom */
538                 ibuf->userflags |= IB_DISPLAY_BUFFER_INVALID;
539
540                 BKE_image_release_ibuf(ima, ibuf, NULL);
541         }
542
543         IMB_freeImBuf(tmpibuf);
544 }
545
546 static void image_undo_free(ListBase *lb)
547 {
548         UndoImageTile *tile;
549
550         for (tile = lb->first; tile; tile = tile->next)
551                 MEM_freeN(tile->rect.pt);
552 }
553
554 /* get active image for face depending on old/new shading system */
555
556 static Image *imapaint_face_image(const ImagePaintState *s, int face_index)
557 {
558         Image *ima;
559
560         if (BKE_scene_use_new_shading_nodes(s->scene)) {
561                 MFace *mf = &s->dm_mface[face_index];
562                 ED_object_get_active_image(s->ob, mf->mat_nr + 1, &ima, NULL, NULL);
563         }
564         else {
565                 MTFace *tf = &s->dm_mtface[face_index];
566                 ima = tf->tpage;
567         }
568
569         return ima;
570 }
571
572 static Image *project_paint_face_image(const ProjPaintState *ps, MTFace *dm_mtface, int face_index)
573 {
574         Image *ima;
575
576         if (ps->do_new_shading_nodes) { /* cached BKE_scene_use_new_shading_nodes result */
577                 MFace *mf = ps->dm_mface + face_index;
578                 ED_object_get_active_image(ps->ob, mf->mat_nr + 1, &ima, NULL, NULL);
579         }
580         else {
581                 ima = dm_mtface[face_index].tpage;
582         }
583
584         return ima;
585 }
586
587 /* fast projection bucket array lookup, use the safe version for bound checking  */
588 static int project_bucket_offset(const ProjPaintState *ps, const float projCoSS[2])
589 {
590         /* If we were not dealing with screenspace 2D coords we could simple do...
591          * ps->bucketRect[x + (y*ps->buckets_y)] */
592         
593         /* please explain?
594          * projCoSS[0] - ps->screenMin[0]   : zero origin
595          * ... / ps->screen_width           : range from 0.0 to 1.0
596          * ... * ps->buckets_x              : use as a bucket index
597          *
598          * Second multiplication does similar but for vertical offset
599          */
600         return ( (int)(((projCoSS[0] - ps->screenMin[0]) / ps->screen_width)  * ps->buckets_x)) +
601                (((int)(((projCoSS[1] - ps->screenMin[1]) / ps->screen_height) * ps->buckets_y)) * ps->buckets_x);
602 }
603
604 static int project_bucket_offset_safe(const ProjPaintState *ps, const float projCoSS[2])
605 {
606         int bucket_index = project_bucket_offset(ps, projCoSS);
607         
608         if (bucket_index < 0 || bucket_index >= ps->buckets_x * ps->buckets_y) {
609                 return -1;
610         }
611         else {
612                 return bucket_index;
613         }
614 }
615
616 /* still use 2D X,Y space but this works for verts transformed by a perspective matrix, using their 4th component as a weight */
617 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])
618 {
619         float wtot_inv, wtot;
620
621         w[0] = area_tri_signed_v2(v2, v3, co) / v1[3];
622         w[1] = area_tri_signed_v2(v3, v1, co) / v2[3];
623         w[2] = area_tri_signed_v2(v1, v2, co) / v3[3];
624         wtot = w[0] + w[1] + w[2];
625
626         if (wtot != 0.0f) {
627                 wtot_inv = 1.0f / wtot;
628
629                 w[0] = w[0] * wtot_inv;
630                 w[1] = w[1] * wtot_inv;
631                 w[2] = w[2] * wtot_inv;
632         }
633         else /* dummy values for zero area face */
634                 w[0] = w[1] = w[2] = 1.0f / 3.0f;
635 }
636
637 static float VecZDepthOrtho(const float pt[2],
638                             const float v1[3], const float v2[3], const float v3[3],
639                             float w[3])
640 {
641         barycentric_weights_v2(v1, v2, v3, pt, w);
642         return (v1[2] * w[0]) + (v2[2] * w[1]) + (v3[2] * w[2]);
643 }
644
645 static float VecZDepthPersp(const float pt[2],
646                             const float v1[4], const float v2[4], const float v3[4],
647                             float w[3])
648 {
649         float wtot_inv, wtot;
650         float w_tmp[3];
651
652         barycentric_weights_v2_persp(v1, v2, v3, pt, w);
653         /* for the depth we need the weights to match what
654          * barycentric_weights_v2 would return, in this case its easiest just to
655          * undo the 4th axis division and make it unit-sum
656          *
657          * don't call barycentric_weights_v2() because our callers expect 'w'
658          * to be weighted from the perspective */
659         w_tmp[0] = w[0] * v1[3];
660         w_tmp[1] = w[1] * v2[3];
661         w_tmp[2] = w[2] * v3[3];
662
663         wtot = w_tmp[0] + w_tmp[1] + w_tmp[2];
664
665         if (wtot != 0.0f) {
666                 wtot_inv = 1.0f / wtot;
667
668                 w_tmp[0] = w_tmp[0] * wtot_inv;
669                 w_tmp[1] = w_tmp[1] * wtot_inv;
670                 w_tmp[2] = w_tmp[2] * wtot_inv;
671         }
672         else /* dummy values for zero area face */
673                 w_tmp[0] = w_tmp[1] = w_tmp[2] = 1.0f / 3.0f;
674         /* done mimicing barycentric_weights_v2() */
675
676         return (v1[2] * w_tmp[0]) + (v2[2] * w_tmp[1]) + (v3[2] * w_tmp[2]);
677 }
678
679
680 /* Return the top-most face index that the screen space coord 'pt' touches (or -1) */
681 static int project_paint_PickFace(const ProjPaintState *ps, float pt[2], float w[3], int *side)
682 {
683         LinkNode *node;
684         float w_tmp[3];
685         float *v1, *v2, *v3, *v4;
686         int bucket_index;
687         int face_index;
688         int best_side = -1;
689         int best_face_index = -1;
690         float z_depth_best = FLT_MAX, z_depth;
691         MFace *mf;
692         
693         bucket_index = project_bucket_offset_safe(ps, pt);
694         if (bucket_index == -1)
695                 return -1;
696         
697         
698         
699         /* we could return 0 for 1 face buckets, as long as this function assumes
700          * that the point its testing is only every originated from an existing face */
701         
702         for (node = ps->bucketFaces[bucket_index]; node; node = node->next) {
703                 face_index = GET_INT_FROM_POINTER(node->link);
704                 mf = ps->dm_mface + face_index;
705                 
706                 v1 = ps->screenCoords[mf->v1];
707                 v2 = ps->screenCoords[mf->v2];
708                 v3 = ps->screenCoords[mf->v3];
709                 
710                 if (isect_point_tri_v2(pt, v1, v2, v3)) {
711                         if (ps->is_ortho) z_depth = VecZDepthOrtho(pt, v1, v2, v3, w_tmp);
712                         else z_depth = VecZDepthPersp(pt, v1, v2, v3, w_tmp);
713                         
714                         if (z_depth < z_depth_best) {
715                                 best_face_index = face_index;
716                                 best_side = 0;
717                                 z_depth_best = z_depth;
718                                 copy_v3_v3(w, w_tmp);
719                         }
720                 }
721                 else if (mf->v4) {
722                         v4 = ps->screenCoords[mf->v4];
723                         
724                         if (isect_point_tri_v2(pt, v1, v3, v4)) {
725                                 if (ps->is_ortho) z_depth = VecZDepthOrtho(pt, v1, v3, v4, w_tmp);
726                                 else z_depth = VecZDepthPersp(pt, v1, v3, v4, w_tmp);
727
728                                 if (z_depth < z_depth_best) {
729                                         best_face_index = face_index;
730                                         best_side = 1;
731                                         z_depth_best = z_depth;
732                                         copy_v3_v3(w, w_tmp);
733                                 }
734                         }
735                 }
736         }
737         
738         *side = best_side;
739         return best_face_index; /* will be -1 or a valid face */
740 }
741
742 /* Converts a uv coord into a pixel location wrapping if the uv is outside 0-1 range */
743 static void uvco_to_wrapped_pxco(float uv[2], int ibuf_x, int ibuf_y, float *x, float *y)
744 {
745         /* use */
746         *x = (float)fmodf(uv[0], 1.0f);
747         *y = (float)fmodf(uv[1], 1.0f);
748         
749         if (*x < 0.0f) *x += 1.0f;
750         if (*y < 0.0f) *y += 1.0f;
751         
752         *x = *x * ibuf_x - 0.5f;
753         *y = *y * ibuf_y - 0.5f;
754 }
755
756 /* Set the top-most face color that the screen space coord 'pt' touches (or return 0 if none touch) */
757 static int project_paint_PickColor(const ProjPaintState *ps, float pt[2], float *rgba_fp, unsigned char *rgba, const int interp)
758 {
759         float w[3], uv[2];
760         int side;
761         int face_index;
762         MTFace *tf;
763         Image *ima;
764         ImBuf *ibuf;
765         int xi, yi;
766         
767         
768         face_index = project_paint_PickFace(ps, pt, w, &side);
769         
770         if (face_index == -1)
771                 return 0;
772         
773         tf = ps->dm_mtface + face_index;
774         
775         if (side == 0) {
776                 interp_v2_v2v2v2(uv, tf->uv[0], tf->uv[1], tf->uv[2], w);
777         }
778         else { /* QUAD */
779                 interp_v2_v2v2v2(uv, tf->uv[0], tf->uv[2], tf->uv[3], w);
780         }
781
782         ima = project_paint_face_image(ps, ps->dm_mtface, face_index);
783         ibuf = ima->ibufs.first; /* we must have got the imbuf before getting here */
784         if (!ibuf) return 0;
785         
786         if (interp) {
787                 float x, y;
788                 uvco_to_wrapped_pxco(uv, ibuf->x, ibuf->y, &x, &y);
789                 
790                 if (ibuf->rect_float) {
791                         if (rgba_fp) {
792                                 bilinear_interpolation_color_wrap(ibuf, NULL, rgba_fp, x, y);
793                         }
794                         else {
795                                 float rgba_tmp_f[4];
796                                 bilinear_interpolation_color_wrap(ibuf, NULL, rgba_tmp_f, x, y);
797                                 IMAPAINT_FLOAT_RGBA_TO_CHAR(rgba, rgba_tmp_f);
798                         }
799                 }
800                 else {
801                         if (rgba) {
802                                 bilinear_interpolation_color_wrap(ibuf, rgba, NULL, x, y);
803                         }
804                         else {
805                                 unsigned char rgba_tmp[4];
806                                 bilinear_interpolation_color_wrap(ibuf, rgba_tmp, NULL, x, y);
807                                 IMAPAINT_CHAR_RGBA_TO_FLOAT(rgba_fp, rgba_tmp);
808                         }
809                 }
810         }
811         else {
812                 //xi = (int)((uv[0]*ibuf->x) + 0.5f);
813                 //yi = (int)((uv[1]*ibuf->y) + 0.5f);
814                 //if (xi < 0 || xi >= ibuf->x  ||  yi < 0 || yi >= ibuf->y) return 0;
815                 
816                 /* wrap */
817                 xi = ((int)(uv[0] * ibuf->x)) % ibuf->x;
818                 if (xi < 0) xi += ibuf->x;
819                 yi = ((int)(uv[1] * ibuf->y)) % ibuf->y;
820                 if (yi < 0) yi += ibuf->y;
821                 
822                 
823                 if (rgba) {
824                         if (ibuf->rect_float) {
825                                 float *rgba_tmp_fp = ibuf->rect_float + (xi + yi * ibuf->x * 4);
826                                 IMAPAINT_FLOAT_RGBA_TO_CHAR(rgba, rgba_tmp_fp);
827                         }
828                         else {
829                                 *((unsigned int *)rgba) = *(unsigned int *)(((char *)ibuf->rect) + ((xi + yi * ibuf->x) * 4));
830                         }
831                 }
832                 
833                 if (rgba_fp) {
834                         if (ibuf->rect_float) {
835                                 copy_v4_v4(rgba_fp, (ibuf->rect_float + ((xi + yi * ibuf->x) * 4)));
836                         }
837                         else {
838                                 char *tmp_ch = ((char *)ibuf->rect) + ((xi + yi * ibuf->x) * 4);
839                                 IMAPAINT_CHAR_RGBA_TO_FLOAT(rgba_fp, tmp_ch);
840                         }
841                 }
842         }
843         return 1;
844 }
845
846 /* Check if 'pt' is infront of the 3 verts on the Z axis (used for screenspace occlusuion test)
847  * return...
848  *  0   : no occlusion
849  * -1   : no occlusion but 2D intersection is true (avoid testing the other half of a quad)
850  *  1   : occluded
851  *  2   : occluded with w[3] weights set (need to know in some cases) */
852
853 static int project_paint_occlude_ptv(float pt[3], float v1[4], float v2[4], float v3[4], float w[3], int is_ortho)
854 {
855         /* if all are behind us, return false */
856         if (v1[2] > pt[2] && v2[2] > pt[2] && v3[2] > pt[2])
857                 return 0;
858                 
859         /* do a 2D point in try intersection */
860         if (!isect_point_tri_v2(pt, v1, v2, v3))
861                 return 0;  /* we know there is  */
862         
863
864         /* From here on we know there IS an intersection */
865         /* if ALL of the verts are infront of us then we know it intersects ? */
866         if (v1[2] < pt[2] && v2[2] < pt[2] && v3[2] < pt[2]) {
867                 return 1;
868         }
869         else {
870                 /* we intersect? - find the exact depth at the point of intersection */
871                 /* Is this point is occluded by another face? */
872                 if (is_ortho) {
873                         if (VecZDepthOrtho(pt, v1, v2, v3, w) < pt[2]) return 2;
874                 }
875                 else {
876                         if (VecZDepthPersp(pt, v1, v2, v3, w) < pt[2]) return 2;
877                 }
878         }
879         return -1;
880 }
881
882
883 static int project_paint_occlude_ptv_clip(const ProjPaintState *ps, const MFace *mf,
884                                           float pt[3], float v1[4], float v2[4], float v3[4],
885                                           const int side)
886 {
887         float w[3], wco[3];
888         int ret = project_paint_occlude_ptv(pt, v1, v2, v3, w, ps->is_ortho);
889
890         if (ret <= 0)
891                 return ret;
892
893         if (ret == 1) { /* weights not calculated */
894                 if (ps->is_ortho) barycentric_weights_v2(v1, v2, v3, pt, w);
895                 else barycentric_weights_v2_persp(v1, v2, v3, pt, w);
896         }
897
898         /* Test if we're in the clipped area, */
899         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);
900         else interp_v3_v3v3v3(wco, ps->dm_mvert[mf->v1].co, ps->dm_mvert[mf->v2].co, ps->dm_mvert[mf->v3].co, w);
901         
902         if (!ED_view3d_clipping_test(ps->rv3d, wco, TRUE)) {
903                 return 1;
904         }
905         
906         return -1;
907 }
908
909
910 /* Check if a screenspace location is occluded by any other faces
911  * check, pixelScreenCo must be in screenspace, its Z-Depth only needs to be used for comparison
912  * and doesn't need to be correct in relation to X and Y coords (this is the case in perspective view) */
913 static int project_bucket_point_occluded(const ProjPaintState *ps, LinkNode *bucketFace, const int orig_face, float pixelScreenCo[4])
914 {
915         MFace *mf;
916         int face_index;
917         int isect_ret;
918         float w[3]; /* not needed when clipping */
919         const short do_clip = ps->rv3d ? ps->rv3d->rflag & RV3D_CLIPPING : 0;
920         
921         /* we could return 0 for 1 face buckets, as long as this function assumes
922          * that the point its testing is only every originated from an existing face */
923
924         for (; bucketFace; bucketFace = bucketFace->next) {
925                 face_index = GET_INT_FROM_POINTER(bucketFace->link);
926
927                 if (orig_face != face_index) {
928                         mf = ps->dm_mface + face_index;
929                         if (do_clip)
930                                 isect_ret = project_paint_occlude_ptv_clip(ps, mf, pixelScreenCo, ps->screenCoords[mf->v1], ps->screenCoords[mf->v2], ps->screenCoords[mf->v3], 0);
931                         else
932                                 isect_ret = project_paint_occlude_ptv(pixelScreenCo, ps->screenCoords[mf->v1], ps->screenCoords[mf->v2], ps->screenCoords[mf->v3], w, ps->is_ortho);
933
934                         /* Note, if (isect_ret == -1) then we don't want to test the other side of the quad */
935                         if (isect_ret == 0 && mf->v4) {
936                                 if (do_clip)
937                                         isect_ret = project_paint_occlude_ptv_clip(ps, mf, pixelScreenCo, ps->screenCoords[mf->v1], ps->screenCoords[mf->v3], ps->screenCoords[mf->v4], 1);
938                                 else
939                                         isect_ret = project_paint_occlude_ptv(pixelScreenCo, ps->screenCoords[mf->v1], ps->screenCoords[mf->v3], ps->screenCoords[mf->v4], w, ps->is_ortho);
940                         }
941                         if (isect_ret >= 1) {
942                                 /* TODO - we may want to cache the first hit,
943                                  * it is not possible to swap the face order in the list anymore */
944                                 return 1;
945                         }
946                 }
947         }
948         return 0;
949 }
950
951 /* basic line intersection, could move to math_geom.c, 2 points with a horiz line
952  * 1 for an intersection, 2 if the first point is aligned, 3 if the second point is aligned */
953 #define ISECT_TRUE 1
954 #define ISECT_TRUE_P1 2
955 #define ISECT_TRUE_P2 3
956 static int line_isect_y(const float p1[2], const float p2[2], const float y_level, float *x_isect)
957 {
958         float y_diff;
959         
960         if (y_level == p1[1]) { /* are we touching the first point? - no interpolation needed */
961                 *x_isect = p1[0];
962                 return ISECT_TRUE_P1;
963         }
964         if (y_level == p2[1]) { /* are we touching the second point? - no interpolation needed */
965                 *x_isect = p2[0];
966                 return ISECT_TRUE_P2;
967         }
968         
969         y_diff = fabsf(p1[1] - p2[1]); /* yuck, horizontal line, we cant do much here */
970         
971         if (y_diff < 0.000001f) {
972                 *x_isect = (p1[0] + p2[0]) * 0.5f;
973                 return ISECT_TRUE;
974         }
975         
976         if (p1[1] > y_level && p2[1] < y_level) {
977                 *x_isect = (p2[0] * (p1[1] - y_level) + p1[0] * (y_level - p2[1])) / y_diff;  /*(p1[1]-p2[1]);*/
978                 return ISECT_TRUE;
979         }
980         else if (p1[1] < y_level && p2[1] > y_level) {
981                 *x_isect = (p2[0] * (y_level - p1[1]) + p1[0] * (p2[1] - y_level)) / y_diff;  /*(p2[1]-p1[1]);*/
982                 return ISECT_TRUE;
983         }
984         else {
985                 return 0;
986         }
987 }
988
989 static int line_isect_x(const float p1[2], const float p2[2], const float x_level, float *y_isect)
990 {
991         float x_diff;
992         
993         if (x_level == p1[0]) { /* are we touching the first point? - no interpolation needed */
994                 *y_isect = p1[1];
995                 return ISECT_TRUE_P1;
996         }
997         if (x_level == p2[0]) { /* are we touching the second point? - no interpolation needed */
998                 *y_isect = p2[1];
999                 return ISECT_TRUE_P2;
1000         }
1001         
1002         x_diff = fabsf(p1[0] - p2[0]); /* yuck, horizontal line, we cant do much here */
1003         
1004         if (x_diff < 0.000001f) { /* yuck, vertical line, we cant do much here */
1005                 *y_isect = (p1[0] + p2[0]) * 0.5f;
1006                 return ISECT_TRUE;
1007         }
1008         
1009         if (p1[0] > x_level && p2[0] < x_level) {
1010                 *y_isect = (p2[1] * (p1[0] - x_level) + p1[1] * (x_level - p2[0])) / x_diff; /*(p1[0]-p2[0]);*/
1011                 return ISECT_TRUE;
1012         }
1013         else if (p1[0] < x_level && p2[0] > x_level) {
1014                 *y_isect = (p2[1] * (x_level - p1[0]) + p1[1] * (p2[0] - x_level)) / x_diff; /*(p2[0]-p1[0]);*/
1015                 return ISECT_TRUE;
1016         }
1017         else {
1018                 return 0;
1019         }
1020 }
1021
1022 /* simple func use for comparing UV locations to check if there are seams.
1023  * Its possible this gives incorrect results, when the UVs for 1 face go into the next 
1024  * tile, but do not do this for the adjacent face, it could return a false positive.
1025  * This is so unlikely that Id not worry about it. */
1026 #ifndef PROJ_DEBUG_NOSEAMBLEED
1027 static int cmp_uv(const float vec2a[2], const float vec2b[2])
1028 {
1029         /* if the UV's are not between 0.0 and 1.0 */
1030         float xa = (float)fmodf(vec2a[0], 1.0f);
1031         float ya = (float)fmodf(vec2a[1], 1.0f);
1032         
1033         float xb = (float)fmodf(vec2b[0], 1.0f);
1034         float yb = (float)fmodf(vec2b[1], 1.0f);
1035         
1036         if (xa < 0.0f) xa += 1.0f;
1037         if (ya < 0.0f) ya += 1.0f;
1038         
1039         if (xb < 0.0f) xb += 1.0f;
1040         if (yb < 0.0f) yb += 1.0f;
1041         
1042         return ((fabsf(xa - xb) < PROJ_GEOM_TOLERANCE) && (fabsf(ya - yb) < PROJ_GEOM_TOLERANCE)) ? 1 : 0;
1043 }
1044 #endif
1045
1046 /* set min_px and max_px to the image space bounds of the UV coords 
1047  * return zero if there is no area in the returned rectangle */
1048 #ifndef PROJ_DEBUG_NOSEAMBLEED
1049 static int pixel_bounds_uv(
1050         const float uv1[2], const float uv2[2], const float uv3[2], const float uv4[2],
1051         rcti *bounds_px,
1052         const int ibuf_x, const int ibuf_y,
1053         int is_quad
1054         )
1055 {
1056         float min_uv[2], max_uv[2]; /* UV bounds */
1057         
1058         INIT_MINMAX2(min_uv, max_uv);
1059         
1060         minmax_v2v2_v2(min_uv, max_uv, uv1);
1061         minmax_v2v2_v2(min_uv, max_uv, uv2);
1062         minmax_v2v2_v2(min_uv, max_uv, uv3);
1063         if (is_quad)
1064                 minmax_v2v2_v2(min_uv, max_uv, uv4);
1065         
1066         bounds_px->xmin = (int)(ibuf_x * min_uv[0]);
1067         bounds_px->ymin = (int)(ibuf_y * min_uv[1]);
1068         
1069         bounds_px->xmax = (int)(ibuf_x * max_uv[0]) + 1;
1070         bounds_px->ymax = (int)(ibuf_y * max_uv[1]) + 1;
1071         
1072         /*printf("%d %d %d %d\n", min_px[0], min_px[1], max_px[0], max_px[1]);*/
1073         
1074         /* face uses no UV area when quantized to pixels? */
1075         return (bounds_px->xmin == bounds_px->xmax || bounds_px->ymin == bounds_px->ymax) ? 0 : 1;
1076 }
1077 #endif
1078
1079 static int pixel_bounds_array(float (*uv)[2], rcti *bounds_px, const int ibuf_x, const int ibuf_y, int tot)
1080 {
1081         float min_uv[2], max_uv[2]; /* UV bounds */
1082         
1083         if (tot == 0) {
1084                 return 0;
1085         }
1086         
1087         INIT_MINMAX2(min_uv, max_uv);
1088         
1089         while (tot--) {
1090                 minmax_v2v2_v2(min_uv, max_uv, (*uv));
1091                 uv++;
1092         }
1093         
1094         bounds_px->xmin = (int)(ibuf_x * min_uv[0]);
1095         bounds_px->ymin = (int)(ibuf_y * min_uv[1]);
1096         
1097         bounds_px->xmax = (int)(ibuf_x * max_uv[0]) + 1;
1098         bounds_px->ymax = (int)(ibuf_y * max_uv[1]) + 1;
1099         
1100         /*printf("%d %d %d %d\n", min_px[0], min_px[1], max_px[0], max_px[1]);*/
1101         
1102         /* face uses no UV area when quantized to pixels? */
1103         return (bounds_px->xmin == bounds_px->xmax || bounds_px->ymin == bounds_px->ymax) ? 0 : 1;
1104 }
1105
1106 #ifndef PROJ_DEBUG_NOSEAMBLEED
1107
1108 /* This function returns 1 if this face has a seam along the 2 face-vert indices
1109  * 'orig_i1_fidx' and 'orig_i2_fidx' */
1110 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)
1111 {
1112         LinkNode *node;
1113         int face_index;
1114         unsigned int i1, i2;
1115         int i1_fidx = -1, i2_fidx = -1; /* index in face */
1116         MFace *mf;
1117         MTFace *tf;
1118         const MFace *orig_mf = ps->dm_mface + orig_face;  
1119         const MTFace *orig_tf = ps->dm_mtface + orig_face;
1120         
1121         /* vert indices from face vert order indices */
1122         i1 = (*(&orig_mf->v1 + orig_i1_fidx));
1123         i2 = (*(&orig_mf->v1 + orig_i2_fidx));
1124         
1125         for (node = ps->vertFaces[i1]; node; node = node->next) {
1126                 face_index = GET_INT_FROM_POINTER(node->link);
1127
1128                 if (face_index != orig_face) {
1129                         mf = ps->dm_mface + face_index;
1130                         /* could check if the 2 faces images match here,
1131                          * but then there wouldn't be a way to return the opposite face's info */
1132                         
1133                         
1134                         /* We need to know the order of the verts in the adjacent face 
1135                          * set the i1_fidx and i2_fidx to (0,1,2,3) */
1136                         if      (mf->v1 == i1) i1_fidx = 0;
1137                         else if (mf->v2 == i1) i1_fidx = 1;
1138                         else if (mf->v3 == i1) i1_fidx = 2;
1139                         else if (mf->v4 && mf->v4 == i1) i1_fidx = 3;
1140
1141                         if      (mf->v1 == i2) i2_fidx = 0;
1142                         else if (mf->v2 == i2) i2_fidx = 1;
1143                         else if (mf->v3 == i2) i2_fidx = 2;
1144                         else if (mf->v4 && mf->v4 == i2) i2_fidx = 3;
1145                         
1146                         /* Only need to check if 'i2_fidx' is valid because we know i1_fidx is the same vert on both faces */
1147                         if (i2_fidx != -1) {
1148                                 Image *tpage = project_paint_face_image(ps, ps->dm_mtface, face_index);
1149                                 Image *orig_tpage = project_paint_face_image(ps, ps->dm_mtface, orig_face);
1150
1151                                 /* This IS an adjacent face!, now lets check if the UVs are ok */
1152                                 tf = ps->dm_mtface + face_index;
1153                                 
1154                                 /* set up the other face */
1155                                 *other_face = face_index;
1156                                 *orig_fidx = (i1_fidx < i2_fidx) ? i1_fidx : i2_fidx;
1157                                 
1158                                 /* first test if they have the same image */
1159                                 if ((orig_tpage == tpage) &&
1160                                     cmp_uv(orig_tf->uv[orig_i1_fidx], tf->uv[i1_fidx]) &&
1161                                     cmp_uv(orig_tf->uv[orig_i2_fidx], tf->uv[i2_fidx]) )
1162                                 {
1163                                         // printf("SEAM (NONE)\n");
1164                                         return 0;
1165                                         
1166                                 }
1167                                 else {
1168                                         // printf("SEAM (UV GAP)\n");
1169                                         return 1;
1170                                 }
1171                         }
1172                 }
1173         }
1174         // printf("SEAM (NO FACE)\n");
1175         *other_face = -1;
1176         return 1;
1177 }
1178
1179 /* Calculate outset UV's, this is not the same as simply scaling the UVs,
1180  * since the outset coords are a margin that keep an even distance from the original UV's,
1181  * note that the image aspect is taken into account */
1182 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)
1183 {
1184         float a1, a2, a3, a4 = 0.0f;
1185         float puv[4][2]; /* pixelspace uv's */
1186         float no1[2], no2[2], no3[2], no4[2]; /* normals */
1187         float dir1[2], dir2[2], dir3[2], dir4[2];
1188         float ibuf_inv[2];
1189
1190         ibuf_inv[0] = 1.0f / (float)ibuf_x;
1191         ibuf_inv[1] = 1.0f / (float)ibuf_y;
1192
1193         /* make UV's in pixel space so we can */
1194         puv[0][0] = orig_uv[0][0] * ibuf_x;
1195         puv[0][1] = orig_uv[0][1] * ibuf_y;
1196         
1197         puv[1][0] = orig_uv[1][0] * ibuf_x;
1198         puv[1][1] = orig_uv[1][1] * ibuf_y;
1199         
1200         puv[2][0] = orig_uv[2][0] * ibuf_x;
1201         puv[2][1] = orig_uv[2][1] * ibuf_y;
1202         
1203         if (is_quad) {
1204                 puv[3][0] = orig_uv[3][0] * ibuf_x;
1205                 puv[3][1] = orig_uv[3][1] * ibuf_y;
1206         }
1207         
1208         /* face edge directions */
1209         sub_v2_v2v2(dir1, puv[1], puv[0]);
1210         sub_v2_v2v2(dir2, puv[2], puv[1]);
1211         normalize_v2(dir1);
1212         normalize_v2(dir2);
1213         
1214         if (is_quad) {
1215                 sub_v2_v2v2(dir3, puv[3], puv[2]);
1216                 sub_v2_v2v2(dir4, puv[0], puv[3]);
1217                 normalize_v2(dir3);
1218                 normalize_v2(dir4);
1219         }
1220         else {
1221                 sub_v2_v2v2(dir3, puv[0], puv[2]);
1222                 normalize_v2(dir3);
1223         }
1224
1225         /* TODO - angle_normalized_v2v2(...) * (M_PI/180.0f)
1226          * This is incorrect. Its already given radians but without it wont work.
1227          * need to look into a fix - campbell */
1228         if (is_quad) {
1229                 a1 = shell_angle_to_dist(angle_normalized_v2v2(dir4, dir1) * ((float)M_PI / 180.0f));
1230                 a2 = shell_angle_to_dist(angle_normalized_v2v2(dir1, dir2) * ((float)M_PI / 180.0f));
1231                 a3 = shell_angle_to_dist(angle_normalized_v2v2(dir2, dir3) * ((float)M_PI / 180.0f));
1232                 a4 = shell_angle_to_dist(angle_normalized_v2v2(dir3, dir4) * ((float)M_PI / 180.0f));
1233         }
1234         else {
1235                 a1 = shell_angle_to_dist(angle_normalized_v2v2(dir3, dir1) * ((float)M_PI / 180.0f));
1236                 a2 = shell_angle_to_dist(angle_normalized_v2v2(dir1, dir2) * ((float)M_PI / 180.0f));
1237                 a3 = shell_angle_to_dist(angle_normalized_v2v2(dir2, dir3) * ((float)M_PI / 180.0f));
1238         }
1239         
1240         if (is_quad) {
1241                 sub_v2_v2v2(no1, dir4, dir1);
1242                 sub_v2_v2v2(no2, dir1, dir2);
1243                 sub_v2_v2v2(no3, dir2, dir3);
1244                 sub_v2_v2v2(no4, dir3, dir4);
1245                 normalize_v2(no1);
1246                 normalize_v2(no2);
1247                 normalize_v2(no3);
1248                 normalize_v2(no4);
1249                 mul_v2_fl(no1, a1 * scaler);
1250                 mul_v2_fl(no2, a2 * scaler);
1251                 mul_v2_fl(no3, a3 * scaler);
1252                 mul_v2_fl(no4, a4 * scaler);
1253                 add_v2_v2v2(outset_uv[0], puv[0], no1);
1254                 add_v2_v2v2(outset_uv[1], puv[1], no2);
1255                 add_v2_v2v2(outset_uv[2], puv[2], no3);
1256                 add_v2_v2v2(outset_uv[3], puv[3], no4);
1257                 mul_v2_v2(outset_uv[0], ibuf_inv);
1258                 mul_v2_v2(outset_uv[1], ibuf_inv);
1259                 mul_v2_v2(outset_uv[2], ibuf_inv);
1260                 mul_v2_v2(outset_uv[3], ibuf_inv);
1261         }
1262         else {
1263                 sub_v2_v2v2(no1, dir3, dir1);
1264                 sub_v2_v2v2(no2, dir1, dir2);
1265                 sub_v2_v2v2(no3, dir2, dir3);
1266                 normalize_v2(no1);
1267                 normalize_v2(no2);
1268                 normalize_v2(no3);
1269                 mul_v2_fl(no1, a1 * scaler);
1270                 mul_v2_fl(no2, a2 * scaler);
1271                 mul_v2_fl(no3, a3 * scaler);
1272                 add_v2_v2v2(outset_uv[0], puv[0], no1);
1273                 add_v2_v2v2(outset_uv[1], puv[1], no2);
1274                 add_v2_v2v2(outset_uv[2], puv[2], no3);
1275
1276                 mul_v2_v2(outset_uv[0], ibuf_inv);
1277                 mul_v2_v2(outset_uv[1], ibuf_inv);
1278                 mul_v2_v2(outset_uv[2], ibuf_inv);
1279         }
1280 }
1281
1282 /* 
1283  * Be tricky with flags, first 4 bits are PROJ_FACE_SEAM1 to 4, last 4 bits are PROJ_FACE_NOSEAM1 to 4
1284  * 1<<i - where i is (0-3) 
1285  * 
1286  * If we're multithreadng, make sure threads are locked when this is called
1287  */
1288 static void project_face_seams_init(const ProjPaintState *ps, const int face_index, const int is_quad)
1289 {
1290         int other_face, other_fidx; /* vars for the other face, we also set its flag */
1291         int fidx1 = is_quad ? 3 : 2;
1292         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 */
1293         
1294         do {
1295                 if ((ps->faceSeamFlags[face_index] & (1 << fidx1 | 16 << fidx1)) == 0) {
1296                         if (check_seam(ps, face_index, fidx1, fidx2, &other_face, &other_fidx)) {
1297                                 ps->faceSeamFlags[face_index] |= 1 << fidx1;
1298                                 if (other_face != -1)
1299                                         ps->faceSeamFlags[other_face] |= 1 << other_fidx;
1300                         }
1301                         else {
1302                                 ps->faceSeamFlags[face_index] |= 16 << fidx1;
1303                                 if (other_face != -1)
1304                                         ps->faceSeamFlags[other_face] |= 16 << other_fidx;  /* second 4 bits for disabled */
1305                         }
1306                 }
1307                 
1308                 fidx2 = fidx1;
1309         } while (fidx1--);
1310 }
1311 #endif // PROJ_DEBUG_NOSEAMBLEED
1312
1313
1314 /* Converts a UV location to a 3D screenspace location
1315  * Takes a 'uv' and 3 UV coords, and sets the values of pixelScreenCo
1316  * 
1317  * This is used for finding a pixels location in screenspace for painting */
1318 static void screen_px_from_ortho(
1319         float uv[2],
1320         float v1co[3], float v2co[3], float v3co[3],  /* Screenspace coords */
1321         float uv1co[2], float uv2co[2], float uv3co[2],
1322         float pixelScreenCo[4],
1323         float w[3])
1324 {
1325         barycentric_weights_v2(uv1co, uv2co, uv3co, uv, w);
1326         interp_v3_v3v3v3(pixelScreenCo, v1co, v2co, v3co, w);
1327 }
1328
1329 /* same as screen_px_from_ortho except we need to take into account
1330  * the perspective W coord for each vert */
1331 static void screen_px_from_persp(
1332         float uv[2],
1333         float v1co[4], float v2co[4], float v3co[4],  /* screenspace coords */
1334         float uv1co[2], float uv2co[2], float uv3co[2],
1335         float pixelScreenCo[4],
1336         float w[3])
1337 {
1338
1339         float wtot_inv, wtot;
1340         barycentric_weights_v2(uv1co, uv2co, uv3co, uv, w);
1341         
1342         /* re-weight from the 4th coord of each screen vert */
1343         w[0] *= v1co[3];
1344         w[1] *= v2co[3];
1345         w[2] *= v3co[3];
1346         
1347         wtot = w[0] + w[1] + w[2];
1348         
1349         if (wtot > 0.0f) {
1350                 wtot_inv = 1.0f / wtot;
1351                 w[0] *= wtot_inv;
1352                 w[1] *= wtot_inv;
1353                 w[2] *= wtot_inv;
1354         }
1355         else {
1356                 w[0] = w[1] = w[2] = 1.0f / 3.0f;  /* dummy values for zero area face */
1357         }
1358         /* done re-weighting */
1359         
1360         interp_v3_v3v3v3(pixelScreenCo, v1co, v2co, v3co, w);
1361 }
1362
1363 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])
1364 {
1365         float *uvCo1, *uvCo2, *uvCo3;
1366         float uv_other[2], x, y;
1367         
1368         uvCo1 =  (float *)tf_other->uv[0];
1369         if (side == 1) {
1370                 uvCo2 =  (float *)tf_other->uv[2];
1371                 uvCo3 =  (float *)tf_other->uv[3];
1372         }
1373         else {
1374                 uvCo2 =  (float *)tf_other->uv[1];
1375                 uvCo3 =  (float *)tf_other->uv[2];
1376         }
1377         
1378         interp_v2_v2v2v2(uv_other, uvCo1, uvCo2, uvCo3, (float *)w);
1379         
1380         /* use */
1381         uvco_to_wrapped_pxco(uv_other, ibuf_other->x, ibuf_other->y, &x, &y);
1382         
1383         
1384         if (ibuf_other->rect_float) { /* from float to float */
1385                 bilinear_interpolation_color_wrap(ibuf_other, NULL, rgba_f, x, y);
1386         }
1387         else { /* from char to float */
1388                 bilinear_interpolation_color_wrap(ibuf_other, rgba_ub, NULL, x, y);
1389         }
1390                 
1391 }
1392
1393 /* run this outside project_paint_uvpixel_init since pixels with mask 0 don't need init */
1394 static float project_paint_uvpixel_mask(
1395         const ProjPaintState *ps,
1396         const int face_index,
1397         const int side,
1398         const float w[3])
1399 {
1400         float mask;
1401         
1402         /* Image Mask */
1403         if (ps->do_layer_stencil) {
1404                 /* another UV maps image is masking this one's */
1405                 ImBuf *ibuf_other;
1406                 Image *other_tpage = project_paint_face_image(ps, ps->dm_mtface_stencil, face_index);
1407                 const MTFace *tf_other = ps->dm_mtface_stencil + face_index;
1408                 
1409                 if (other_tpage && (ibuf_other = BKE_image_acquire_ibuf(other_tpage, NULL, NULL))) {
1410                         /* BKE_image_acquire_ibuf - TODO - this may be slow */
1411                         unsigned char rgba_ub[4];
1412                         float rgba_f[4];
1413                         
1414                         project_face_pixel(tf_other, ibuf_other, w, side, rgba_ub, rgba_f);
1415                         
1416                         if (ibuf_other->rect_float) { /* from float to float */
1417                                 mask = ((rgba_f[0] + rgba_f[1] + rgba_f[2]) / 3.0f) * rgba_f[3];
1418                         }
1419                         else { /* from char to float */
1420                                 mask = ((rgba_ub[0] + rgba_ub[1] + rgba_ub[2]) / (256 * 3.0f)) * (rgba_ub[3] / 256.0f);
1421                         }
1422
1423                         BKE_image_release_ibuf(other_tpage, ibuf_other, NULL);
1424
1425                         if (!ps->do_layer_stencil_inv) /* matching the gimps layer mask black/white rules, white==full opacity */
1426                                 mask = (1.0f - mask);
1427
1428                         if (mask == 0.0f) {
1429                                 return 0.0f;
1430                         }
1431                 }
1432                 else {
1433                         return 0.0f;
1434                 }
1435         }
1436         else {
1437                 mask = 1.0f;
1438         }
1439         
1440         /* calculate mask */
1441         if (ps->do_mask_normal) {
1442                 MFace *mf = &ps->dm_mface[face_index];
1443                 float no[3], angle;
1444                 if (mf->flag & ME_SMOOTH) {
1445                         short *no1, *no2, *no3;
1446                         no1 = ps->dm_mvert[mf->v1].no;
1447                         if (side == 1) {
1448                                 no2 = ps->dm_mvert[mf->v3].no;
1449                                 no3 = ps->dm_mvert[mf->v4].no;
1450                         }
1451                         else {
1452                                 no2 = ps->dm_mvert[mf->v2].no;
1453                                 no3 = ps->dm_mvert[mf->v3].no;
1454                         }
1455
1456                         no[0] = w[0] * no1[0] + w[1] * no2[0] + w[2] * no3[0];
1457                         no[1] = w[0] * no1[1] + w[1] * no2[1] + w[2] * no3[1];
1458                         no[2] = w[0] * no1[2] + w[1] * no2[2] + w[2] * no3[2];
1459                         normalize_v3(no);
1460                 }
1461                 else {
1462                         /* incase the */
1463 #if 1
1464                         /* normalizing per pixel isn't optimal, we could cache or check ps->*/
1465                         if (mf->v4)
1466                                 normal_quad_v3(no,
1467                                                ps->dm_mvert[mf->v1].co,
1468                                                ps->dm_mvert[mf->v2].co,
1469                                                ps->dm_mvert[mf->v3].co,
1470                                                ps->dm_mvert[mf->v4].co);
1471                         else
1472                                 normal_tri_v3(no,
1473                                               ps->dm_mvert[mf->v1].co,
1474                                               ps->dm_mvert[mf->v2].co,
1475                                               ps->dm_mvert[mf->v3].co);
1476 #else
1477                         /* don't use because some modifiers dont have normal data (subsurf for eg) */
1478                         copy_v3_v3(no, (float *)ps->dm->getTessFaceData(ps->dm, face_index, CD_NORMAL));
1479 #endif
1480                 }
1481                 
1482                 /* now we can use the normal as a mask */
1483                 if (ps->is_ortho) {
1484                         angle = angle_normalized_v3v3((float *)ps->viewDir, no);
1485                 }
1486                 else {
1487                         /* Annoying but for the perspective view we need to get the pixels location in 3D space :/ */
1488                         float viewDirPersp[3];
1489                         float *co1, *co2, *co3;
1490                         co1 = ps->dm_mvert[mf->v1].co;
1491                         if (side == 1) {
1492                                 co2 = ps->dm_mvert[mf->v3].co;
1493                                 co3 = ps->dm_mvert[mf->v4].co;
1494                         }
1495                         else {
1496                                 co2 = ps->dm_mvert[mf->v2].co;
1497                                 co3 = ps->dm_mvert[mf->v3].co;
1498                         }
1499
1500                         /* Get the direction from the viewPoint to the pixel and normalize */
1501                         viewDirPersp[0] = (ps->viewPos[0] - (w[0] * co1[0] + w[1] * co2[0] + w[2] * co3[0]));
1502                         viewDirPersp[1] = (ps->viewPos[1] - (w[0] * co1[1] + w[1] * co2[1] + w[2] * co3[1]));
1503                         viewDirPersp[2] = (ps->viewPos[2] - (w[0] * co1[2] + w[1] * co2[2] + w[2] * co3[2]));
1504                         normalize_v3(viewDirPersp);
1505                         
1506                         angle = angle_normalized_v3v3(viewDirPersp, no);
1507                 }
1508                 
1509                 if (angle >= ps->normal_angle) {
1510                         return 0.0f; /* outsize the normal limit*/
1511                 }
1512                 else if (angle > ps->normal_angle_inner) {
1513                         mask *= (ps->normal_angle - angle) / ps->normal_angle_range;
1514                 } /* otherwise no mask normal is needed, were within the limit */
1515         }
1516         
1517         /* This only works when the opacity dosnt change while painting, stylus pressure messes with this
1518          * so don't use it. */
1519         // if (ps->is_airbrush == 0) mask *= BKE_brush_alpha_get(ps->brush);
1520         
1521         return mask;
1522 }
1523
1524 static int project_paint_pixel_sizeof(const short tool)
1525 {
1526         if ((tool == PAINT_TOOL_CLONE) || (tool == PAINT_TOOL_SMEAR)) {
1527                 return sizeof(ProjPixelClone);
1528         }
1529         else {
1530                 return sizeof(ProjPixel);
1531         }
1532 }
1533
1534
1535 /* run this function when we know a bucket's, face's pixel can be initialized,
1536  * return the ProjPixel which is added to 'ps->bucketRect[bucket_index]' */
1537 static ProjPixel *project_paint_uvpixel_init(
1538         const ProjPaintState *ps,
1539         MemArena *arena,
1540         const ImBuf *ibuf,
1541         short x_px, short y_px,
1542         const float mask,
1543         const int face_index,
1544         const int image_index,
1545         const float pixelScreenCo[4],
1546         const float world_spaceCo[3],
1547         const int side,
1548         const float w[3])
1549 {
1550         ProjPixel *projPixel;
1551
1552         /* wrap pixel location */
1553         x_px = x_px % ibuf->x;
1554         if (x_px < 0) x_px += ibuf->x;
1555         y_px = y_px % ibuf->y;
1556         if (y_px < 0) y_px += ibuf->y;
1557
1558         BLI_assert(ps->pixel_sizeof == project_paint_pixel_sizeof(ps->tool));
1559         projPixel = (ProjPixel *)BLI_memarena_alloc(arena, ps->pixel_sizeof);
1560         //memset(projPixel, 0, size);
1561         
1562         if (ibuf->rect_float) {
1563                 projPixel->pixel.f_pt = ibuf->rect_float + ((x_px + y_px * ibuf->x) * 4);
1564                 projPixel->origColor.f[0] = projPixel->newColor.f[0] = projPixel->pixel.f_pt[0];
1565                 projPixel->origColor.f[1] = projPixel->newColor.f[1] = projPixel->pixel.f_pt[1];
1566                 projPixel->origColor.f[2] = projPixel->newColor.f[2] = projPixel->pixel.f_pt[2];
1567                 projPixel->origColor.f[3] = projPixel->newColor.f[3] = projPixel->pixel.f_pt[3];
1568         }
1569         else {
1570                 projPixel->pixel.ch_pt = ((unsigned char *)ibuf->rect + ((x_px + y_px * ibuf->x) * 4));
1571                 projPixel->origColor.uint = projPixel->newColor.uint = *projPixel->pixel.uint_pt;
1572         }
1573         
1574         /* screenspace unclamped, we could keep its z and w values but don't need them at the moment */
1575         if (ps->brush->mtex.brush_map_mode == MTEX_MAP_MODE_3D) {
1576                 copy_v3_v3(projPixel->worldCoSS, world_spaceCo);
1577         }
1578
1579         copy_v2_v2(projPixel->projCoSS, pixelScreenCo);
1580         
1581         projPixel->x_px = x_px;
1582         projPixel->y_px = y_px;
1583         
1584         projPixel->mask = (unsigned short)(mask * 65535);
1585         projPixel->mask_max = 0;
1586         
1587         /* which bounding box cell are we in?, needed for undo */
1588         projPixel->bb_cell_index = ((int)(((float)x_px / (float)ibuf->x) * PROJ_BOUNDBOX_DIV)) +
1589                                    ((int)(((float)y_px / (float)ibuf->y) * PROJ_BOUNDBOX_DIV)) * PROJ_BOUNDBOX_DIV;
1590         
1591         /* done with view3d_project_float inline */
1592         if (ps->tool == PAINT_TOOL_CLONE) {
1593                 if (ps->dm_mtface_clone) {
1594                         ImBuf *ibuf_other;
1595                         Image *other_tpage = project_paint_face_image(ps, ps->dm_mtface_clone, face_index);
1596                         const MTFace *tf_other = ps->dm_mtface_clone + face_index;
1597                         
1598                         if (other_tpage && (ibuf_other = BKE_image_acquire_ibuf(other_tpage, NULL, NULL))) {
1599                                 /* BKE_image_acquire_ibuf - TODO - this may be slow */
1600                                 
1601                                 if (ibuf->rect_float) {
1602                                         if (ibuf_other->rect_float) { /* from float to float */
1603                                                 project_face_pixel(tf_other, ibuf_other, w, side, NULL, ((ProjPixelClone *)projPixel)->clonepx.f);
1604                                         }
1605                                         else { /* from char to float */
1606                                                 unsigned char rgba_ub[4];
1607                                                 project_face_pixel(tf_other, ibuf_other, w, side, rgba_ub, NULL);
1608                                                 IMAPAINT_CHAR_RGBA_TO_FLOAT(((ProjPixelClone *)projPixel)->clonepx.f, rgba_ub);
1609                                         }
1610                                 }
1611                                 else {
1612                                         if (ibuf_other->rect_float) { /* float to char */
1613                                                 float rgba[4];
1614                                                 project_face_pixel(tf_other, ibuf_other, w, side, NULL, rgba);
1615                                                 IMAPAINT_FLOAT_RGBA_TO_CHAR(((ProjPixelClone *)projPixel)->clonepx.ch, rgba);
1616                                         }
1617                                         else { /* char to char */
1618                                                 project_face_pixel(tf_other, ibuf_other, w, side, ((ProjPixelClone *)projPixel)->clonepx.ch, NULL);
1619                                         }
1620                                 }
1621
1622                                 BKE_image_release_ibuf(other_tpage, ibuf_other, NULL);
1623                         }
1624                         else {
1625                                 if (ibuf->rect_float) {
1626                                         ((ProjPixelClone *)projPixel)->clonepx.f[3] = 0;
1627                                 }
1628                                 else {
1629                                         ((ProjPixelClone *)projPixel)->clonepx.ch[3] = 0;
1630                                 }
1631                         }
1632                         
1633                 }
1634                 else {
1635                         float co[2];
1636                         sub_v2_v2v2(co, projPixel->projCoSS, (float *)ps->cloneOffset);
1637                         
1638                         /* no need to initialize the bucket, we're only checking buckets faces and for this
1639                          * the faces are already initialized in project_paint_delayed_face_init(...) */
1640                         if (ibuf->rect_float) {
1641                                 if (!project_paint_PickColor(ps, co, ((ProjPixelClone *)projPixel)->clonepx.f, NULL, 1)) {
1642                                         ((ProjPixelClone *)projPixel)->clonepx.f[3] = 0; /* zero alpha - ignore */
1643                                 }
1644                         }
1645                         else {
1646                                 if (!project_paint_PickColor(ps, co, NULL, ((ProjPixelClone *)projPixel)->clonepx.ch, 1)) {
1647                                         ((ProjPixelClone *)projPixel)->clonepx.ch[3] = 0; /* zero alpha - ignore */
1648                                 }
1649                         }
1650                 }
1651         }
1652         
1653 #ifdef PROJ_DEBUG_PAINT
1654         if (ibuf->rect_float) projPixel->pixel.f_pt[0] = 0;
1655         else                  projPixel->pixel.ch_pt[0] = 0;
1656 #endif
1657         projPixel->image_index = image_index;
1658         
1659         return projPixel;
1660 }
1661
1662 static int line_clip_rect2f(
1663         rctf *rect,
1664         const float l1[2], const float l2[2],
1665         float l1_clip[2], float l2_clip[2])
1666 {
1667         /* first account for horizontal, then vertical lines */
1668         /* horiz */
1669         if (fabsf(l1[1] - l2[1]) < PROJ_GEOM_TOLERANCE) {
1670                 /* is the line out of range on its Y axis? */
1671                 if (l1[1] < rect->ymin || l1[1] > rect->ymax) {
1672                         return 0;
1673                 }
1674                 /* line is out of range on its X axis */
1675                 if ((l1[0] < rect->xmin && l2[0] < rect->xmin) || (l1[0] > rect->xmax && l2[0] > rect->xmax)) {
1676                         return 0;
1677                 }
1678                 
1679                 
1680                 if (fabsf(l1[0] - l2[0]) < PROJ_GEOM_TOLERANCE) { /* this is a single point  (or close to)*/
1681                         if (BLI_rctf_isect_pt_v(rect, l1)) {
1682                                 copy_v2_v2(l1_clip, l1);
1683                                 copy_v2_v2(l2_clip, l2);
1684                                 return 1;
1685                         }
1686                         else {
1687                                 return 0;
1688                         }
1689                 }
1690                 
1691                 copy_v2_v2(l1_clip, l1);
1692                 copy_v2_v2(l2_clip, l2);
1693                 CLAMP(l1_clip[0], rect->xmin, rect->xmax);
1694                 CLAMP(l2_clip[0], rect->xmin, rect->xmax);
1695                 return 1;
1696         }
1697         else if (fabsf(l1[0] - l2[0]) < PROJ_GEOM_TOLERANCE) {
1698                 /* is the line out of range on its X axis? */
1699                 if (l1[0] < rect->xmin || l1[0] > rect->xmax) {
1700                         return 0;
1701                 }
1702                 
1703                 /* line is out of range on its Y axis */
1704                 if ((l1[1] < rect->ymin && l2[1] < rect->ymin) || (l1[1] > rect->ymax && l2[1] > rect->ymax)) {
1705                         return 0;
1706                 }
1707                 
1708                 if (fabsf(l1[1] - l2[1]) < PROJ_GEOM_TOLERANCE) { /* this is a single point  (or close to)*/
1709                         if (BLI_rctf_isect_pt_v(rect, l1)) {
1710                                 copy_v2_v2(l1_clip, l1);
1711                                 copy_v2_v2(l2_clip, l2);
1712                                 return 1;
1713                         }
1714                         else {
1715                                 return 0;
1716                         }
1717                 }
1718                 
1719                 copy_v2_v2(l1_clip, l1);
1720                 copy_v2_v2(l2_clip, l2);
1721                 CLAMP(l1_clip[1], rect->ymin, rect->ymax);
1722                 CLAMP(l2_clip[1], rect->ymin, rect->ymax);
1723                 return 1;
1724         }
1725         else {
1726                 float isect;
1727                 short ok1 = 0;
1728                 short ok2 = 0;
1729                 
1730                 /* Done with vertical lines */
1731                 
1732                 /* are either of the points inside the rectangle ? */
1733                 if (BLI_rctf_isect_pt_v(rect, l1)) {
1734                         copy_v2_v2(l1_clip, l1);
1735                         ok1 = 1;
1736                 }
1737                 
1738                 if (BLI_rctf_isect_pt_v(rect, l2)) {
1739                         copy_v2_v2(l2_clip, l2);
1740                         ok2 = 1;
1741                 }
1742                 
1743                 /* line inside rect */
1744                 if (ok1 && ok2) return 1;
1745                 
1746                 /* top/bottom */
1747                 if (line_isect_y(l1, l2, rect->ymin, &isect) && (isect >= rect->xmin) && (isect <= rect->xmax)) {
1748                         if (l1[1] < l2[1]) { /* line 1 is outside */
1749                                 l1_clip[0] = isect;
1750                                 l1_clip[1] = rect->ymin;
1751                                 ok1 = 1;
1752                         }
1753                         else {
1754                                 l2_clip[0] = isect;
1755                                 l2_clip[1] = rect->ymin;
1756                                 ok2 = 2;
1757                         }
1758                 }
1759                 
1760                 if (ok1 && ok2) return 1;
1761                 
1762                 if (line_isect_y(l1, l2, rect->ymax, &isect) && (isect >= rect->xmin) && (isect <= rect->xmax)) {
1763                         if (l1[1] > l2[1]) { /* line 1 is outside */
1764                                 l1_clip[0] = isect;
1765                                 l1_clip[1] = rect->ymax;
1766                                 ok1 = 1;
1767                         }
1768                         else {
1769                                 l2_clip[0] = isect;
1770                                 l2_clip[1] = rect->ymax;
1771                                 ok2 = 2;
1772                         }
1773                 }
1774                 
1775                 if (ok1 && ok2) return 1;
1776                 
1777                 /* left/right */
1778                 if (line_isect_x(l1, l2, rect->xmin, &isect) && (isect >= rect->ymin) && (isect <= rect->ymax)) {
1779                         if (l1[0] < l2[0]) { /* line 1 is outside */
1780                                 l1_clip[0] = rect->xmin;
1781                                 l1_clip[1] = isect;
1782                                 ok1 = 1;
1783                         }
1784                         else {
1785                                 l2_clip[0] = rect->xmin;
1786                                 l2_clip[1] = isect;
1787                                 ok2 = 2;
1788                         }
1789                 }
1790         
1791                 if (ok1 && ok2) return 1;
1792                 
1793                 if (line_isect_x(l1, l2, rect->xmax, &isect) && (isect >= rect->ymin) && (isect <= rect->ymax)) {
1794                         if (l1[0] > l2[0]) { /* line 1 is outside */
1795                                 l1_clip[0] = rect->xmax;
1796                                 l1_clip[1] = isect;
1797                                 ok1 = 1;
1798                         }
1799                         else {
1800                                 l2_clip[0] = rect->xmax;
1801                                 l2_clip[1] = isect;
1802                                 ok2 = 2;
1803                         }
1804                 }
1805                 
1806                 if (ok1 && ok2) {
1807                         return 1;
1808                 }
1809                 else {
1810                         return 0;
1811                 }
1812         }
1813 }
1814
1815
1816
1817 /* scale the quad & tri about its center
1818  * scaling by PROJ_FACE_SCALE_SEAM (0.99x) is used for getting fake UV pixel coords that are on the
1819  * edge of the face but slightly inside it occlusion tests don't return hits on adjacent faces */
1820 #ifndef PROJ_DEBUG_NOSEAMBLEED
1821 static void scale_quad(float insetCos[4][3], float *origCos[4], const float inset)
1822 {
1823         float cent[3];
1824         cent[0] = (origCos[0][0] + origCos[1][0] + origCos[2][0] + origCos[3][0]) / 4.0f;
1825         cent[1] = (origCos[0][1] + origCos[1][1] + origCos[2][1] + origCos[3][1]) / 4.0f;
1826         cent[2] = (origCos[0][2] + origCos[1][2] + origCos[2][2] + origCos[3][2]) / 4.0f;
1827         
1828         sub_v3_v3v3(insetCos[0], origCos[0], cent);
1829         sub_v3_v3v3(insetCos[1], origCos[1], cent);
1830         sub_v3_v3v3(insetCos[2], origCos[2], cent);
1831         sub_v3_v3v3(insetCos[3], origCos[3], cent);
1832         
1833         mul_v3_fl(insetCos[0], inset);
1834         mul_v3_fl(insetCos[1], inset);
1835         mul_v3_fl(insetCos[2], inset);
1836         mul_v3_fl(insetCos[3], inset);
1837         
1838         add_v3_v3(insetCos[0], cent);
1839         add_v3_v3(insetCos[1], cent);
1840         add_v3_v3(insetCos[2], cent);
1841         add_v3_v3(insetCos[3], cent);
1842 }
1843
1844
1845 static void scale_tri(float insetCos[4][3], float *origCos[4], const float inset)
1846 {
1847         float cent[3];
1848         cent[0] = (origCos[0][0] + origCos[1][0] + origCos[2][0]) / 3.0f;
1849         cent[1] = (origCos[0][1] + origCos[1][1] + origCos[2][1]) / 3.0f;
1850         cent[2] = (origCos[0][2] + origCos[1][2] + origCos[2][2]) / 3.0f;
1851         
1852         sub_v3_v3v3(insetCos[0], origCos[0], cent);
1853         sub_v3_v3v3(insetCos[1], origCos[1], cent);
1854         sub_v3_v3v3(insetCos[2], origCos[2], cent);
1855         
1856         mul_v3_fl(insetCos[0], inset);
1857         mul_v3_fl(insetCos[1], inset);
1858         mul_v3_fl(insetCos[2], inset);
1859         
1860         add_v3_v3(insetCos[0], cent);
1861         add_v3_v3(insetCos[1], cent);
1862         add_v3_v3(insetCos[2], cent);
1863 }
1864 #endif //PROJ_DEBUG_NOSEAMBLEED
1865
1866 static float len_squared_v2v2_alt(const float *v1, const float v2_1, const float v2_2)
1867 {
1868         float x, y;
1869
1870         x = v1[0] - v2_1;
1871         y = v1[1] - v2_2;
1872         return x * x + y * y;
1873 }
1874
1875 /* note, use a squared value so we can use len_squared_v2v2
1876  * be sure that you have done a bounds check first or this may fail */
1877 /* only give bucket_bounds as an arg because we need it elsewhere */
1878 static int project_bucket_isect_circle(const float cent[2], const float radius_squared, rctf *bucket_bounds)
1879 {
1880          
1881         /* Would normally to a simple intersection test, however we know the bounds of these 2 already intersect 
1882          * so we only need to test if the center is inside the vertical or horizontal bounds on either axis,
1883          * this is even less work then an intersection test
1884          */
1885 #if 0
1886         if (BLI_rctf_isect_pt_v(bucket_bounds, cent))
1887                 return 1;
1888 #endif
1889         
1890         if ((bucket_bounds->xmin <= cent[0] && bucket_bounds->xmax >= cent[0]) ||
1891             (bucket_bounds->ymin <= cent[1] && bucket_bounds->ymax >= cent[1]))
1892         {
1893                 return 1;
1894         }
1895         
1896         /* out of bounds left */
1897         if (cent[0] < bucket_bounds->xmin) {
1898                 /* lower left out of radius test */
1899                 if (cent[1] < bucket_bounds->ymin) {
1900                         return (len_squared_v2v2_alt(cent, bucket_bounds->xmin, bucket_bounds->ymin) < radius_squared) ? 1 : 0;
1901                 }
1902                 /* top left test */
1903                 else if (cent[1] > bucket_bounds->ymax) {
1904                         return (len_squared_v2v2_alt(cent, bucket_bounds->xmin, bucket_bounds->ymax) < radius_squared) ? 1 : 0;
1905                 }
1906         }
1907         else if (cent[0] > bucket_bounds->xmax) {
1908                 /* lower right out of radius test */
1909                 if (cent[1] < bucket_bounds->ymin) {
1910                         return (len_squared_v2v2_alt(cent, bucket_bounds->xmax, bucket_bounds->ymin) < radius_squared) ? 1 : 0;
1911                 }
1912                 /* top right test */
1913                 else if (cent[1] > bucket_bounds->ymax) {
1914                         return (len_squared_v2v2_alt(cent, bucket_bounds->xmax, bucket_bounds->ymax) < radius_squared) ? 1 : 0;
1915                 }
1916         }
1917         
1918         return 0;
1919 }
1920
1921
1922
1923 /* Note for rect_to_uvspace_ortho() and rect_to_uvspace_persp()
1924  * in ortho view this function gives good results when bucket_bounds are outside the triangle
1925  * however in some cases, perspective view will mess up with faces that have minimal screenspace area
1926  * (viewed from the side)
1927  * 
1928  * for this reason its not reliable in this case so we'll use the Simple Barycentric'
1929  * funcs that only account for points inside the triangle.
1930  * however switching back to this for ortho is always an option */
1931
1932 static void rect_to_uvspace_ortho(
1933         rctf *bucket_bounds,
1934         float *v1coSS, float *v2coSS, float *v3coSS,
1935         float *uv1co, float *uv2co, float *uv3co,
1936         float bucket_bounds_uv[4][2],
1937         const int flip)
1938 {
1939         float uv[2];
1940         float w[3];
1941         
1942         /* get the UV space bounding box */
1943         uv[0] = bucket_bounds->xmax;
1944         uv[1] = bucket_bounds->ymin;
1945         barycentric_weights_v2(v1coSS, v2coSS, v3coSS, uv, w);
1946         interp_v2_v2v2v2(bucket_bounds_uv[flip ? 3 : 0], uv1co, uv2co, uv3co, w);
1947
1948         //uv[0] = bucket_bounds->xmax; // set above
1949         uv[1] = bucket_bounds->ymax;
1950         barycentric_weights_v2(v1coSS, v2coSS, v3coSS, uv, w);
1951         interp_v2_v2v2v2(bucket_bounds_uv[flip ? 2 : 1], uv1co, uv2co, uv3co, w);
1952
1953         uv[0] = bucket_bounds->xmin;
1954         //uv[1] = bucket_bounds->ymax; // set above
1955         barycentric_weights_v2(v1coSS, v2coSS, v3coSS, uv, w);
1956         interp_v2_v2v2v2(bucket_bounds_uv[flip ? 1 : 2], uv1co, uv2co, uv3co, w);
1957
1958         //uv[0] = bucket_bounds->xmin; // set above
1959         uv[1] = bucket_bounds->ymin;
1960         barycentric_weights_v2(v1coSS, v2coSS, v3coSS, uv, w);
1961         interp_v2_v2v2v2(bucket_bounds_uv[flip ? 0 : 3], uv1co, uv2co, uv3co, w);
1962 }
1963
1964 /* same as above but use barycentric_weights_v2_persp */
1965 static void rect_to_uvspace_persp(
1966         rctf *bucket_bounds,
1967         float *v1coSS, float *v2coSS, float *v3coSS,
1968         float *uv1co, float *uv2co, float *uv3co,
1969         float bucket_bounds_uv[4][2],
1970         const int flip
1971         )
1972 {
1973         float uv[2];
1974         float w[3];
1975         
1976         /* get the UV space bounding box */
1977         uv[0] = bucket_bounds->xmax;
1978         uv[1] = bucket_bounds->ymin;
1979         barycentric_weights_v2_persp(v1coSS, v2coSS, v3coSS, uv, w);
1980         interp_v2_v2v2v2(bucket_bounds_uv[flip ? 3 : 0], uv1co, uv2co, uv3co, w);
1981
1982         //uv[0] = bucket_bounds->xmax; // set above
1983         uv[1] = bucket_bounds->ymax;
1984         barycentric_weights_v2_persp(v1coSS, v2coSS, v3coSS, uv, w);
1985         interp_v2_v2v2v2(bucket_bounds_uv[flip ? 2 : 1], uv1co, uv2co, uv3co, w);
1986
1987         uv[0] = bucket_bounds->xmin;
1988         //uv[1] = bucket_bounds->ymax; // set above
1989         barycentric_weights_v2_persp(v1coSS, v2coSS, v3coSS, uv, w);
1990         interp_v2_v2v2v2(bucket_bounds_uv[flip ? 1 : 2], uv1co, uv2co, uv3co, w);
1991
1992         //uv[0] = bucket_bounds->xmin; // set above
1993         uv[1] = bucket_bounds->ymin;
1994         barycentric_weights_v2_persp(v1coSS, v2coSS, v3coSS, uv, w);
1995         interp_v2_v2v2v2(bucket_bounds_uv[flip ? 0 : 3], uv1co, uv2co, uv3co, w);
1996 }
1997
1998 /* This works as we need it to but we can save a few steps and not use it */
1999
2000 #if 0
2001 static float angle_2d_clockwise(const float p1[2], const float p2[2], const float p3[2])
2002 {
2003         float v1[2], v2[2];
2004         
2005         v1[0] = p1[0] - p2[0];    v1[1] = p1[1] - p2[1];
2006         v2[0] = p3[0] - p2[0];    v2[1] = p3[1] - p2[1];
2007         
2008         return -atan2(v1[0] * v2[1] - v1[1] * v2[0], v1[0] * v2[0] + v1[1] * v2[1]);
2009 }
2010 #endif
2011
2012 #define ISECT_1 (1)
2013 #define ISECT_2 (1 << 1)
2014 #define ISECT_3 (1 << 2)
2015 #define ISECT_4 (1 << 3)
2016 #define ISECT_ALL3 ((1 << 3) - 1)
2017 #define ISECT_ALL4 ((1 << 4) - 1)
2018
2019 /* limit must be a fraction over 1.0f */
2020 static int IsectPT2Df_limit(float pt[2], float v1[2], float v2[2], float v3[2], float limit)
2021 {
2022         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;
2023 }
2024
2025 /* Clip the face by a bucket and set the uv-space bucket_bounds_uv
2026  * so we have the clipped UV's to do pixel intersection tests with 
2027  * */
2028 static int float_z_sort_flip(const void *p1, const void *p2)
2029 {
2030         return (((float *)p1)[2] < ((float *)p2)[2] ? 1 : -1);
2031 }
2032
2033 static int float_z_sort(const void *p1, const void *p2)
2034 {
2035         return (((float *)p1)[2] < ((float *)p2)[2] ? -1 : 1);
2036 }
2037
2038 static void project_bucket_clip_face(
2039         const int is_ortho,
2040         rctf *bucket_bounds,
2041         float *v1coSS, float *v2coSS, float *v3coSS,
2042         float *uv1co, float *uv2co, float *uv3co,
2043         float bucket_bounds_uv[8][2],
2044         int *tot)
2045 {
2046         int inside_bucket_flag = 0;
2047         int inside_face_flag = 0;
2048         const int flip = ((line_point_side_v2(v1coSS, v2coSS, v3coSS) > 0.0f) != (line_point_side_v2(uv1co, uv2co, uv3co) > 0.0f));
2049         
2050         float bucket_bounds_ss[4][2];
2051
2052         /* get the UV space bounding box */
2053         inside_bucket_flag |= BLI_rctf_isect_pt_v(bucket_bounds, v1coSS);
2054         inside_bucket_flag |= BLI_rctf_isect_pt_v(bucket_bounds, v2coSS) << 1;
2055         inside_bucket_flag |= BLI_rctf_isect_pt_v(bucket_bounds, v3coSS) << 2;
2056         
2057         if (inside_bucket_flag == ISECT_ALL3) {
2058                 /* all screenspace points are inside the bucket bounding box, this means we don't need to clip and can simply return the UVs */
2059                 if (flip) { /* facing the back? */
2060                         copy_v2_v2(bucket_bounds_uv[0], uv3co);
2061                         copy_v2_v2(bucket_bounds_uv[1], uv2co);
2062                         copy_v2_v2(bucket_bounds_uv[2], uv1co);
2063                 }
2064                 else {
2065                         copy_v2_v2(bucket_bounds_uv[0], uv1co);
2066                         copy_v2_v2(bucket_bounds_uv[1], uv2co);
2067                         copy_v2_v2(bucket_bounds_uv[2], uv3co);
2068                 }
2069                 
2070                 *tot = 3; 
2071                 return;
2072         }
2073         
2074         /* get the UV space bounding box */
2075         /* use IsectPT2Df_limit here so we catch points are are touching the tri edge (or a small fraction over) */
2076         bucket_bounds_ss[0][0] = bucket_bounds->xmax;
2077         bucket_bounds_ss[0][1] = bucket_bounds->ymin;
2078         inside_face_flag |= (IsectPT2Df_limit(bucket_bounds_ss[0], v1coSS, v2coSS, v3coSS, 1 + PROJ_GEOM_TOLERANCE) ? ISECT_1 : 0);
2079         
2080         bucket_bounds_ss[1][0] = bucket_bounds->xmax;
2081         bucket_bounds_ss[1][1] = bucket_bounds->ymax;
2082         inside_face_flag |= (IsectPT2Df_limit(bucket_bounds_ss[1], v1coSS, v2coSS, v3coSS, 1 + PROJ_GEOM_TOLERANCE) ? ISECT_2 : 0);
2083
2084         bucket_bounds_ss[2][0] = bucket_bounds->xmin;
2085         bucket_bounds_ss[2][1] = bucket_bounds->ymax;
2086         inside_face_flag |= (IsectPT2Df_limit(bucket_bounds_ss[2], v1coSS, v2coSS, v3coSS, 1 + PROJ_GEOM_TOLERANCE) ? ISECT_3 : 0);
2087
2088         bucket_bounds_ss[3][0] = bucket_bounds->xmin;
2089         bucket_bounds_ss[3][1] = bucket_bounds->ymin;
2090         inside_face_flag |= (IsectPT2Df_limit(bucket_bounds_ss[3], v1coSS, v2coSS, v3coSS, 1 + PROJ_GEOM_TOLERANCE) ? ISECT_4 : 0);
2091         
2092         if (inside_face_flag == ISECT_ALL4) {
2093                 /* bucket is totally inside the screenspace face, we can safely use weights */
2094                 
2095                 if (is_ortho) rect_to_uvspace_ortho(bucket_bounds, v1coSS, v2coSS, v3coSS, uv1co, uv2co, uv3co, bucket_bounds_uv, flip);
2096                 else rect_to_uvspace_persp(bucket_bounds, v1coSS, v2coSS, v3coSS, uv1co, uv2co, uv3co, bucket_bounds_uv, flip);
2097                 
2098                 *tot = 4;
2099                 return;
2100         }
2101         else {
2102                 /* The Complicated Case! 
2103                  * 
2104                  * The 2 cases above are where the face is inside the bucket or the bucket is inside the face.
2105                  * 
2106                  * we need to make a convex polyline from the intersection between the screenspace face
2107                  * and the bucket bounds.
2108                  * 
2109                  * There are a number of ways this could be done, currently it just collects all intersecting verts,
2110                  * and line intersections,  then sorts them clockwise, this is a lot easier then evaluating the geometry to
2111                  * do a correct clipping on both shapes. */
2112                 
2113                 
2114                 /* add a bunch of points, we know must make up the convex hull which is the clipped rect and triangle */
2115                 
2116                 
2117                 
2118                 /* Maximum possible 6 intersections when using a rectangle and triangle */
2119                 float isectVCosSS[8][3]; /* The 3rd float is used to store angle for qsort(), NOT as a Z location */
2120                 float v1_clipSS[2], v2_clipSS[2];
2121                 float w[3];
2122                 
2123                 /* calc center */
2124                 float cent[2] = {0.0f, 0.0f};
2125                 /*float up[2] = {0.0f, 1.0f};*/
2126                 int i;
2127                 short doubles;
2128                 
2129                 (*tot) = 0;
2130                 
2131                 if (inside_face_flag & ISECT_1) { copy_v2_v2(isectVCosSS[*tot], bucket_bounds_ss[0]); (*tot)++; }
2132                 if (inside_face_flag & ISECT_2) { copy_v2_v2(isectVCosSS[*tot], bucket_bounds_ss[1]); (*tot)++; }
2133                 if (inside_face_flag & ISECT_3) { copy_v2_v2(isectVCosSS[*tot], bucket_bounds_ss[2]); (*tot)++; }
2134                 if (inside_face_flag & ISECT_4) { copy_v2_v2(isectVCosSS[*tot], bucket_bounds_ss[3]); (*tot)++; }
2135
2136                 if (inside_bucket_flag & ISECT_1) { copy_v2_v2(isectVCosSS[*tot], v1coSS); (*tot)++; }
2137                 if (inside_bucket_flag & ISECT_2) { copy_v2_v2(isectVCosSS[*tot], v2coSS); (*tot)++; }
2138                 if (inside_bucket_flag & ISECT_3) { copy_v2_v2(isectVCosSS[*tot], v3coSS); (*tot)++; }
2139                 
2140                 if ((inside_bucket_flag & (ISECT_1 | ISECT_2)) != (ISECT_1 | ISECT_2)) {
2141                         if (line_clip_rect2f(bucket_bounds, v1coSS, v2coSS, v1_clipSS, v2_clipSS)) {
2142                                 if ((inside_bucket_flag & ISECT_1) == 0) { copy_v2_v2(isectVCosSS[*tot], v1_clipSS); (*tot)++; }
2143                                 if ((inside_bucket_flag & ISECT_2) == 0) { copy_v2_v2(isectVCosSS[*tot], v2_clipSS); (*tot)++; }
2144                         }
2145                 }
2146                 
2147                 if ((inside_bucket_flag & (ISECT_2 | ISECT_3)) != (ISECT_2 | ISECT_3)) {
2148                         if (line_clip_rect2f(bucket_bounds, v2coSS, v3coSS, v1_clipSS, v2_clipSS)) {
2149                                 if ((inside_bucket_flag & ISECT_2) == 0) { copy_v2_v2(isectVCosSS[*tot], v1_clipSS); (*tot)++; }
2150                                 if ((inside_bucket_flag & ISECT_3) == 0) { copy_v2_v2(isectVCosSS[*tot], v2_clipSS); (*tot)++; }
2151                         }
2152                 }
2153                 
2154                 if ((inside_bucket_flag & (ISECT_3 | ISECT_1)) != (ISECT_3 | ISECT_1)) {
2155                         if (line_clip_rect2f(bucket_bounds, v3coSS, v1coSS, v1_clipSS, v2_clipSS)) {
2156                                 if ((inside_bucket_flag & ISECT_3) == 0) { copy_v2_v2(isectVCosSS[*tot], v1_clipSS); (*tot)++; }
2157                                 if ((inside_bucket_flag & ISECT_1) == 0) { copy_v2_v2(isectVCosSS[*tot], v2_clipSS); (*tot)++; }
2158                         }
2159                 }
2160                 
2161                 
2162                 if ((*tot) < 3) { /* no intersections to speak of */
2163                         *tot = 0;
2164                         return;
2165                 }
2166         
2167                 /* now we have all points we need, collect their angles and sort them clockwise */
2168                 
2169                 for (i = 0; i < (*tot); i++) {
2170                         cent[0] += isectVCosSS[i][0];
2171                         cent[1] += isectVCosSS[i][1];
2172                 }
2173                 cent[0] = cent[0] / (float)(*tot);
2174                 cent[1] = cent[1] / (float)(*tot);
2175                 
2176                 
2177                 
2178                 /* Collect angles for every point around the center point */
2179
2180                 
2181 #if 0   /* uses a few more cycles then the above loop */
2182                 for (i = 0; i < (*tot); i++) {
2183                         isectVCosSS[i][2] = angle_2d_clockwise(up, cent, isectVCosSS[i]);
2184                 }
2185 #endif
2186
2187                 v1_clipSS[0] = cent[0]; /* Abuse this var for the loop below */
2188                 v1_clipSS[1] = cent[1] + 1.0f;
2189                 
2190                 for (i = 0; i < (*tot); i++) {
2191                         v2_clipSS[0] = isectVCosSS[i][0] - cent[0];
2192                         v2_clipSS[1] = isectVCosSS[i][1] - cent[1];
2193                         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]);
2194                 }
2195                 
2196                 if (flip) qsort(isectVCosSS, *tot, sizeof(float) * 3, float_z_sort_flip);
2197                 else      qsort(isectVCosSS, *tot, sizeof(float) * 3, float_z_sort);
2198                 
2199                 /* remove doubles */
2200                 /* first/last check */
2201                 if (fabsf(isectVCosSS[0][0] - isectVCosSS[(*tot) - 1][0]) < PROJ_GEOM_TOLERANCE &&
2202                     fabsf(isectVCosSS[0][1] - isectVCosSS[(*tot) - 1][1]) < PROJ_GEOM_TOLERANCE)
2203                 {
2204                         (*tot)--;
2205                 }
2206                 
2207                 /* its possible there is only a few left after remove doubles */
2208                 if ((*tot) < 3) {
2209                         // printf("removed too many doubles A\n");
2210                         *tot = 0;
2211                         return;
2212                 }
2213                 
2214                 doubles = TRUE;
2215                 while (doubles == TRUE) {
2216                         doubles = FALSE;
2217                         for (i = 1; i < (*tot); i++) {
2218                                 if (fabsf(isectVCosSS[i - 1][0] - isectVCosSS[i][0]) < PROJ_GEOM_TOLERANCE &&
2219                                     fabsf(isectVCosSS[i - 1][1] - isectVCosSS[i][1]) < PROJ_GEOM_TOLERANCE)
2220                                 {
2221                                         int j;
2222                                         for (j = i + 1; j < (*tot); j++) {
2223                                                 isectVCosSS[j - 1][0] = isectVCosSS[j][0];
2224                                                 isectVCosSS[j - 1][1] = isectVCosSS[j][1];
2225                                         }
2226                                         doubles = TRUE; /* keep looking for more doubles */
2227                                         (*tot)--;
2228                                 }
2229                         }
2230                 }
2231                 
2232                 /* its possible there is only a few left after remove doubles */
2233                 if ((*tot) < 3) {
2234                         // printf("removed too many doubles B\n");
2235                         *tot = 0;
2236                         return;
2237                 }
2238                 
2239                 
2240                 if (is_ortho) {
2241                         for (i = 0; i < (*tot); i++) {
2242                                 barycentric_weights_v2(v1coSS, v2coSS, v3coSS, isectVCosSS[i], w);
2243                                 interp_v2_v2v2v2(bucket_bounds_uv[i], uv1co, uv2co, uv3co, w);
2244                         }
2245                 }
2246                 else {
2247                         for (i = 0; i < (*tot); i++) {
2248                                 barycentric_weights_v2_persp(v1coSS, v2coSS, v3coSS, isectVCosSS[i], w);
2249                                 interp_v2_v2v2v2(bucket_bounds_uv[i], uv1co, uv2co, uv3co, w);
2250                         }
2251                 }
2252         }
2253
2254 #ifdef PROJ_DEBUG_PRINT_CLIP
2255         /* include this at the bottom of the above function to debug the output */
2256
2257         {
2258                 /* If there are ever any problems, */
2259                 float test_uv[4][2];
2260                 int i;
2261                 if (is_ortho) rect_to_uvspace_ortho(bucket_bounds, v1coSS, v2coSS, v3coSS, uv1co, uv2co, uv3co, test_uv, flip);
2262                 else          rect_to_uvspace_persp(bucket_bounds, v1coSS, v2coSS, v3coSS, uv1co, uv2co, uv3co, test_uv, flip);
2263                 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]);
2264                 
2265                 printf("  [(%f,%f), (%f,%f), (%f,%f)], ", uv1co[0], uv1co[1],   uv2co[0], uv2co[1],    uv3co[0], uv3co[1]);
2266                 
2267                 printf("[");
2268                 for (i = 0; i < (*tot); i++) {
2269                         printf("(%f, %f),", bucket_bounds_uv[i][0], bucket_bounds_uv[i][1]);
2270                 }
2271                 printf("]),\\\n");
2272         }
2273 #endif
2274 }
2275
2276 /*
2277  * # This script creates faces in a blender scene from printed data above.
2278  *
2279  * project_ls = [
2280  * ...(output from above block)...
2281  * ]
2282  *
2283  * from Blender import Scene, Mesh, Window, sys, Mathutils
2284  *
2285  * import bpy
2286  *
2287  * V = Mathutils.Vector
2288  *
2289  * def main():
2290  *     sce = bpy.data.scenes.active
2291  *     
2292  *     for item in project_ls:
2293  *         bb = item[0]
2294  *         uv = item[1]
2295  *         poly = item[2]
2296  *         
2297  *         me = bpy.data.meshes.new()
2298  *         ob = sce.objects.new(me)
2299  *         
2300  *         me.verts.extend([V(bb[0]).xyz, V(bb[1]).xyz, V(bb[2]).xyz, V(bb[3]).xyz])
2301  *         me.faces.extend([(0,1,2,3),])
2302  *         me.verts.extend([V(uv[0]).xyz, V(uv[1]).xyz, V(uv[2]).xyz])
2303  *         me.faces.extend([(4,5,6),])
2304  *         
2305  *         vs = [V(p).xyz for p in poly]
2306  *         print len(vs)
2307  *         l = len(me.verts)
2308  *         me.verts.extend(vs)
2309  *         
2310  *         i = l
2311  *         while i < len(me.verts):
2312  *             ii = i + 1
2313  *             if ii == len(me.verts):
2314  *                 ii = l
2315  *             me.edges.extend([i, ii])
2316  *             i += 1
2317  * 
2318  * if __name__ == '__main__':
2319  *     main()
2320  */
2321
2322
2323 #undef ISECT_1
2324 #undef ISECT_2
2325 #undef ISECT_3
2326 #undef ISECT_4
2327 #undef ISECT_ALL3
2328 #undef ISECT_ALL4
2329
2330         
2331 /* checks if pt is inside a convex 2D polyline, the polyline must be ordered rotating clockwise
2332  * otherwise it would have to test for mixed (line_point_side_v2 > 0.0f) cases */
2333 static int IsectPoly2Df(const float pt[2], float uv[][2], const int tot)
2334 {
2335         int i;
2336         if (line_point_side_v2(uv[tot - 1], uv[0], pt) < 0.0f)
2337                 return 0;
2338         
2339         for (i = 1; i < tot; i++) {
2340                 if (line_point_side_v2(uv[i - 1], uv[i], pt) < 0.0f)
2341                         return 0;
2342                 
2343         }
2344         
2345         return 1;
2346 }
2347 static int IsectPoly2Df_twoside(const float pt[2], float uv[][2], const int tot)
2348 {
2349         int i;
2350         int side = (line_point_side_v2(uv[tot - 1], uv[0], pt) > 0.0f);
2351         
2352         for (i = 1; i < tot; i++) {
2353                 if ((line_point_side_v2(uv[i - 1], uv[i], pt) > 0.0f) != side)
2354                         return 0;
2355                 
2356         }
2357         
2358         return 1;
2359 }
2360
2361 /* One of the most important function for projection painting, since it selects the pixels to be added into each bucket.
2362  * initialize pixels from this face where it intersects with the bucket_index, optionally initialize pixels for removing seams */
2363 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)
2364 {
2365         /* Projection vars, to get the 3D locations into screen space  */
2366         MemArena *arena = ps->arena_mt[thread_index];
2367         LinkNode **bucketPixelNodes = ps->bucketRect + bucket_index;
2368         LinkNode *bucketFaceNodes = ps->bucketFaces[bucket_index];
2369         
2370         const MFace *mf = ps->dm_mface + face_index;
2371         const MTFace *tf = ps->dm_mtface + face_index;
2372         
2373         /* UV/pixel seeking data */
2374         int x; /* Image X-Pixel */
2375         int y; /* Image Y-Pixel */
2376         float mask;
2377         float uv[2]; /* Image floating point UV - same as x, y but from 0.0-1.0 */
2378         
2379         int side;
2380         float *v1coSS, *v2coSS, *v3coSS; /* vert co screen-space, these will be assigned to mf->v1,2,3 or mf->v1,3,4 */
2381         
2382         float *vCo[4]; /* vertex screenspace coords */
2383         
2384         float w[3], wco[3];
2385         
2386         float *uv1co, *uv2co, *uv3co; /* for convenience only, these will be assigned to tf->uv[0],1,2 or tf->uv[0],2,3 */
2387         float pixelScreenCo[4];
2388         bool do_3d_mapping = ps->brush->mtex.brush_map_mode == MTEX_MAP_MODE_3D;
2389         
2390         rcti bounds_px; /* ispace bounds */
2391         /* vars for getting uvspace bounds */
2392         
2393         float tf_uv_pxoffset[4][2]; /* bucket bounds in UV space so we can init pixels only for this face,  */
2394         float xhalfpx, yhalfpx;
2395         const float ibuf_xf = (float)ibuf->x, ibuf_yf = (float)ibuf->y;
2396         
2397         int has_x_isect = 0, has_isect = 0; /* for early loop exit */
2398         
2399         int i1, i2, i3;
2400         
2401         float uv_clip[8][2];
2402         int uv_clip_tot;
2403         const short is_ortho = ps->is_ortho;
2404         const short do_backfacecull = ps->do_backfacecull;
2405         const short do_clip = ps->rv3d ? ps->rv3d->rflag & RV3D_CLIPPING : 0;
2406         
2407         vCo[0] = ps->dm_mvert[mf->v1].co;
2408         vCo[1] = ps->dm_mvert[mf->v2].co;
2409         vCo[2] = ps->dm_mvert[mf->v3].co;
2410         
2411         
2412         /* Use tf_uv_pxoffset instead of tf->uv so we can offset the UV half a pixel
2413          * this is done so we can avoid offsetting all the pixels by 0.5 which causes
2414          * problems when wrapping negative coords */
2415         xhalfpx = (0.5f + (PROJ_GEOM_TOLERANCE / 3.0f)) / ibuf_xf;
2416         yhalfpx = (0.5f + (PROJ_GEOM_TOLERANCE / 4.0f)) / ibuf_yf;
2417         
2418         /* Note about (PROJ_GEOM_TOLERANCE/x) above...
2419          * Needed to add this offset since UV coords are often quads aligned to pixels.
2420          * In this case pixels can be exactly between 2 triangles causing nasty
2421          * artifacts.
2422          * 
2423          * This workaround can be removed and painting will still work on most cases
2424          * but since the first thing most people try is painting onto a quad- better make it work.
2425          */
2426
2427
2428
2429         tf_uv_pxoffset[0][0] = tf->uv[0][0] - xhalfpx;
2430         tf_uv_pxoffset[0][1] = tf->uv[0][1] - yhalfpx;
2431
2432         tf_uv_pxoffset[1][0] = tf->uv[1][0] - xhalfpx;
2433         tf_uv_pxoffset[1][1] = tf->uv[1][1] - yhalfpx;
2434         
2435         tf_uv_pxoffset[2][0] = tf->uv[2][0] - xhalfpx;
2436         tf_uv_pxoffset[2][1] = tf->uv[2][1] - yhalfpx;
2437         
2438         if (mf->v4) {
2439                 vCo[3] = ps->dm_mvert[mf->v4].co;
2440                 
2441                 tf_uv_pxoffset[3][0] = tf->uv[3][0] - xhalfpx;
2442                 tf_uv_pxoffset[3][1] = tf->uv[3][1] - yhalfpx;
2443                 side = 1;
2444         }
2445         else {
2446                 side = 0;
2447         }
2448         
2449         do {
2450                 if (side == 1) {
2451                         i1 = 0; i2 = 2; i3 = 3;
2452                 }
2453                 else {
2454                         i1 = 0; i2 = 1; i3 = 2;
2455                 }
2456                 
2457                 uv1co = tf_uv_pxoffset[i1]; // was tf->uv[i1];
2458                 uv2co = tf_uv_pxoffset[i2]; // was tf->uv[i2];
2459                 uv3co = tf_uv_pxoffset[i3]; // was tf->uv[i3];
2460
2461                 v1coSS = ps->screenCoords[(*(&mf->v1 + i1))];
2462                 v2coSS = ps->screenCoords[(*(&mf->v1 + i2))];
2463                 v3coSS = ps->screenCoords[(*(&mf->v1 + i3))];
2464
2465                 /* This funtion gives is a concave polyline in UV space from the clipped quad and tri*/
2466                 project_bucket_clip_face(
2467                         is_ortho, bucket_bounds,
2468                         v1coSS, v2coSS, v3coSS,
2469                         uv1co, uv2co, uv3co,
2470                         uv_clip, &uv_clip_tot
2471                         );
2472
2473                 /* sometimes this happens, better just allow for 8 intersectiosn even though there should be max 6 */
2474 #if 0
2475                 if (uv_clip_tot > 6) {
2476                         printf("this should never happen! %d\n", uv_clip_tot);
2477                 }
2478 #endif
2479
2480                 if (pixel_bounds_array(uv_clip, &bounds_px, ibuf->x, ibuf->y, uv_clip_tot)) {
2481
2482                         if (clamp_u) {
2483                                 CLAMP(bounds_px.xmin, 0, ibuf->x);
2484                                 CLAMP(bounds_px.xmax, 0, ibuf->x);
2485                         }
2486
2487                         if (clamp_v) {
2488                                 CLAMP(bounds_px.ymin, 0, ibuf->y);
2489                                 CLAMP(bounds_px.ymax, 0, ibuf->y);
2490                         }
2491
2492                         /* clip face and */
2493                         
2494                         has_isect = 0;
2495                         for (y = bounds_px.ymin; y < bounds_px.ymax; y++) {
2496                                 //uv[1] = (((float)y) + 0.5f) / (float)ibuf->y;
2497                                 uv[1] = (float)y / ibuf_yf; /* use pixel offset UV coords instead */
2498
2499                                 has_x_isect = 0;
2500                                 for (x = bounds_px.xmin; x < bounds_px.xmax; x++) {
2501                                         //uv[0] = (((float)x) + 0.5f) / ibuf->x;
2502                                         uv[0] = (float)x / ibuf_xf; /* use pixel offset UV coords instead */
2503                                         
2504                                         /* Note about IsectPoly2Df_twoside, checking the face or uv flipping doesnt work,
2505                                          * could check the poly direction but better to do this */
2506                                         if ((do_backfacecull == TRUE  && IsectPoly2Df(uv, uv_clip, uv_clip_tot)) ||
2507                                             (do_backfacecull == FALSE && IsectPoly2Df_twoside(uv, uv_clip, uv_clip_tot)))
2508                                         {
2509                                                 
2510                                                 has_x_isect = has_isect = 1;
2511                                                 
2512                                                 if (is_ortho) screen_px_from_ortho(uv, v1coSS, v2coSS, v3coSS, uv1co, uv2co, uv3co, pixelScreenCo, w);
2513                                                 else          screen_px_from_persp(uv, v1coSS, v2coSS, v3coSS, uv1co, uv2co, uv3co, pixelScreenCo, w);
2514                                                 
2515                                                 /* a pity we need to get the worldspace pixel location here */
2516                                                 if (do_clip || do_3d_mapping) {
2517                                                         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);
2518                                                         if (do_clip && ED_view3d_clipping_test(ps->rv3d, wco, TRUE)) {
2519                                                                 continue; /* Watch out that no code below this needs to run */
2520                                                         }
2521                                                 }
2522                                                 
2523                                                 /* Is this UV visible from the view? - raytrace */
2524                                                 /* project_paint_PickFace is less complex, use for testing */
2525                                                 //if (project_paint_PickFace(ps, pixelScreenCo, w, &side) == face_index) {
2526                                                 if ((ps->do_occlude == FALSE) ||
2527                                                     !project_bucket_point_occluded(ps, bucketFaceNodes, face_index, pixelScreenCo))
2528                                                 {
2529                                                         mask = project_paint_uvpixel_mask(ps, face_index, side, w);
2530
2531                                                         if (mask > 0.0f) {
2532                                                                 BLI_linklist_prepend_arena(
2533                                                                         bucketPixelNodes,
2534                                                                         project_paint_uvpixel_init(ps, arena, ibuf, x, y, mask, face_index,
2535                                                                                                    image_index, pixelScreenCo, wco, side, w),
2536                                                                         arena
2537                                                                         );
2538                                                         }
2539                                                 }
2540                                                 
2541                                         }
2542 //#if 0
2543                                         else if (has_x_isect) {
2544                                                 /* assuming the face is not a bow-tie - we know we cant intersect again on the X */
2545                                                 break;
2546                                         }
2547 //#endif
2548                                 }
2549                                 
2550                                 
2551 #if 0           /* TODO - investigate why this dosnt work sometimes! it should! */
2552                                 /* no intersection for this entire row, after some intersection above means we can quit now */
2553                                 if (has_x_isect == 0 && has_isect) {
2554                                         break;
2555                                 }
2556 #endif
2557                         }
2558                 }
2559         } while (side--);
2560
2561         
2562         
2563 #ifndef PROJ_DEBUG_NOSEAMBLEED
2564         if (ps->seam_bleed_px > 0.0f) {
2565                 int face_seam_flag;
2566                 
2567                 if (ps->thread_tot > 1)
2568                         BLI_lock_thread(LOCK_CUSTOM1);  /* Other threads could be modifying these vars */
2569                 
2570                 face_seam_flag = ps->faceSeamFlags[face_index];
2571                 
2572                 /* are any of our edges un-initialized? */
2573                 if ((face_seam_flag & (PROJ_FACE_SEAM1 | PROJ_FACE_NOSEAM1)) == 0 ||
2574                     (face_seam_flag & (PROJ_FACE_SEAM2 | PROJ_FACE_NOSEAM2)) == 0 ||
2575                     (face_seam_flag & (PROJ_FACE_SEAM3 | PROJ_FACE_NOSEAM3)) == 0 ||
2576                     (face_seam_flag & (PROJ_FACE_SEAM4 | PROJ_FACE_NOSEAM4)) == 0)
2577                 {
2578                         project_face_seams_init(ps, face_index, mf->v4);
2579                         face_seam_flag = ps->faceSeamFlags[face_index];
2580                         //printf("seams - %d %d %d %d\n", flag&PROJ_FACE_SEAM1, flag&PROJ_FACE_SEAM2, flag&PROJ_FACE_SEAM3, flag&PROJ_FACE_SEAM4);
2581                 }
2582                 
2583                 if ((face_seam_flag & (PROJ_FACE_SEAM1 | PROJ_FACE_SEAM2 | PROJ_FACE_SEAM3 | PROJ_FACE_SEAM4)) == 0) {
2584                         
2585                         if (ps->thread_tot > 1)
2586                                 BLI_unlock_thread(LOCK_CUSTOM1);  /* Other threads could be modifying these vars */
2587                         
2588                 }
2589                 else {
2590                         /* we have a seam - deal with it! */
2591                         
2592                         /* Now create new UV's for the seam face */
2593                         float (*outset_uv)[2] = ps->faceSeamUVs[face_index];
2594                         float insetCos[4][3]; /* inset face coords.  NOTE!!! ScreenSace for ortho, Worldspace in prespective view */
2595
2596                         float *vCoSS[4]; /* vertex screenspace coords */
2597                         
2598                         float bucket_clip_edges[2][2]; /* store the screenspace coords of the face, clipped by the bucket's screen aligned rectangle */
2599                         float edge_verts_inset_clip[2][3];
2600                         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 */
2601                         
2602                         float seam_subsection[4][2];
2603                         float fac1, fac2, ftot;
2604                         
2605                         
2606                         if (outset_uv[0][0] == FLT_MAX) /* first time initialize */
2607                                 uv_image_outset(tf_uv_pxoffset, outset_uv, ps->seam_bleed_px, ibuf->x, ibuf->y, mf->v4);
2608                         
2609                         /* ps->faceSeamUVs cant be modified when threading, now this is done we can unlock */
2610                         if (ps->thread_tot > 1)
2611                                 BLI_unlock_thread(LOCK_CUSTOM1);  /* Other threads could be modifying these vars */
2612                         
2613                         vCoSS[0] = ps->screenCoords[mf->v1];
2614                         vCoSS[1] = ps->screenCoords[mf->v2];
2615                         vCoSS[2] = ps->screenCoords[mf->v3];
2616                         if (mf->v4)
2617                                 vCoSS[3] = ps->screenCoords[mf->v4];
2618                         
2619                         /* PROJ_FACE_SCALE_SEAM must be slightly less then 1.0f */
2620                         if (is_ortho) {
2621                                 if (mf->v4) scale_quad(insetCos, vCoSS, PROJ_FACE_SCALE_SEAM);
2622                                 else        scale_tri(insetCos, vCoSS, PROJ_FACE_SCALE_SEAM);
2623                         }
2624                         else {
2625                                 if (mf->v4) scale_quad(insetCos, vCo, PROJ_FACE_SCALE_SEAM);
2626                                 else        scale_tri(insetCos, vCo, PROJ_FACE_SCALE_SEAM);
2627                         }
2628                         
2629                         side = 0; /* for triangles this wont need to change */
2630                         
2631                         for (fidx1 = 0; fidx1 < (mf->v4 ? 4 : 3); fidx1++) {
2632                                 if (mf->v4) fidx2 = (fidx1 == 3) ? 0 : fidx1 + 1;  /* next fidx in the face (0,1,2,3) -> (1,2,3,0) */
2633                                 else        fidx2 = (fidx1 == 2) ? 0 : fidx1 + 1;  /* next fidx in the face (0,1,2) -> (1,2,0) */
2634                                 
2635                                 if ((face_seam_flag & (1 << fidx1)) && /* 1<<fidx1 -> PROJ_FACE_SEAM# */
2636                                     line_clip_rect2f(bucket_bounds, vCoSS[fidx1], vCoSS[fidx2], bucket_clip_edges[0], bucket_clip_edges[1]))
2637                                 {
2638
2639                                         ftot = len_v2v2(vCoSS[fidx1], vCoSS[fidx2]); /* screenspace edge length */
2640                                         
2641                                         if (ftot > 0.0f) { /* avoid div by zero */
2642                                                 if (mf->v4) {
2643                                                         if (fidx1 == 2 || fidx2 == 2) side = 1;
2644                                                         else side = 0;
2645                                                 }
2646                                                 
2647                                                 fac1 = len_v2v2(vCoSS[fidx1], bucket_clip_edges[0]) / ftot;
2648                                                 fac2 = len_v2v2(vCoSS[fidx1], bucket_clip_edges[1]) / ftot;
2649                                                 
2650                                                 interp_v2_v2v2(seam_subsection[0], tf_uv_pxoffset[fidx1], tf_uv_pxoffset[fidx2], fac1);
2651                                                 interp_v2_v2v2(seam_subsection[1], tf_uv_pxoffset[fidx1], tf_uv_pxoffset[fidx2], fac2);
2652
2653                                                 interp_v2_v2v2(seam_subsection[2], outset_uv[fidx1], outset_uv[fidx2], fac2);
2654                                                 interp_v2_v2v2(seam_subsection[3], outset_uv[fidx1], outset_uv[fidx2], fac1);
2655                                                 
2656                                                 /* if the bucket_clip_edges values Z values was kept we could avoid this
2657                                                  * Inset needs to be added so occlusion tests wont hit adjacent faces */
2658                                                 interp_v3_v3v3(edge_verts_inset_clip[0], insetCos[fidx1], insetCos[fidx2], fac1);
2659                                                 interp_v3_v3v3(edge_verts_inset_clip[1], insetCos[fidx1], insetCos[fidx2], fac2);
2660                                                 
2661
2662                                                 if (pixel_bounds_uv(seam_subsection[0], seam_subsection[1], seam_subsection[2], seam_subsection[3], &bounds_px, ibuf->x, ibuf->y, 1)) {
2663                                                         /* bounds between the seam rect and the uvspace bucket pixels */
2664                                                         
2665                                                         has_isect = 0;
2666                                                         for (y = bounds_px.ymin; y < bounds_px.ymax; y++) {
2667                                                                 // uv[1] = (((float)y) + 0.5f) / (float)ibuf->y;
2668                                                                 uv[1] = (float)y / ibuf_yf; /* use offset uvs instead */
2669                                                                 
2670                                                                 has_x_isect = 0;
2671                                                                 for (x = bounds_px.xmin; x < bounds_px.xmax; x++) {
2672                                                                         //uv[0] = (((float)x) + 0.5f) / (float)ibuf->x;
2673                                                                         uv[0] = (float)x / ibuf_xf; /* use offset uvs instead */
2674                                                                         
2675                                                                         /* test we're inside uvspace bucket and triangle bounds */
2676                                                                         if (isect_point_quad_v2(uv, seam_subsection[0], seam_subsection[1], seam_subsection[2], seam_subsection[3])) {
2677                                                                                 float fac;
2678                                                                                 
2679                                                                                 /* We need to find the closest point along the face edge,
2680                                                                                  * getting the screen_px_from_*** wont work because our actual location
2681                                                                                  * is not relevant, since we are outside the face, Use VecLerpf to find
2682                                                                                  * our location on the side of the face's UV */
2683 #if 0
2684                                                                                 if (is_ortho) screen_px_from_ortho(ps, uv, v1co, v2co, v3co, uv1co, uv2co, uv3co, pixelScreenCo);
2685                                                                                 else          screen_px_from_persp(ps, uv, v1co, v2co, v3co, uv1co, uv2co, uv3co, pixelScreenCo);
2686 #endif
2687                                                                                 
2688                                                                                 /* Since this is a seam we need to work out where on the line this pixel is */
2689                                                                                 //fac = line_point_factor_v2(uv, uv_seam_quad[0], uv_seam_quad[1]);
2690                                                                                 
2691                                                                                 fac = line_point_factor_v2(uv, seam_subsection[0], seam_subsection[1]);
2692                                                                                 if      (fac < 0.0f) { copy_v3_v3(pixelScreenCo, edge_verts_inset_clip[0]); }
2693                                                                                 else if (fac > 1.0f) { copy_v3_v3(pixelScreenCo, edge_verts_inset_clip[1]); }
2694                                                                                 else                 { interp_v3_v3v3(pixelScreenCo, edge_verts_inset_clip[0], edge_verts_inset_clip[1], fac); }
2695                                                                                 
2696                                                                                 if (!is_ortho) {
2697                                                                                         pixelScreenCo[3] = 1.0f;
2698                                                                                         mul_m4_v4((float(*)[4])ps->projectMat, pixelScreenCo); /* cast because of const */
2699                                                                                         pixelScreenCo[0] = (float)(ps->winx / 2.0f) + (ps->winx / 2.0f) * pixelScreenCo[0] / pixelScreenCo[3];
2700                                                                                         pixelScreenCo[1] = (float)(ps->winy / 2.0f) + (ps->winy / 2.0f) * pixelScreenCo[1] / pixelScreenCo[3];
2701                                                                                         pixelScreenCo[2] = pixelScreenCo[2] / pixelScreenCo[3]; /* Use the depth for bucket point occlusion */
2702                                                                                 }
2703                                                                                 
2704                                                                                 if ((ps->do_occlude == FALSE) ||
2705                                                                                     !project_bucket_point_occluded(ps, bucketFaceNodes, face_index, pixelScreenCo))
2706                                                                                 {
2707                                                                                         /* Only bother calculating the weights if we intersect */
2708                                                                                         if (ps->do_mask_normal || ps->dm_mtface_clone) {
2709 #if 1
2710                                                                                                 /* get the UV on the line since we want to copy the pixels from there for bleeding */
2711                                                                                                 float uv_close[2];
2712                                                                                                 float uv_fac = closest_to_line_v2(uv_close, uv, tf_uv_pxoffset[fidx1], tf_uv_pxoffset[fidx2]);
2713                                                                                                 if      (uv_fac < 0.0f) copy_v2_v2(uv_close, tf_uv_pxoffset[fidx1]);
2714                                                                                                 else if (uv_fac > 1.0f) copy_v2_v2(uv_close, tf_uv_pxoffset[fidx2]);
2715
2716                                                                                                 if (side) {
2717                                                                                                         barycentric_weights_v2(tf_uv_pxoffset[0], tf_uv_pxoffset[2], tf_uv_pxoffset[3], uv_close, w);
2718                                                                                                 }
2719                                                                                                 else {
2720                                                                                                         barycentric_weights_v2(tf_uv_pxoffset[0], tf_uv_pxoffset[1], tf_uv_pxoffset[2], uv_close, w);
2721                                                                                                 }
2722 #else                                                                                   /* this is buggy with quads, don't use for now */
2723
2724                                                                                                 /* Cheat, we know where we are along the edge so work out the weights from that */
2725                                                                                                 uv_fac = fac1 + (uv_fac * (fac2 - fac1));
2726
2727                                                                                                 w[0] = w[1] = w[2] = 0.0;
2728                                                                                                 if (side) {
2729                                                                                                         w[fidx1 ? fidx1 - 1 : 0] = 1.0f - uv_fac;
2730                                                                                                         w[fidx2 ? fidx2 - 1 : 0] = uv_fac;
2731                                                                                                 }
2732                                                                                                 else {
2733                                                                                                         w[fidx1] = 1.0f - uv_fac;
2734                                                                                                         w[fidx2] = uv_fac;
2735                                                                                                 }
2736 #endif
2737                                                                                         }
2738                                                                                         
2739                                                                                         /* a pity we need to get the worldspace pixel location here */
2740                                                                                         if (do_clip || do_3d_mapping) {
2741                                                                                                 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);
2742                                                                                                 else      interp_v3_v3v3v3(wco, ps->dm_mvert[mf->v1].co, ps->dm_mvert[mf->v2].co, ps->dm_mvert[mf->v3].co, w);
2743
2744                                                                                                 if (do_clip && ED_view3d_clipping_test(ps->rv3d, wco, TRUE)) {
2745                                                                                                         continue; /* Watch out that no code below this needs to run */
2746                                                                                                 }
2747                                                                                         }
2748                                                                                         
2749                                                                                         mask = project_paint_uvpixel_mask(ps, face_index, side, w);
2750                                                                                         
2751                                                                                         if (mask > 0.0f) {
2752                                                                                                 BLI_linklist_prepend_arena(
2753                                                                                                         bucketPixelNodes,
2754                                                                                                         project_paint_uvpixel_init(ps, arena, ibuf, x, y, mask, face_index, image_index, pixelScreenCo, wco, side, w),
2755                                                                                                         arena
2756                                                                                                         );
2757                                                                                         }
2758                                                                                         
2759                                                                                 }
2760                                                                         }
2761                                                                         else if (has_x_isect) {
2762                                                                                 /* assuming the face is not a bow-tie - we know we cant intersect again on the X */
2763                                                                                 break;
2764                                                                         }
2765                                                                 }
2766                                                                 
2767 #if 0                           /* TODO - investigate why this dosnt work sometimes! it should! */
2768                                                                 /* no intersection for this entire row, after some intersection above means we can quit now */
2769                                                                 if (has_x_isect == 0 && has_isect) {
2770                                                                         break;
2771                                                                 }
2772 #endif
2773                                                         }
2774                                                 }
2775                                         }
2776                                 }
2777                         }
2778                 }
2779         }
2780 #endif // PROJ_DEBUG_NOSEAMBLEED
2781 }
2782
2783
2784 /* takes floating point screenspace min/max and returns int min/max to be used as indices for ps->bucketRect, ps->bucketFlags */
2785 static void project_paint_bucket_bounds(const ProjPaintState *ps, const float min[2], const float max[2], int bucketMin[2], int bucketMax[2])
2786 {
2787         /* divide by bucketWidth & bucketHeight so the bounds are offset in bucket grid units */
2788         /* 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 */
2789         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 */
2790         bucketMin[1] = (int)((int)(((float)(min[1] - ps->screenMin[1]) / ps->screen_height) * ps->buckets_y) + 0.5f);
2791         
2792         bucketMax[0] = (int)((int)(((float)(max[0] - ps->screenMin[0]) / ps->screen_width) * ps->buckets_x) + 1.5f);
2793         bucketMax[1] = (int)((int)(((float)(max[1] - ps->screenMin[1]) / ps->screen_height) * ps->buckets_y) + 1.5f);
2794         
2795         /* in case the rect is outside the mesh 2d bounds */
2796         CLAMP(bucketMin[0], 0, ps->buckets_x);
2797         CLAMP(bucketMin[1], 0, ps->buckets_y);
2798         
2799         CLAMP(bucketMax[0], 0, ps->buckets_x);
2800         CLAMP(bucketMax[1], 0, ps->buckets_y);
2801 }
2802
2803 /* set bucket_bounds to a screen space-aligned floating point bound-box */
2804 static void project_bucket_bounds(const ProjPaintState *ps, const int bucket_x, const int bucket_y, rctf *bucket_bounds)
2805 {
2806         bucket_bounds->xmin = ps->screenMin[0] + ((bucket_x) * (ps->screen_width / ps->buckets_x));     /* left */
2807         bucket_bounds->xmax = ps->screenMin[0] + ((bucket_x + 1) * (ps->screen_width / ps->buckets_x)); /* right */
2808         
2809         bucket_bounds->ymin = ps->screenMin[1] + ((bucket_y) * (ps->screen_height / ps->buckets_y));      /* bottom */
2810         bucket_bounds->ymax = ps->screenMin[1] + ((bucket_y + 1) * (ps->screen_height  / ps->buckets_y)); /* top */
2811 }
2812
2813 /* Fill this bucket with pixels from the faces that intersect it.
2814  * 
2815  * have bucket_bounds as an argument so we don't need to give bucket_x/y the rect function needs */
2816 static void project_bucket_init(const ProjPaintState *ps, const int thread_index, const int bucket_index, rctf *bucket_bounds)
2817 {
2818         LinkNode *node;
2819         int face_index, image_index = 0;
2820         ImBuf *ibuf = NULL;
2821         Image *tpage_last = NULL, *tpage;
2822         Image *ima = NULL;
2823
2824         if (ps->image_tot == 1) {
2825                 /* Simple loop, no context switching */
2826                 ibuf = ps->projImages[0].ibuf;
2827                 ima = ps->projImages[0].ima;
2828
2829                 for (node = ps->bucketFaces[bucket_index]; node; node = node->next) {
2830                         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);
2831                 }
2832         }
2833         else {
2834                 
2835                 /* More complicated loop, switch between images */
2836                 for (node = ps->bucketFaces[bucket_index]; node; node = node->next) {
2837                         face_index = GET_INT_FROM_POINTER(node->link);
2838                                 
2839                         /* Image context switching */
2840                         tpage = project_paint_face_image(ps, ps->dm_mtface, face_index);
2841                         if (tpage_last != tpage) {
2842                                 tpage_last = tpage;
2843
2844                                 for (image_index = 0; image_index < ps->image_tot; image_index++) {
2845                                         if (ps->projImages[image_index].ima == tpage_last) {
2846                                                 ibuf = ps->projImages[image_index].ibuf;
2847                                                 ima = ps->projImages[image_index].ima;
2848                                                 break;
2849                                         }
2850                                 }