fix [#32531] Texturepainting always uses smooth shaded normals
[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_dynstr.h"
46 #include "BLI_linklist.h"
47 #include "BLI_memarena.h"
48 #include "BLI_threads.h"
49 #include "BLI_utildefines.h"
50
51 #include "PIL_time.h"
52
53 #include "IMB_imbuf.h"
54 #include "IMB_imbuf_types.h"
55
56 #include "DNA_brush_types.h"
57 #include "DNA_camera_types.h"
58 #include "DNA_mesh_types.h"
59 #include "DNA_meshdata_types.h"
60 #include "DNA_node_types.h"
61 #include "DNA_object_types.h"
62 #include "DNA_scene_types.h"
63 #include "DNA_texture_types.h"
64
65 #include "BKE_camera.h"
66 #include "BKE_context.h"
67 #include "BKE_depsgraph.h"
68 #include "BKE_DerivedMesh.h"
69 #include "BKE_idprop.h"
70 #include "BKE_brush.h"
71 #include "BKE_image.h"
72 #include "BKE_library.h"
73 #include "BKE_main.h"
74 #include "BKE_mesh.h"
75 #include "BKE_node.h"
76 #include "BKE_object.h"
77 #include "BKE_paint.h"
78 #include "BKE_report.h"
79 #include "BKE_scene.h"
80 #include "BKE_global.h"
81 #include "BKE_deform.h"
82
83 #include "BKE_tessmesh.h"
84
85 #include "BIF_gl.h"
86 #include "BIF_glutil.h"
87
88 #include "UI_view2d.h"
89
90 #include "ED_image.h"
91 #include "ED_screen.h"
92 #include "ED_sculpt.h"
93 #include "ED_uvedit.h"
94 #include "ED_view3d.h"
95 #include "ED_mesh.h"
96
97 #include "WM_api.h"
98 #include "WM_types.h"
99
100 #include "RNA_access.h"
101 #include "RNA_define.h"
102 #include "RNA_enum_types.h"
103
104 #include "GPU_draw.h"
105 #include "GPU_extensions.h"
106
107 #include "paint_intern.h"
108
109 /* Defines and Structs */
110
111 #define IMAPAINT_CHAR_TO_FLOAT(c) ((c) / 255.0f)
112
113 #define IMAPAINT_FLOAT_RGB_TO_CHAR(c, f)  {                                   \
114         (c)[0]= FTOCHAR((f)[0]);                                                  \
115         (c)[1]= FTOCHAR((f)[1]);                                                  \
116         (c)[2]= FTOCHAR((f)[2]);                                                  \
117 } (void)0
118 #define IMAPAINT_FLOAT_RGBA_TO_CHAR(c, f)  {                                  \
119         (c)[0]= FTOCHAR((f)[0]);                                                  \
120         (c)[1]= FTOCHAR((f)[1]);                                                  \
121         (c)[2]= FTOCHAR((f)[2]);                                                  \
122         (c)[3]= FTOCHAR((f)[3]);                                                  \
123 } (void)0
124 #define IMAPAINT_CHAR_RGB_TO_FLOAT(f, c)  {                                   \
125         (f)[0]= IMAPAINT_CHAR_TO_FLOAT((c)[0]);                                   \
126         (f)[1]= IMAPAINT_CHAR_TO_FLOAT((c)[1]);                                   \
127         (f)[2]= IMAPAINT_CHAR_TO_FLOAT((c)[2]);                                   \
128 } (void)0
129 #define IMAPAINT_CHAR_RGBA_TO_FLOAT(f, c)  {                                  \
130         (f)[0]= IMAPAINT_CHAR_TO_FLOAT((c)[0]);                                   \
131         (f)[1]= IMAPAINT_CHAR_TO_FLOAT((c)[1]);                                   \
132         (f)[2]= IMAPAINT_CHAR_TO_FLOAT((c)[2]);                                   \
133         (f)[3]= IMAPAINT_CHAR_TO_FLOAT((c)[3]);                                   \
134 } (void)0
135
136 #define IMAPAINT_FLOAT_RGB_COPY(a, b) copy_v3_v3(a, b)
137
138 #define IMAPAINT_TILE_BITS          6
139 #define IMAPAINT_TILE_SIZE          (1 << IMAPAINT_TILE_BITS)
140 #define IMAPAINT_TILE_NUMBER(size)  (((size) + IMAPAINT_TILE_SIZE - 1) >> IMAPAINT_TILE_BITS)
141
142 static void imapaint_image_update(SpaceImage *sima, Image *image, ImBuf *ibuf, short texpaint);
143
144
145 typedef struct ImagePaintState {
146         SpaceImage *sima;
147         View2D *v2d;
148         Scene *scene;
149         bScreen *screen;
150
151         Brush *brush;
152         short tool, blend;
153         Image *image;
154         ImBuf *canvas;
155         ImBuf *clonecanvas;
156         short clonefreefloat;
157         char *warnpackedfile;
158         char *warnmultifile;
159
160         /* viewport texture paint only, but _not_ project paint */
161         Object *ob;
162         int faceindex;
163         float uv[2];
164         int do_facesel;
165
166         DerivedMesh    *dm;
167         int             dm_totface;
168         int             dm_release;
169
170         MFace          *dm_mface;
171         MTFace         *dm_mtface;
172 } ImagePaintState;
173
174 typedef struct ImagePaintPartialRedraw {
175         int x1, y1, x2, y2;
176         int enabled;
177 } ImagePaintPartialRedraw;
178
179 typedef struct ImagePaintRegion {
180         int destx, desty;
181         int srcx, srcy;
182         int width, height;
183 } ImagePaintRegion;
184
185 /* ProjectionPaint defines */
186
187 /* approx the number of buckets to have under the brush,
188  * used with the brush size to set the ps->buckets_x and ps->buckets_y value.
189  * 
190  * When 3 - a brush should have ~9 buckets under it at once
191  * ...this helps for threading while painting as well as
192  * avoiding initializing pixels that wont touch the brush */
193 #define PROJ_BUCKET_BRUSH_DIV 4
194
195 #define PROJ_BUCKET_RECT_MIN 4
196 #define PROJ_BUCKET_RECT_MAX 256
197
198 #define PROJ_BOUNDBOX_DIV 8
199 #define PROJ_BOUNDBOX_SQUARED  (PROJ_BOUNDBOX_DIV * PROJ_BOUNDBOX_DIV)
200
201 //#define PROJ_DEBUG_PAINT 1
202 //#define PROJ_DEBUG_NOSEAMBLEED 1
203 //#define PROJ_DEBUG_PRINT_CLIP 1
204 #define PROJ_DEBUG_WINCLIP 1
205
206 /* projectFaceSeamFlags options */
207 //#define PROJ_FACE_IGNORE      (1<<0)  /* When the face is hidden, backfacing or occluded */
208 //#define PROJ_FACE_INIT        (1<<1)  /* When we have initialized the faces data */
209 #define PROJ_FACE_SEAM1 (1 << 0)  /* If this face has a seam on any of its edges */
210 #define PROJ_FACE_SEAM2 (1 << 1)
211 #define PROJ_FACE_SEAM3 (1 << 2)
212 #define PROJ_FACE_SEAM4 (1 << 3)
213
214 #define PROJ_FACE_NOSEAM1   (1 << 4)
215 #define PROJ_FACE_NOSEAM2   (1 << 5)
216 #define PROJ_FACE_NOSEAM3   (1 << 6)
217 #define PROJ_FACE_NOSEAM4   (1 << 7)
218
219 #define PROJ_SRC_VIEW       1
220 #define PROJ_SRC_IMAGE_CAM  2
221 #define PROJ_SRC_IMAGE_VIEW 3
222
223 #define PROJ_VIEW_DATA_ID "view_data"
224 #define PROJ_VIEW_DATA_SIZE (4 * 4 + 4 * 4 + 3) /* viewmat + winmat + clipsta + clipend + is_ortho */
225
226
227 /* a slightly scaled down face is used to get fake 3D location for edge pixels in the seams
228  * as this number approaches  1.0f the likelihood increases of float precision errors where
229  * it is occluded by an adjacent face */
230 #define PROJ_FACE_SCALE_SEAM    0.99f
231
232 #define PROJ_BUCKET_NULL        0
233 #define PROJ_BUCKET_INIT        (1 << 0)
234 // #define PROJ_BUCKET_CLONE_INIT       (1<<1)
235
236 /* used for testing doubles, if a point is on a line etc */
237 #define PROJ_GEOM_TOLERANCE 0.00075f
238
239 /* vert flags */
240 #define PROJ_VERT_CULL 1
241
242 #define PI_80_DEG ((M_PI_2 / 9) * 8)
243
244 /* This is mainly a convenience struct used so we can keep an array of images we use
245  * Thir imbufs, etc, in 1 array, When using threads this array is copied for each thread
246  * because 'partRedrawRect' and 'touch' values would not be thread safe */
247 typedef struct ProjPaintImage {
248         Image *ima;
249         ImBuf *ibuf;
250         ImagePaintPartialRedraw *partRedrawRect;
251         void **undoRect; /* only used to build undo tiles after painting */
252         int touch;
253 } ProjPaintImage;
254
255 /* Main projection painting struct passed to all projection painting functions */
256 typedef struct ProjPaintState {
257         View3D *v3d;
258         RegionView3D *rv3d;
259         ARegion *ar;
260         Scene *scene;
261         int source; /* PROJ_SRC_**** */
262
263         Brush *brush;
264         short tool, blend;
265         Object *ob;
266         /* end similarities with ImagePaintState */
267         
268         DerivedMesh    *dm;
269         int dm_totface;
270         int dm_totvert;
271         int dm_release;
272
273         MVert          *dm_mvert;
274         MFace          *dm_mface;
275         MTFace         *dm_mtface;
276         MTFace         *dm_mtface_clone;    /* other UV map, use for cloning between layers */
277         MTFace         *dm_mtface_stencil;
278         
279         /* projection painting only */
280         MemArena *arena_mt[BLENDER_MAX_THREADS]; /* for multithreading, the first item is sometimes used for non threaded cases too */
281         LinkNode **bucketRect;              /* screen sized 2D array, each pixel has a linked list of ProjPixel's */
282         LinkNode **bucketFaces;             /* bucketRect aligned array linkList of faces overlapping each bucket */
283         unsigned char *bucketFlags;         /* store if the bucks have been initialized  */
284 #ifndef PROJ_DEBUG_NOSEAMBLEED
285         char *faceSeamFlags;                /* store info about faces, if they are initialized etc*/
286         float (*faceSeamUVs)[4][2];         /* expanded UVs for faces to use as seams */
287         LinkNode **vertFaces;               /* Only needed for when seam_bleed_px is enabled, use to find UV seams */
288 #endif
289         char *vertFlags;                    /* store options per vert, now only store if the vert is pointing away from the view */
290         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 */
291         int buckets_y;
292         
293         ProjPaintImage *projImages;
294         
295         int image_tot;              /* size of projectImages array */
296         
297         float (*screenCoords)[4];   /* verts projected into floating point screen space */
298         
299         float screenMin[2];         /* 2D bounds for mesh verts on the screen's plane (screenspace) */
300         float screenMax[2]; 
301         float screen_width;         /* Calculated from screenMin & screenMax */
302         float screen_height;
303         int winx, winy;             /* from the carea or from the projection render */
304         
305         /* options for projection painting */
306         int do_layer_clone;
307         int do_layer_stencil;
308         int do_layer_stencil_inv;
309         
310         short do_occlude;               /* Use raytraced occlusion? - ortherwise will paint right through to the back*/
311         short do_backfacecull;          /* ignore faces with normals pointing away, skips a lot of raycasts if your normals are correctly flipped */
312         short do_mask_normal;           /* mask out pixels based on their normals */
313         short do_new_shading_nodes;     /* cache BKE_scene_use_new_shading_nodes value */
314         float normal_angle;             /* what angle to mask at*/
315         float normal_angle_inner;
316         float normal_angle_range;       /* difference between normal_angle and normal_angle_inner, for easy access */
317         
318         short is_ortho;
319         short is_airbrush;              /* only to avoid using (ps.brush->flag & BRUSH_AIRBRUSH) */
320         short is_texbrush;              /* only to avoid running  */
321 #ifndef PROJ_DEBUG_NOSEAMBLEED
322         float seam_bleed_px;
323 #endif
324         /* clone vars */
325         float cloneOffset[2];
326         
327         float projectMat[4][4];     /* Projection matrix, use for getting screen coords */
328         float viewDir[3];           /* View vector, use for do_backfacecull and for ray casting with an ortho viewport  */
329         float viewPos[3];           /* View location in object relative 3D space, so can compare to verts  */
330         float clipsta, clipend;
331         
332         /* reproject vars */
333         Image *reproject_image;
334         ImBuf *reproject_ibuf;
335
336
337         /* threads */
338         int thread_tot;
339         int bucketMin[2];
340         int bucketMax[2];
341         int context_bucket_x, context_bucket_y; /* must lock threads while accessing these */
342 } ProjPaintState;
343
344 typedef union pixelPointer {
345         float *f_pt;            /* float buffer */
346         unsigned int *uint_pt; /* 2 ways to access a char buffer */
347         unsigned char *ch_pt;
348 } PixelPointer;
349
350 typedef union pixelStore {
351         unsigned char ch[4];
352         unsigned int uint;
353         float f[4];
354 } PixelStore;
355
356 typedef struct ProjPixel {
357         float projCoSS[2]; /* the floating point screen projection of this pixel */
358         
359         /* Only used when the airbrush is disabled.
360          * Store the max mask value to avoid painting over an area with a lower opacity
361          * with an advantage that we can avoid touching the pixel at all, if the 
362          * new mask value is lower then mask_max */
363         unsigned short mask_max;
364         
365         /* for various reasons we may want to mask out painting onto this pixel */
366         unsigned short mask;
367         
368         short x_px, y_px;
369         
370         PixelStore origColor;
371         PixelStore newColor;
372         PixelPointer pixel;
373         
374         short image_index; /* if anyone wants to paint onto more then 32768 images they can bite me */
375         unsigned char bb_cell_index;
376 } ProjPixel;
377
378 typedef struct ProjPixelClone {
379         struct ProjPixel __pp;
380         PixelStore clonepx;
381 } ProjPixelClone;
382
383 /* Finish projection painting structs */
384
385 typedef struct UndoImageTile {
386         struct UndoImageTile *next, *prev;
387
388         char idname[MAX_ID_NAME];  /* name instead of pointer*/
389         char ibufname[IB_FILENAME_SIZE];
390
391         union {
392                 float        *fp;
393                 unsigned int *uint;
394                 void         *pt;
395         } rect;
396         int x, y;
397
398         short source, use_float;
399         char gen_type;
400 } UndoImageTile;
401
402 static ImagePaintPartialRedraw imapaintpartial = {0, 0, 0, 0, 0};
403
404 /* UNDO */
405
406 static void undo_copy_tile(UndoImageTile *tile, ImBuf *tmpibuf, ImBuf *ibuf, int restore)
407 {
408         /* copy or swap contents of tile->rect and region in ibuf->rect */
409         IMB_rectcpy(tmpibuf, ibuf, 0, 0, tile->x * IMAPAINT_TILE_SIZE,
410                     tile->y * IMAPAINT_TILE_SIZE, IMAPAINT_TILE_SIZE, IMAPAINT_TILE_SIZE);
411
412         if (ibuf->rect_float) {
413                 SWAP(float *, tmpibuf->rect_float, tile->rect.fp);
414         }
415         else {
416                 SWAP(unsigned int *, tmpibuf->rect, tile->rect.uint);
417         }
418         
419         if (restore)
420                 IMB_rectcpy(ibuf, tmpibuf, tile->x * IMAPAINT_TILE_SIZE,
421                             tile->y * IMAPAINT_TILE_SIZE, 0, 0, IMAPAINT_TILE_SIZE, IMAPAINT_TILE_SIZE);
422 }
423
424 static void *image_undo_push_tile(Image *ima, ImBuf *ibuf, ImBuf **tmpibuf, int x_tile, int y_tile)
425 {
426         ListBase *lb = undo_paint_push_get_list(UNDO_PAINT_IMAGE);
427         UndoImageTile *tile;
428         int allocsize;
429         short use_float = ibuf->rect_float ? 1 : 0;
430
431         for (tile = lb->first; tile; tile = tile->next)
432                 if (tile->x == x_tile && tile->y == y_tile && ima->gen_type == tile->gen_type && ima->source == tile->source)
433                         if (tile->use_float == use_float)
434                                 if (strcmp(tile->idname, ima->id.name) == 0 && strcmp(tile->ibufname, ibuf->name) == 0)
435                                         return tile->rect.pt;
436         
437         if (*tmpibuf == NULL)
438                 *tmpibuf = IMB_allocImBuf(IMAPAINT_TILE_SIZE, IMAPAINT_TILE_SIZE, 32, IB_rectfloat | IB_rect);
439         
440         tile = MEM_callocN(sizeof(UndoImageTile), "UndoImageTile");
441         BLI_strncpy(tile->idname, ima->id.name, sizeof(tile->idname));
442         tile->x = x_tile;
443         tile->y = y_tile;
444
445         allocsize = IMAPAINT_TILE_SIZE * IMAPAINT_TILE_SIZE * 4;
446         allocsize *= (ibuf->rect_float) ? sizeof(float) : sizeof(char);
447         tile->rect.pt = MEM_mapallocN(allocsize, "UndeImageTile.rect");
448
449         BLI_strncpy(tile->ibufname, ibuf->name, sizeof(tile->ibufname));
450
451         tile->gen_type = ima->gen_type;
452         tile->source = ima->source;
453         tile->use_float = use_float;
454
455         undo_copy_tile(tile, *tmpibuf, ibuf, 0);
456         undo_paint_push_count_alloc(UNDO_PAINT_IMAGE, allocsize);
457
458         BLI_addtail(lb, tile);
459         
460         return tile->rect.pt;
461 }
462
463 static void image_undo_restore(bContext *C, ListBase *lb)
464 {
465         Main *bmain = CTX_data_main(C);
466         Image *ima = NULL;
467         ImBuf *ibuf, *tmpibuf;
468         UndoImageTile *tile;
469
470         tmpibuf = IMB_allocImBuf(IMAPAINT_TILE_SIZE, IMAPAINT_TILE_SIZE, 32,
471                                  IB_rectfloat | IB_rect);
472         
473         for (tile = lb->first; tile; tile = tile->next) {
474                 short use_float;
475
476                 /* find image based on name, pointer becomes invalid with global undo */
477                 if (ima && strcmp(tile->idname, ima->id.name) == 0) {
478                         /* ima is valid */
479                 }
480                 else {
481                         ima = BLI_findstring(&bmain->image, tile->idname, offsetof(ID, name));
482                 }
483
484                 ibuf = BKE_image_get_ibuf(ima, NULL);
485
486                 if (ima && ibuf && strcmp(tile->ibufname, ibuf->name) != 0) {
487                         /* current ImBuf filename was changed, probably current frame
488                          * was changed when paiting on image sequence, rather than storing
489                          * full image user (which isn't so obvious, btw) try to find ImBuf with
490                          * matched file name in list of already loaded images */
491
492                         ibuf = BLI_findstring(&ima->ibufs, tile->ibufname, offsetof(ImBuf, name));
493                 }
494
495                 if (!ima || !ibuf || !(ibuf->rect || ibuf->rect_float))
496                         continue;
497
498                 if (ima->gen_type != tile->gen_type || ima->source != tile->source)
499                         continue;
500
501                 use_float = ibuf->rect_float ? 1 : 0;
502
503                 if (use_float != tile->use_float)
504                         continue;
505
506                 undo_copy_tile(tile, tmpibuf, ibuf, 1);
507
508                 GPU_free_image(ima); /* force OpenGL reload */
509                 if (ibuf->rect_float)
510                         ibuf->userflags |= IB_RECT_INVALID; /* force recreate of char rect */
511                 if (ibuf->mipmap[0])
512                         ibuf->userflags |= IB_MIPMAP_INVALID;  /* force mipmap recreatiom */
513
514         }
515
516         IMB_freeImBuf(tmpibuf);
517 }
518
519 static void image_undo_free(ListBase *lb)
520 {
521         UndoImageTile *tile;
522
523         for (tile = lb->first; tile; tile = tile->next)
524                 MEM_freeN(tile->rect.pt);
525 }
526
527 /* get active image for face depending on old/new shading system */
528
529 static Image *imapaint_face_image(const ImagePaintState *s, int face_index)
530 {
531         Image *ima;
532
533         if (BKE_scene_use_new_shading_nodes(s->scene)) {
534                 MFace *mf = &s->dm_mface[face_index];
535                 ED_object_get_active_image(s->ob, mf->mat_nr + 1, &ima, NULL, NULL);
536         }
537         else {
538                 MTFace *tf = &s->dm_mtface[face_index];
539                 ima = tf->tpage;
540         }
541
542         return ima;
543 }
544
545 static Image *project_paint_face_image(const ProjPaintState *ps, MTFace *dm_mtface, int face_index)
546 {
547         Image *ima;
548
549         if (ps->do_new_shading_nodes) { /* cached BKE_scene_use_new_shading_nodes result */
550                 MFace *mf = ps->dm_mface + face_index;
551                 ED_object_get_active_image(ps->ob, mf->mat_nr + 1, &ima, NULL, NULL);
552         }
553         else {
554                 ima = dm_mtface[face_index].tpage;
555         }
556
557         return ima;
558 }
559
560 /* fast projection bucket array lookup, use the safe version for bound checking  */
561 static int project_bucket_offset(const ProjPaintState *ps, const float projCoSS[2])
562 {
563         /* If we were not dealing with screenspace 2D coords we could simple do...
564          * ps->bucketRect[x + (y*ps->buckets_y)] */
565         
566         /* please explain?
567          * projCoSS[0] - ps->screenMin[0]   : zero origin
568          * ... / ps->screen_width           : range from 0.0 to 1.0
569          * ... * ps->buckets_x              : use as a bucket index
570          *
571          * Second multiplication does similar but for vertical offset
572          */
573         return ( (int)(((projCoSS[0] - ps->screenMin[0]) / ps->screen_width)  * ps->buckets_x)) +
574                (((int)(((projCoSS[1] - ps->screenMin[1]) / ps->screen_height) * ps->buckets_y)) * ps->buckets_x);
575 }
576
577 static int project_bucket_offset_safe(const ProjPaintState *ps, const float projCoSS[2])
578 {
579         int bucket_index = project_bucket_offset(ps, projCoSS);
580         
581         if (bucket_index < 0 || bucket_index >= ps->buckets_x * ps->buckets_y) {
582                 return -1;
583         }
584         else {
585                 return bucket_index;
586         }
587 }
588
589 /* still use 2D X,Y space but this works for verts transformed by a perspective matrix, using their 4th component as a weight */
590 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])
591 {
592         float wtot_inv, wtot;
593
594         w[0] = area_tri_signed_v2(v2, v3, co) / v1[3];
595         w[1] = area_tri_signed_v2(v3, v1, co) / v2[3];
596         w[2] = area_tri_signed_v2(v1, v2, co) / v3[3];
597         wtot = w[0] + w[1] + w[2];
598
599         if (wtot != 0.0f) {
600                 wtot_inv = 1.0f / wtot;
601
602                 w[0] = w[0] * wtot_inv;
603                 w[1] = w[1] * wtot_inv;
604                 w[2] = w[2] * wtot_inv;
605         }
606         else /* dummy values for zero area face */
607                 w[0] = w[1] = w[2] = 1.0f / 3.0f;
608 }
609
610 static float VecZDepthOrtho(const float pt[2],
611                             const float v1[3], const float v2[3], const float v3[3],
612                             float w[3])
613 {
614         barycentric_weights_v2(v1, v2, v3, pt, w);
615         return (v1[2] * w[0]) + (v2[2] * w[1]) + (v3[2] * w[2]);
616 }
617
618 static float VecZDepthPersp(const float pt[2],
619                             const float v1[4], const float v2[4], const float v3[4],
620                             float w[3])
621 {
622         float wtot_inv, wtot;
623         float w_tmp[3];
624
625         barycentric_weights_v2_persp(v1, v2, v3, pt, w);
626         /* for the depth we need the weights to match what
627          * barycentric_weights_v2 would return, in this case its easiest just to
628          * undo the 4th axis division and make it unit-sum
629          *
630          * don't call barycentric_weights_v2() becaue our callers expect 'w'
631          * to be weighted from the perspective */
632         w_tmp[0] = w[0] * v1[3];
633         w_tmp[1] = w[1] * v2[3];
634         w_tmp[2] = w[2] * v3[3];
635
636         wtot = w_tmp[0] + w_tmp[1] + w_tmp[2];
637
638         if (wtot != 0.0f) {
639                 wtot_inv = 1.0f / wtot;
640
641                 w_tmp[0] = w_tmp[0] * wtot_inv;
642                 w_tmp[1] = w_tmp[1] * wtot_inv;
643                 w_tmp[2] = w_tmp[2] * wtot_inv;
644         }
645         else /* dummy values for zero area face */
646                 w_tmp[0] = w_tmp[1] = w_tmp[2] = 1.0f / 3.0f;
647         /* done mimicing barycentric_weights_v2() */
648
649         return (v1[2] * w_tmp[0]) + (v2[2] * w_tmp[1]) + (v3[2] * w_tmp[2]);
650 }
651
652
653 /* Return the top-most face index that the screen space coord 'pt' touches (or -1) */
654 static int project_paint_PickFace(const ProjPaintState *ps, float pt[2], float w[3], int *side)
655 {
656         LinkNode *node;
657         float w_tmp[3];
658         float *v1, *v2, *v3, *v4;
659         int bucket_index;
660         int face_index;
661         int best_side = -1;
662         int best_face_index = -1;
663         float z_depth_best = FLT_MAX, z_depth;
664         MFace *mf;
665         
666         bucket_index = project_bucket_offset_safe(ps, pt);
667         if (bucket_index == -1)
668                 return -1;
669         
670         
671         
672         /* we could return 0 for 1 face buckets, as long as this function assumes
673          * that the point its testing is only every originated from an existing face */
674         
675         for (node = ps->bucketFaces[bucket_index]; node; node = node->next) {
676                 face_index = GET_INT_FROM_POINTER(node->link);
677                 mf = ps->dm_mface + face_index;
678                 
679                 v1 = ps->screenCoords[mf->v1];
680                 v2 = ps->screenCoords[mf->v2];
681                 v3 = ps->screenCoords[mf->v3];
682                 
683                 if (isect_point_tri_v2(pt, v1, v2, v3)) {
684                         if (ps->is_ortho) z_depth = VecZDepthOrtho(pt, v1, v2, v3, w_tmp);
685                         else z_depth = VecZDepthPersp(pt, v1, v2, v3, w_tmp);
686                         
687                         if (z_depth < z_depth_best) {
688                                 best_face_index = face_index;
689                                 best_side = 0;
690                                 z_depth_best = z_depth;
691                                 copy_v3_v3(w, w_tmp);
692                         }
693                 }
694                 else if (mf->v4) {
695                         v4 = ps->screenCoords[mf->v4];
696                         
697                         if (isect_point_tri_v2(pt, v1, v3, v4)) {
698                                 if (ps->is_ortho) z_depth = VecZDepthOrtho(pt, v1, v3, v4, w_tmp);
699                                 else z_depth = VecZDepthPersp(pt, v1, v3, v4, w_tmp);
700
701                                 if (z_depth < z_depth_best) {
702                                         best_face_index = face_index;
703                                         best_side = 1;
704                                         z_depth_best = z_depth;
705                                         copy_v3_v3(w, w_tmp);
706                                 }
707                         }
708                 }
709         }
710         
711         *side = best_side;
712         return best_face_index; /* will be -1 or a valid face */
713 }
714
715 /* Converts a uv coord into a pixel location wrapping if the uv is outside 0-1 range */
716 static void uvco_to_wrapped_pxco(float uv[2], int ibuf_x, int ibuf_y, float *x, float *y)
717 {
718         /* use */
719         *x = (float)fmodf(uv[0], 1.0f);
720         *y = (float)fmodf(uv[1], 1.0f);
721         
722         if (*x < 0.0f) *x += 1.0f;
723         if (*y < 0.0f) *y += 1.0f;
724         
725         *x = *x * ibuf_x - 0.5f;
726         *y = *y * ibuf_y - 0.5f;
727 }
728
729 /* Set the top-most face color that the screen space coord 'pt' touches (or return 0 if none touch) */
730 static int project_paint_PickColor(const ProjPaintState *ps, float pt[2], float *rgba_fp, unsigned char *rgba, const int interp)
731 {
732         float w[3], uv[2];
733         int side;
734         int face_index;
735         MTFace *tf;
736         Image *ima;
737         ImBuf *ibuf;
738         int xi, yi;
739         
740         
741         face_index = project_paint_PickFace(ps, pt, w, &side);
742         
743         if (face_index == -1)
744                 return 0;
745         
746         tf = ps->dm_mtface + face_index;
747         
748         if (side == 0) {
749                 interp_v2_v2v2v2(uv, tf->uv[0], tf->uv[1], tf->uv[2], w);
750         }
751         else { /* QUAD */
752                 interp_v2_v2v2v2(uv, tf->uv[0], tf->uv[2], tf->uv[3], w);
753         }
754
755         ima = project_paint_face_image(ps, ps->dm_mtface, face_index);
756         ibuf = ima->ibufs.first; /* we must have got the imbuf before getting here */
757         if (!ibuf) return 0;
758         
759         if (interp) {
760                 float x, y;
761                 uvco_to_wrapped_pxco(uv, ibuf->x, ibuf->y, &x, &y);
762                 
763                 if (ibuf->rect_float) {
764                         if (rgba_fp) {
765                                 bilinear_interpolation_color_wrap(ibuf, NULL, rgba_fp, x, y);
766                         }
767                         else {
768                                 float rgba_tmp_f[4];
769                                 bilinear_interpolation_color_wrap(ibuf, NULL, rgba_tmp_f, x, y);
770                                 IMAPAINT_FLOAT_RGBA_TO_CHAR(rgba, rgba_tmp_f);
771                         }
772                 }
773                 else {
774                         if (rgba) {
775                                 bilinear_interpolation_color_wrap(ibuf, rgba, NULL, x, y);
776                         }
777                         else {
778                                 unsigned char rgba_tmp[4];
779                                 bilinear_interpolation_color_wrap(ibuf, rgba_tmp, NULL, x, y);
780                                 IMAPAINT_CHAR_RGBA_TO_FLOAT(rgba_fp, rgba_tmp);
781                         }
782                 }
783         }
784         else {
785                 //xi = (int)((uv[0]*ibuf->x) + 0.5f);
786                 //yi = (int)((uv[1]*ibuf->y) + 0.5f);
787                 //if (xi<0 || xi>=ibuf->x  ||  yi<0 || yi>=ibuf->y) return 0;
788                 
789                 /* wrap */
790                 xi = ((int)(uv[0] * ibuf->x)) % ibuf->x;
791                 if (xi < 0) xi += ibuf->x;
792                 yi = ((int)(uv[1] * ibuf->y)) % ibuf->y;
793                 if (yi < 0) yi += ibuf->y;
794                 
795                 
796                 if (rgba) {
797                         if (ibuf->rect_float) {
798                                 float *rgba_tmp_fp = ibuf->rect_float + (xi + yi * ibuf->x * 4);
799                                 IMAPAINT_FLOAT_RGBA_TO_CHAR(rgba, rgba_tmp_fp);
800                         }
801                         else {
802                                 *((unsigned int *)rgba) = *(unsigned int *)(((char *)ibuf->rect) + ((xi + yi * ibuf->x) * 4));
803                         }
804                 }
805                 
806                 if (rgba_fp) {
807                         if (ibuf->rect_float) {
808                                 copy_v4_v4(rgba_fp, (ibuf->rect_float + ((xi + yi * ibuf->x) * 4)));
809                         }
810                         else {
811                                 char *tmp_ch = ((char *)ibuf->rect) + ((xi + yi * ibuf->x) * 4);
812                                 IMAPAINT_CHAR_RGBA_TO_FLOAT(rgba_fp, tmp_ch);
813                         }
814                 }
815         }
816         return 1;
817 }
818
819 /* Check if 'pt' is infront of the 3 verts on the Z axis (used for screenspace occlusuion test)
820  * return...
821  *  0   : no occlusion
822  * -1   : no occlusion but 2D intersection is true (avoid testing the other half of a quad)
823  *  1   : occluded
824  *  2   : occluded with w[3] weights set (need to know in some cases) */
825
826 static int project_paint_occlude_ptv(float pt[3], float v1[4], float v2[4], float v3[4], float w[3], int is_ortho)
827 {
828         /* if all are behind us, return false */
829         if (v1[2] > pt[2] && v2[2] > pt[2] && v3[2] > pt[2])
830                 return 0;
831                 
832         /* do a 2D point in try intersection */
833         if (!isect_point_tri_v2(pt, v1, v2, v3))
834                 return 0;  /* we know there is  */
835         
836
837         /* From here on we know there IS an intersection */
838         /* if ALL of the verts are infront of us then we know it intersects ? */
839         if (v1[2] < pt[2] && v2[2] < pt[2] && v3[2] < pt[2]) {
840                 return 1;
841         }
842         else {
843                 /* we intersect? - find the exact depth at the point of intersection */
844                 /* Is this point is occluded by another face? */
845                 if (is_ortho) {
846                         if (VecZDepthOrtho(pt, v1, v2, v3, w) < pt[2]) return 2;
847                 }
848                 else {
849                         if (VecZDepthPersp(pt, v1, v2, v3, w) < pt[2]) return 2;
850                 }
851         }
852         return -1;
853 }
854
855
856 static int project_paint_occlude_ptv_clip(const ProjPaintState *ps, const MFace *mf,
857                                           float pt[3], float v1[4], float v2[4], float v3[4],
858                                           const int side)
859 {
860         float w[3], wco[3];
861         int ret = project_paint_occlude_ptv(pt, v1, v2, v3, w, ps->is_ortho);
862
863         if (ret <= 0)
864                 return ret;
865
866         if (ret == 1) { /* weights not calculated */
867                 if (ps->is_ortho) barycentric_weights_v2(v1, v2, v3, pt, w);
868                 else barycentric_weights_v2_persp(v1, v2, v3, pt, w);
869         }
870
871         /* Test if we're in the clipped area, */
872         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);
873         else interp_v3_v3v3v3(wco, ps->dm_mvert[mf->v1].co, ps->dm_mvert[mf->v2].co, ps->dm_mvert[mf->v3].co, w);
874         
875         if (!ED_view3d_clipping_test(ps->rv3d, wco, TRUE)) {
876                 return 1;
877         }
878         
879         return -1;
880 }
881
882
883 /* Check if a screenspace location is occluded by any other faces
884  * check, pixelScreenCo must be in screenspace, its Z-Depth only needs to be used for comparison
885  * and dosn't need to be correct in relation to X and Y coords (this is the case in perspective view) */
886 static int project_bucket_point_occluded(const ProjPaintState *ps, LinkNode *bucketFace, const int orig_face, float pixelScreenCo[4])
887 {
888         MFace *mf;
889         int face_index;
890         int isect_ret;
891         float w[3]; /* not needed when clipping */
892         const short do_clip = ps->rv3d ? ps->rv3d->rflag & RV3D_CLIPPING : 0;
893         
894         /* we could return 0 for 1 face buckets, as long as this function assumes
895          * that the point its testing is only every originated from an existing face */
896
897         for (; bucketFace; bucketFace = bucketFace->next) {
898                 face_index = GET_INT_FROM_POINTER(bucketFace->link);
899
900                 if (orig_face != face_index) {
901                         mf = ps->dm_mface + face_index;
902                         if (do_clip)
903                                 isect_ret = project_paint_occlude_ptv_clip(ps, mf, pixelScreenCo, ps->screenCoords[mf->v1], ps->screenCoords[mf->v2], ps->screenCoords[mf->v3], 0);
904                         else
905                                 isect_ret = project_paint_occlude_ptv(pixelScreenCo, ps->screenCoords[mf->v1], ps->screenCoords[mf->v2], ps->screenCoords[mf->v3], w, ps->is_ortho);
906
907                         /* Note, if isect_ret==-1 then we don't want to test the other side of the quad */
908                         if (isect_ret == 0 && mf->v4) {
909                                 if (do_clip)
910                                         isect_ret = project_paint_occlude_ptv_clip(ps, mf, pixelScreenCo, ps->screenCoords[mf->v1], ps->screenCoords[mf->v3], ps->screenCoords[mf->v4], 1);
911                                 else
912                                         isect_ret = project_paint_occlude_ptv(pixelScreenCo, ps->screenCoords[mf->v1], ps->screenCoords[mf->v3], ps->screenCoords[mf->v4], w, ps->is_ortho);
913                         }
914                         if (isect_ret >= 1) {
915                                 /* TODO - we may want to cache the first hit,
916                                  * it is not possible to swap the face order in the list anymore */
917                                 return 1;
918                         }
919                 }
920         }
921         return 0;
922 }
923
924 /* basic line intersection, could move to math_geom.c, 2 points with a horiz line
925  * 1 for an intersection, 2 if the first point is aligned, 3 if the second point is aligned */
926 #define ISECT_TRUE 1
927 #define ISECT_TRUE_P1 2
928 #define ISECT_TRUE_P2 3
929 static int line_isect_y(const float p1[2], const float p2[2], const float y_level, float *x_isect)
930 {
931         float y_diff;
932         
933         if (y_level == p1[1]) { /* are we touching the first point? - no interpolation needed */
934                 *x_isect = p1[0];
935                 return ISECT_TRUE_P1;
936         }
937         if (y_level == p2[1]) { /* are we touching the second point? - no interpolation needed */
938                 *x_isect = p2[0];
939                 return ISECT_TRUE_P2;
940         }
941         
942         y_diff = fabsf(p1[1] - p2[1]); /* yuck, horizontal line, we cant do much here */
943         
944         if (y_diff < 0.000001f) {
945                 *x_isect = (p1[0] + p2[0]) * 0.5f;
946                 return ISECT_TRUE;              
947         }
948         
949         if (p1[1] > y_level && p2[1] < y_level) {
950                 *x_isect = (p2[0] * (p1[1] - y_level) + p1[0] * (y_level - p2[1])) / y_diff;  /*(p1[1]-p2[1]);*/
951                 return ISECT_TRUE;
952         }
953         else if (p1[1] < y_level && p2[1] > y_level) {
954                 *x_isect = (p2[0] * (y_level - p1[1]) + p1[0] * (p2[1] - y_level)) / y_diff;  /*(p2[1]-p1[1]);*/
955                 return ISECT_TRUE;
956         }
957         else {
958                 return 0;
959         }
960 }
961
962 static int line_isect_x(const float p1[2], const float p2[2], const float x_level, float *y_isect)
963 {
964         float x_diff;
965         
966         if (x_level == p1[0]) { /* are we touching the first point? - no interpolation needed */
967                 *y_isect = p1[1];
968                 return ISECT_TRUE_P1;
969         }
970         if (x_level == p2[0]) { /* are we touching the second point? - no interpolation needed */
971                 *y_isect = p2[1];
972                 return ISECT_TRUE_P2;
973         }
974         
975         x_diff = fabsf(p1[0] - p2[0]); /* yuck, horizontal line, we cant do much here */
976         
977         if (x_diff < 0.000001f) { /* yuck, vertical line, we cant do much here */
978                 *y_isect = (p1[0] + p2[0]) * 0.5f;
979                 return ISECT_TRUE;              
980         }
981         
982         if (p1[0] > x_level && p2[0] < x_level) {
983                 *y_isect = (p2[1] * (p1[0] - x_level) + p1[1] * (x_level - p2[0])) / x_diff; /*(p1[0]-p2[0]);*/
984                 return ISECT_TRUE;
985         }
986         else if (p1[0] < x_level && p2[0] > x_level) {
987                 *y_isect = (p2[1] * (x_level - p1[0]) + p1[1] * (p2[0] - x_level)) / x_diff; /*(p2[0]-p1[0]);*/
988                 return ISECT_TRUE;
989         }
990         else {
991                 return 0;
992         }
993 }
994
995 /* simple func use for comparing UV locations to check if there are seams.
996  * Its possible this gives incorrect results, when the UVs for 1 face go into the next 
997  * tile, but do not do this for the adjacent face, it could return a false positive.
998  * This is so unlikely that Id not worry about it. */
999 #ifndef PROJ_DEBUG_NOSEAMBLEED
1000 static int cmp_uv(const float vec2a[2], const float vec2b[2])
1001 {
1002         /* if the UV's are not between 0.0 and 1.0 */
1003         float xa = (float)fmodf(vec2a[0], 1.0f);
1004         float ya = (float)fmodf(vec2a[1], 1.0f);
1005         
1006         float xb = (float)fmodf(vec2b[0], 1.0f);
1007         float yb = (float)fmodf(vec2b[1], 1.0f);        
1008         
1009         if (xa < 0.0f) xa += 1.0f;
1010         if (ya < 0.0f) ya += 1.0f;
1011         
1012         if (xb < 0.0f) xb += 1.0f;
1013         if (yb < 0.0f) yb += 1.0f;
1014         
1015         return ((fabsf(xa - xb) < PROJ_GEOM_TOLERANCE) && (fabsf(ya - yb) < PROJ_GEOM_TOLERANCE)) ? 1 : 0;
1016 }
1017 #endif
1018
1019 /* set min_px and max_px to the image space bounds of the UV coords 
1020  * return zero if there is no area in the returned rectangle */
1021 #ifndef PROJ_DEBUG_NOSEAMBLEED
1022 static int pixel_bounds_uv(
1023         const float uv1[2], const float uv2[2], const float uv3[2], const float uv4[2],
1024         rcti *bounds_px,
1025         const int ibuf_x, const int ibuf_y,
1026         int is_quad
1027         )
1028 {
1029         float min_uv[2], max_uv[2]; /* UV bounds */
1030         
1031         INIT_MINMAX2(min_uv, max_uv);
1032         
1033         DO_MINMAX2(uv1, min_uv, max_uv);
1034         DO_MINMAX2(uv2, min_uv, max_uv);
1035         DO_MINMAX2(uv3, min_uv, max_uv);
1036         if (is_quad)
1037                 DO_MINMAX2(uv4, min_uv, max_uv);
1038         
1039         bounds_px->xmin = (int)(ibuf_x * min_uv[0]);
1040         bounds_px->ymin = (int)(ibuf_y * min_uv[1]);
1041         
1042         bounds_px->xmax = (int)(ibuf_x * max_uv[0]) + 1;
1043         bounds_px->ymax = (int)(ibuf_y * max_uv[1]) + 1;
1044         
1045         /*printf("%d %d %d %d\n", min_px[0], min_px[1], max_px[0], max_px[1]);*/
1046         
1047         /* face uses no UV area when quantized to pixels? */
1048         return (bounds_px->xmin == bounds_px->xmax || bounds_px->ymin == bounds_px->ymax) ? 0 : 1;
1049 }
1050 #endif
1051
1052 static int pixel_bounds_array(float (*uv)[2], rcti *bounds_px, const int ibuf_x, const int ibuf_y, int tot)
1053 {
1054         float min_uv[2], max_uv[2]; /* UV bounds */
1055         
1056         if (tot == 0) {
1057                 return 0;
1058         }
1059         
1060         INIT_MINMAX2(min_uv, max_uv);
1061         
1062         while (tot--) {
1063                 DO_MINMAX2((*uv), min_uv, max_uv);
1064                 uv++;
1065         }
1066         
1067         bounds_px->xmin = (int)(ibuf_x * min_uv[0]);
1068         bounds_px->ymin = (int)(ibuf_y * min_uv[1]);
1069         
1070         bounds_px->xmax = (int)(ibuf_x * max_uv[0]) + 1;
1071         bounds_px->ymax = (int)(ibuf_y * max_uv[1]) + 1;
1072         
1073         /*printf("%d %d %d %d\n", min_px[0], min_px[1], max_px[0], max_px[1]);*/
1074         
1075         /* face uses no UV area when quantized to pixels? */
1076         return (bounds_px->xmin == bounds_px->xmax || bounds_px->ymin == bounds_px->ymax) ? 0 : 1;
1077 }
1078
1079 #ifndef PROJ_DEBUG_NOSEAMBLEED
1080
1081 /* This function returns 1 if this face has a seam along the 2 face-vert indices
1082  * 'orig_i1_fidx' and 'orig_i2_fidx' */
1083 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)
1084 {
1085         LinkNode *node;
1086         int face_index;
1087         unsigned int i1, i2;
1088         int i1_fidx = -1, i2_fidx = -1; /* index in face */
1089         MFace *mf;
1090         MTFace *tf;
1091         const MFace *orig_mf = ps->dm_mface + orig_face;  
1092         const MTFace *orig_tf = ps->dm_mtface + orig_face;
1093         
1094         /* vert indices from face vert order indices */
1095         i1 = (*(&orig_mf->v1 + orig_i1_fidx));
1096         i2 = (*(&orig_mf->v1 + orig_i2_fidx));
1097         
1098         for (node = ps->vertFaces[i1]; node; node = node->next) {
1099                 face_index = GET_INT_FROM_POINTER(node->link);
1100
1101                 if (face_index != orig_face) {
1102                         mf = ps->dm_mface + face_index;
1103                         /* could check if the 2 faces images match here,
1104                          * but then there wouldn't be a way to return the opposite face's info */
1105                         
1106                         
1107                         /* We need to know the order of the verts in the adjacent face 
1108                          * set the i1_fidx and i2_fidx to (0,1,2,3) */
1109                         if      (mf->v1 == i1) i1_fidx = 0;
1110                         else if (mf->v2 == i1) i1_fidx = 1;
1111                         else if (mf->v3 == i1) i1_fidx = 2;
1112                         else if (mf->v4 && mf->v4 == i1) i1_fidx = 3;
1113
1114                         if      (mf->v1 == i2) i2_fidx = 0;
1115                         else if (mf->v2 == i2) i2_fidx = 1;
1116                         else if (mf->v3 == i2) i2_fidx = 2;
1117                         else if (mf->v4 && mf->v4 == i2) i2_fidx = 3;
1118                         
1119                         /* Only need to check if 'i2_fidx' is valid because we know i1_fidx is the same vert on both faces */
1120                         if (i2_fidx != -1) {
1121                                 Image *tpage = project_paint_face_image(ps, ps->dm_mtface, face_index);
1122                                 Image *orig_tpage = project_paint_face_image(ps, ps->dm_mtface, orig_face);
1123
1124                                 /* This IS an adjacent face!, now lets check if the UVs are ok */
1125                                 tf = ps->dm_mtface + face_index;
1126                                 
1127                                 /* set up the other face */
1128                                 *other_face = face_index;
1129                                 *orig_fidx = (i1_fidx < i2_fidx) ? i1_fidx : i2_fidx;
1130                                 
1131                                 /* first test if they have the same image */
1132                                 if ((orig_tpage == tpage) &&
1133                                     cmp_uv(orig_tf->uv[orig_i1_fidx], tf->uv[i1_fidx]) &&
1134                                     cmp_uv(orig_tf->uv[orig_i2_fidx], tf->uv[i2_fidx]) )
1135                                 {
1136                                         // printf("SEAM (NONE)\n");
1137                                         return 0;
1138                                         
1139                                 }
1140                                 else {
1141                                         // printf("SEAM (UV GAP)\n");
1142                                         return 1;
1143                                 }
1144                         }
1145                 }
1146         }
1147         // printf("SEAM (NO FACE)\n");
1148         *other_face = -1;
1149         return 1;
1150 }
1151
1152 /* Calculate outset UV's, this is not the same as simply scaling the UVs,
1153  * since the outset coords are a margin that keep an even distance from the original UV's,
1154  * note that the image aspect is taken into account */
1155 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)
1156 {
1157         float a1, a2, a3, a4 = 0.0f;
1158         float puv[4][2]; /* pixelspace uv's */
1159         float no1[2], no2[2], no3[2], no4[2]; /* normals */
1160         float dir1[2], dir2[2], dir3[2], dir4[2];
1161         float ibuf_inv[2];
1162
1163         ibuf_inv[0] = 1.0f / (float)ibuf_x;
1164         ibuf_inv[1] = 1.0f / (float)ibuf_y;
1165
1166         /* make UV's in pixel space so we can */
1167         puv[0][0] = orig_uv[0][0] * ibuf_x;
1168         puv[0][1] = orig_uv[0][1] * ibuf_y;
1169         
1170         puv[1][0] = orig_uv[1][0] * ibuf_x;
1171         puv[1][1] = orig_uv[1][1] * ibuf_y;
1172         
1173         puv[2][0] = orig_uv[2][0] * ibuf_x;
1174         puv[2][1] = orig_uv[2][1] * ibuf_y;
1175         
1176         if (is_quad) {
1177                 puv[3][0] = orig_uv[3][0] * ibuf_x;
1178                 puv[3][1] = orig_uv[3][1] * ibuf_y;
1179         }
1180         
1181         /* face edge directions */
1182         sub_v2_v2v2(dir1, puv[1], puv[0]);
1183         sub_v2_v2v2(dir2, puv[2], puv[1]);
1184         normalize_v2(dir1);
1185         normalize_v2(dir2);
1186         
1187         if (is_quad) {
1188                 sub_v2_v2v2(dir3, puv[3], puv[2]);
1189                 sub_v2_v2v2(dir4, puv[0], puv[3]);
1190                 normalize_v2(dir3);
1191                 normalize_v2(dir4);
1192         }
1193         else {
1194                 sub_v2_v2v2(dir3, puv[0], puv[2]);
1195                 normalize_v2(dir3);
1196         }
1197
1198         /* TODO - angle_normalized_v2v2(...) * (M_PI/180.0f)
1199          * This is incorrect. Its already given radians but without it wont work.
1200          * need to look into a fix - campbell */
1201         if (is_quad) {
1202                 a1 = shell_angle_to_dist(angle_normalized_v2v2(dir4, dir1) * ((float)M_PI / 180.0f));
1203                 a2 = shell_angle_to_dist(angle_normalized_v2v2(dir1, dir2) * ((float)M_PI / 180.0f));
1204                 a3 = shell_angle_to_dist(angle_normalized_v2v2(dir2, dir3) * ((float)M_PI / 180.0f));
1205                 a4 = shell_angle_to_dist(angle_normalized_v2v2(dir3, dir4) * ((float)M_PI / 180.0f));
1206         }
1207         else {
1208                 a1 = shell_angle_to_dist(angle_normalized_v2v2(dir3, dir1) * ((float)M_PI / 180.0f));
1209                 a2 = shell_angle_to_dist(angle_normalized_v2v2(dir1, dir2) * ((float)M_PI / 180.0f));
1210                 a3 = shell_angle_to_dist(angle_normalized_v2v2(dir2, dir3) * ((float)M_PI / 180.0f));
1211         }
1212         
1213         if (is_quad) {
1214                 sub_v2_v2v2(no1, dir4, dir1);
1215                 sub_v2_v2v2(no2, dir1, dir2);
1216                 sub_v2_v2v2(no3, dir2, dir3);
1217                 sub_v2_v2v2(no4, dir3, dir4);
1218                 normalize_v2(no1);
1219                 normalize_v2(no2);
1220                 normalize_v2(no3);
1221                 normalize_v2(no4);
1222                 mul_v2_fl(no1, a1 * scaler);
1223                 mul_v2_fl(no2, a2 * scaler);
1224                 mul_v2_fl(no3, a3 * scaler);
1225                 mul_v2_fl(no4, a4 * scaler);
1226                 add_v2_v2v2(outset_uv[0], puv[0], no1);
1227                 add_v2_v2v2(outset_uv[1], puv[1], no2);
1228                 add_v2_v2v2(outset_uv[2], puv[2], no3);
1229                 add_v2_v2v2(outset_uv[3], puv[3], no4);
1230                 mul_v2_v2(outset_uv[0], ibuf_inv);
1231                 mul_v2_v2(outset_uv[1], ibuf_inv);
1232                 mul_v2_v2(outset_uv[2], ibuf_inv);
1233                 mul_v2_v2(outset_uv[3], ibuf_inv);
1234         }
1235         else {
1236                 sub_v2_v2v2(no1, dir3, dir1);
1237                 sub_v2_v2v2(no2, dir1, dir2);
1238                 sub_v2_v2v2(no3, dir2, dir3);
1239                 normalize_v2(no1);
1240                 normalize_v2(no2);
1241                 normalize_v2(no3);
1242                 mul_v2_fl(no1, a1 * scaler);
1243                 mul_v2_fl(no2, a2 * scaler);
1244                 mul_v2_fl(no3, a3 * scaler);
1245                 add_v2_v2v2(outset_uv[0], puv[0], no1);
1246                 add_v2_v2v2(outset_uv[1], puv[1], no2);
1247                 add_v2_v2v2(outset_uv[2], puv[2], no3);
1248
1249                 mul_v2_v2(outset_uv[0], ibuf_inv);
1250                 mul_v2_v2(outset_uv[1], ibuf_inv);
1251                 mul_v2_v2(outset_uv[2], ibuf_inv);
1252         }
1253 }
1254
1255 /* 
1256  * Be tricky with flags, first 4 bits are PROJ_FACE_SEAM1 to 4, last 4 bits are PROJ_FACE_NOSEAM1 to 4
1257  * 1<<i - where i is (0-3) 
1258  * 
1259  * If we're multithreadng, make sure threads are locked when this is called
1260  */
1261 static void project_face_seams_init(const ProjPaintState *ps, const int face_index, const int is_quad)
1262 {
1263         int other_face, other_fidx; /* vars for the other face, we also set its flag */
1264         int fidx1 = is_quad ? 3 : 2;
1265         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 */
1266         
1267         do {
1268                 if ((ps->faceSeamFlags[face_index] & (1 << fidx1 | 16 << fidx1)) == 0) {
1269                         if (check_seam(ps, face_index, fidx1, fidx2, &other_face, &other_fidx)) {
1270                                 ps->faceSeamFlags[face_index] |= 1 << fidx1;
1271                                 if (other_face != -1)
1272                                         ps->faceSeamFlags[other_face] |= 1 << other_fidx;
1273                         }
1274                         else {
1275                                 ps->faceSeamFlags[face_index] |= 16 << fidx1;
1276                                 if (other_face != -1)
1277                                         ps->faceSeamFlags[other_face] |= 16 << other_fidx;  /* second 4 bits for disabled */
1278                         }
1279                 }
1280                 
1281                 fidx2 = fidx1;
1282         } while (fidx1--);
1283 }
1284 #endif // PROJ_DEBUG_NOSEAMBLEED
1285
1286
1287 /* Converts a UV location to a 3D screenspace location
1288  * Takes a 'uv' and 3 UV coords, and sets the values of pixelScreenCo
1289  * 
1290  * This is used for finding a pixels location in screenspace for painting */
1291 static void screen_px_from_ortho(
1292         float uv[2],
1293         float v1co[3], float v2co[3], float v3co[3],  /* Screenspace coords */
1294         float uv1co[2], float uv2co[2], float uv3co[2],
1295         float pixelScreenCo[4],
1296         float w[3])
1297 {
1298         barycentric_weights_v2(uv1co, uv2co, uv3co, uv, w);
1299         interp_v3_v3v3v3(pixelScreenCo, v1co, v2co, v3co, w);
1300 }
1301
1302 /* same as screen_px_from_ortho except we need to take into account
1303  * the perspective W coord for each vert */
1304 static void screen_px_from_persp(
1305         float uv[2],
1306         float v1co[4], float v2co[4], float v3co[4],  /* screenspace coords */
1307         float uv1co[2], float uv2co[2], float uv3co[2],
1308         float pixelScreenCo[4],
1309         float w[3])
1310 {
1311
1312         float wtot_inv, wtot;
1313         barycentric_weights_v2(uv1co, uv2co, uv3co, uv, w);
1314         
1315         /* re-weight from the 4th coord of each screen vert */
1316         w[0] *= v1co[3];
1317         w[1] *= v2co[3];
1318         w[2] *= v3co[3];
1319         
1320         wtot = w[0] + w[1] + w[2];
1321         
1322         if (wtot > 0.0f) {
1323                 wtot_inv = 1.0f / wtot;
1324                 w[0] *= wtot_inv;
1325                 w[1] *= wtot_inv;
1326                 w[2] *= wtot_inv;
1327         }
1328         else {
1329                 w[0] = w[1] = w[2] = 1.0f / 3.0f;  /* dummy values for zero area face */
1330         }
1331         /* done re-weighting */
1332         
1333         interp_v3_v3v3v3(pixelScreenCo, v1co, v2co, v3co, w);
1334 }
1335
1336 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])
1337 {
1338         float *uvCo1, *uvCo2, *uvCo3;
1339         float uv_other[2], x, y;
1340         
1341         uvCo1 =  (float *)tf_other->uv[0];
1342         if (side == 1) {
1343                 uvCo2 =  (float *)tf_other->uv[2];
1344                 uvCo3 =  (float *)tf_other->uv[3];
1345         }
1346         else {
1347                 uvCo2 =  (float *)tf_other->uv[1];
1348                 uvCo3 =  (float *)tf_other->uv[2];
1349         }
1350         
1351         interp_v2_v2v2v2(uv_other, uvCo1, uvCo2, uvCo3, (float *)w);
1352         
1353         /* use */
1354         uvco_to_wrapped_pxco(uv_other, ibuf_other->x, ibuf_other->y, &x, &y);
1355         
1356         
1357         if (ibuf_other->rect_float) { /* from float to float */
1358                 bilinear_interpolation_color_wrap(ibuf_other, NULL, rgba_f, x, y);
1359         }
1360         else { /* from char to float */
1361                 bilinear_interpolation_color_wrap(ibuf_other, rgba_ub, NULL, x, y);
1362         }
1363                 
1364 }
1365
1366 /* run this outside project_paint_uvpixel_init since pixels with mask 0 don't need init */
1367 static float project_paint_uvpixel_mask(
1368         const ProjPaintState *ps,
1369         const int face_index,
1370         const int side,
1371         const float w[3])
1372 {
1373         float mask;
1374         
1375         /* Image Mask */
1376         if (ps->do_layer_stencil) {
1377                 /* another UV maps image is masking this one's */
1378                 ImBuf *ibuf_other;
1379                 Image *other_tpage = project_paint_face_image(ps, ps->dm_mtface_stencil, face_index);
1380                 const MTFace *tf_other = ps->dm_mtface_stencil + face_index;
1381                 
1382                 if (other_tpage && (ibuf_other = BKE_image_get_ibuf(other_tpage, NULL))) {
1383                         /* BKE_image_get_ibuf - TODO - this may be slow */
1384                         unsigned char rgba_ub[4];
1385                         float rgba_f[4];
1386                         
1387                         project_face_pixel(tf_other, ibuf_other, w, side, rgba_ub, rgba_f);
1388                         
1389                         if (ibuf_other->rect_float) { /* from float to float */
1390                                 mask = ((rgba_f[0] + rgba_f[1] + rgba_f[2]) / 3.0f) * rgba_f[3];
1391                         }
1392                         else { /* from char to float */
1393                                 mask = ((rgba_ub[0] + rgba_ub[1] + rgba_ub[2]) / (256 * 3.0f)) * (rgba_ub[3] / 256.0f);
1394                         }
1395                         
1396                         if (!ps->do_layer_stencil_inv) /* matching the gimps layer mask black/white rules, white==full opacity */
1397                                 mask = (1.0f - mask);
1398
1399                         if (mask == 0.0f) {
1400                                 return 0.0f;
1401                         }
1402                 }
1403                 else {
1404                         return 0.0f;
1405                 }
1406         }
1407         else {
1408                 mask = 1.0f;
1409         }
1410         
1411         /* calculate mask */
1412         if (ps->do_mask_normal) {
1413                 MFace *mf = &ps->dm_mface[face_index];
1414                 float no[3], angle;
1415                 if (mf->flag & ME_SMOOTH) {
1416                         short *no1, *no2, *no3;
1417                         no1 = ps->dm_mvert[mf->v1].no;
1418                         if (side == 1) {
1419                                 no2 = ps->dm_mvert[mf->v3].no;
1420                                 no3 = ps->dm_mvert[mf->v4].no;
1421                         }
1422                         else {
1423                                 no2 = ps->dm_mvert[mf->v2].no;
1424                                 no3 = ps->dm_mvert[mf->v3].no;
1425                         }
1426
1427                         no[0] = w[0] * no1[0] + w[1] * no2[0] + w[2] * no3[0];
1428                         no[1] = w[0] * no1[1] + w[1] * no2[1] + w[2] * no3[1];
1429                         no[2] = w[0] * no1[2] + w[1] * no2[2] + w[2] * no3[2];
1430                         normalize_v3(no);
1431                 }
1432                 else {
1433                         /* incase the */
1434 #if 1
1435                         /* normalizing per pixel isn't optimal, we could cache or check ps->*/
1436                         if (mf->v4)
1437                                 normal_quad_v3(no,
1438                                                ps->dm_mvert[mf->v1].co,
1439                                                ps->dm_mvert[mf->v2].co,
1440                                                ps->dm_mvert[mf->v3].co,
1441                                                ps->dm_mvert[mf->v4].co);
1442                         else
1443                                 normal_tri_v3(no,
1444                                               ps->dm_mvert[mf->v1].co,
1445                                               ps->dm_mvert[mf->v2].co,
1446                                               ps->dm_mvert[mf->v3].co);
1447 #else
1448                         /* don't use because some modifiers dont have normal data (subsurf for eg) */
1449                         copy_v3_v3(no, (float *)ps->dm->getTessFaceData(ps->dm, face_index, CD_NORMAL));
1450 #endif
1451                 }
1452                 
1453                 /* now we can use the normal as a mask */
1454                 if (ps->is_ortho) {
1455                         angle = angle_normalized_v3v3((float *)ps->viewDir, no);
1456                 }
1457                 else {
1458                         /* Annoying but for the perspective view we need to get the pixels location in 3D space :/ */
1459                         float viewDirPersp[3];
1460                         float *co1, *co2, *co3;
1461                         co1 = ps->dm_mvert[mf->v1].co;
1462                         if (side == 1) {
1463                                 co2 = ps->dm_mvert[mf->v3].co;
1464                                 co3 = ps->dm_mvert[mf->v4].co;
1465                         }
1466                         else {
1467                                 co2 = ps->dm_mvert[mf->v2].co;
1468                                 co3 = ps->dm_mvert[mf->v3].co;
1469                         }
1470
1471                         /* Get the direction from the viewPoint to the pixel and normalize */
1472                         viewDirPersp[0] = (ps->viewPos[0] - (w[0] * co1[0] + w[1] * co2[0] + w[2] * co3[0]));
1473                         viewDirPersp[1] = (ps->viewPos[1] - (w[0] * co1[1] + w[1] * co2[1] + w[2] * co3[1]));
1474                         viewDirPersp[2] = (ps->viewPos[2] - (w[0] * co1[2] + w[1] * co2[2] + w[2] * co3[2]));
1475                         normalize_v3(viewDirPersp);
1476                         
1477                         angle = angle_normalized_v3v3(viewDirPersp, no);
1478                 }
1479                 
1480                 if (angle >= ps->normal_angle) {
1481                         return 0.0f; /* outsize the normal limit*/
1482                 }
1483                 else if (angle > ps->normal_angle_inner) {
1484                         mask *= (ps->normal_angle - angle) / ps->normal_angle_range;
1485                 } /* otherwise no mask normal is needed, were within the limit */
1486         }
1487         
1488         /* This only works when the opacity dosnt change while painting, stylus pressure messes with this
1489          * so don't use it. */
1490         // if (ps->is_airbrush == 0) mask *= BKE_brush_alpha_get(ps->brush);
1491         
1492         return mask;
1493 }
1494
1495 /* run this function when we know a bucket's, face's pixel can be initialized,
1496  * return the ProjPixel which is added to 'ps->bucketRect[bucket_index]' */
1497 static ProjPixel *project_paint_uvpixel_init(
1498         const ProjPaintState *ps,
1499         MemArena *arena,
1500         const ImBuf *ibuf,
1501         short x_px, short y_px,
1502         const float mask,
1503         const int face_index,
1504         const int image_index,
1505         const float pixelScreenCo[4],
1506         const int side,
1507         const float w[3])
1508 {
1509         ProjPixel *projPixel;
1510         short size;
1511         
1512         /* wrap pixel location */
1513         x_px = x_px % ibuf->x;
1514         if (x_px < 0) x_px += ibuf->x;
1515         y_px = y_px % ibuf->y;
1516         if (y_px < 0) y_px += ibuf->y;
1517         
1518         if (ps->tool == PAINT_TOOL_CLONE) {
1519                 size = sizeof(ProjPixelClone);
1520         }
1521         else if (ps->tool == PAINT_TOOL_SMEAR) {
1522                 size = sizeof(ProjPixelClone);
1523         }
1524         else {
1525                 size = sizeof(ProjPixel);
1526         }
1527         
1528         projPixel = (ProjPixel *)BLI_memarena_alloc(arena, size);
1529         //memset(projPixel, 0, size);
1530         
1531         if (ibuf->rect_float) {
1532                 projPixel->pixel.f_pt = ibuf->rect_float + ((x_px + y_px * ibuf->x) * 4);
1533                 projPixel->origColor.f[0] = projPixel->newColor.f[0] = projPixel->pixel.f_pt[0];  
1534                 projPixel->origColor.f[1] = projPixel->newColor.f[1] = projPixel->pixel.f_pt[1];  
1535                 projPixel->origColor.f[2] = projPixel->newColor.f[2] = projPixel->pixel.f_pt[2];  
1536                 projPixel->origColor.f[3] = projPixel->newColor.f[3] = projPixel->pixel.f_pt[3];  
1537         }
1538         else {
1539                 projPixel->pixel.ch_pt = ((unsigned char *)ibuf->rect + ((x_px + y_px * ibuf->x) * 4));
1540                 projPixel->origColor.uint = projPixel->newColor.uint = *projPixel->pixel.uint_pt;
1541         }
1542         
1543         /* screenspace unclamped, we could keep its z and w values but don't need them at the moment */
1544         copy_v2_v2(projPixel->projCoSS, pixelScreenCo);
1545         
1546         projPixel->x_px = x_px;
1547         projPixel->y_px = y_px;
1548         
1549         projPixel->mask = (unsigned short)(mask * 65535);
1550         projPixel->mask_max = 0;
1551         
1552         /* which bounding box cell are we in?, needed for undo */
1553         projPixel->bb_cell_index = ((int)(((float)x_px / (float)ibuf->x) * PROJ_BOUNDBOX_DIV)) +
1554                                    ((int)(((float)y_px / (float)ibuf->y) * PROJ_BOUNDBOX_DIV)) * PROJ_BOUNDBOX_DIV;
1555         
1556         /* done with view3d_project_float inline */
1557         if (ps->tool == PAINT_TOOL_CLONE) {
1558                 if (ps->dm_mtface_clone) {
1559                         ImBuf *ibuf_other;
1560                         Image *other_tpage = project_paint_face_image(ps, ps->dm_mtface_clone, face_index);
1561                         const MTFace *tf_other = ps->dm_mtface_clone + face_index;
1562                         
1563                         if (other_tpage && (ibuf_other = BKE_image_get_ibuf(other_tpage, NULL))) {
1564                                 /* BKE_image_get_ibuf - TODO - this may be slow */
1565                                 
1566                                 if (ibuf->rect_float) {
1567                                         if (ibuf_other->rect_float) { /* from float to float */
1568                                                 project_face_pixel(tf_other, ibuf_other, w, side, NULL, ((ProjPixelClone *)projPixel)->clonepx.f);
1569                                         }
1570                                         else { /* from char to float */
1571                                                 unsigned char rgba_ub[4];
1572                                                 project_face_pixel(tf_other, ibuf_other, w, side, rgba_ub, NULL);
1573                                                 IMAPAINT_CHAR_RGBA_TO_FLOAT(((ProjPixelClone *)projPixel)->clonepx.f, rgba_ub);
1574                                         }
1575                                 }
1576                                 else {
1577                                         if (ibuf_other->rect_float) { /* float to char */
1578                                                 float rgba[4];
1579                                                 project_face_pixel(tf_other, ibuf_other, w, side, NULL, rgba);
1580                                                 IMAPAINT_FLOAT_RGBA_TO_CHAR(((ProjPixelClone *)projPixel)->clonepx.ch, rgba);
1581                                         }
1582                                         else { /* char to char */
1583                                                 project_face_pixel(tf_other, ibuf_other, w, side, ((ProjPixelClone *)projPixel)->clonepx.ch, NULL);
1584                                         }
1585                                 }
1586                         }
1587                         else {
1588                                 if (ibuf->rect_float) {
1589                                         ((ProjPixelClone *)projPixel)->clonepx.f[3] = 0;
1590                                 }
1591                                 else {
1592                                         ((ProjPixelClone *)projPixel)->clonepx.ch[3] = 0;
1593                                 }
1594                         }
1595                         
1596                 }
1597                 else {
1598                         float co[2];
1599                         sub_v2_v2v2(co, projPixel->projCoSS, (float *)ps->cloneOffset);
1600                         
1601                         /* no need to initialize the bucket, we're only checking buckets faces and for this
1602                          * the faces are already initialized in project_paint_delayed_face_init(...) */
1603                         if (ibuf->rect_float) {
1604                                 if (!project_paint_PickColor(ps, co, ((ProjPixelClone *)projPixel)->clonepx.f, NULL, 1)) {
1605                                         ((ProjPixelClone *)projPixel)->clonepx.f[3] = 0; /* zero alpha - ignore */
1606                                 }
1607                         }
1608                         else {
1609                                 if (!project_paint_PickColor(ps, co, NULL, ((ProjPixelClone *)projPixel)->clonepx.ch, 1)) {
1610                                         ((ProjPixelClone *)projPixel)->clonepx.ch[3] = 0; /* zero alpha - ignore */
1611                                 }
1612                         }
1613                 }
1614         }
1615         
1616 #ifdef PROJ_DEBUG_PAINT
1617         if (ibuf->rect_float) projPixel->pixel.f_pt[0] = 0;
1618         else                  projPixel->pixel.ch_pt[0] = 0;
1619 #endif
1620         projPixel->image_index = image_index;
1621         
1622         return projPixel;
1623 }
1624
1625 static int line_clip_rect2f(
1626         rctf *rect,
1627         const float l1[2], const float l2[2],
1628         float l1_clip[2], float l2_clip[2])
1629 {
1630         /* first account for horizontal, then vertical lines */
1631         /* horiz */
1632         if (fabsf(l1[1] - l2[1]) < PROJ_GEOM_TOLERANCE) {
1633                 /* is the line out of range on its Y axis? */
1634                 if (l1[1] < rect->ymin || l1[1] > rect->ymax) {
1635                         return 0;
1636                 }
1637                 /* line is out of range on its X axis */
1638                 if ((l1[0] < rect->xmin && l2[0] < rect->xmin) || (l1[0] > rect->xmax && l2[0] > rect->xmax)) {
1639                         return 0;
1640                 }
1641                 
1642                 
1643                 if (fabsf(l1[0] - l2[0]) < PROJ_GEOM_TOLERANCE) { /* this is a single point  (or close to)*/
1644                         if (BLI_rctf_isect_pt_v(rect, l1)) {
1645                                 copy_v2_v2(l1_clip, l1);
1646                                 copy_v2_v2(l2_clip, l2);
1647                                 return 1;
1648                         }
1649                         else {
1650                                 return 0;
1651                         }
1652                 }
1653                 
1654                 copy_v2_v2(l1_clip, l1);
1655                 copy_v2_v2(l2_clip, l2);
1656                 CLAMP(l1_clip[0], rect->xmin, rect->xmax);
1657                 CLAMP(l2_clip[0], rect->xmin, rect->xmax);
1658                 return 1;
1659         }
1660         else if (fabsf(l1[0] - l2[0]) < PROJ_GEOM_TOLERANCE) {
1661                 /* is the line out of range on its X axis? */
1662                 if (l1[0] < rect->xmin || l1[0] > rect->xmax) {
1663                         return 0;
1664                 }
1665                 
1666                 /* line is out of range on its Y axis */
1667                 if ((l1[1] < rect->ymin && l2[1] < rect->ymin) || (l1[1] > rect->ymax && l2[1] > rect->ymax)) {
1668                         return 0;
1669                 }
1670                 
1671                 if (fabsf(l1[1] - l2[1]) < PROJ_GEOM_TOLERANCE) { /* this is a single point  (or close to)*/
1672                         if (BLI_rctf_isect_pt_v(rect, l1)) {
1673                                 copy_v2_v2(l1_clip, l1);
1674                                 copy_v2_v2(l2_clip, l2);
1675                                 return 1;
1676                         }
1677                         else {
1678                                 return 0;
1679                         }
1680                 }
1681                 
1682                 copy_v2_v2(l1_clip, l1);
1683                 copy_v2_v2(l2_clip, l2);
1684                 CLAMP(l1_clip[1], rect->ymin, rect->ymax);
1685                 CLAMP(l2_clip[1], rect->ymin, rect->ymax);
1686                 return 1;
1687         }
1688         else {
1689                 float isect;
1690                 short ok1 = 0;
1691                 short ok2 = 0;
1692                 
1693                 /* Done with vertical lines */
1694                 
1695                 /* are either of the points inside the rectangle ? */
1696                 if (BLI_rctf_isect_pt_v(rect, l1)) {
1697                         copy_v2_v2(l1_clip, l1);
1698                         ok1 = 1;
1699                 }
1700                 
1701                 if (BLI_rctf_isect_pt_v(rect, l2)) {
1702                         copy_v2_v2(l2_clip, l2);
1703                         ok2 = 1;
1704                 }
1705                 
1706                 /* line inside rect */
1707                 if (ok1 && ok2) return 1;
1708                 
1709                 /* top/bottom */
1710                 if (line_isect_y(l1, l2, rect->ymin, &isect) && (isect >= rect->xmin) && (isect <= rect->xmax)) {
1711                         if (l1[1] < l2[1]) { /* line 1 is outside */
1712                                 l1_clip[0] = isect;
1713                                 l1_clip[1] = rect->ymin;
1714                                 ok1 = 1;
1715                         }
1716                         else {
1717                                 l2_clip[0] = isect;
1718                                 l2_clip[1] = rect->ymin;
1719                                 ok2 = 2;
1720                         }
1721                 }
1722                 
1723                 if (ok1 && ok2) return 1;
1724                 
1725                 if (line_isect_y(l1, l2, rect->ymax, &isect) && (isect >= rect->xmin) && (isect <= rect->xmax)) {
1726                         if (l1[1] > l2[1]) { /* line 1 is outside */
1727                                 l1_clip[0] = isect;
1728                                 l1_clip[1] = rect->ymax;
1729                                 ok1 = 1;
1730                         }
1731                         else {
1732                                 l2_clip[0] = isect;
1733                                 l2_clip[1] = rect->ymax;
1734                                 ok2 = 2;
1735                         }
1736                 }
1737                 
1738                 if (ok1 && ok2) return 1;
1739                 
1740                 /* left/right */
1741                 if (line_isect_x(l1, l2, rect->xmin, &isect) && (isect >= rect->ymin) && (isect <= rect->ymax)) {
1742                         if (l1[0] < l2[0]) { /* line 1 is outside */
1743                                 l1_clip[0] = rect->xmin;
1744                                 l1_clip[1] = isect;
1745                                 ok1 = 1;
1746                         }
1747                         else {
1748                                 l2_clip[0] = rect->xmin;
1749                                 l2_clip[1] = isect;
1750                                 ok2 = 2;
1751                         }
1752                 }
1753         
1754                 if (ok1 && ok2) return 1;
1755                 
1756                 if (line_isect_x(l1, l2, rect->xmax, &isect) && (isect >= rect->ymin) && (isect <= rect->ymax)) {
1757                         if (l1[0] > l2[0]) { /* line 1 is outside */
1758                                 l1_clip[0] = rect->xmax;
1759                                 l1_clip[1] = isect;
1760                                 ok1 = 1;
1761                         }
1762                         else {
1763                                 l2_clip[0] = rect->xmax;
1764                                 l2_clip[1] = isect;
1765                                 ok2 = 2;
1766                         }
1767                 }
1768                 
1769                 if (ok1 && ok2) {
1770                         return 1;
1771                 }
1772                 else {
1773                         return 0;
1774                 }
1775         }
1776 }
1777
1778
1779
1780 /* scale the quad & tri about its center
1781  * scaling by PROJ_FACE_SCALE_SEAM (0.99x) is used for getting fake UV pixel coords that are on the
1782  * edge of the face but slightly inside it occlusion tests don't return hits on adjacent faces */
1783 #ifndef PROJ_DEBUG_NOSEAMBLEED
1784 static void scale_quad(float insetCos[4][3], float *origCos[4], const float inset)
1785 {
1786         float cent[3];
1787         cent[0] = (origCos[0][0] + origCos[1][0] + origCos[2][0] + origCos[3][0]) / 4.0f;
1788         cent[1] = (origCos[0][1] + origCos[1][1] + origCos[2][1] + origCos[3][1]) / 4.0f;
1789         cent[2] = (origCos[0][2] + origCos[1][2] + origCos[2][2] + origCos[3][2]) / 4.0f;
1790         
1791         sub_v3_v3v3(insetCos[0], origCos[0], cent);
1792         sub_v3_v3v3(insetCos[1], origCos[1], cent);
1793         sub_v3_v3v3(insetCos[2], origCos[2], cent);
1794         sub_v3_v3v3(insetCos[3], origCos[3], cent);
1795         
1796         mul_v3_fl(insetCos[0], inset);
1797         mul_v3_fl(insetCos[1], inset);
1798         mul_v3_fl(insetCos[2], inset);
1799         mul_v3_fl(insetCos[3], inset);
1800         
1801         add_v3_v3(insetCos[0], cent);
1802         add_v3_v3(insetCos[1], cent);
1803         add_v3_v3(insetCos[2], cent);
1804         add_v3_v3(insetCos[3], cent);
1805 }
1806
1807
1808 static void scale_tri(float insetCos[4][3], float *origCos[4], const float inset)
1809 {
1810         float cent[3];
1811         cent[0] = (origCos[0][0] + origCos[1][0] + origCos[2][0]) / 3.0f;
1812         cent[1] = (origCos[0][1] + origCos[1][1] + origCos[2][1]) / 3.0f;
1813         cent[2] = (origCos[0][2] + origCos[1][2] + origCos[2][2]) / 3.0f;
1814         
1815         sub_v3_v3v3(insetCos[0], origCos[0], cent);
1816         sub_v3_v3v3(insetCos[1], origCos[1], cent);
1817         sub_v3_v3v3(insetCos[2], origCos[2], cent);
1818         
1819         mul_v3_fl(insetCos[0], inset);
1820         mul_v3_fl(insetCos[1], inset);
1821         mul_v3_fl(insetCos[2], inset);
1822         
1823         add_v3_v3(insetCos[0], cent);
1824         add_v3_v3(insetCos[1], cent);
1825         add_v3_v3(insetCos[2], cent);
1826 }
1827 #endif //PROJ_DEBUG_NOSEAMBLEED
1828
1829 static float len_squared_v2v2_alt(const float *v1, const float v2_1, const float v2_2)
1830 {
1831         float x, y;
1832
1833         x = v1[0] - v2_1;
1834         y = v1[1] - v2_2;
1835         return x * x + y * y;
1836 }
1837
1838 /* note, use a squared value so we can use len_squared_v2v2
1839  * be sure that you have done a bounds check first or this may fail */
1840 /* only give bucket_bounds as an arg because we need it elsewhere */
1841 static int project_bucket_isect_circle(const float cent[2], const float radius_squared, rctf *bucket_bounds)
1842 {
1843          
1844         /* Would normally to a simple intersection test, however we know the bounds of these 2 already intersect 
1845          * so we only need to test if the center is inside the vertical or horizontal bounds on either axis,
1846          * this is even less work then an intersection test
1847          */
1848 #if 0
1849         if (BLI_rctf_isect_pt_v(bucket_bounds, cent))
1850                 return 1;
1851 #endif
1852         
1853         if ((bucket_bounds->xmin <= cent[0] && bucket_bounds->xmax >= cent[0]) ||
1854             (bucket_bounds->ymin <= cent[1] && bucket_bounds->ymax >= cent[1]))
1855         {
1856                 return 1;
1857         }
1858         
1859         /* out of bounds left */
1860         if (cent[0] < bucket_bounds->xmin) {
1861                 /* lower left out of radius test */
1862                 if (cent[1] < bucket_bounds->ymin) {
1863                         return (len_squared_v2v2_alt(cent, bucket_bounds->xmin, bucket_bounds->ymin) < radius_squared) ? 1 : 0;
1864                 } 
1865                 /* top left test */
1866                 else if (cent[1] > bucket_bounds->ymax) {
1867                         return (len_squared_v2v2_alt(cent, bucket_bounds->xmin, bucket_bounds->ymax) < radius_squared) ? 1 : 0;
1868                 }
1869         }
1870         else if (cent[0] > bucket_bounds->xmax) {
1871                 /* lower right out of radius test */
1872                 if (cent[1] < bucket_bounds->ymin) {
1873                         return (len_squared_v2v2_alt(cent, bucket_bounds->xmax, bucket_bounds->ymin) < radius_squared) ? 1 : 0;
1874                 } 
1875                 /* top right test */
1876                 else if (cent[1] > bucket_bounds->ymax) {
1877                         return (len_squared_v2v2_alt(cent, bucket_bounds->xmax, bucket_bounds->ymax) < radius_squared) ? 1 : 0;
1878                 }
1879         }
1880         
1881         return 0;
1882 }
1883
1884
1885
1886 /* Note for rect_to_uvspace_ortho() and rect_to_uvspace_persp()
1887  * in ortho view this function gives good results when bucket_bounds are outside the triangle
1888  * however in some cases, perspective view will mess up with faces that have minimal screenspace area
1889  * (viewed from the side)
1890  * 
1891  * for this reason its not reliable in this case so we'll use the Simple Barycentric'
1892  * funcs that only account for points inside the triangle.
1893  * however switching back to this for ortho is always an option */
1894
1895 static void rect_to_uvspace_ortho(
1896         rctf *bucket_bounds,
1897         float *v1coSS, float *v2coSS, float *v3coSS,
1898         float *uv1co, float *uv2co, float *uv3co,
1899         float bucket_bounds_uv[4][2],
1900         const int flip)
1901 {
1902         float uv[2];
1903         float w[3];
1904         
1905         /* get the UV space bounding box */
1906         uv[0] = bucket_bounds->xmax;
1907         uv[1] = bucket_bounds->ymin;
1908         barycentric_weights_v2(v1coSS, v2coSS, v3coSS, uv, w);
1909         interp_v2_v2v2v2(bucket_bounds_uv[flip ? 3 : 0], uv1co, uv2co, uv3co, w);
1910
1911         //uv[0] = bucket_bounds->xmax; // set above
1912         uv[1] = bucket_bounds->ymax;
1913         barycentric_weights_v2(v1coSS, v2coSS, v3coSS, uv, w);
1914         interp_v2_v2v2v2(bucket_bounds_uv[flip ? 2 : 1], uv1co, uv2co, uv3co, w);
1915
1916         uv[0] = bucket_bounds->xmin;
1917         //uv[1] = bucket_bounds->ymax; // set above
1918         barycentric_weights_v2(v1coSS, v2coSS, v3coSS, uv, w);
1919         interp_v2_v2v2v2(bucket_bounds_uv[flip ? 1 : 2], uv1co, uv2co, uv3co, w);
1920
1921         //uv[0] = bucket_bounds->xmin; // set above
1922         uv[1] = bucket_bounds->ymin;
1923         barycentric_weights_v2(v1coSS, v2coSS, v3coSS, uv, w);
1924         interp_v2_v2v2v2(bucket_bounds_uv[flip ? 0 : 3], uv1co, uv2co, uv3co, w);
1925 }
1926
1927 /* same as above but use barycentric_weights_v2_persp */
1928 static void rect_to_uvspace_persp(
1929         rctf *bucket_bounds,
1930         float *v1coSS, float *v2coSS, float *v3coSS,
1931         float *uv1co, float *uv2co, float *uv3co,
1932         float bucket_bounds_uv[4][2],
1933         const int flip
1934         )
1935 {
1936         float uv[2];
1937         float w[3];
1938         
1939         /* get the UV space bounding box */
1940         uv[0] = bucket_bounds->xmax;
1941         uv[1] = bucket_bounds->ymin;
1942         barycentric_weights_v2_persp(v1coSS, v2coSS, v3coSS, uv, w);
1943         interp_v2_v2v2v2(bucket_bounds_uv[flip ? 3 : 0], uv1co, uv2co, uv3co, w);
1944
1945         //uv[0] = bucket_bounds->xmax; // set above
1946         uv[1] = bucket_bounds->ymax;
1947         barycentric_weights_v2_persp(v1coSS, v2coSS, v3coSS, uv, w);
1948         interp_v2_v2v2v2(bucket_bounds_uv[flip ? 2 : 1], uv1co, uv2co, uv3co, w);
1949
1950         uv[0] = bucket_bounds->xmin;
1951         //uv[1] = bucket_bounds->ymax; // set above
1952         barycentric_weights_v2_persp(v1coSS, v2coSS, v3coSS, uv, w);
1953         interp_v2_v2v2v2(bucket_bounds_uv[flip ? 1 : 2], uv1co, uv2co, uv3co, w);
1954
1955         //uv[0] = bucket_bounds->xmin; // set above
1956         uv[1] = bucket_bounds->ymin;
1957         barycentric_weights_v2_persp(v1coSS, v2coSS, v3coSS, uv, w);
1958         interp_v2_v2v2v2(bucket_bounds_uv[flip ? 0 : 3], uv1co, uv2co, uv3co, w);
1959 }
1960
1961 /* This works as we need it to but we can save a few steps and not use it */
1962
1963 #if 0
1964 static float angle_2d_clockwise(const float p1[2], const float p2[2], const float p3[2])
1965 {
1966         float v1[2], v2[2];
1967         
1968         v1[0] = p1[0] - p2[0];    v1[1] = p1[1] - p2[1];
1969         v2[0] = p3[0] - p2[0];    v2[1] = p3[1] - p2[1];
1970         
1971         return -atan2(v1[0] * v2[1] - v1[1] * v2[0], v1[0] * v2[0] + v1[1] * v2[1]);
1972 }
1973 #endif
1974
1975 #define ISECT_1 (1)
1976 #define ISECT_2 (1 << 1)
1977 #define ISECT_3 (1 << 2)
1978 #define ISECT_4 (1 << 3)
1979 #define ISECT_ALL3 ((1 << 3) - 1)
1980 #define ISECT_ALL4 ((1 << 4) - 1)
1981
1982 /* limit must be a fraction over 1.0f */
1983 static int IsectPT2Df_limit(float pt[2], float v1[2], float v2[2], float v3[2], float limit)
1984 {
1985         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;
1986 }
1987
1988 /* Clip the face by a bucket and set the uv-space bucket_bounds_uv
1989  * so we have the clipped UV's to do pixel intersection tests with 
1990  * */
1991 static int float_z_sort_flip(const void *p1, const void *p2)
1992 {
1993         return (((float *)p1)[2] < ((float *)p2)[2] ? 1 : -1);
1994 }
1995
1996 static int float_z_sort(const void *p1, const void *p2)
1997 {
1998         return (((float *)p1)[2] < ((float *)p2)[2] ? -1 : 1);
1999 }
2000
2001 static void project_bucket_clip_face(
2002         const int is_ortho,
2003         rctf *bucket_bounds,
2004         float *v1coSS, float *v2coSS, float *v3coSS,
2005         float *uv1co, float *uv2co, float *uv3co,
2006         float bucket_bounds_uv[8][2],
2007         int *tot)
2008 {
2009         int inside_bucket_flag = 0;
2010         int inside_face_flag = 0;
2011         const int flip = ((line_point_side_v2(v1coSS, v2coSS, v3coSS) > 0.0f) != (line_point_side_v2(uv1co, uv2co, uv3co) > 0.0f));
2012         
2013         float bucket_bounds_ss[4][2];
2014
2015         /* get the UV space bounding box */
2016         inside_bucket_flag |= BLI_rctf_isect_pt_v(bucket_bounds, v1coSS);
2017         inside_bucket_flag |= BLI_rctf_isect_pt_v(bucket_bounds, v2coSS) << 1;
2018         inside_bucket_flag |= BLI_rctf_isect_pt_v(bucket_bounds, v3coSS) << 2;
2019         
2020         if (inside_bucket_flag == ISECT_ALL3) {
2021                 /* all screenspace points are inside the bucket bounding box, this means we don't need to clip and can simply return the UVs */
2022                 if (flip) { /* facing the back? */
2023                         copy_v2_v2(bucket_bounds_uv[0], uv3co);
2024                         copy_v2_v2(bucket_bounds_uv[1], uv2co);
2025                         copy_v2_v2(bucket_bounds_uv[2], uv1co);
2026                 }
2027                 else {
2028                         copy_v2_v2(bucket_bounds_uv[0], uv1co);
2029                         copy_v2_v2(bucket_bounds_uv[1], uv2co);
2030                         copy_v2_v2(bucket_bounds_uv[2], uv3co);
2031                 }
2032                 
2033                 *tot = 3; 
2034                 return;
2035         }
2036         
2037         /* get the UV space bounding box */
2038         /* use IsectPT2Df_limit here so we catch points are are touching the tri edge (or a small fraction over) */
2039         bucket_bounds_ss[0][0] = bucket_bounds->xmax;
2040         bucket_bounds_ss[0][1] = bucket_bounds->ymin;
2041         inside_face_flag |= (IsectPT2Df_limit(bucket_bounds_ss[0], v1coSS, v2coSS, v3coSS, 1 + PROJ_GEOM_TOLERANCE) ? ISECT_1 : 0);
2042         
2043         bucket_bounds_ss[1][0] = bucket_bounds->xmax;
2044         bucket_bounds_ss[1][1] = bucket_bounds->ymax;
2045         inside_face_flag |= (IsectPT2Df_limit(bucket_bounds_ss[1], v1coSS, v2coSS, v3coSS, 1 + PROJ_GEOM_TOLERANCE) ? ISECT_2 : 0);
2046
2047         bucket_bounds_ss[2][0] = bucket_bounds->xmin;
2048         bucket_bounds_ss[2][1] = bucket_bounds->ymax;
2049         inside_face_flag |= (IsectPT2Df_limit(bucket_bounds_ss[2], v1coSS, v2coSS, v3coSS, 1 + PROJ_GEOM_TOLERANCE) ? ISECT_3 : 0);
2050
2051         bucket_bounds_ss[3][0] = bucket_bounds->xmin;
2052         bucket_bounds_ss[3][1] = bucket_bounds->ymin;
2053         inside_face_flag |= (IsectPT2Df_limit(bucket_bounds_ss[3], v1coSS, v2coSS, v3coSS, 1 + PROJ_GEOM_TOLERANCE) ? ISECT_4 : 0);
2054         
2055         if (inside_face_flag == ISECT_ALL4) {
2056                 /* bucket is totally inside the screenspace face, we can safely use weights */
2057                 
2058                 if (is_ortho) rect_to_uvspace_ortho(bucket_bounds, v1coSS, v2coSS, v3coSS, uv1co, uv2co, uv3co, bucket_bounds_uv, flip);
2059                 else rect_to_uvspace_persp(bucket_bounds, v1coSS, v2coSS, v3coSS, uv1co, uv2co, uv3co, bucket_bounds_uv, flip);
2060                 
2061                 *tot = 4;
2062                 return;
2063         }
2064         else {
2065                 /* The Complicated Case! 
2066                  * 
2067                  * The 2 cases above are where the face is inside the bucket or the bucket is inside the face.
2068                  * 
2069                  * we need to make a convex polyline from the intersection between the screenspace face
2070                  * and the bucket bounds.
2071                  * 
2072                  * There are a number of ways this could be done, currently it just collects all intersecting verts,
2073                  * and line intersections,  then sorts them clockwise, this is a lot easier then evaluating the geometry to
2074                  * do a correct clipping on both shapes. */
2075                 
2076                 
2077                 /* add a bunch of points, we know must make up the convex hull which is the clipped rect and triangle */
2078                 
2079                 
2080                 
2081                 /* Maximum possible 6 intersections when using a rectangle and triangle */
2082                 float isectVCosSS[8][3]; /* The 3rd float is used to store angle for qsort(), NOT as a Z location */
2083                 float v1_clipSS[2], v2_clipSS[2];
2084                 float w[3];
2085                 
2086                 /* calc center */
2087                 float cent[2] = {0.0f, 0.0f};
2088                 /*float up[2] = {0.0f, 1.0f};*/
2089                 int i;
2090                 short doubles;
2091                 
2092                 (*tot) = 0;
2093                 
2094                 if (inside_face_flag & ISECT_1) { copy_v2_v2(isectVCosSS[*tot], bucket_bounds_ss[0]); (*tot)++; }
2095                 if (inside_face_flag & ISECT_2) { copy_v2_v2(isectVCosSS[*tot], bucket_bounds_ss[1]); (*tot)++; }
2096                 if (inside_face_flag & ISECT_3) { copy_v2_v2(isectVCosSS[*tot], bucket_bounds_ss[2]); (*tot)++; }
2097                 if (inside_face_flag & ISECT_4) { copy_v2_v2(isectVCosSS[*tot], bucket_bounds_ss[3]); (*tot)++; }
2098
2099                 if (inside_bucket_flag & ISECT_1) { copy_v2_v2(isectVCosSS[*tot], v1coSS); (*tot)++; }
2100                 if (inside_bucket_flag & ISECT_2) { copy_v2_v2(isectVCosSS[*tot], v2coSS); (*tot)++; }
2101                 if (inside_bucket_flag & ISECT_3) { copy_v2_v2(isectVCosSS[*tot], v3coSS); (*tot)++; }
2102                 
2103                 if ((inside_bucket_flag & (ISECT_1 | ISECT_2)) != (ISECT_1 | ISECT_2)) {
2104                         if (line_clip_rect2f(bucket_bounds, v1coSS, v2coSS, v1_clipSS, v2_clipSS)) {
2105                                 if ((inside_bucket_flag & ISECT_1) == 0) { copy_v2_v2(isectVCosSS[*tot], v1_clipSS); (*tot)++; }
2106                                 if ((inside_bucket_flag & ISECT_2) == 0) { copy_v2_v2(isectVCosSS[*tot], v2_clipSS); (*tot)++; }
2107                         }
2108                 }
2109                 
2110                 if ((inside_bucket_flag & (ISECT_2 | ISECT_3)) != (ISECT_2 | ISECT_3)) {
2111                         if (line_clip_rect2f(bucket_bounds, v2coSS, v3coSS, v1_clipSS, v2_clipSS)) {
2112                                 if ((inside_bucket_flag & ISECT_2) == 0) { copy_v2_v2(isectVCosSS[*tot], v1_clipSS); (*tot)++; }
2113                                 if ((inside_bucket_flag & ISECT_3) == 0) { copy_v2_v2(isectVCosSS[*tot], v2_clipSS); (*tot)++; }
2114                         }
2115                 }       
2116                 
2117                 if ((inside_bucket_flag & (ISECT_3 | ISECT_1)) != (ISECT_3 | ISECT_1)) {
2118                         if (line_clip_rect2f(bucket_bounds, v3coSS, v1coSS, v1_clipSS, v2_clipSS)) {
2119                                 if ((inside_bucket_flag & ISECT_3) == 0) { copy_v2_v2(isectVCosSS[*tot], v1_clipSS); (*tot)++; }
2120                                 if ((inside_bucket_flag & ISECT_1) == 0) { copy_v2_v2(isectVCosSS[*tot], v2_clipSS); (*tot)++; }
2121                         }
2122                 }
2123                 
2124                 
2125                 if ((*tot) < 3) { /* no intersections to speak of */
2126                         *tot = 0;
2127                         return;
2128                 }
2129         
2130                 /* now we have all points we need, collect their angles and sort them clockwise */
2131                 
2132                 for (i = 0; i < (*tot); i++) {
2133                         cent[0] += isectVCosSS[i][0];
2134                         cent[1] += isectVCosSS[i][1];
2135                 }
2136                 cent[0] = cent[0] / (float)(*tot);
2137                 cent[1] = cent[1] / (float)(*tot);
2138                 
2139                 
2140                 
2141                 /* Collect angles for every point around the center point */
2142
2143                 
2144 #if 0   /* uses a few more cycles then the above loop */
2145                 for (i = 0; i < (*tot); i++) {
2146                         isectVCosSS[i][2] = angle_2d_clockwise(up, cent, isectVCosSS[i]);
2147                 }
2148 #endif
2149
2150                 v1_clipSS[0] = cent[0]; /* Abuse this var for the loop below */
2151                 v1_clipSS[1] = cent[1] + 1.0f;
2152                 
2153                 for (i = 0; i < (*tot); i++) {
2154                         v2_clipSS[0] = isectVCosSS[i][0] - cent[0];
2155                         v2_clipSS[1] = isectVCosSS[i][1] - cent[1];
2156                         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]);
2157                 }
2158                 
2159                 if (flip) qsort(isectVCosSS, *tot, sizeof(float) * 3, float_z_sort_flip);
2160                 else      qsort(isectVCosSS, *tot, sizeof(float) * 3, float_z_sort);
2161                 
2162                 /* remove doubles */
2163                 /* first/last check */
2164                 if (fabsf(isectVCosSS[0][0] - isectVCosSS[(*tot) - 1][0]) < PROJ_GEOM_TOLERANCE &&
2165                     fabsf(isectVCosSS[0][1] - isectVCosSS[(*tot) - 1][1]) < PROJ_GEOM_TOLERANCE)
2166                 {
2167                         (*tot)--;
2168                 }
2169                 
2170                 /* its possible there is only a few left after remove doubles */
2171                 if ((*tot) < 3) {
2172                         // printf("removed too many doubles A\n");
2173                         *tot = 0;
2174                         return;
2175                 }
2176                 
2177                 doubles = TRUE;
2178                 while (doubles == TRUE) {
2179                         doubles = FALSE;
2180                         for (i = 1; i < (*tot); i++) {
2181                                 if (fabsf(isectVCosSS[i - 1][0] - isectVCosSS[i][0]) < PROJ_GEOM_TOLERANCE &&
2182                                     fabsf(isectVCosSS[i - 1][1] - isectVCosSS[i][1]) < PROJ_GEOM_TOLERANCE)
2183                                 {
2184                                         int j;
2185                                         for (j = i + 1; j < (*tot); j++) {
2186                                                 isectVCosSS[j - 1][0] = isectVCosSS[j][0];
2187                                                 isectVCosSS[j - 1][1] = isectVCosSS[j][1];
2188                                         }
2189                                         doubles = TRUE; /* keep looking for more doubles */
2190                                         (*tot)--;
2191                                 }
2192                         }
2193                 }
2194                 
2195                 /* its possible there is only a few left after remove doubles */
2196                 if ((*tot) < 3) {
2197                         // printf("removed too many doubles B\n");
2198                         *tot = 0;
2199                         return;
2200                 }
2201                 
2202                 
2203                 if (is_ortho) {
2204                         for (i = 0; i < (*tot); i++) {
2205                                 barycentric_weights_v2(v1coSS, v2coSS, v3coSS, isectVCosSS[i], w);
2206                                 interp_v2_v2v2v2(bucket_bounds_uv[i], uv1co, uv2co, uv3co, w);
2207                         }
2208                 }
2209                 else {
2210                         for (i = 0; i < (*tot); i++) {
2211                                 barycentric_weights_v2_persp(v1coSS, v2coSS, v3coSS, isectVCosSS[i], w);
2212                                 interp_v2_v2v2v2(bucket_bounds_uv[i], uv1co, uv2co, uv3co, w);
2213                         }
2214                 }
2215         }
2216
2217 #ifdef PROJ_DEBUG_PRINT_CLIP
2218         /* include this at the bottom of the above function to debug the output */
2219
2220         {
2221                 /* If there are ever any problems, */
2222                 float test_uv[4][2];
2223                 int i;
2224                 if (is_ortho) rect_to_uvspace_ortho(bucket_bounds, v1coSS, v2coSS, v3coSS, uv1co, uv2co, uv3co, test_uv, flip);
2225                 else          rect_to_uvspace_persp(bucket_bounds, v1coSS, v2coSS, v3coSS, uv1co, uv2co, uv3co, test_uv, flip);
2226                 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]);
2227                 
2228                 printf("  [(%f,%f), (%f,%f), (%f,%f)], ", uv1co[0], uv1co[1],   uv2co[0], uv2co[1],    uv3co[0], uv3co[1]);
2229                 
2230                 printf("[");
2231                 for (i = 0; i < (*tot); i++) {
2232                         printf("(%f, %f),", bucket_bounds_uv[i][0], bucket_bounds_uv[i][1]);
2233                 }
2234                 printf("]),\\\n");
2235         }
2236 #endif
2237 }
2238
2239 /*
2240  * # This script creates faces in a blender scene from printed data above.
2241  *
2242  * project_ls = [
2243  * ...(output from above block)...
2244  * ]
2245  *
2246  * from Blender import Scene, Mesh, Window, sys, Mathutils
2247  *
2248  * import bpy
2249  *
2250  * V = Mathutils.Vector
2251  *
2252  * def main():
2253  *     sce = bpy.data.scenes.active
2254  *     
2255  *     for item in project_ls:
2256  *         bb = item[0]
2257  *         uv = item[1]
2258  *         poly = item[2]
2259  *         
2260  *         me = bpy.data.meshes.new()
2261  *         ob = sce.objects.new(me)
2262  *         
2263  *         me.verts.extend([V(bb[0]).xyz, V(bb[1]).xyz, V(bb[2]).xyz, V(bb[3]).xyz])
2264  *         me.faces.extend([(0,1,2,3),])
2265  *         me.verts.extend([V(uv[0]).xyz, V(uv[1]).xyz, V(uv[2]).xyz])
2266  *         me.faces.extend([(4,5,6),])
2267  *         
2268  *         vs = [V(p).xyz for p in poly]
2269  *         print len(vs)
2270  *         l = len(me.verts)
2271  *         me.verts.extend(vs)
2272  *         
2273  *         i = l
2274  *         while i < len(me.verts):
2275  *             ii = i + 1
2276  *             if ii == len(me.verts):
2277  *                 ii = l
2278  *             me.edges.extend([i, ii])
2279  *             i += 1
2280  * 
2281  * if __name__ == '__main__':
2282  *     main()
2283  */
2284
2285
2286 #undef ISECT_1
2287 #undef ISECT_2
2288 #undef ISECT_3
2289 #undef ISECT_4
2290 #undef ISECT_ALL3
2291 #undef ISECT_ALL4
2292
2293         
2294 /* checks if pt is inside a convex 2D polyline, the polyline must be ordered rotating clockwise
2295  * otherwise it would have to test for mixed (line_point_side_v2 > 0.0f) cases */
2296 static int IsectPoly2Df(const float pt[2], float uv[][2], const int tot)
2297 {
2298         int i;
2299         if (line_point_side_v2(uv[tot - 1], uv[0], pt) < 0.0f)
2300                 return 0;
2301         
2302         for (i = 1; i < tot; i++) {
2303                 if (line_point_side_v2(uv[i - 1], uv[i], pt) < 0.0f)
2304                         return 0;
2305                 
2306         }
2307         
2308         return 1;
2309 }
2310 static int IsectPoly2Df_twoside(const float pt[2], float uv[][2], const int tot)
2311 {
2312         int i;
2313         int side = (line_point_side_v2(uv[tot - 1], uv[0], pt) > 0.0f);
2314         
2315         for (i = 1; i < tot; i++) {
2316                 if ((line_point_side_v2(uv[i - 1], uv[i], pt) > 0.0f) != side)
2317                         return 0;
2318                 
2319         }
2320         
2321         return 1;
2322 }
2323
2324 /* One of the most important function for projectiopn painting, since it selects the pixels to be added into each bucket.
2325  * initialize pixels from this face where it intersects with the bucket_index, optionally initialize pixels for removing seams */
2326 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)
2327 {
2328         /* Projection vars, to get the 3D locations into screen space  */
2329         MemArena *arena = ps->arena_mt[thread_index];
2330         LinkNode **bucketPixelNodes = ps->bucketRect + bucket_index;
2331         LinkNode *bucketFaceNodes = ps->bucketFaces[bucket_index];
2332         
2333         const MFace *mf = ps->dm_mface + face_index;
2334         const MTFace *tf = ps->dm_mtface + face_index;
2335         
2336         /* UV/pixel seeking data */
2337         int x; /* Image X-Pixel */
2338         int y; /* Image Y-Pixel */
2339         float mask;
2340         float uv[2]; /* Image floating point UV - same as x, y but from 0.0-1.0 */
2341         
2342         int side;
2343         float *v1coSS, *v2coSS, *v3coSS; /* vert co screen-space, these will be assigned to mf->v1,2,3 or mf->v1,3,4 */
2344         
2345         float *vCo[4]; /* vertex screenspace coords */
2346         
2347         float w[3], wco[3];
2348         
2349         float *uv1co, *uv2co, *uv3co; /* for convenience only, these will be assigned to tf->uv[0],1,2 or tf->uv[0],2,3 */
2350         float pixelScreenCo[4];
2351         
2352         rcti bounds_px; /* ispace bounds */
2353         /* vars for getting uvspace bounds */
2354         
2355         float tf_uv_pxoffset[4][2]; /* bucket bounds in UV space so we can init pixels only for this face,  */
2356         float xhalfpx, yhalfpx;
2357         const float ibuf_xf = (float)ibuf->x, ibuf_yf = (float)ibuf->y;
2358         
2359         int has_x_isect = 0, has_isect = 0; /* for early loop exit */
2360         
2361         int i1, i2, i3;
2362         
2363         float uv_clip[8][2];
2364         int uv_clip_tot;
2365         const short is_ortho = ps->is_ortho;
2366         const short do_backfacecull = ps->do_backfacecull;
2367         const short do_clip = ps->rv3d ? ps->rv3d->rflag & RV3D_CLIPPING : 0;
2368         
2369         vCo[0] = ps->dm_mvert[mf->v1].co;
2370         vCo[1] = ps->dm_mvert[mf->v2].co;
2371         vCo[2] = ps->dm_mvert[mf->v3].co;
2372         
2373         
2374         /* Use tf_uv_pxoffset instead of tf->uv so we can offset the UV half a pixel
2375          * this is done so we can avoid offsetting all the pixels by 0.5 which causes
2376          * problems when wrapping negative coords */
2377         xhalfpx = (0.5f + (PROJ_GEOM_TOLERANCE / 3.0f)) / ibuf_xf;
2378         yhalfpx = (0.5f + (PROJ_GEOM_TOLERANCE / 4.0f)) / ibuf_yf;
2379         
2380         /* Note about (PROJ_GEOM_TOLERANCE/x) above...
2381          * Needed to add this offset since UV coords are often quads aligned to pixels.
2382          * In this case pixels can be exactly between 2 triangles causing nasty
2383          * artifacts.
2384          * 
2385          * This workaround can be removed and painting will still work on most cases
2386          * but since the first thing most people try is painting onto a quad- better make it work.
2387          */
2388
2389
2390
2391         tf_uv_pxoffset[0][0] = tf->uv[0][0] - xhalfpx;
2392         tf_uv_pxoffset[0][1] = tf->uv[0][1] - yhalfpx;
2393
2394         tf_uv_pxoffset[1][0] = tf->uv[1][0] - xhalfpx;
2395         tf_uv_pxoffset[1][1] = tf->uv[1][1] - yhalfpx;
2396         
2397         tf_uv_pxoffset[2][0] = tf->uv[2][0] - xhalfpx;
2398         tf_uv_pxoffset[2][1] = tf->uv[2][1] - yhalfpx;  
2399         
2400         if (mf->v4) {
2401                 vCo[3] = ps->dm_mvert[mf->v4].co;
2402                 
2403                 tf_uv_pxoffset[3][0] = tf->uv[3][0] - xhalfpx;
2404                 tf_uv_pxoffset[3][1] = tf->uv[3][1] - yhalfpx;
2405                 side = 1;
2406         }
2407         else {
2408                 side = 0;
2409         }
2410         
2411         do {
2412                 if (side == 1) {
2413                         i1 = 0; i2 = 2; i3 = 3;
2414                 }
2415                 else {
2416                         i1 = 0; i2 = 1; i3 = 2;
2417                 }
2418                 
2419                 uv1co = tf_uv_pxoffset[i1]; // was tf->uv[i1];
2420                 uv2co = tf_uv_pxoffset[i2]; // was tf->uv[i2];
2421                 uv3co = tf_uv_pxoffset[i3]; // was tf->uv[i3];
2422
2423                 v1coSS = ps->screenCoords[(*(&mf->v1 + i1))];
2424                 v2coSS = ps->screenCoords[(*(&mf->v1 + i2))];
2425                 v3coSS = ps->screenCoords[(*(&mf->v1 + i3))];
2426                 
2427                 /* This funtion gives is a concave polyline in UV space from the clipped quad and tri*/
2428                 project_bucket_clip_face(
2429                         is_ortho, bucket_bounds,
2430                         v1coSS, v2coSS, v3coSS,
2431                         uv1co, uv2co, uv3co,
2432                         uv_clip, &uv_clip_tot
2433                         );
2434
2435                 /* sometimes this happens, better just allow for 8 intersectiosn even though there should be max 6 */
2436 #if 0
2437                 if (uv_clip_tot > 6) {
2438                         printf("this should never happen! %d\n", uv_clip_tot);
2439                 }
2440 #endif
2441
2442                 if (pixel_bounds_array(uv_clip, &bounds_px, ibuf->x, ibuf->y, uv_clip_tot)) {
2443
2444                         if (clamp_u) {
2445                                 CLAMP(bounds_px.xmin, 0, ibuf->x);
2446                                 CLAMP(bounds_px.xmax, 0, ibuf->x);
2447                         }
2448
2449                         if (clamp_v) {
2450                                 CLAMP(bounds_px.ymin, 0, ibuf->y);
2451                                 CLAMP(bounds_px.ymax, 0, ibuf->y);
2452                         }
2453
2454                         /* clip face and */
2455                         
2456                         has_isect = 0;
2457                         for (y = bounds_px.ymin; y < bounds_px.ymax; y++) {
2458                                 //uv[1] = (((float)y) + 0.5f) / (float)ibuf->y;
2459                                 uv[1] = (float)y / ibuf_yf; /* use pixel offset UV coords instead */
2460
2461                                 has_x_isect = 0;
2462                                 for (x = bounds_px.xmin; x < bounds_px.xmax; x++) {
2463                                         //uv[0] = (((float)x) + 0.5f) / ibuf->x;
2464                                         uv[0] = (float)x / ibuf_xf; /* use pixel offset UV coords instead */
2465                                         
2466                                         /* Note about IsectPoly2Df_twoside, checking the face or uv flipping doesnt work,
2467                                          * could check the poly direction but better to do this */
2468                                         if ((do_backfacecull == TRUE  && IsectPoly2Df(uv, uv_clip, uv_clip_tot)) ||
2469                                             (do_backfacecull == FALSE && IsectPoly2Df_twoside(uv, uv_clip, uv_clip_tot)))
2470                                         {
2471                                                 
2472                                                 has_x_isect = has_isect = 1;
2473                                                 
2474                                                 if (is_ortho) screen_px_from_ortho(uv, v1coSS, v2coSS, v3coSS, uv1co, uv2co, uv3co, pixelScreenCo, w);
2475                                                 else          screen_px_from_persp(uv, v1coSS, v2coSS, v3coSS, uv1co, uv2co, uv3co, pixelScreenCo, w);
2476                                                 
2477                                                 /* a pity we need to get the worldspace pixel location here */
2478                                                 if (do_clip) {
2479                                                         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);
2480                                                         if (ED_view3d_clipping_test(ps->rv3d, wco, TRUE)) {
2481                                                                 continue; /* Watch out that no code below this needs to run */
2482                                                         }
2483                                                 }
2484                                                 
2485                                                 /* Is this UV visible from the view? - raytrace */
2486                                                 /* project_paint_PickFace is less complex, use for testing */
2487                                                 //if (project_paint_PickFace(ps, pixelScreenCo, w, &side) == face_index) {
2488                                                 if ((ps->do_occlude == FALSE) ||
2489                                                     !project_bucket_point_occluded(ps, bucketFaceNodes, face_index, pixelScreenCo))
2490                                                 {
2491                                                         
2492                                                         mask = project_paint_uvpixel_mask(ps, face_index, side, w);
2493                                                         
2494                                                         if (mask > 0.0f) {
2495                                                                 BLI_linklist_prepend_arena(
2496                                                                         bucketPixelNodes,
2497                                                                         project_paint_uvpixel_init(ps, arena, ibuf, x, y, mask, face_index, image_index, pixelScreenCo, side, w),
2498                                                                         arena
2499                                                                         );
2500                                                         }
2501                                                 }
2502                                                 
2503                                         }
2504 //#if 0
2505                                         else if (has_x_isect) {
2506                                                 /* assuming the face is not a bow-tie - we know we cant intersect again on the X */
2507                                                 break;
2508                                         }
2509 //#endif
2510                                 }
2511                                 
2512                                 
2513 #if 0           /* TODO - investigate why this dosnt work sometimes! it should! */
2514                                 /* no intersection for this entire row, after some intersection above means we can quit now */
2515                                 if (has_x_isect == 0 && has_isect) {
2516                                         break;
2517                                 }
2518 #endif
2519                         }
2520                 }
2521         } while (side--);
2522
2523         
2524         
2525 #ifndef PROJ_DEBUG_NOSEAMBLEED
2526         if (ps->seam_bleed_px > 0.0f) {
2527                 int face_seam_flag;
2528                 
2529                 if (ps->thread_tot > 1)
2530                         BLI_lock_thread(LOCK_CUSTOM1);  /* Other threads could be modifying these vars */
2531                 
2532                 face_seam_flag = ps->faceSeamFlags[face_index];
2533                 
2534                 /* are any of our edges un-initialized? */
2535                 if ((face_seam_flag & (PROJ_FACE_SEAM1 | PROJ_FACE_NOSEAM1)) == 0 ||
2536                     (face_seam_flag & (PROJ_FACE_SEAM2 | PROJ_FACE_NOSEAM2)) == 0 ||
2537                     (face_seam_flag & (PROJ_FACE_SEAM3 | PROJ_FACE_NOSEAM3)) == 0 ||
2538                     (face_seam_flag & (PROJ_FACE_SEAM4 | PROJ_FACE_NOSEAM4)) == 0)
2539                 {
2540                         project_face_seams_init(ps, face_index, mf->v4);
2541                         face_seam_flag = ps->faceSeamFlags[face_index];
2542                         //printf("seams - %d %d %d %d\n", flag&PROJ_FACE_SEAM1, flag&PROJ_FACE_SEAM2, flag&PROJ_FACE_SEAM3, flag&PROJ_FACE_SEAM4);
2543                 }
2544                 
2545                 if ((face_seam_flag & (PROJ_FACE_SEAM1 | PROJ_FACE_SEAM2 | PROJ_FACE_SEAM3 | PROJ_FACE_SEAM4)) == 0) {
2546                         
2547                         if (ps->thread_tot > 1)
2548                                 BLI_unlock_thread(LOCK_CUSTOM1);  /* Other threads could be modifying these vars */
2549                         
2550                 }
2551                 else {
2552                         /* we have a seam - deal with it! */
2553                         
2554                         /* Now create new UV's for the seam face */
2555                         float (*outset_uv)[2] = ps->faceSeamUVs[face_index];
2556                         float insetCos[4][3]; /* inset face coords.  NOTE!!! ScreenSace for ortho, Worldspace in prespective view */
2557
2558                         float fac;
2559                         float *vCoSS[4]; /* vertex screenspace coords */
2560                         
2561                         float bucket_clip_edges[2][2]; /* store the screenspace coords of the face, clipped by the bucket's screen aligned rectangle */
2562                         float edge_verts_inset_clip[2][3];
2563                         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 */
2564                         
2565                         float seam_subsection[4][2];
2566                         float fac1, fac2, ftot;
2567                         
2568                         
2569                         if (outset_uv[0][0] == FLT_MAX) /* first time initialize */
2570                                 uv_image_outset(tf_uv_pxoffset, outset_uv, ps->seam_bleed_px, ibuf->x, ibuf->y, mf->v4);
2571                         
2572                         /* ps->faceSeamUVs cant be modified when threading, now this is done we can unlock */
2573                         if (ps->thread_tot > 1)
2574                                 BLI_unlock_thread(LOCK_CUSTOM1);  /* Other threads could be modifying these vars */
2575                         
2576                         vCoSS[0] = ps->screenCoords[mf->v1];
2577                         vCoSS[1] = ps->screenCoords[mf->v2];
2578                         vCoSS[2] = ps->screenCoords[mf->v3];
2579                         if (mf->v4)
2580                                 vCoSS[3] = ps->screenCoords[mf->v4];
2581                         
2582                         /* PROJ_FACE_SCALE_SEAM must be slightly less then 1.0f */
2583                         if (is_ortho) {
2584                                 if (mf->v4) scale_quad(insetCos, vCoSS, PROJ_FACE_SCALE_SEAM);
2585                                 else        scale_tri(insetCos, vCoSS, PROJ_FACE_SCALE_SEAM);
2586                         }
2587                         else {
2588                                 if (mf->v4) scale_quad(insetCos, vCo, PROJ_FACE_SCALE_SEAM);
2589                                 else        scale_tri(insetCos, vCo, PROJ_FACE_SCALE_SEAM);
2590                         }
2591                         
2592                         side = 0; /* for triangles this wont need to change */
2593                         
2594                         for (fidx1 = 0; fidx1 < (mf->v4 ? 4 : 3); fidx1++) {
2595                                 if (mf->v4) fidx2 = (fidx1 == 3) ? 0 : fidx1 + 1;  /* next fidx in the face (0,1,2,3) -> (1,2,3,0) */
2596                                 else        fidx2 = (fidx1 == 2) ? 0 : fidx1 + 1;  /* next fidx in the face (0,1,2) -> (1,2,0) */
2597                                 
2598                                 if ((face_seam_flag & (1 << fidx1)) && /* 1<<fidx1 -> PROJ_FACE_SEAM# */
2599                                     line_clip_rect2f(bucket_bounds, vCoSS[fidx1], vCoSS[fidx2], bucket_clip_edges[0], bucket_clip_edges[1]))
2600                                 {
2601
2602                                         ftot = len_v2v2(vCoSS[fidx1], vCoSS[fidx2]); /* screenspace edge length */
2603                                         
2604                                         if (ftot > 0.0f) { /* avoid div by zero */
2605                                                 if (mf->v4) {
2606                                                         if (fidx1 == 2 || fidx2 == 2) side = 1;
2607                                                         else side = 0;
2608                                                 }
2609                                                 
2610                                                 fac1 = len_v2v2(vCoSS[fidx1], bucket_clip_edges[0]) / ftot;
2611                                                 fac2 = len_v2v2(vCoSS[fidx1], bucket_clip_edges[1]) / ftot;
2612                                                 
2613                                                 interp_v2_v2v2(seam_subsection[0], tf_uv_pxoffset[fidx1], tf_uv_pxoffset[fidx2], fac1);
2614                                                 interp_v2_v2v2(seam_subsection[1], tf_uv_pxoffset[fidx1], tf_uv_pxoffset[fidx2], fac2);
2615
2616                                                 interp_v2_v2v2(seam_subsection[2], outset_uv[fidx1], outset_uv[fidx2], fac2);
2617                                                 interp_v2_v2v2(seam_subsection[3], outset_uv[fidx1], outset_uv[fidx2], fac1);
2618                                                 
2619                                                 /* if the bucket_clip_edges values Z values was kept we could avoid this
2620                                                  * Inset needs to be added so occlusion tests wont hit adjacent faces */
2621                                                 interp_v3_v3v3(edge_verts_inset_clip[0], insetCos[fidx1], insetCos[fidx2], fac1);
2622                                                 interp_v3_v3v3(edge_verts_inset_clip[1], insetCos[fidx1], insetCos[fidx2], fac2);
2623                                                 
2624
2625                                                 if (pixel_bounds_uv(seam_subsection[0], seam_subsection[1], seam_subsection[2], seam_subsection[3], &bounds_px, ibuf->x, ibuf->y, 1)) {
2626                                                         /* bounds between the seam rect and the uvspace bucket pixels */
2627                                                         
2628                                                         has_isect = 0;
2629                                                         for (y = bounds_px.ymin; y < bounds_px.ymax; y++) {
2630                                                                 // uv[1] = (((float)y) + 0.5f) / (float)ibuf->y;
2631                                                                 uv[1] = (float)y / ibuf_yf; /* use offset uvs instead */
2632                                                                 
2633                                                                 has_x_isect = 0;
2634                                                                 for (x = bounds_px.xmin; x < bounds_px.xmax; x++) {
2635                                                                         //uv[0] = (((float)x) + 0.5f) / (float)ibuf->x;
2636                                                                         uv[0] = (float)x / ibuf_xf; /* use offset uvs instead */
2637                                                                         
2638                                                                         /* test we're inside uvspace bucket and triangle bounds */
2639                                                                         if (isect_point_quad_v2(uv, seam_subsection[0], seam_subsection[1], seam_subsection[2], seam_subsection[3])) {
2640                                                                                 
2641                                                                                 /* We need to find the closest point along the face edge,
2642                                                                                  * getting the screen_px_from_*** wont work because our actual location
2643                                                                                  * is not relevant, since we are outside the face, Use VecLerpf to find
2644                                                                                  * our location on the side of the face's UV */
2645 #if 0
2646                                                                                 if (is_ortho) screen_px_from_ortho(ps, uv, v1co, v2co, v3co, uv1co, uv2co, uv3co, pixelScreenCo);
2647                                                                                 else          screen_px_from_persp(ps, uv, v1co, v2co, v3co, uv1co, uv2co, uv3co, pixelScreenCo);
2648 #endif
2649                                                                                 
2650                                                                                 /* Since this is a seam we need to work out where on the line this pixel is */
2651                                                                                 //fac = line_point_factor_v2(uv, uv_seam_quad[0], uv_seam_quad[1]);
2652                                                                                 
2653                                                                                 fac = line_point_factor_v2(uv, seam_subsection[0], seam_subsection[1]);
2654                                                                                 if      (fac < 0.0f) { copy_v3_v3(pixelScreenCo, edge_verts_inset_clip[0]); }
2655                                                                                 else if (fac > 1.0f) { copy_v3_v3(pixelScreenCo, edge_verts_inset_clip[1]); }
2656                                                                                 else                 { interp_v3_v3v3(pixelScreenCo, edge_verts_inset_clip[0], edge_verts_inset_clip[1], fac); }
2657                                                                                 
2658                                                                                 if (!is_ortho) {
2659                                                                                         pixelScreenCo[3] = 1.0f;
2660                                                                                         mul_m4_v4((float(*)[4])ps->projectMat, pixelScreenCo); /* cast because of const */
2661                                                                                         pixelScreenCo[0] = (float)(ps->winx / 2.0f) + (ps->winx / 2.0f) * pixelScreenCo[0] / pixelScreenCo[3];
2662                                                                                         pixelScreenCo[1] = (float)(ps->winy / 2.0f) + (ps->winy / 2.0f) * pixelScreenCo[1] / pixelScreenCo[3];
2663                                                                                         pixelScreenCo[2] = pixelScreenCo[2] / pixelScreenCo[3]; /* Use the depth for bucket point occlusion */
2664                                                                                 }
2665                                                                                 
2666                                                                                 if ((ps->do_occlude == FALSE) ||
2667                                                                                     !project_bucket_point_occluded(ps, bucketFaceNodes, face_index, pixelScreenCo))
2668                                                                                 {
2669                                                                                         /* Only bother calculating the weights if we intersect */
2670                                                                                         if (ps->do_mask_normal || ps->dm_mtface_clone) {
2671 #if 1
2672                                                                                                 /* get the UV on the line since we want to copy the pixels from there for bleeding */
2673                                                                                                 float uv_close[2];
2674                                                                                                 float fac = closest_to_line_v2(uv_close, uv, tf_uv_pxoffset[fidx1], tf_uv_pxoffset[fidx2]);
2675                                                                                                 if      (fac < 0.0f) copy_v2_v2(uv_close, tf_uv_pxoffset[fidx1]);
2676                                                                                                 else if (fac > 1.0f) copy_v2_v2(uv_close, tf_uv_pxoffset[fidx2]);
2677
2678                                                                                                 if (side) {
2679                                                                                                         barycentric_weights_v2(tf_uv_pxoffset[0], tf_uv_pxoffset[2], tf_uv_pxoffset[3], uv_close, w);
2680                                                                                                 }
2681                                                                                                 else {
2682                                                                                                         barycentric_weights_v2(tf_uv_pxoffset[0], tf_uv_pxoffset[1], tf_uv_pxoffset[2], uv_close, w);
2683                                                                                                 }
2684 #else                                                                                   /* this is buggy with quads, don't use for now */
2685
2686                                                                                                 /* Cheat, we know where we are along the edge so work out the weights from that */
2687                                                                                                 fac = fac1 + (fac * (fac2 - fac1));
2688
2689                                                                                                 w[0] = w[1] = w[2] = 0.0;
2690                                                                                                 if (side) {
2691                                                                                                         w[fidx1 ? fidx1 - 1 : 0] = 1.0f - fac;
2692                                                                                                         w[fidx2 ? fidx2 - 1 : 0] = fac;
2693                                                                                                 }
2694                                                                                                 else {
2695                                                                                                         w[fidx1] = 1.0f - fac;
2696                                                                                                         w[fidx2] = fac;
2697                                                                                                 }
2698 #endif
2699                                                                                         }
2700                                                                                         
2701                                                                                         /* a pity we need to get the worldspace pixel location here */
2702                                                                                         if (do_clip) {
2703                                                                                                 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);
2704                                                                                                 else      interp_v3_v3v3v3(wco, ps->dm_mvert[mf->v1].co, ps->dm_mvert[mf->v2].co, ps->dm_mvert[mf->v3].co, w);
2705
2706                                                                                                 if (ED_view3d_clipping_test(ps->rv3d, wco, TRUE)) {
2707                                                                                                         continue; /* Watch out that no code below this needs to run */
2708                                                                                                 }
2709                                                                                         }
2710                                                                                         
2711                                                                                         mask = project_paint_uvpixel_mask(ps, face_index, side, w);
2712                                                                                         
2713                                                                                         if (mask > 0.0f) {
2714                                                                                                 BLI_linklist_prepend_arena(
2715                                                                                                         bucketPixelNodes,
2716                                                                                                         project_paint_uvpixel_init(ps, arena, ibuf, x, y, mask, face_index, image_index, pixelScreenCo, side, w),
2717                                                                                                         arena
2718                                                                                                         );
2719                                                                                         }
2720                                                                                         
2721                                                                                 }
2722                                                                         }
2723                                                                         else if (has_x_isect) {
2724                                                                                 /* assuming the face is not a bow-tie - we know we cant intersect again on the X */
2725                                                                                 break;
2726                                                                         }
2727                                                                 }
2728                                                                 
2729 #if 0                           /* TODO - investigate why this dosnt work sometimes! it should! */
2730                                                                 /* no intersection for this entire row, after some intersection above means we can quit now */
2731                                                                 if (has_x_isect == 0 && has_isect) {
2732                                                                         break;
2733                                                                 }
2734 #endif
2735                                                         }
2736                                                 }
2737                                         }
2738                                 }
2739                         }
2740                 }
2741         }
2742 #endif // PROJ_DEBUG_NOSEAMBLEED
2743 }
2744
2745
2746 /* takes floating point screenspace min/max and returns int min/max to be used as indices for ps->bucketRect, ps->bucketFlags */
2747 static void project_paint_bucket_bounds(const ProjPaintState *ps, const float min[2], const float max[2], int bucketMin[2], int bucketMax[2])
2748 {
2749         /* divide by bucketWidth & bucketHeight so the bounds are offset in bucket grid units */
2750         /* 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 */
2751         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 */
2752         bucketMin[1] = (int)((int)(((float)(min[1] - ps->screenMin[1]) / ps->screen_height) * ps->buckets_y) + 0.5f);
2753         
2754         bucketMax[0] = (int)((int)(((float)(max[0] - ps->screenMin[0]) / ps->screen_width) * ps->buckets_x) + 1.5f);
2755         bucketMax[1] = (int)((int)(((float)(max[1] - ps->screenMin[1]) / ps->screen_height) * ps->buckets_y) + 1.5f);
2756         
2757         /* in case the rect is outside the mesh 2d bounds */
2758         CLAMP(bucketMin[0], 0, ps->buckets_x);
2759         CLAMP(bucketMin[1], 0, ps->buckets_y);
2760         
2761         CLAMP(bucketMax[0], 0, ps->buckets_x);
2762         CLAMP(bucketMax[1], 0, ps->buckets_y);
2763 }
2764
2765 /* set bucket_bounds to a screen space-aligned floating point bound-box */
2766 static void project_bucket_bounds(const ProjPaintState *ps, const int bucket_x, const int bucket_y, rctf *bucket_bounds)
2767 {
2768         bucket_bounds->xmin = ps->screenMin[0] + ((bucket_x) * (ps->screen_width / ps->buckets_x));     /* left */
2769         bucket_bounds->xmax = ps->screenMin[0] + ((bucket_x + 1) * (ps->screen_width / ps->buckets_x)); /* right */
2770         
2771         bucket_bounds->ymin = ps->screenMin[1] + ((bucket_y) * (ps->screen_height / ps->buckets_y));      /* bottom */
2772         bucket_bounds->ymax = ps->screenMin[1] + ((bucket_y + 1) * (ps->screen_height  / ps->buckets_y)); /* top */
2773 }
2774
2775 /* Fill this bucket with pixels from the faces that intersect it.
2776  * 
2777  * have bucket_bounds as an argument so we don't need to give bucket_x/y the rect function needs */
2778 static void project_bucket_init(const ProjPaintState *ps, const int thread_index, const int bucket_index, rctf *bucket_bounds)
2779 {
2780         LinkNode *node;
2781         int face_index, image_index = 0;
2782         ImBuf *ibuf = NULL;
2783         Image *tpage_last = NULL, *tpage;
2784         Image *ima = NULL;
2785
2786         if (ps->image_tot == 1) {
2787                 /* Simple loop, no context switching */
2788                 ibuf = ps->projImages[0].ibuf;
2789                 ima = ps->projImages[0].ima;
2790
2791                 for (node = ps->bucketFaces[bucket_index]; node; node = node->next) {
2792                         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);
2793                 }
2794         }
2795         else {
2796                 
2797                 /* More complicated loop, switch between images */
2798                 for (node = ps->bucketFaces[bucket_index]; node; node = node->next) {
2799                         face_index = GET_INT_FROM_POINTER(node->link);
2800                                 
2801                         /* Image context switching */
2802                         tpage = project_paint_face_image(ps, ps->dm_mtface, face_index);
2803                         if (tpage_last != tpage) {
2804                                 tpage_last = tpage;
2805
2806                                 for (image_index = 0; image_index < ps->image_tot; image_index++) {
2807                                         if (ps->projImages[image_index].ima == tpage_last) {
2808                                                 ibuf = ps->projImages[image_index].ibuf;
2809                                                 ima = ps->projImages[image_index].ima;
2810                                                 break;
2811                                         }
2812                                 }
2813                         }
2814                         /* context switching done */
2815                         
2816                         project_paint_face_init(ps, thread_index, bucket_index, face_index, image_index, bucket_bounds, ibuf, ima->tpageflag & IMA_CLAMP_U, ima->tpageflag & IMA_CLAMP_V);
2817                 }
2818         }
2819         
2820         ps->bucketFlags[bucket_index] |= PROJ_BUCKET_INIT;
2821 }
2822
2823
2824 /* We want to know if a bucket and a face overlap in screen-space
2825  * 
2826  * Note, if this ever returns false positives its not that bad, since a face in the bounding area will have its pixels
2827  * calculated when it might not be needed later, (at the moment at least)
2828  * obviously it shouldn't have bugs though */
2829
2830 static int project_bucket_face_isect(ProjPaintState *ps, int bucket_x, int bucket_y, const MFace *mf)
2831 {
2832         /* TODO - replace this with a tricker method that uses sideofline for all screenCoords's edges against the closest bucket corner */
2833         rctf bucket_bounds;
2834         float p1[2], p2[2], p3[2], p4[2];
2835         float *v, *v1, *v2, *v3, *v4 = NULL;
2836         int fidx;
2837         
2838         project_bucket_bounds(ps, bucket_x, bucket_y, &bucket_bounds);
2839         
2840         /* Is one of the faces verts in the bucket bounds? */
2841         
2842         fidx = mf->v4 ? 3 : 2;
2843         do {
2844                 v = ps->screenCoords[(*(&mf->v1 + fidx))];
2845                 if (BLI_rctf_isect_pt_v(&bucket_bounds, v)) {
2846                         return 1;
2847                 }
2848         } while (fidx--);
2849         
2850         v1 = ps->screenCoords[mf->v1];
2851         v2 = ps->screenCoords[mf->v2];
2852         v3 = ps->screenCoords[mf->v3];
2853         if (mf->v4) {
2854<