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