Fix T42984 detail flood fill not respecting mask values for smooth/sharp
[blender.git] / source / blender / editors / sculpt_paint / paint_image_proj.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_proj.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_blenlib.h"
44 #include "BLI_linklist.h"
45 #include "BLI_math.h"
46 #include "BLI_math_color_blend.h"
47 #include "BLI_memarena.h"
48 #include "BLI_threads.h"
49 #include "BLI_utildefines.h"
50
51 #include "BLF_translation.h"
52
53
54 #include "IMB_imbuf.h"
55 #include "IMB_imbuf_types.h"
56
57 #include "DNA_brush_types.h"
58 #include "DNA_material_types.h"
59 #include "DNA_mesh_types.h"
60 #include "DNA_node_types.h"
61 #include "DNA_object_types.h"
62
63 #include "BKE_camera.h"
64 #include "BKE_context.h"
65 #include "BKE_depsgraph.h"
66 #include "BKE_DerivedMesh.h"
67 #include "BKE_idprop.h"
68 #include "BKE_brush.h"
69 #include "BKE_image.h"
70 #include "BKE_library.h"
71 #include "BKE_main.h"
72 #include "BKE_material.h"
73 #include "BKE_mesh.h"
74 #include "BKE_mesh_mapping.h"
75 #include "BKE_node.h"
76 #include "BKE_paint.h"
77 #include "BKE_report.h"
78 #include "BKE_scene.h"
79 #include "BKE_texture.h"
80
81 #include "UI_interface.h"
82
83 #include "ED_mesh.h"
84 #include "ED_node.h"
85 #include "ED_paint.h"
86 #include "ED_screen.h"
87 #include "ED_uvedit.h"
88 #include "ED_view3d.h"
89
90 #include "GPU_extensions.h"
91
92 #include "WM_api.h"
93 #include "WM_types.h"
94
95 #include "RNA_access.h"
96 #include "RNA_define.h"
97 #include "RNA_enum_types.h"
98
99 #include "GPU_draw.h"
100
101 #include "IMB_colormanagement.h"
102
103 #include "bmesh.h"
104 //#include "bmesh_tools.h"
105
106 #include "paint_intern.h"
107
108 /* Defines and Structs */
109 /* FTOCHAR as inline function */
110 BLI_INLINE unsigned char f_to_char(const float val)
111 {
112         return FTOCHAR(val);
113 }
114
115 /* ProjectionPaint defines */
116
117 /* approx the number of buckets to have under the brush,
118  * used with the brush size to set the ps->buckets_x and ps->buckets_y value.
119  *
120  * When 3 - a brush should have ~9 buckets under it at once
121  * ...this helps for threading while painting as well as
122  * avoiding initializing pixels that wont touch the brush */
123 #define PROJ_BUCKET_BRUSH_DIV 4
124
125 #define PROJ_BUCKET_RECT_MIN 4
126 #define PROJ_BUCKET_RECT_MAX 256
127
128 #define PROJ_BOUNDBOX_DIV 8
129 #define PROJ_BOUNDBOX_SQUARED  (PROJ_BOUNDBOX_DIV * PROJ_BOUNDBOX_DIV)
130
131 //#define PROJ_DEBUG_PAINT 1
132 //#define PROJ_DEBUG_NOSEAMBLEED 1
133 //#define PROJ_DEBUG_PRINT_CLIP 1
134 #define PROJ_DEBUG_WINCLIP 1
135
136 /* projectFaceSeamFlags options */
137 //#define PROJ_FACE_IGNORE      (1<<0)  /* When the face is hidden, backfacing or occluded */
138 //#define PROJ_FACE_INIT        (1<<1)  /* When we have initialized the faces data */
139 #define PROJ_FACE_SEAM1 (1 << 0)  /* If this face has a seam on any of its edges */
140 #define PROJ_FACE_SEAM2 (1 << 1)
141 #define PROJ_FACE_SEAM3 (1 << 2)
142 #define PROJ_FACE_SEAM4 (1 << 3)
143
144 #define PROJ_FACE_NOSEAM1   (1 << 4)
145 #define PROJ_FACE_NOSEAM2   (1 << 5)
146 #define PROJ_FACE_NOSEAM3   (1 << 6)
147 #define PROJ_FACE_NOSEAM4   (1 << 7)
148
149 /* face winding */
150 #define PROJ_FACE_WINDING_INIT 1
151 #define PROJ_FACE_WINDING_CW 2
152
153 #define PROJ_SRC_VIEW       1
154 #define PROJ_SRC_IMAGE_CAM  2
155 #define PROJ_SRC_IMAGE_VIEW 3
156 #define PROJ_SRC_VIEW_FILL  4
157
158 #define PROJ_VIEW_DATA_ID "view_data"
159 #define PROJ_VIEW_DATA_SIZE (4 * 4 + 4 * 4 + 3) /* viewmat + winmat + clipsta + clipend + is_ortho */
160
161
162 /* a slightly scaled down face is used to get fake 3D location for edge pixels in the seams
163  * as this number approaches  1.0f the likelihood increases of float precision errors where
164  * it is occluded by an adjacent face */
165 #define PROJ_FACE_SCALE_SEAM    0.99f
166
167 #define PROJ_BUCKET_NULL        0
168 #define PROJ_BUCKET_INIT        (1 << 0)
169 // #define PROJ_BUCKET_CLONE_INIT       (1<<1)
170
171 /* used for testing doubles, if a point is on a line etc */
172 #define PROJ_GEOM_TOLERANCE 0.00075f
173 #define PROJ_PIXEL_TOLERANCE 0.01f
174
175 /* vert flags */
176 #define PROJ_VERT_CULL 1
177
178 /* to avoid locking in tile initialization */
179 #define TILE_PENDING SET_INT_IN_POINTER(-1)
180
181 /* This is mainly a convenience struct used so we can keep an array of images we use
182  * Thir imbufs, etc, in 1 array, When using threads this array is copied for each thread
183  * because 'partRedrawRect' and 'touch' values would not be thread safe */
184 typedef struct ProjPaintImage {
185         Image *ima;
186         ImBuf *ibuf;
187         ImagePaintPartialRedraw *partRedrawRect;
188         volatile void **undoRect; /* only used to build undo tiles during painting */
189         unsigned short **maskRect; /* the mask accumulation must happen on canvas, not on space screen bucket.
190                           * Here we store the mask rectangle */
191         bool **valid; /* store flag to enforce validation of undo rectangle */
192         int touch;
193 } ProjPaintImage;
194
195 /* Main projection painting struct passed to all projection painting functions */
196 typedef struct ProjPaintState {
197         View3D *v3d;
198         RegionView3D *rv3d;
199         ARegion *ar;
200         Scene *scene;
201         int source; /* PROJ_SRC_**** */
202
203         /* the paint color. It can change depending of inverted mode or not */
204         float paint_color[3];
205         float paint_color_linear[3];
206
207         Brush *brush;
208         short tool, blend, mode;
209         int orig_brush_size;
210         float brush_size;
211         Object *ob;
212         /* end similarities with ImagePaintState */
213
214         DerivedMesh    *dm;
215         int dm_totface;
216         int dm_totvert;
217         int dm_release;
218
219         MVert          *dm_mvert;
220         MFace          *dm_mface;
221         MTFace         **dm_mtface;
222         MTFace         **dm_mtface_clone;    /* other UV map, use for cloning between layers */
223         MTFace         *dm_mtface_stencil;
224
225         Image *stencil_ima;
226         Image *canvas_ima;
227         Image *clone_ima;
228         float stencil_value;
229
230         /* projection painting only */
231         MemArena *arena_mt[BLENDER_MAX_THREADS]; /* for multithreading, the first item is sometimes used for non threaded cases too */
232         LinkNode **bucketRect;              /* screen sized 2D array, each pixel has a linked list of ProjPixel's */
233         LinkNode **bucketFaces;             /* bucketRect aligned array linkList of faces overlapping each bucket */
234         unsigned char *bucketFlags;         /* store if the bucks have been initialized  */
235 #ifndef PROJ_DEBUG_NOSEAMBLEED
236         char *faceSeamFlags;                /* store info about faces, if they are initialized etc*/
237         char *faceWindingFlags;             /* save the winding of the face in uv space, helps as an extra validation step for seam detection */
238         float (*faceSeamUVs)[4][2];         /* expanded UVs for faces to use as seams */
239         LinkNode **vertFaces;               /* Only needed for when seam_bleed_px is enabled, use to find UV seams */
240 #endif
241         char *vertFlags;                    /* store options per vert, now only store if the vert is pointing away from the view */
242         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 */
243         int buckets_y;
244
245         ProjPaintImage *projImages;
246
247         int pixel_sizeof;           /* result of project_paint_pixel_sizeof(), constant per stroke */
248
249         int image_tot;              /* size of projectImages array */
250
251         float (*screenCoords)[4];   /* verts projected into floating point screen space */
252
253         float screenMin[2];         /* 2D bounds for mesh verts on the screen's plane (screenspace) */
254         float screenMax[2];
255         float screen_width;         /* Calculated from screenMin & screenMax */
256         float screen_height;
257         int winx, winy;             /* from the carea or from the projection render */
258
259         /* options for projection painting */
260         bool  do_layer_clone;
261         bool  do_layer_stencil;
262         bool  do_layer_stencil_inv;
263         bool  do_stencil_brush;
264         bool  do_material_slots;
265
266         bool  do_occlude;               /* Use raytraced occlusion? - ortherwise will paint right through to the back*/
267         bool  do_backfacecull;          /* ignore faces with normals pointing away, skips a lot of raycasts if your normals are correctly flipped */
268         bool  do_mask_normal;           /* mask out pixels based on their normals */
269         bool  do_new_shading_nodes;     /* cache BKE_scene_use_new_shading_nodes value */
270         float normal_angle;             /* what angle to mask at*/
271         float normal_angle_inner;
272         float normal_angle_range;       /* difference between normal_angle and normal_angle_inner, for easy access */
273
274         bool do_face_sel;               /* quick access to (me->editflag & ME_EDIT_PAINT_FACE_SEL) */
275         bool is_ortho;
276         bool do_masking;              /* use masking during painting. Some operations such as airbrush may disable */
277         bool is_texbrush;              /* only to avoid running  */
278         bool is_maskbrush;            /* mask brush is applied before masking */
279 #ifndef PROJ_DEBUG_NOSEAMBLEED
280         float seam_bleed_px;
281 #endif
282         /* clone vars */
283         float cloneOffset[2];
284
285         float projectMat[4][4];     /* Projection matrix, use for getting screen coords */
286         float viewDir[3];           /* View vector, use for do_backfacecull and for ray casting with an ortho viewport  */
287         float viewPos[3];           /* View location in object relative 3D space, so can compare to verts  */
288         float clipsta, clipend;
289
290         /* reproject vars */
291         Image *reproject_image;
292         ImBuf *reproject_ibuf;
293
294         /* threads */
295         int thread_tot;
296         int bucketMin[2];
297         int bucketMax[2];
298         int context_bucket_x, context_bucket_y; /* must lock threads while accessing these */
299
300         /* redraw */
301         bool need_redraw;
302
303         BlurKernel *blurkernel;
304
305         SpinLock *tile_lock;
306 } ProjPaintState;
307
308 typedef union pixelPointer {
309         float *f_pt;            /* float buffer */
310         unsigned int *uint_pt; /* 2 ways to access a char buffer */
311         unsigned char *ch_pt;
312 } PixelPointer;
313
314 typedef union pixelStore {
315         unsigned char ch[4];
316         unsigned int uint;
317         float f[4];
318 } PixelStore;
319
320 typedef struct ProjPixel {
321         float projCoSS[2]; /* the floating point screen projection of this pixel */
322         float worldCoSS[3];
323         /* Only used when the airbrush is disabled.
324          * Store the max mask value to avoid painting over an area with a lower opacity
325          * with an advantage that we can avoid touching the pixel at all, if the
326          * new mask value is lower then mask_accum */
327         unsigned short *mask_accum;
328
329         /* for various reasons we may want to mask out painting onto this pixel */
330         unsigned short mask;
331
332         short x_px, y_px;
333         /* horrible hack, store tile valid flag pointer here to re-validate tiles used for anchored and drag-dot strokes */
334         bool *valid;
335
336         PixelPointer origColor;
337         PixelStore newColor;
338         PixelPointer pixel;
339
340         short image_index; /* if anyone wants to paint onto more than 32768 images they can bite me */
341         unsigned char bb_cell_index;
342 } ProjPixel;
343
344 typedef struct ProjPixelClone {
345         struct ProjPixel __pp;
346         PixelStore clonepx;
347 } ProjPixelClone;
348
349 /* undo tile pushing */
350 typedef struct {
351         SpinLock *lock;
352         bool masked;
353         unsigned short tile_width;
354         ImBuf **tmpibuf;
355         ProjPaintImage *pjima;
356 } TileInfo;
357
358
359 /* Finish projection painting structs */
360
361 static TexPaintSlot *project_paint_face_paint_slot(const ProjPaintState *ps, int face_index)
362 {
363         MFace *mf = ps->dm_mface + face_index;
364         Material *ma = ps->dm->mat[mf->mat_nr];
365         return ma ? ma->texpaintslot + ma->paint_active_slot : NULL;
366 }
367
368 static Image *project_paint_face_paint_image(const ProjPaintState *ps, int face_index)
369 {
370         if (ps->do_stencil_brush) {
371                 return ps->stencil_ima;
372         }
373         else {
374                 MFace *mf = ps->dm_mface + face_index;
375                 Material *ma = ps->dm->mat[mf->mat_nr];
376                 TexPaintSlot *slot = ma ? ma->texpaintslot + ma->paint_active_slot : NULL;
377                 return slot ? slot->ima : ps->canvas_ima;
378         }
379 }
380
381 static TexPaintSlot *project_paint_face_clone_slot(const ProjPaintState *ps, int face_index)
382 {
383         MFace *mf = ps->dm_mface + face_index;
384         Material *ma = ps->dm->mat[mf->mat_nr];
385         return ma ? ma->texpaintslot + ma->paint_clone_slot : NULL;
386 }
387
388 static Image *project_paint_face_clone_image(const ProjPaintState *ps, int face_index)
389 {
390         MFace *mf = ps->dm_mface + face_index;
391         Material *ma = ps->dm->mat[mf->mat_nr];
392         TexPaintSlot *slot = ma ? ma->texpaintslot + ma->paint_clone_slot : NULL;
393         return slot ? slot->ima : ps->clone_ima;
394 }
395
396 /* fast projection bucket array lookup, use the safe version for bound checking  */
397 static int project_bucket_offset(const ProjPaintState *ps, const float projCoSS[2])
398 {
399         /* If we were not dealing with screenspace 2D coords we could simple do...
400          * ps->bucketRect[x + (y*ps->buckets_y)] */
401
402         /* please explain?
403          * projCoSS[0] - ps->screenMin[0]   : zero origin
404          * ... / ps->screen_width           : range from 0.0 to 1.0
405          * ... * ps->buckets_x              : use as a bucket index
406          *
407          * Second multiplication does similar but for vertical offset
408          */
409         return ( (int)(((projCoSS[0] - ps->screenMin[0]) / ps->screen_width)  * ps->buckets_x)) +
410                (((int)(((projCoSS[1] - ps->screenMin[1]) / ps->screen_height) * ps->buckets_y)) * ps->buckets_x);
411 }
412
413 static int project_bucket_offset_safe(const ProjPaintState *ps, const float projCoSS[2])
414 {
415         int bucket_index = project_bucket_offset(ps, projCoSS);
416
417         if (bucket_index < 0 || bucket_index >= ps->buckets_x * ps->buckets_y) {
418                 return -1;
419         }
420         else {
421                 return bucket_index;
422         }
423 }
424
425 static float VecZDepthOrtho(const float pt[2],
426                             const float v1[3], const float v2[3], const float v3[3],
427                             float w[3])
428 {
429         barycentric_weights_v2(v1, v2, v3, pt, w);
430         return (v1[2] * w[0]) + (v2[2] * w[1]) + (v3[2] * w[2]);
431 }
432
433 static float VecZDepthPersp(const float pt[2],
434                             const float v1[4], const float v2[4], const float v3[4],
435                             float w[3])
436 {
437         float wtot_inv, wtot;
438         float w_tmp[3];
439
440         barycentric_weights_v2_persp(v1, v2, v3, pt, w);
441         /* for the depth we need the weights to match what
442          * barycentric_weights_v2 would return, in this case its easiest just to
443          * undo the 4th axis division and make it unit-sum
444          *
445          * don't call barycentric_weights_v2() because our callers expect 'w'
446          * to be weighted from the perspective */
447         w_tmp[0] = w[0] * v1[3];
448         w_tmp[1] = w[1] * v2[3];
449         w_tmp[2] = w[2] * v3[3];
450
451         wtot = w_tmp[0] + w_tmp[1] + w_tmp[2];
452
453         if (wtot != 0.0f) {
454                 wtot_inv = 1.0f / wtot;
455
456                 w_tmp[0] = w_tmp[0] * wtot_inv;
457                 w_tmp[1] = w_tmp[1] * wtot_inv;
458                 w_tmp[2] = w_tmp[2] * wtot_inv;
459         }
460         else /* dummy values for zero area face */
461                 w_tmp[0] = w_tmp[1] = w_tmp[2] = 1.0f / 3.0f;
462         /* done mimicing barycentric_weights_v2() */
463
464         return (v1[2] * w_tmp[0]) + (v2[2] * w_tmp[1]) + (v3[2] * w_tmp[2]);
465 }
466
467
468 /* Return the top-most face index that the screen space coord 'pt' touches (or -1) */
469 static int project_paint_PickFace(const ProjPaintState *ps, const float pt[2], float w[3], int *side)
470 {
471         LinkNode *node;
472         float w_tmp[3];
473         const float *v1, *v2, *v3, *v4;
474         int bucket_index;
475         int face_index;
476         int best_side = -1;
477         int best_face_index = -1;
478         float z_depth_best = FLT_MAX, z_depth;
479         MFace *mf;
480
481         bucket_index = project_bucket_offset_safe(ps, pt);
482         if (bucket_index == -1)
483                 return -1;
484
485
486
487         /* we could return 0 for 1 face buckets, as long as this function assumes
488          * that the point its testing is only every originated from an existing face */
489
490         for (node = ps->bucketFaces[bucket_index]; node; node = node->next) {
491                 face_index = GET_INT_FROM_POINTER(node->link);
492                 mf = ps->dm_mface + face_index;
493
494                 v1 = ps->screenCoords[mf->v1];
495                 v2 = ps->screenCoords[mf->v2];
496                 v3 = ps->screenCoords[mf->v3];
497
498                 if (isect_point_tri_v2(pt, v1, v2, v3)) {
499                         if (ps->is_ortho) z_depth = VecZDepthOrtho(pt, v1, v2, v3, w_tmp);
500                         else z_depth = VecZDepthPersp(pt, v1, v2, v3, w_tmp);
501
502                         if (z_depth < z_depth_best) {
503                                 best_face_index = face_index;
504                                 best_side = 0;
505                                 z_depth_best = z_depth;
506                                 copy_v3_v3(w, w_tmp);
507                         }
508                 }
509                 else if (mf->v4) {
510                         v4 = ps->screenCoords[mf->v4];
511
512                         if (isect_point_tri_v2(pt, v1, v3, v4)) {
513                                 if (ps->is_ortho) z_depth = VecZDepthOrtho(pt, v1, v3, v4, w_tmp);
514                                 else z_depth = VecZDepthPersp(pt, v1, v3, v4, w_tmp);
515
516                                 if (z_depth < z_depth_best) {
517                                         best_face_index = face_index;
518                                         best_side = 1;
519                                         z_depth_best = z_depth;
520                                         copy_v3_v3(w, w_tmp);
521                                 }
522                         }
523                 }
524         }
525
526         *side = best_side;
527         return best_face_index; /* will be -1 or a valid face */
528 }
529
530 /* Converts a uv coord into a pixel location wrapping if the uv is outside 0-1 range */
531 static void uvco_to_wrapped_pxco(const float uv[2], int ibuf_x, int ibuf_y, float *x, float *y)
532 {
533         /* use */
534         *x = fmodf(uv[0], 1.0f);
535         *y = fmodf(uv[1], 1.0f);
536
537         if (*x < 0.0f) *x += 1.0f;
538         if (*y < 0.0f) *y += 1.0f;
539
540         *x = *x * ibuf_x - 0.5f;
541         *y = *y * ibuf_y - 0.5f;
542 }
543
544 /* Set the top-most face color that the screen space coord 'pt' touches (or return 0 if none touch) */
545 static bool project_paint_PickColor(const ProjPaintState *ps, const float pt[2],
546                                     float *rgba_fp, unsigned char *rgba, const bool interp)
547 {
548         float w[3], uv[2];
549         int side;
550         int face_index;
551         MTFace *tf;
552         Image *ima;
553         ImBuf *ibuf;
554         int xi, yi;
555
556
557         face_index = project_paint_PickFace(ps, pt, w, &side);
558
559         if (face_index == -1)
560                 return 0;
561
562         tf = *(ps->dm_mtface + face_index);
563
564         if (side == 0) {
565                 interp_v2_v2v2v2(uv, tf->uv[0], tf->uv[1], tf->uv[2], w);
566         }
567         else { /* QUAD */
568                 interp_v2_v2v2v2(uv, tf->uv[0], tf->uv[2], tf->uv[3], w);
569         }
570
571         ima = project_paint_face_paint_image(ps, face_index);
572         ibuf = BKE_image_get_first_ibuf(ima); /* we must have got the imbuf before getting here */
573         if (!ibuf) return 0;
574
575         if (interp) {
576                 float x, y;
577                 uvco_to_wrapped_pxco(uv, ibuf->x, ibuf->y, &x, &y);
578
579                 if (ibuf->rect_float) {
580                         if (rgba_fp) {
581                                 bilinear_interpolation_color_wrap(ibuf, NULL, rgba_fp, x, y);
582                         }
583                         else {
584                                 float rgba_tmp_f[4];
585                                 bilinear_interpolation_color_wrap(ibuf, NULL, rgba_tmp_f, x, y);
586                                 premul_float_to_straight_uchar(rgba, rgba_tmp_f);
587                         }
588                 }
589                 else {
590                         if (rgba) {
591                                 bilinear_interpolation_color_wrap(ibuf, rgba, NULL, x, y);
592                         }
593                         else {
594                                 unsigned char rgba_tmp[4];
595                                 bilinear_interpolation_color_wrap(ibuf, rgba_tmp, NULL, x, y);
596                                 straight_uchar_to_premul_float(rgba_fp, rgba_tmp);
597                         }
598                 }
599         }
600         else {
601                 //xi = (int)((uv[0]*ibuf->x) + 0.5f);
602                 //yi = (int)((uv[1]*ibuf->y) + 0.5f);
603                 //if (xi < 0 || xi >= ibuf->x  ||  yi < 0 || yi >= ibuf->y) return 0;
604
605                 /* wrap */
606                 xi = mod_i((int)(uv[0] * ibuf->x), ibuf->x);
607                 yi = mod_i((int)(uv[1] * ibuf->y), ibuf->y);
608
609                 if (rgba) {
610                         if (ibuf->rect_float) {
611                                 const float *rgba_tmp_fp = ibuf->rect_float + (xi + yi * ibuf->x * 4);
612                                 premul_float_to_straight_uchar(rgba, rgba_tmp_fp);
613                         }
614                         else {
615                                 *((unsigned int *)rgba) = *(unsigned int *)(((char *)ibuf->rect) + ((xi + yi * ibuf->x) * 4));
616                         }
617                 }
618
619                 if (rgba_fp) {
620                         if (ibuf->rect_float) {
621                                 copy_v4_v4(rgba_fp, (ibuf->rect_float + ((xi + yi * ibuf->x) * 4)));
622                         }
623                         else {
624                                 unsigned char *tmp_ch = ((unsigned char *)ibuf->rect) + ((xi + yi * ibuf->x) * 4);
625                                 straight_uchar_to_premul_float(rgba_fp, tmp_ch);
626                         }
627                 }
628         }
629         BKE_image_release_ibuf(ima, ibuf, NULL);
630         return 1;
631 }
632
633 /* Check if 'pt' is infront of the 3 verts on the Z axis (used for screenspace occlusuion test)
634  * return...
635  *  0   : no occlusion
636  * -1   : no occlusion but 2D intersection is true (avoid testing the other half of a quad)
637  *  1   : occluded
638  *  2   : occluded with w[3] weights set (need to know in some cases) */
639
640 static int project_paint_occlude_ptv(const float pt[3],
641                                      const float v1[4], const float v2[4], const float v3[4],
642                                      float w[3], const bool is_ortho)
643 {
644         /* if all are behind us, return false */
645         if (v1[2] > pt[2] && v2[2] > pt[2] && v3[2] > pt[2])
646                 return 0;
647
648         /* do a 2D point in try intersection */
649         if (!isect_point_tri_v2(pt, v1, v2, v3))
650                 return 0;  /* we know there is  */
651
652
653         /* From here on we know there IS an intersection */
654         /* if ALL of the verts are infront of us then we know it intersects ? */
655         if (v1[2] < pt[2] && v2[2] < pt[2] && v3[2] < pt[2]) {
656                 return 1;
657         }
658         else {
659                 /* we intersect? - find the exact depth at the point of intersection */
660                 /* Is this point is occluded by another face? */
661                 if (is_ortho) {
662                         if (VecZDepthOrtho(pt, v1, v2, v3, w) < pt[2]) return 2;
663                 }
664                 else {
665                         if (VecZDepthPersp(pt, v1, v2, v3, w) < pt[2]) return 2;
666                 }
667         }
668         return -1;
669 }
670
671
672 static int project_paint_occlude_ptv_clip(const ProjPaintState *ps, const MFace *mf,
673                                           const float pt[3], const float v1[4], const float v2[4], const float v3[4],
674                                           const int side)
675 {
676         float w[3], wco[3];
677         int ret = project_paint_occlude_ptv(pt, v1, v2, v3, w, ps->is_ortho);
678
679         if (ret <= 0)
680                 return ret;
681
682         if (ret == 1) { /* weights not calculated */
683                 if (ps->is_ortho) barycentric_weights_v2(v1, v2, v3, pt, w);
684                 else barycentric_weights_v2_persp(v1, v2, v3, pt, w);
685         }
686
687         /* Test if we're in the clipped area, */
688         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);
689         else interp_v3_v3v3v3(wco, ps->dm_mvert[mf->v1].co, ps->dm_mvert[mf->v2].co, ps->dm_mvert[mf->v3].co, w);
690
691         if (!ED_view3d_clipping_test(ps->rv3d, wco, true)) {
692                 return 1;
693         }
694
695         return -1;
696 }
697
698
699 /* Check if a screenspace location is occluded by any other faces
700  * check, pixelScreenCo must be in screenspace, its Z-Depth only needs to be used for comparison
701  * and doesn't need to be correct in relation to X and Y coords (this is the case in perspective view) */
702 static bool project_bucket_point_occluded(const ProjPaintState *ps, LinkNode *bucketFace,
703                                           const int orig_face, const float pixelScreenCo[4])
704 {
705         MFace *mf;
706         int face_index;
707         int isect_ret;
708         float w[3]; /* not needed when clipping */
709         const short do_clip = ps->rv3d ? ps->rv3d->rflag & RV3D_CLIPPING : 0;
710
711         /* we could return 0 for 1 face buckets, as long as this function assumes
712          * that the point its testing is only every originated from an existing face */
713
714         for (; bucketFace; bucketFace = bucketFace->next) {
715                 face_index = GET_INT_FROM_POINTER(bucketFace->link);
716
717                 if (orig_face != face_index) {
718                         mf = ps->dm_mface + face_index;
719                         if (do_clip)
720                                 isect_ret = project_paint_occlude_ptv_clip(ps, mf, pixelScreenCo, ps->screenCoords[mf->v1], ps->screenCoords[mf->v2], ps->screenCoords[mf->v3], 0);
721                         else
722                                 isect_ret = project_paint_occlude_ptv(pixelScreenCo, ps->screenCoords[mf->v1], ps->screenCoords[mf->v2], ps->screenCoords[mf->v3], w, ps->is_ortho);
723
724                         /* Note, if (isect_ret == -1) then we don't want to test the other side of the quad */
725                         if (isect_ret == 0 && mf->v4) {
726                                 if (do_clip)
727                                         isect_ret = project_paint_occlude_ptv_clip(ps, mf, pixelScreenCo, ps->screenCoords[mf->v1], ps->screenCoords[mf->v3], ps->screenCoords[mf->v4], 1);
728                                 else
729                                         isect_ret = project_paint_occlude_ptv(pixelScreenCo, ps->screenCoords[mf->v1], ps->screenCoords[mf->v3], ps->screenCoords[mf->v4], w, ps->is_ortho);
730                         }
731                         if (isect_ret >= 1) {
732                                 /* TODO - we may want to cache the first hit,
733                                  * it is not possible to swap the face order in the list anymore */
734                                 return true;
735                         }
736                 }
737         }
738         return false;
739 }
740
741 /* basic line intersection, could move to math_geom.c, 2 points with a horiz line
742  * 1 for an intersection, 2 if the first point is aligned, 3 if the second point is aligned */
743 #define ISECT_TRUE 1
744 #define ISECT_TRUE_P1 2
745 #define ISECT_TRUE_P2 3
746 static int line_isect_y(const float p1[2], const float p2[2], const float y_level, float *x_isect)
747 {
748         float y_diff;
749
750         if (y_level == p1[1]) { /* are we touching the first point? - no interpolation needed */
751                 *x_isect = p1[0];
752                 return ISECT_TRUE_P1;
753         }
754         if (y_level == p2[1]) { /* are we touching the second point? - no interpolation needed */
755                 *x_isect = p2[0];
756                 return ISECT_TRUE_P2;
757         }
758
759         y_diff = fabsf(p1[1] - p2[1]); /* yuck, horizontal line, we cant do much here */
760
761         if (y_diff < 0.000001f) {
762                 *x_isect = (p1[0] + p2[0]) * 0.5f;
763                 return ISECT_TRUE;
764         }
765
766         if (p1[1] > y_level && p2[1] < y_level) {
767                 *x_isect = (p2[0] * (p1[1] - y_level) + p1[0] * (y_level - p2[1])) / y_diff;  /*(p1[1]-p2[1]);*/
768                 return ISECT_TRUE;
769         }
770         else if (p1[1] < y_level && p2[1] > y_level) {
771                 *x_isect = (p2[0] * (y_level - p1[1]) + p1[0] * (p2[1] - y_level)) / y_diff;  /*(p2[1]-p1[1]);*/
772                 return ISECT_TRUE;
773         }
774         else {
775                 return 0;
776         }
777 }
778
779 static int line_isect_x(const float p1[2], const float p2[2], const float x_level, float *y_isect)
780 {
781         float x_diff;
782
783         if (x_level == p1[0]) { /* are we touching the first point? - no interpolation needed */
784                 *y_isect = p1[1];
785                 return ISECT_TRUE_P1;
786         }
787         if (x_level == p2[0]) { /* are we touching the second point? - no interpolation needed */
788                 *y_isect = p2[1];
789                 return ISECT_TRUE_P2;
790         }
791
792         x_diff = fabsf(p1[0] - p2[0]); /* yuck, horizontal line, we cant do much here */
793
794         if (x_diff < 0.000001f) { /* yuck, vertical line, we cant do much here */
795                 *y_isect = (p1[0] + p2[0]) * 0.5f;
796                 return ISECT_TRUE;
797         }
798
799         if (p1[0] > x_level && p2[0] < x_level) {
800                 *y_isect = (p2[1] * (p1[0] - x_level) + p1[1] * (x_level - p2[0])) / x_diff; /*(p1[0]-p2[0]);*/
801                 return ISECT_TRUE;
802         }
803         else if (p1[0] < x_level && p2[0] > x_level) {
804                 *y_isect = (p2[1] * (x_level - p1[0]) + p1[1] * (p2[0] - x_level)) / x_diff; /*(p2[0]-p1[0]);*/
805                 return ISECT_TRUE;
806         }
807         else {
808                 return 0;
809         }
810 }
811
812 /* simple func use for comparing UV locations to check if there are seams.
813  * Its possible this gives incorrect results, when the UVs for 1 face go into the next
814  * tile, but do not do this for the adjacent face, it could return a false positive.
815  * This is so unlikely that Id not worry about it. */
816 #ifndef PROJ_DEBUG_NOSEAMBLEED
817 static bool cmp_uv(const float vec2a[2], const float vec2b[2])
818 {
819         /* if the UV's are not between 0.0 and 1.0 */
820         float xa = fmodf(vec2a[0], 1.0f);
821         float ya = fmodf(vec2a[1], 1.0f);
822
823         float xb = fmodf(vec2b[0], 1.0f);
824         float yb = fmodf(vec2b[1], 1.0f);
825
826         if (xa < 0.0f) xa += 1.0f;
827         if (ya < 0.0f) ya += 1.0f;
828
829         if (xb < 0.0f) xb += 1.0f;
830         if (yb < 0.0f) yb += 1.0f;
831
832         return ((fabsf(xa - xb) < PROJ_GEOM_TOLERANCE) && (fabsf(ya - yb) < PROJ_GEOM_TOLERANCE)) ? 1 : 0;
833 }
834 #endif
835
836 /* set min_px and max_px to the image space bounds of the UV coords
837  * return zero if there is no area in the returned rectangle */
838 #ifndef PROJ_DEBUG_NOSEAMBLEED
839 static bool pixel_bounds_uv(
840         const float uv1[2], const float uv2[2], const float uv3[2], const float uv4[2],
841         rcti *bounds_px,
842         const int ibuf_x, const int ibuf_y,
843         const bool is_quad
844         )
845 {
846         float min_uv[2], max_uv[2]; /* UV bounds */
847
848         INIT_MINMAX2(min_uv, max_uv);
849
850         minmax_v2v2_v2(min_uv, max_uv, uv1);
851         minmax_v2v2_v2(min_uv, max_uv, uv2);
852         minmax_v2v2_v2(min_uv, max_uv, uv3);
853         if (is_quad)
854                 minmax_v2v2_v2(min_uv, max_uv, uv4);
855
856         bounds_px->xmin = (int)(ibuf_x * min_uv[0]);
857         bounds_px->ymin = (int)(ibuf_y * min_uv[1]);
858
859         bounds_px->xmax = (int)(ibuf_x * max_uv[0]) + 1;
860         bounds_px->ymax = (int)(ibuf_y * max_uv[1]) + 1;
861
862         /*printf("%d %d %d %d\n", min_px[0], min_px[1], max_px[0], max_px[1]);*/
863
864         /* face uses no UV area when quantized to pixels? */
865         return (bounds_px->xmin == bounds_px->xmax || bounds_px->ymin == bounds_px->ymax) ? 0 : 1;
866 }
867 #endif
868
869 static bool pixel_bounds_array(float (*uv)[2], rcti *bounds_px, const int ibuf_x, const int ibuf_y, int tot)
870 {
871         float min_uv[2], max_uv[2]; /* UV bounds */
872
873         if (tot == 0) {
874                 return 0;
875         }
876
877         INIT_MINMAX2(min_uv, max_uv);
878
879         while (tot--) {
880                 minmax_v2v2_v2(min_uv, max_uv, (*uv));
881                 uv++;
882         }
883
884         bounds_px->xmin = (int)(ibuf_x * min_uv[0]);
885         bounds_px->ymin = (int)(ibuf_y * min_uv[1]);
886
887         bounds_px->xmax = (int)(ibuf_x * max_uv[0]) + 1;
888         bounds_px->ymax = (int)(ibuf_y * max_uv[1]) + 1;
889
890         /*printf("%d %d %d %d\n", min_px[0], min_px[1], max_px[0], max_px[1]);*/
891
892         /* face uses no UV area when quantized to pixels? */
893         return (bounds_px->xmin == bounds_px->xmax || bounds_px->ymin == bounds_px->ymax) ? 0 : 1;
894 }
895
896 #ifndef PROJ_DEBUG_NOSEAMBLEED
897
898 static void project_face_winding_init(const ProjPaintState *ps, const int face_index)
899 {
900         /* detect the winding of faces in uv space */
901         MTFace *tf = ps->dm_mtface[face_index];
902         float winding = cross_tri_v2(tf->uv[0], tf->uv[1], tf->uv[2]);
903
904         if (ps->dm_mface[face_index].v4)
905                 winding += cross_tri_v2(tf->uv[2], tf->uv[3], tf->uv[0]);
906
907         if (winding > 0)
908                 ps->faceWindingFlags[face_index] |= PROJ_FACE_WINDING_CW;
909
910         ps->faceWindingFlags[face_index] |= PROJ_FACE_WINDING_INIT;
911 }
912
913 /* This function returns 1 if this face has a seam along the 2 face-vert indices
914  * 'orig_i1_fidx' and 'orig_i2_fidx' */
915 static bool check_seam(const ProjPaintState *ps,
916                        const int orig_face, const int orig_i1_fidx, const int orig_i2_fidx,
917                        int *other_face, int *orig_fidx)
918 {
919         LinkNode *node;
920         int face_index;
921         unsigned int i1, i2;
922         int i1_fidx = -1, i2_fidx = -1; /* index in face */
923         MFace *mf;
924         MTFace *tf;
925         const MFace *orig_mf = ps->dm_mface + orig_face;
926         const MTFace *orig_tf = ps->dm_mtface[orig_face];
927
928         /* vert indices from face vert order indices */
929         i1 = (*(&orig_mf->v1 + orig_i1_fidx));
930         i2 = (*(&orig_mf->v1 + orig_i2_fidx));
931
932         for (node = ps->vertFaces[i1]; node; node = node->next) {
933                 face_index = GET_INT_FROM_POINTER(node->link);
934
935                 if (face_index != orig_face) {
936                         mf = ps->dm_mface + face_index;
937                         /* could check if the 2 faces images match here,
938                          * but then there wouldn't be a way to return the opposite face's info */
939
940
941                         /* We need to know the order of the verts in the adjacent face
942                          * set the i1_fidx and i2_fidx to (0,1,2,3) */
943                         i1_fidx = BKE_MESH_TESSFACE_VINDEX_ORDER(mf, i1);
944                         i2_fidx = BKE_MESH_TESSFACE_VINDEX_ORDER(mf, i2);
945
946                         /* Only need to check if 'i2_fidx' is valid because we know i1_fidx is the same vert on both faces */
947                         if (i2_fidx != -1) {
948                                 Image *tpage = project_paint_face_paint_image(ps, face_index);
949                                 Image *orig_tpage = project_paint_face_paint_image(ps, orig_face);
950
951                                 BLI_assert(i1_fidx != -1);
952
953                                 /* This IS an adjacent face!, now lets check if the UVs are ok */
954                                 tf = ps->dm_mtface[face_index];
955
956                                 /* set up the other face */
957                                 *other_face = face_index;
958                                 
959                                 /* we check if difference is 1 here, else we might have a case of edge 2-0 or 3-0 for quads */
960                                 *orig_fidx = (i1_fidx < i2_fidx && (i2_fidx - i1_fidx == 1)) ? i1_fidx : i2_fidx;
961
962                                 /* initialize face winding if needed */
963                                 if ((ps->faceWindingFlags[face_index] & PROJ_FACE_WINDING_INIT) == 0)
964                                         project_face_winding_init(ps, face_index);
965
966                                 /* first test if they have the same image */
967                                 if ((orig_tpage == tpage) &&
968                                     cmp_uv(orig_tf->uv[orig_i1_fidx], tf->uv[i1_fidx]) &&
969                                     cmp_uv(orig_tf->uv[orig_i2_fidx], tf->uv[i2_fidx]))
970                                 {
971                                         /* if faces don't have the same winding in uv space,
972                                          * they are on the same side so edge is boundary */
973                                         if ((ps->faceWindingFlags[face_index] & PROJ_FACE_WINDING_CW) !=
974                                             (ps->faceWindingFlags[orig_face] & PROJ_FACE_WINDING_CW))
975                                         {
976                                                 return 1;
977                                         }
978
979                                         // printf("SEAM (NONE)\n");
980                                         return 0;
981
982                                 }
983                                 else {
984                                         // printf("SEAM (UV GAP)\n");
985                                         return 1;
986                                 }
987                         }
988                 }
989         }
990         // printf("SEAM (NO FACE)\n");
991         *other_face = -1;
992         return 1;
993 }
994
995 #define SMALL_NUMBER  1.e-6f
996 BLI_INLINE float shell_v2v2_normal_dir_to_dist(float n[2], float d[2])
997 {
998         const float angle_cos = (normalize_v2(n) < SMALL_NUMBER) ? fabsf(dot_v2v2(d, n)) : 0.0f;
999         return (UNLIKELY(angle_cos < SMALL_NUMBER)) ? 1.0f : (1.0f / angle_cos);
1000 }
1001 #undef SMALL_NUMBER
1002
1003 /* Calculate outset UV's, this is not the same as simply scaling the UVs,
1004  * since the outset coords are a margin that keep an even distance from the original UV's,
1005  * note that the image aspect is taken into account */
1006 static void uv_image_outset(float (*orig_uv)[2], float (*outset_uv)[2], const float scaler,
1007                             const int ibuf_x, const int ibuf_y, const bool is_quad, const bool cw)
1008 {
1009         float a1, a2, a3, a4 = 0.0f;
1010         float puv[4][2]; /* pixelspace uv's */
1011         float no1[2], no2[2], no3[2], no4[2]; /* normals */
1012         float dir1[2], dir2[2], dir3[2], dir4[2];
1013         float ibuf_inv[2];
1014
1015         ibuf_inv[0] = 1.0f / (float)ibuf_x;
1016         ibuf_inv[1] = 1.0f / (float)ibuf_y;
1017
1018         /* make UV's in pixel space so we can */
1019         puv[0][0] = orig_uv[0][0] * ibuf_x;
1020         puv[0][1] = orig_uv[0][1] * ibuf_y;
1021
1022         puv[1][0] = orig_uv[1][0] * ibuf_x;
1023         puv[1][1] = orig_uv[1][1] * ibuf_y;
1024
1025         puv[2][0] = orig_uv[2][0] * ibuf_x;
1026         puv[2][1] = orig_uv[2][1] * ibuf_y;
1027
1028         if (is_quad) {
1029                 puv[3][0] = orig_uv[3][0] * ibuf_x;
1030                 puv[3][1] = orig_uv[3][1] * ibuf_y;
1031         }
1032
1033         /* face edge directions */
1034         sub_v2_v2v2(dir1, puv[1], puv[0]);
1035         sub_v2_v2v2(dir2, puv[2], puv[1]);
1036         normalize_v2(dir1);
1037         normalize_v2(dir2);
1038
1039         if (is_quad) {
1040                 sub_v2_v2v2(dir3, puv[3], puv[2]);
1041                 sub_v2_v2v2(dir4, puv[0], puv[3]);
1042                 normalize_v2(dir3);
1043                 normalize_v2(dir4);
1044         }
1045         else {
1046                 sub_v2_v2v2(dir3, puv[0], puv[2]);
1047                 normalize_v2(dir3);
1048         }
1049
1050         if (is_quad) {
1051                 /* here we just use the orthonormality property (a1, a2) dot (a2, -a1) = 0
1052                  * to get normals from the edge directions based on the winding */
1053                 if (cw) {
1054                         no1[0] = -dir4[1] - dir1[1];
1055                         no1[1] = dir4[0] + dir1[0];
1056                         no2[0] = -dir1[1] - dir2[1];
1057                         no2[1] = dir1[0] + dir2[0];
1058                         no3[0] = -dir2[1] - dir3[1];
1059                         no3[1] = dir2[0] + dir3[0];
1060                         no4[0] = -dir3[1] - dir4[1];
1061                         no4[1] = dir3[0] + dir4[0];
1062                 }
1063                 else {
1064                         no1[0] = dir4[1] + dir1[1];
1065                         no1[1] = -dir4[0] - dir1[0];
1066                         no2[0] = dir1[1] + dir2[1];
1067                         no2[1] = -dir1[0] - dir2[0];
1068                         no3[0] = dir2[1] + dir3[1];
1069                         no3[1] = -dir2[0] - dir3[0];
1070                         no4[0] = dir3[1] + dir4[1];
1071                         no4[1] = -dir3[0] - dir4[0];
1072                 }
1073
1074                 a1 = shell_v2v2_normal_dir_to_dist(no1, dir4);
1075                 a2 = shell_v2v2_normal_dir_to_dist(no2, dir1);
1076                 a3 = shell_v2v2_normal_dir_to_dist(no3, dir2);
1077                 a4 = shell_v2v2_normal_dir_to_dist(no4, dir3);
1078
1079                 mul_v2_fl(no1, a1 * scaler);
1080                 mul_v2_fl(no2, a2 * scaler);
1081                 mul_v2_fl(no3, a3 * scaler);
1082                 mul_v2_fl(no4, a4 * scaler);
1083                 add_v2_v2v2(outset_uv[0], puv[0], no1);
1084                 add_v2_v2v2(outset_uv[1], puv[1], no2);
1085                 add_v2_v2v2(outset_uv[2], puv[2], no3);
1086                 add_v2_v2v2(outset_uv[3], puv[3], no4);
1087                 mul_v2_v2(outset_uv[0], ibuf_inv);
1088                 mul_v2_v2(outset_uv[1], ibuf_inv);
1089                 mul_v2_v2(outset_uv[2], ibuf_inv);
1090                 mul_v2_v2(outset_uv[3], ibuf_inv);
1091         }
1092         else {
1093                 if (cw) {
1094                         no1[0] = -dir3[1] - dir1[1];
1095                         no1[1] = dir3[0] + dir1[0];
1096                         no2[0] = -dir1[1] - dir2[1];
1097                         no2[1] = dir1[0] + dir2[0];
1098                         no3[0] = -dir2[1] - dir3[1];
1099                         no3[1] = dir2[0] + dir3[0];
1100                 }
1101                 else {
1102                         no1[0] = dir3[1] + dir1[1];
1103                         no1[1] = -dir3[0] - dir1[0];
1104                         no2[0] = dir1[1] + dir2[1];
1105                         no2[1] = -dir1[0] - dir2[0];
1106                         no3[0] = dir2[1] + dir3[1];
1107                         no3[1] = -dir2[0] - dir3[0];
1108                 }
1109
1110                 a1 = shell_v2v2_normal_dir_to_dist(no1, dir3);
1111                 a2 = shell_v2v2_normal_dir_to_dist(no2, dir1);
1112                 a3 = shell_v2v2_normal_dir_to_dist(no3, dir2);
1113
1114                 mul_v2_fl(no1, a1 * scaler);
1115                 mul_v2_fl(no2, a2 * scaler);
1116                 mul_v2_fl(no3, a3 * scaler);
1117                 add_v2_v2v2(outset_uv[0], puv[0], no1);
1118                 add_v2_v2v2(outset_uv[1], puv[1], no2);
1119                 add_v2_v2v2(outset_uv[2], puv[2], no3);
1120
1121                 mul_v2_v2(outset_uv[0], ibuf_inv);
1122                 mul_v2_v2(outset_uv[1], ibuf_inv);
1123                 mul_v2_v2(outset_uv[2], ibuf_inv);
1124         }
1125 }
1126
1127 /*
1128  * Be tricky with flags, first 4 bits are PROJ_FACE_SEAM1 to 4, last 4 bits are PROJ_FACE_NOSEAM1 to 4
1129  * 1<<i - where i is (0-3)
1130  *
1131  * If we're multithreadng, make sure threads are locked when this is called
1132  */
1133 static void project_face_seams_init(const ProjPaintState *ps, const int face_index, const int is_quad)
1134 {
1135         int other_face, other_fidx; /* vars for the other face, we also set its flag */
1136         int fidx1 = is_quad ? 3 : 2;
1137         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 */
1138
1139         /* initialize face winding if needed */
1140         if ((ps->faceWindingFlags[face_index] & PROJ_FACE_WINDING_INIT) == 0)
1141                 project_face_winding_init(ps, face_index);
1142
1143         do {
1144                 if ((ps->faceSeamFlags[face_index] & (1 << fidx1 | 16 << fidx1)) == 0) {
1145                         if (check_seam(ps, face_index, fidx1, fidx2, &other_face, &other_fidx)) {
1146                                 ps->faceSeamFlags[face_index] |= 1 << fidx1;
1147                                 if (other_face != -1)
1148                                         ps->faceSeamFlags[other_face] |= 1 << other_fidx;
1149                         }
1150                         else {
1151                                 ps->faceSeamFlags[face_index] |= 16 << fidx1;
1152                                 if (other_face != -1)
1153                                         ps->faceSeamFlags[other_face] |= 16 << other_fidx;  /* second 4 bits for disabled */
1154                         }
1155                 }
1156
1157                 fidx2 = fidx1;
1158         } while (fidx1--);
1159 }
1160 #endif // PROJ_DEBUG_NOSEAMBLEED
1161
1162
1163 /* Converts a UV location to a 3D screenspace location
1164  * Takes a 'uv' and 3 UV coords, and sets the values of pixelScreenCo
1165  *
1166  * This is used for finding a pixels location in screenspace for painting */
1167 static void screen_px_from_ortho(
1168         const float uv[2],
1169         const float v1co[3], const float v2co[3], const float v3co[3],  /* Screenspace coords */
1170         const float uv1co[2], const float uv2co[2], const float uv3co[2],
1171         float pixelScreenCo[4],
1172         float w[3])
1173 {
1174         barycentric_weights_v2(uv1co, uv2co, uv3co, uv, w);
1175         interp_v3_v3v3v3(pixelScreenCo, v1co, v2co, v3co, w);
1176 }
1177
1178 /* same as screen_px_from_ortho except we
1179  * do perspective correction on the pixel coordinate */
1180 static void screen_px_from_persp(
1181         const float uv[2],
1182         const float v1co[4], const float v2co[4], const float v3co[4],  /* screenspace coords */
1183         const float uv1co[2], const float uv2co[2], const float uv3co[2],
1184         float pixelScreenCo[4],
1185         float w[3])
1186 {
1187         float w_int[3];
1188         float wtot_inv, wtot;
1189         barycentric_weights_v2(uv1co, uv2co, uv3co, uv, w);
1190
1191         /* re-weight from the 4th coord of each screen vert */
1192         w_int[0] = w[0] * v1co[3];
1193         w_int[1] = w[1] * v2co[3];
1194         w_int[2] = w[2] * v3co[3];
1195
1196         wtot = w_int[0] + w_int[1] + w_int[2];
1197
1198         if (wtot > 0.0f) {
1199                 wtot_inv = 1.0f / wtot;
1200                 w_int[0] *= wtot_inv;
1201                 w_int[1] *= wtot_inv;
1202                 w_int[2] *= wtot_inv;
1203         }
1204         else {
1205                 w[0] = w[1] = w[2] =
1206                 w_int[0] = w_int[1] = w_int[2] = 1.0f / 3.0f;  /* dummy values for zero area face */
1207         }
1208         /* done re-weighting */
1209
1210         /* do interpolation based on projected weight */
1211         interp_v3_v3v3v3(pixelScreenCo, v1co, v2co, v3co, w_int);
1212 }
1213
1214
1215 static void project_face_pixel(const MTFace *tf_other, ImBuf *ibuf_other, const float w[3],
1216                                int side, unsigned char rgba_ub[4], float rgba_f[4])
1217 {
1218         const float *uvCo1, *uvCo2, *uvCo3;
1219         float uv_other[2], x, y;
1220
1221         uvCo1 =  (float *)tf_other->uv[0];
1222         if (side == 1) {
1223                 uvCo2 =  (float *)tf_other->uv[2];
1224                 uvCo3 =  (float *)tf_other->uv[3];
1225         }
1226         else {
1227                 uvCo2 =  (float *)tf_other->uv[1];
1228                 uvCo3 =  (float *)tf_other->uv[2];
1229         }
1230
1231         interp_v2_v2v2v2(uv_other, uvCo1, uvCo2, uvCo3, (float *)w);
1232
1233         /* use */
1234         uvco_to_wrapped_pxco(uv_other, ibuf_other->x, ibuf_other->y, &x, &y);
1235
1236
1237         if (ibuf_other->rect_float) { /* from float to float */
1238                 bilinear_interpolation_color_wrap(ibuf_other, NULL, rgba_f, x, y);
1239         }
1240         else { /* from char to float */
1241                 bilinear_interpolation_color_wrap(ibuf_other, rgba_ub, NULL, x, y);
1242         }
1243
1244 }
1245
1246 /* run this outside project_paint_uvpixel_init since pixels with mask 0 don't need init */
1247 static float project_paint_uvpixel_mask(
1248         const ProjPaintState *ps,
1249         const int face_index,
1250         const int side,
1251         const float w[3])
1252 {
1253         float mask;
1254
1255         /* Image Mask */
1256         if (ps->do_layer_stencil) {
1257                 /* another UV maps image is masking this one's */
1258                 ImBuf *ibuf_other;
1259                 Image *other_tpage = ps->stencil_ima;
1260                 const MTFace *tf_other = ps->dm_mtface_stencil + face_index;
1261
1262                 if (other_tpage && (ibuf_other = BKE_image_acquire_ibuf(other_tpage, NULL, NULL))) {
1263                         /* BKE_image_acquire_ibuf - TODO - this may be slow */
1264                         unsigned char rgba_ub[4];
1265                         float rgba_f[4];
1266
1267                         project_face_pixel(tf_other, ibuf_other, w, side, rgba_ub, rgba_f);
1268
1269                         if (ibuf_other->rect_float) { /* from float to float */
1270                                 mask = ((rgba_f[0] + rgba_f[1] + rgba_f[2]) * (1.0f / 3.0f)) * rgba_f[3];
1271                         }
1272                         else { /* from char to float */
1273                                 mask = ((rgba_ub[0] + rgba_ub[1] + rgba_ub[2]) * (1.0f / (255.0f * 3.0f))) * (rgba_ub[3] * (1.0f / 255.0f));
1274                         }
1275
1276                         BKE_image_release_ibuf(other_tpage, ibuf_other, NULL);
1277
1278                         if (!ps->do_layer_stencil_inv) /* matching the gimps layer mask black/white rules, white==full opacity */
1279                                 mask = (1.0f - mask);
1280
1281                         if (mask == 0.0f) {
1282                                 return 0.0f;
1283                         }
1284                 }
1285                 else {
1286                         return 0.0f;
1287                 }
1288         }
1289         else {
1290                 mask = 1.0f;
1291         }
1292
1293         /* calculate mask */
1294         if (ps->do_mask_normal) {
1295                 MFace *mf = &ps->dm_mface[face_index];
1296                 float no[3], angle;
1297                 if (mf->flag & ME_SMOOTH) {
1298                         const short *no1, *no2, *no3;
1299                         no1 = ps->dm_mvert[mf->v1].no;
1300                         if (side == 1) {
1301                                 no2 = ps->dm_mvert[mf->v3].no;
1302                                 no3 = ps->dm_mvert[mf->v4].no;
1303                         }
1304                         else {
1305                                 no2 = ps->dm_mvert[mf->v2].no;
1306                                 no3 = ps->dm_mvert[mf->v3].no;
1307                         }
1308
1309                         no[0] = w[0] * no1[0] + w[1] * no2[0] + w[2] * no3[0];
1310                         no[1] = w[0] * no1[1] + w[1] * no2[1] + w[2] * no3[1];
1311                         no[2] = w[0] * no1[2] + w[1] * no2[2] + w[2] * no3[2];
1312                         normalize_v3(no);
1313                 }
1314                 else {
1315                         /* incase the */
1316 #if 1
1317                         /* normalizing per pixel isn't optimal, we could cache or check ps->*/
1318                         if (mf->v4)
1319                                 normal_quad_v3(no,
1320                                                ps->dm_mvert[mf->v1].co,
1321                                                ps->dm_mvert[mf->v2].co,
1322                                                ps->dm_mvert[mf->v3].co,
1323                                                ps->dm_mvert[mf->v4].co);
1324                         else
1325                                 normal_tri_v3(no,
1326                                               ps->dm_mvert[mf->v1].co,
1327                                               ps->dm_mvert[mf->v2].co,
1328                                               ps->dm_mvert[mf->v3].co);
1329 #else
1330                         /* don't use because some modifiers dont have normal data (subsurf for eg) */
1331                         copy_v3_v3(no, (float *)ps->dm->getTessFaceData(ps->dm, face_index, CD_NORMAL));
1332 #endif
1333                 }
1334
1335                 /* now we can use the normal as a mask */
1336                 if (ps->is_ortho) {
1337                         angle = angle_normalized_v3v3((float *)ps->viewDir, no);
1338                 }
1339                 else {
1340                         /* Annoying but for the perspective view we need to get the pixels location in 3D space :/ */
1341                         float viewDirPersp[3];
1342                         const float *co1, *co2, *co3;
1343                         co1 = ps->dm_mvert[mf->v1].co;
1344                         if (side == 1) {
1345                                 co2 = ps->dm_mvert[mf->v3].co;
1346                                 co3 = ps->dm_mvert[mf->v4].co;
1347                         }
1348                         else {
1349                                 co2 = ps->dm_mvert[mf->v2].co;
1350                                 co3 = ps->dm_mvert[mf->v3].co;
1351                         }
1352
1353                         /* Get the direction from the viewPoint to the pixel and normalize */
1354                         viewDirPersp[0] = (ps->viewPos[0] - (w[0] * co1[0] + w[1] * co2[0] + w[2] * co3[0]));
1355                         viewDirPersp[1] = (ps->viewPos[1] - (w[0] * co1[1] + w[1] * co2[1] + w[2] * co3[1]));
1356                         viewDirPersp[2] = (ps->viewPos[2] - (w[0] * co1[2] + w[1] * co2[2] + w[2] * co3[2]));
1357                         normalize_v3(viewDirPersp);
1358
1359                         angle = angle_normalized_v3v3(viewDirPersp, no);
1360                 }
1361
1362                 if (angle >= ps->normal_angle) {
1363                         return 0.0f; /* outsize the normal limit*/
1364                 }
1365                 else if (angle > ps->normal_angle_inner) {
1366                         mask *= (ps->normal_angle - angle) / ps->normal_angle_range;
1367                 } /* otherwise no mask normal is needed, were within the limit */
1368         }
1369
1370         /* This only works when the opacity dosnt change while painting, stylus pressure messes with this
1371          * so don't use it. */
1372         // if (ps->is_airbrush == 0) mask *= BKE_brush_alpha_get(ps->brush);
1373
1374         return mask;
1375 }
1376
1377 static int project_paint_pixel_sizeof(const short tool)
1378 {
1379         if ((tool == PAINT_TOOL_CLONE) || (tool == PAINT_TOOL_SMEAR)) {
1380                 return sizeof(ProjPixelClone);
1381         }
1382         else {
1383                 return sizeof(ProjPixel);
1384         }
1385 }
1386
1387 static int project_paint_undo_subtiles(const TileInfo *tinf, int tx, int ty)
1388 {
1389         ProjPaintImage *pjIma = tinf->pjima;
1390         int tile_index = tx + ty * tinf->tile_width;
1391         bool generate_tile = false;
1392
1393         /* double check lock to avoid locking */
1394         if (UNLIKELY(!pjIma->undoRect[tile_index])) {
1395                 if (tinf->lock)
1396                         BLI_spin_lock(tinf->lock);
1397                 if (LIKELY(!pjIma->undoRect[tile_index])) {
1398                         pjIma->undoRect[tile_index] = TILE_PENDING;
1399                         generate_tile = true;
1400                 }
1401                 if (tinf->lock)
1402                         BLI_spin_unlock(tinf->lock);
1403         }
1404
1405
1406         if (generate_tile) {
1407                 volatile void *undorect;
1408                 if (tinf->masked) {
1409                         undorect = image_undo_push_tile(pjIma->ima, pjIma->ibuf, tinf->tmpibuf, tx, ty, &pjIma->maskRect[tile_index], &pjIma->valid[tile_index], true);
1410                 }
1411                 else {
1412                         undorect = image_undo_push_tile(pjIma->ima, pjIma->ibuf, tinf->tmpibuf, tx, ty, NULL, &pjIma->valid[tile_index], true);
1413                 }
1414
1415                 pjIma->ibuf->userflags |= IB_BITMAPDIRTY;
1416                 /* tile ready, publish */
1417                 if (tinf->lock)
1418                         BLI_spin_lock(tinf->lock);
1419                 pjIma->undoRect[tile_index] = undorect;
1420                 if (tinf->lock)
1421                         BLI_spin_unlock(tinf->lock);
1422
1423         }
1424
1425         return tile_index;
1426 }
1427
1428 /* run this function when we know a bucket's, face's pixel can be initialized,
1429  * return the ProjPixel which is added to 'ps->bucketRect[bucket_index]' */
1430 static ProjPixel *project_paint_uvpixel_init(
1431         const ProjPaintState *ps,
1432         MemArena *arena,
1433         const TileInfo *tinf,
1434         int x_px, int y_px,
1435         const float mask,
1436         const int face_index,
1437         const float pixelScreenCo[4],
1438         const float world_spaceCo[3],
1439         const int side,
1440         const float w[3])
1441 {
1442         ProjPixel *projPixel;
1443         int x_tile, y_tile;
1444         int x_round, y_round;
1445         int tile_offset;
1446         /* volatile is important here to ensure pending check is not optimized away by compiler*/
1447         volatile int tile_index;
1448
1449         ProjPaintImage *projima = tinf->pjima;
1450         ImBuf *ibuf = projima->ibuf;
1451         /* wrap pixel location */
1452
1453         x_px = mod_i(x_px, ibuf->x);
1454         y_px = mod_i(y_px, ibuf->y);
1455
1456         BLI_assert(ps->pixel_sizeof == project_paint_pixel_sizeof(ps->tool));
1457         projPixel = (ProjPixel *)BLI_memarena_alloc(arena, ps->pixel_sizeof);
1458
1459         /* calculate the undo tile offset of the pixel, used to store the original
1460          * pixel color and accumulated mask if any */
1461         x_tile =  x_px >> IMAPAINT_TILE_BITS;
1462         y_tile =  y_px >> IMAPAINT_TILE_BITS;
1463
1464         x_round = x_tile * IMAPAINT_TILE_SIZE;
1465         y_round = y_tile * IMAPAINT_TILE_SIZE;
1466         //memset(projPixel, 0, size);
1467
1468         tile_offset = (x_px - x_round) + (y_px - y_round) * IMAPAINT_TILE_SIZE;
1469         tile_index = project_paint_undo_subtiles(tinf, x_tile, y_tile);
1470
1471         /* other thread may be initializing the tile so wait here */
1472         while (projima->undoRect[tile_index] == TILE_PENDING)
1473                 ;
1474
1475         BLI_assert(tile_index < (IMAPAINT_TILE_NUMBER(ibuf->x) * IMAPAINT_TILE_NUMBER(ibuf->y)));
1476         BLI_assert(tile_offset < (IMAPAINT_TILE_SIZE * IMAPAINT_TILE_SIZE));
1477
1478         projPixel->valid = projima->valid[tile_index];
1479
1480         if (ibuf->rect_float) {
1481                 projPixel->pixel.f_pt = ibuf->rect_float + ((x_px + y_px * ibuf->x) * 4);
1482                 projPixel->origColor.f_pt = (float *)projima->undoRect[tile_index] + 4 * tile_offset;
1483                 zero_v4(projPixel->newColor.f);
1484         }
1485         else {
1486                 projPixel->pixel.ch_pt = (unsigned char *)(ibuf->rect + (x_px + y_px * ibuf->x));
1487                 projPixel->origColor.uint_pt = (unsigned int *)projima->undoRect[tile_index] + tile_offset;
1488                 projPixel->newColor.uint = 0;
1489         }
1490
1491         /* screenspace unclamped, we could keep its z and w values but don't need them at the moment */
1492         if (ps->brush->mtex.brush_map_mode == MTEX_MAP_MODE_3D) {
1493                 copy_v3_v3(projPixel->worldCoSS, world_spaceCo);
1494         }
1495
1496         copy_v2_v2(projPixel->projCoSS, pixelScreenCo);
1497
1498         projPixel->x_px = x_px;
1499         projPixel->y_px = y_px;
1500
1501         projPixel->mask = (unsigned short)(mask * 65535);
1502         if (ps->do_masking)
1503                 projPixel->mask_accum = projima->maskRect[tile_index] + tile_offset;
1504         else
1505                 projPixel->mask_accum = NULL;
1506
1507         /* which bounding box cell are we in?, needed for undo */
1508         projPixel->bb_cell_index = ((int)(((float)x_px / (float)ibuf->x) * PROJ_BOUNDBOX_DIV)) +
1509                                    ((int)(((float)y_px / (float)ibuf->y) * PROJ_BOUNDBOX_DIV)) * PROJ_BOUNDBOX_DIV;
1510
1511         /* done with view3d_project_float inline */
1512         if (ps->tool == PAINT_TOOL_CLONE) {
1513                 if (ps->dm_mtface_clone) {
1514                         ImBuf *ibuf_other;
1515                         Image *other_tpage = project_paint_face_clone_image(ps, face_index);
1516                         const MTFace *tf_other = ps->dm_mtface_clone[face_index];
1517
1518                         if (other_tpage && (ibuf_other = BKE_image_acquire_ibuf(other_tpage, NULL, NULL))) {
1519                                 /* BKE_image_acquire_ibuf - TODO - this may be slow */
1520
1521                                 if (ibuf->rect_float) {
1522                                         if (ibuf_other->rect_float) { /* from float to float */
1523                                                 project_face_pixel(tf_other, ibuf_other, w, side, NULL, ((ProjPixelClone *)projPixel)->clonepx.f);
1524                                         }
1525                                         else { /* from char to float */
1526                                                 unsigned char rgba_ub[4];
1527                                                 float rgba[4];
1528                                                 project_face_pixel(tf_other, ibuf_other, w, side, rgba_ub, NULL);
1529                                                 srgb_to_linearrgb_uchar4(rgba, rgba_ub);
1530                                                 straight_to_premul_v4_v4(((ProjPixelClone *)projPixel)->clonepx.f, rgba);
1531                                         }
1532                                 }
1533                                 else {
1534                                         if (ibuf_other->rect_float) { /* float to char */
1535                                                 float rgba[4];
1536                                                 project_face_pixel(tf_other, ibuf_other, w, side, NULL, rgba);
1537                                                 premul_to_straight_v4(rgba);
1538                                                 linearrgb_to_srgb_uchar3(((ProjPixelClone *)projPixel)->clonepx.ch, rgba);
1539                                                 ((ProjPixelClone *)projPixel)->clonepx.ch[3] =  rgba[3] * 255;
1540                                         }
1541                                         else { /* char to char */
1542                                                 project_face_pixel(tf_other, ibuf_other, w, side, ((ProjPixelClone *)projPixel)->clonepx.ch, NULL);
1543                                         }
1544                                 }
1545
1546                                 BKE_image_release_ibuf(other_tpage, ibuf_other, NULL);
1547                         }
1548                         else {
1549                                 if (ibuf->rect_float) {
1550                                         ((ProjPixelClone *)projPixel)->clonepx.f[3] = 0;
1551                                 }
1552                                 else {
1553                                         ((ProjPixelClone *)projPixel)->clonepx.ch[3] = 0;
1554                                 }
1555                         }
1556
1557                 }
1558                 else {
1559                         float co[2];
1560                         sub_v2_v2v2(co, projPixel->projCoSS, (float *)ps->cloneOffset);
1561
1562                         /* no need to initialize the bucket, we're only checking buckets faces and for this
1563                          * the faces are already initialized in project_paint_delayed_face_init(...) */
1564                         if (ibuf->rect_float) {
1565                                 if (!project_paint_PickColor(ps, co, ((ProjPixelClone *)projPixel)->clonepx.f, NULL, 1)) {
1566                                         ((ProjPixelClone *)projPixel)->clonepx.f[3] = 0; /* zero alpha - ignore */
1567                                 }
1568                         }
1569                         else {
1570                                 if (!project_paint_PickColor(ps, co, NULL, ((ProjPixelClone *)projPixel)->clonepx.ch, 1)) {
1571                                         ((ProjPixelClone *)projPixel)->clonepx.ch[3] = 0; /* zero alpha - ignore */
1572                                 }
1573                         }
1574                 }
1575         }
1576
1577 #ifdef PROJ_DEBUG_PAINT
1578         if (ibuf->rect_float) projPixel->pixel.f_pt[0] = 0;
1579         else                  projPixel->pixel.ch_pt[0] = 0;
1580 #endif
1581         /* pointer arithmetics */
1582         projPixel->image_index = projima - ps->projImages;
1583
1584         return projPixel;
1585 }
1586
1587 static bool line_clip_rect2f(
1588         rctf *rect,
1589         const float l1[2], const float l2[2],
1590         float l1_clip[2], float l2_clip[2])
1591 {
1592         /* first account for horizontal, then vertical lines */
1593         /* horiz */
1594         if (fabsf(l1[1] - l2[1]) < PROJ_GEOM_TOLERANCE) {
1595                 /* is the line out of range on its Y axis? */
1596                 if (l1[1] < rect->ymin || l1[1] > rect->ymax) {
1597                         return 0;
1598                 }
1599                 /* line is out of range on its X axis */
1600                 if ((l1[0] < rect->xmin && l2[0] < rect->xmin) || (l1[0] > rect->xmax && l2[0] > rect->xmax)) {
1601                         return 0;
1602                 }
1603
1604
1605                 if (fabsf(l1[0] - l2[0]) < PROJ_GEOM_TOLERANCE) { /* this is a single point  (or close to)*/
1606                         if (BLI_rctf_isect_pt_v(rect, l1)) {
1607                                 copy_v2_v2(l1_clip, l1);
1608                                 copy_v2_v2(l2_clip, l2);
1609                                 return 1;
1610                         }
1611                         else {
1612                                 return 0;
1613                         }
1614                 }
1615
1616                 copy_v2_v2(l1_clip, l1);
1617                 copy_v2_v2(l2_clip, l2);
1618                 CLAMP(l1_clip[0], rect->xmin, rect->xmax);
1619                 CLAMP(l2_clip[0], rect->xmin, rect->xmax);
1620                 return 1;
1621         }
1622         else if (fabsf(l1[0] - l2[0]) < PROJ_GEOM_TOLERANCE) {
1623                 /* is the line out of range on its X axis? */
1624                 if (l1[0] < rect->xmin || l1[0] > rect->xmax) {
1625                         return 0;
1626                 }
1627
1628                 /* line is out of range on its Y axis */
1629                 if ((l1[1] < rect->ymin && l2[1] < rect->ymin) || (l1[1] > rect->ymax && l2[1] > rect->ymax)) {
1630                         return 0;
1631                 }
1632
1633                 if (fabsf(l1[1] - l2[1]) < PROJ_GEOM_TOLERANCE) { /* this is a single point  (or close to)*/
1634                         if (BLI_rctf_isect_pt_v(rect, l1)) {
1635                                 copy_v2_v2(l1_clip, l1);
1636                                 copy_v2_v2(l2_clip, l2);
1637                                 return 1;
1638                         }
1639                         else {
1640                                 return 0;
1641                         }
1642                 }
1643
1644                 copy_v2_v2(l1_clip, l1);
1645                 copy_v2_v2(l2_clip, l2);
1646                 CLAMP(l1_clip[1], rect->ymin, rect->ymax);
1647                 CLAMP(l2_clip[1], rect->ymin, rect->ymax);
1648                 return 1;
1649         }
1650         else {
1651                 float isect;
1652                 short ok1 = 0;
1653                 short ok2 = 0;
1654
1655                 /* Done with vertical lines */
1656
1657                 /* are either of the points inside the rectangle ? */
1658                 if (BLI_rctf_isect_pt_v(rect, l1)) {
1659                         copy_v2_v2(l1_clip, l1);
1660                         ok1 = 1;
1661                 }
1662
1663                 if (BLI_rctf_isect_pt_v(rect, l2)) {
1664                         copy_v2_v2(l2_clip, l2);
1665                         ok2 = 1;
1666                 }
1667
1668                 /* line inside rect */
1669                 if (ok1 && ok2) return 1;
1670
1671                 /* top/bottom */
1672                 if (line_isect_y(l1, l2, rect->ymin, &isect) && (isect >= rect->xmin) && (isect <= rect->xmax)) {
1673                         if (l1[1] < l2[1]) { /* line 1 is outside */
1674                                 l1_clip[0] = isect;
1675                                 l1_clip[1] = rect->ymin;
1676                                 ok1 = 1;
1677                         }
1678                         else {
1679                                 l2_clip[0] = isect;
1680                                 l2_clip[1] = rect->ymin;
1681                                 ok2 = 2;
1682                         }
1683                 }
1684
1685                 if (ok1 && ok2) return 1;
1686
1687                 if (line_isect_y(l1, l2, rect->ymax, &isect) && (isect >= rect->xmin) && (isect <= rect->xmax)) {
1688                         if (l1[1] > l2[1]) { /* line 1 is outside */
1689                                 l1_clip[0] = isect;
1690                                 l1_clip[1] = rect->ymax;
1691                                 ok1 = 1;
1692                         }
1693                         else {
1694                                 l2_clip[0] = isect;
1695                                 l2_clip[1] = rect->ymax;
1696                                 ok2 = 2;
1697                         }
1698                 }
1699
1700                 if (ok1 && ok2) return 1;
1701
1702                 /* left/right */
1703                 if (line_isect_x(l1, l2, rect->xmin, &isect) && (isect >= rect->ymin) && (isect <= rect->ymax)) {
1704                         if (l1[0] < l2[0]) { /* line 1 is outside */
1705                                 l1_clip[0] = rect->xmin;
1706                                 l1_clip[1] = isect;
1707                                 ok1 = 1;
1708                         }
1709                         else {
1710                                 l2_clip[0] = rect->xmin;
1711                                 l2_clip[1] = isect;
1712                                 ok2 = 2;
1713                         }
1714                 }
1715
1716                 if (ok1 && ok2) return 1;
1717
1718                 if (line_isect_x(l1, l2, rect->xmax, &isect) && (isect >= rect->ymin) && (isect <= rect->ymax)) {
1719                         if (l1[0] > l2[0]) { /* line 1 is outside */
1720                                 l1_clip[0] = rect->xmax;
1721                                 l1_clip[1] = isect;
1722                                 ok1 = 1;
1723                         }
1724                         else {
1725                                 l2_clip[0] = rect->xmax;
1726                                 l2_clip[1] = isect;
1727                                 ok2 = 2;
1728                         }
1729                 }
1730
1731                 if (ok1 && ok2) {
1732                         return 1;
1733                 }
1734                 else {
1735                         return 0;
1736                 }
1737         }
1738 }
1739
1740
1741
1742 /* scale the quad & tri about its center
1743  * scaling by PROJ_FACE_SCALE_SEAM (0.99x) is used for getting fake UV pixel coords that are on the
1744  * edge of the face but slightly inside it occlusion tests don't return hits on adjacent faces */
1745 #ifndef PROJ_DEBUG_NOSEAMBLEED
1746 static void scale_quad(float insetCos[4][3], float *origCos[4], const float inset)
1747 {
1748         float cent[3];
1749         cent[0] = (origCos[0][0] + origCos[1][0] + origCos[2][0] + origCos[3][0]) * (1.0f / 4.0f);
1750         cent[1] = (origCos[0][1] + origCos[1][1] + origCos[2][1] + origCos[3][1]) * (1.0f / 4.0f);
1751         cent[2] = (origCos[0][2] + origCos[1][2] + origCos[2][2] + origCos[3][2]) * (1.0f / 4.0f);
1752
1753         sub_v3_v3v3(insetCos[0], origCos[0], cent);
1754         sub_v3_v3v3(insetCos[1], origCos[1], cent);
1755         sub_v3_v3v3(insetCos[2], origCos[2], cent);
1756         sub_v3_v3v3(insetCos[3], origCos[3], cent);
1757
1758         mul_v3_fl(insetCos[0], inset);
1759         mul_v3_fl(insetCos[1], inset);
1760         mul_v3_fl(insetCos[2], inset);
1761         mul_v3_fl(insetCos[3], inset);
1762
1763         add_v3_v3(insetCos[0], cent);
1764         add_v3_v3(insetCos[1], cent);
1765         add_v3_v3(insetCos[2], cent);
1766         add_v3_v3(insetCos[3], cent);
1767 }
1768
1769
1770 static void scale_tri(float insetCos[4][3], float *origCos[4], const float inset)
1771 {
1772         float cent[3];
1773         cent[0] = (origCos[0][0] + origCos[1][0] + origCos[2][0]) * (1.0f / 3.0f);
1774         cent[1] = (origCos[0][1] + origCos[1][1] + origCos[2][1]) * (1.0f / 3.0f);
1775         cent[2] = (origCos[0][2] + origCos[1][2] + origCos[2][2]) * (1.0f / 3.0f);
1776
1777         sub_v3_v3v3(insetCos[0], origCos[0], cent);
1778         sub_v3_v3v3(insetCos[1], origCos[1], cent);
1779         sub_v3_v3v3(insetCos[2], origCos[2], cent);
1780
1781         mul_v3_fl(insetCos[0], inset);
1782         mul_v3_fl(insetCos[1], inset);
1783         mul_v3_fl(insetCos[2], inset);
1784
1785         add_v3_v3(insetCos[0], cent);
1786         add_v3_v3(insetCos[1], cent);
1787         add_v3_v3(insetCos[2], cent);
1788 }
1789 #endif //PROJ_DEBUG_NOSEAMBLEED
1790
1791 static float len_squared_v2v2_alt(const float v1[2], const float v2_1, const float v2_2)
1792 {
1793         float x, y;
1794
1795         x = v1[0] - v2_1;
1796         y = v1[1] - v2_2;
1797         return x * x + y * y;
1798 }
1799
1800 /* note, use a squared value so we can use len_squared_v2v2
1801  * be sure that you have done a bounds check first or this may fail */
1802 /* only give bucket_bounds as an arg because we need it elsewhere */
1803 static bool project_bucket_isect_circle(const float cent[2], const float radius_squared, rctf *bucket_bounds)
1804 {
1805
1806         /* Would normally to a simple intersection test, however we know the bounds of these 2 already intersect
1807          * so we only need to test if the center is inside the vertical or horizontal bounds on either axis,
1808          * this is even less work then an intersection test
1809          */
1810 #if 0
1811         if (BLI_rctf_isect_pt_v(bucket_bounds, cent))
1812                 return 1;
1813 #endif
1814
1815         if ((bucket_bounds->xmin <= cent[0] && bucket_bounds->xmax >= cent[0]) ||
1816             (bucket_bounds->ymin <= cent[1] && bucket_bounds->ymax >= cent[1]))
1817         {
1818                 return 1;
1819         }
1820
1821         /* out of bounds left */
1822         if (cent[0] < bucket_bounds->xmin) {
1823                 /* lower left out of radius test */
1824                 if (cent[1] < bucket_bounds->ymin) {
1825                         return (len_squared_v2v2_alt(cent, bucket_bounds->xmin, bucket_bounds->ymin) < radius_squared) ? 1 : 0;
1826                 }
1827                 /* top left test */
1828                 else if (cent[1] > bucket_bounds->ymax) {
1829                         return (len_squared_v2v2_alt(cent, bucket_bounds->xmin, bucket_bounds->ymax) < radius_squared) ? 1 : 0;
1830                 }
1831         }
1832         else if (cent[0] > bucket_bounds->xmax) {
1833                 /* lower right out of radius test */
1834                 if (cent[1] < bucket_bounds->ymin) {
1835                         return (len_squared_v2v2_alt(cent, bucket_bounds->xmax, bucket_bounds->ymin) < radius_squared) ? 1 : 0;
1836                 }
1837                 /* top right test */
1838                 else if (cent[1] > bucket_bounds->ymax) {
1839                         return (len_squared_v2v2_alt(cent, bucket_bounds->xmax, bucket_bounds->ymax) < radius_squared) ? 1 : 0;
1840                 }
1841         }
1842
1843         return 0;
1844 }
1845
1846
1847
1848 /* Note for rect_to_uvspace_ortho() and rect_to_uvspace_persp()
1849  * in ortho view this function gives good results when bucket_bounds are outside the triangle
1850  * however in some cases, perspective view will mess up with faces that have minimal screenspace area
1851  * (viewed from the side)
1852  *
1853  * for this reason its not reliable in this case so we'll use the Simple Barycentric'
1854  * funcs that only account for points inside the triangle.
1855  * however switching back to this for ortho is always an option */
1856
1857 static void rect_to_uvspace_ortho(
1858         rctf *bucket_bounds,
1859         const float *v1coSS, const float *v2coSS, const float *v3coSS,
1860         const float *uv1co, const float *uv2co, const float *uv3co,
1861         float bucket_bounds_uv[4][2],
1862         const int flip)
1863 {
1864         float uv[2];
1865         float w[3];
1866
1867         /* get the UV space bounding box */
1868         uv[0] = bucket_bounds->xmax;
1869         uv[1] = bucket_bounds->ymin;
1870         barycentric_weights_v2(v1coSS, v2coSS, v3coSS, uv, w);
1871         interp_v2_v2v2v2(bucket_bounds_uv[flip ? 3 : 0], uv1co, uv2co, uv3co, w);
1872
1873         //uv[0] = bucket_bounds->xmax; // set above
1874         uv[1] = bucket_bounds->ymax;
1875         barycentric_weights_v2(v1coSS, v2coSS, v3coSS, uv, w);
1876         interp_v2_v2v2v2(bucket_bounds_uv[flip ? 2 : 1], uv1co, uv2co, uv3co, w);
1877
1878         uv[0] = bucket_bounds->xmin;
1879         //uv[1] = bucket_bounds->ymax; // set above
1880         barycentric_weights_v2(v1coSS, v2coSS, v3coSS, uv, w);
1881         interp_v2_v2v2v2(bucket_bounds_uv[flip ? 1 : 2], uv1co, uv2co, uv3co, w);
1882
1883         //uv[0] = bucket_bounds->xmin; // set above
1884         uv[1] = bucket_bounds->ymin;
1885         barycentric_weights_v2(v1coSS, v2coSS, v3coSS, uv, w);
1886         interp_v2_v2v2v2(bucket_bounds_uv[flip ? 0 : 3], uv1co, uv2co, uv3co, w);
1887 }
1888
1889 /* same as above but use barycentric_weights_v2_persp */
1890 static void rect_to_uvspace_persp(
1891         rctf *bucket_bounds,
1892         const float *v1coSS, const float *v2coSS, const float *v3coSS,
1893         const float *uv1co, const float *uv2co, const float *uv3co,
1894         float bucket_bounds_uv[4][2],
1895         const int flip
1896         )
1897 {
1898         float uv[2];
1899         float w[3];
1900
1901         /* get the UV space bounding box */
1902         uv[0] = bucket_bounds->xmax;
1903         uv[1] = bucket_bounds->ymin;
1904         barycentric_weights_v2_persp(v1coSS, v2coSS, v3coSS, uv, w);
1905         interp_v2_v2v2v2(bucket_bounds_uv[flip ? 3 : 0], uv1co, uv2co, uv3co, w);
1906
1907         //uv[0] = bucket_bounds->xmax; // set above
1908         uv[1] = bucket_bounds->ymax;
1909         barycentric_weights_v2_persp(v1coSS, v2coSS, v3coSS, uv, w);
1910         interp_v2_v2v2v2(bucket_bounds_uv[flip ? 2 : 1], uv1co, uv2co, uv3co, w);
1911
1912         uv[0] = bucket_bounds->xmin;
1913         //uv[1] = bucket_bounds->ymax; // set above
1914         barycentric_weights_v2_persp(v1coSS, v2coSS, v3coSS, uv, w);
1915         interp_v2_v2v2v2(bucket_bounds_uv[flip ? 1 : 2], uv1co, uv2co, uv3co, w);
1916
1917         //uv[0] = bucket_bounds->xmin; // set above
1918         uv[1] = bucket_bounds->ymin;
1919         barycentric_weights_v2_persp(v1coSS, v2coSS, v3coSS, uv, w);
1920         interp_v2_v2v2v2(bucket_bounds_uv[flip ? 0 : 3], uv1co, uv2co, uv3co, w);
1921 }
1922
1923 /* This works as we need it to but we can save a few steps and not use it */
1924
1925 #if 0
1926 static float angle_2d_clockwise(const float p1[2], const float p2[2], const float p3[2])
1927 {
1928         float v1[2], v2[2];
1929
1930         v1[0] = p1[0] - p2[0];    v1[1] = p1[1] - p2[1];
1931         v2[0] = p3[0] - p2[0];    v2[1] = p3[1] - p2[1];
1932
1933         return -atan2(v1[0] * v2[1] - v1[1] * v2[0], v1[0] * v2[0] + v1[1] * v2[1]);
1934 }
1935 #endif
1936
1937 #define ISECT_1 (1)
1938 #define ISECT_2 (1 << 1)
1939 #define ISECT_3 (1 << 2)
1940 #define ISECT_4 (1 << 3)
1941 #define ISECT_ALL3 ((1 << 3) - 1)
1942 #define ISECT_ALL4 ((1 << 4) - 1)
1943
1944 /* limit must be a fraction over 1.0f */
1945 static bool IsectPT2Df_limit(float pt[2], float v1[2], float v2[2], float v3[2], float limit)
1946 {
1947         return ((area_tri_v2(pt, v1, v2) +
1948                  area_tri_v2(pt, v2, v3) +
1949                  area_tri_v2(pt, v3, v1)) / (area_tri_v2(v1, v2, v3))) < limit;
1950 }
1951
1952 /* Clip the face by a bucket and set the uv-space bucket_bounds_uv
1953  * so we have the clipped UV's to do pixel intersection tests with
1954  * */
1955 static int float_z_sort_flip(const void *p1, const void *p2)
1956 {
1957         return (((float *)p1)[2] < ((float *)p2)[2] ? 1 : -1);
1958 }
1959
1960 static int float_z_sort(const void *p1, const void *p2)
1961 {
1962         return (((float *)p1)[2] < ((float *)p2)[2] ? -1 : 1);
1963 }
1964
1965 /* assumes one point is within the rectangle */
1966 static void line_rect_clip(
1967         rctf *rect,
1968         const float l1[4], const float l2[4],
1969         const float uv1[2], const float uv2[2],
1970         float uv[2], bool is_ortho)
1971 {
1972         float min = FLT_MAX, tmp;
1973         if ((l1[0] - rect->xmin) * (l2[0] - rect->xmin) < 0) {
1974                 tmp = rect->xmin;
1975                 min = min_ff((tmp - l1[0]) / (l2[0] - l1[0]), min);
1976         }
1977         else if ((l1[0] - rect->xmax) * (l2[0] - rect->xmax) < 0) {
1978                 tmp = rect->xmax;
1979                 min = min_ff((tmp - l1[0]) / (l2[0] - l1[0]), min);
1980         }
1981         if ((l1[1] - rect->ymin) * (l2[1] - rect->ymin) < 0) {
1982                 tmp = rect->ymin;
1983                 min = min_ff((tmp - l1[1]) / (l2[1] - l1[1]), min);
1984         }
1985         else if ((l1[1] - rect->ymax) * (l2[1] - rect->ymax) < 0) {
1986                 tmp = rect->ymax;
1987                 min = min_ff((tmp - l1[1]) / (l2[1] - l1[1]), min);
1988         }
1989         
1990         tmp = (is_ortho) ? 1.0f : (l1[3] + min * (l2[3] - l1[3]));
1991         
1992         uv[0] = (uv1[0] + min * (uv2[0] - uv1[0])) / tmp;
1993         uv[1] = (uv1[1] + min * (uv2[1] - uv1[1])) / tmp;
1994 }
1995
1996
1997 static void project_bucket_clip_face(
1998         const bool is_ortho,
1999         rctf *bucket_bounds,
2000         float *v1coSS, float *v2coSS, float *v3coSS,
2001         const float *uv1co, const float *uv2co, const float *uv3co,
2002         float bucket_bounds_uv[8][2],
2003         int *tot, bool cull)
2004 {
2005         int inside_bucket_flag = 0;
2006         int inside_face_flag = 0;
2007         const int flip = ((line_point_side_v2(v1coSS, v2coSS, v3coSS) > 0.0f) != (line_point_side_v2(uv1co, uv2co, uv3co) > 0.0f));
2008         bool colinear = false;
2009         
2010         float bucket_bounds_ss[4][2];
2011
2012         /* detect pathological case where face the three vertices are almost colinear in screen space.
2013          * mostly those will be culled but when flood filling or with smooth shading */
2014         if (dist_squared_to_line_v2(v1coSS, v2coSS, v3coSS) < PROJ_PIXEL_TOLERANCE)
2015                 colinear = true;
2016         
2017         /* get the UV space bounding box */
2018         inside_bucket_flag |= BLI_rctf_isect_pt_v(bucket_bounds, v1coSS);
2019         inside_bucket_flag |= BLI_rctf_isect_pt_v(bucket_bounds, v2coSS) << 1;
2020         inside_bucket_flag |= BLI_rctf_isect_pt_v(bucket_bounds, v3coSS) << 2;
2021         
2022         if (inside_bucket_flag == ISECT_ALL3) {
2023                 /* all screenspace points are inside the bucket bounding box, this means we don't need to clip and can simply return the UVs */
2024                 if (flip) { /* facing the back? */
2025                         copy_v2_v2(bucket_bounds_uv[0], uv3co);
2026                         copy_v2_v2(bucket_bounds_uv[1], uv2co);
2027                         copy_v2_v2(bucket_bounds_uv[2], uv1co);
2028                 }
2029                 else {
2030                         copy_v2_v2(bucket_bounds_uv[0], uv1co);
2031                         copy_v2_v2(bucket_bounds_uv[1], uv2co);
2032                         copy_v2_v2(bucket_bounds_uv[2], uv3co);
2033                 }               
2034                 
2035                 *tot = 3;
2036                 return;
2037         }
2038         /* handle pathological case here, no need for further intersections below since tringle area is almost zero */
2039         if (colinear) {
2040                 int flag;
2041                 
2042                 (*tot) = 0;
2043                 
2044                 if (cull)
2045                         return;
2046                 
2047                 if (inside_bucket_flag & ISECT_1) { copy_v2_v2(bucket_bounds_uv[*tot], uv1co); (*tot)++; }
2048
2049                 flag = inside_bucket_flag & (ISECT_1 | ISECT_2);
2050                 if (flag && flag != (ISECT_1 | ISECT_2)) {
2051                         line_rect_clip(bucket_bounds, v1coSS, v2coSS, uv1co, uv2co, bucket_bounds_uv[*tot], is_ortho);
2052                         (*tot)++;
2053                 }
2054                 
2055                 if (inside_bucket_flag & ISECT_2) { copy_v2_v2(bucket_bounds_uv[*tot], uv2co); (*tot)++; }
2056                 
2057                 flag = inside_bucket_flag & (ISECT_2 | ISECT_3);
2058                 if (flag && flag != (ISECT_2 | ISECT_3)) {
2059                         line_rect_clip(bucket_bounds, v2coSS, v3coSS, uv2co, uv3co, bucket_bounds_uv[*tot], is_ortho);
2060                         (*tot)++;
2061                 }
2062
2063                 if (inside_bucket_flag & ISECT_3) { copy_v2_v2(bucket_bounds_uv[*tot], uv3co); (*tot)++; }
2064
2065                 flag = inside_bucket_flag & (ISECT_3 | ISECT_1);
2066                 if (flag && flag != (ISECT_3 | ISECT_1)) {
2067                         line_rect_clip(bucket_bounds, v3coSS, v1coSS, uv3co, uv1co, bucket_bounds_uv[*tot], is_ortho);
2068                         (*tot)++;
2069                 }
2070                 
2071                 if ((*tot) < 3) { /* no intersections to speak of */
2072                         *tot = 0;
2073                         return;
2074                 }
2075
2076                 /* at this point we have all uv points needed in a row. all that's needed is to invert them if necessary */
2077                 if (flip) {
2078                         /* flip only to the middle of the array */
2079                         int i, max = *tot / 2;
2080                         for (i = 0; i < max; i++) {
2081                                 SWAP(float, bucket_bounds_uv[i][0], bucket_bounds_uv[max - i][0]);
2082                                 SWAP(float, bucket_bounds_uv[i][1], bucket_bounds_uv[max - i][1]);
2083                         }
2084                 }
2085                 
2086                 return;
2087         }
2088
2089         /* get the UV space bounding box */
2090         /* use IsectPT2Df_limit here so we catch points are are touching the tri edge (or a small fraction over) */
2091         bucket_bounds_ss[0][0] = bucket_bounds->xmax;
2092         bucket_bounds_ss[0][1] = bucket_bounds->ymin;
2093         inside_face_flag |= (IsectPT2Df_limit(bucket_bounds_ss[0], v1coSS, v2coSS, v3coSS, 1 + PROJ_GEOM_TOLERANCE) ? ISECT_1 : 0);
2094
2095         bucket_bounds_ss[1][0] = bucket_bounds->xmax;
2096         bucket_bounds_ss[1][1] = bucket_bounds->ymax;
2097         inside_face_flag |= (IsectPT2Df_limit(bucket_bounds_ss[1], v1coSS, v2coSS, v3coSS, 1 + PROJ_GEOM_TOLERANCE) ? ISECT_2 : 0);
2098
2099         bucket_bounds_ss[2][0] = bucket_bounds->xmin;
2100         bucket_bounds_ss[2][1] = bucket_bounds->ymax;
2101         inside_face_flag |= (IsectPT2Df_limit(bucket_bounds_ss[2], v1coSS, v2coSS, v3coSS, 1 + PROJ_GEOM_TOLERANCE) ? ISECT_3 : 0);
2102
2103         bucket_bounds_ss[3][0] = bucket_bounds->xmin;
2104         bucket_bounds_ss[3][1] = bucket_bounds->ymin;
2105         inside_face_flag |= (IsectPT2Df_limit(bucket_bounds_ss[3], v1coSS, v2coSS, v3coSS, 1 + PROJ_GEOM_TOLERANCE) ? ISECT_4 : 0);
2106
2107         if (inside_face_flag == ISECT_ALL4) {
2108                 /* bucket is totally inside the screenspace face, we can safely use weights */
2109
2110                 if (is_ortho) rect_to_uvspace_ortho(bucket_bounds, v1coSS, v2coSS, v3coSS, uv1co, uv2co, uv3co, bucket_bounds_uv, flip);
2111                 else rect_to_uvspace_persp(bucket_bounds, v1coSS, v2coSS, v3coSS, uv1co, uv2co, uv3co, bucket_bounds_uv, flip);
2112
2113                 *tot = 4;
2114                 return;
2115         }
2116         else {
2117                 /* The Complicated Case!
2118                  *
2119                  * The 2 cases above are where the face is inside the bucket or the bucket is inside the face.
2120                  *
2121                  * we need to make a convex polyline from the intersection between the screenspace face
2122                  * and the bucket bounds.
2123                  *
2124                  * There are a number of ways this could be done, currently it just collects all intersecting verts,
2125                  * and line intersections,  then sorts them clockwise, this is a lot easier then evaluating the geometry to
2126                  * do a correct clipping on both shapes. */
2127
2128
2129                 /* add a bunch of points, we know must make up the convex hull which is the clipped rect and triangle */
2130
2131
2132
2133                 /* Maximum possible 6 intersections when using a rectangle and triangle */
2134                 float isectVCosSS[8][3]; /* The 3rd float is used to store angle for qsort(), NOT as a Z location */
2135                 float v1_clipSS[2], v2_clipSS[2];
2136                 float w[3];
2137
2138                 /* calc center */
2139                 float cent[2] = {0.0f, 0.0f};
2140                 /*float up[2] = {0.0f, 1.0f};*/
2141                 int i;
2142                 short doubles;
2143
2144                 (*tot) = 0;
2145
2146                 if (inside_face_flag & ISECT_1) { copy_v2_v2(isectVCosSS[*tot], bucket_bounds_ss[0]); (*tot)++; }
2147                 if (inside_face_flag & ISECT_2) { copy_v2_v2(isectVCosSS[*tot], bucket_bounds_ss[1]); (*tot)++; }
2148                 if (inside_face_flag & ISECT_3) { copy_v2_v2(isectVCosSS[*tot], bucket_bounds_ss[2]); (*tot)++; }
2149                 if (inside_face_flag & ISECT_4) { copy_v2_v2(isectVCosSS[*tot], bucket_bounds_ss[3]); (*tot)++; }
2150
2151                 if (inside_bucket_flag & ISECT_1) { copy_v2_v2(isectVCosSS[*tot], v1coSS); (*tot)++; }
2152                 if (inside_bucket_flag & ISECT_2) { copy_v2_v2(isectVCosSS[*tot], v2coSS); (*tot)++; }
2153                 if (inside_bucket_flag & ISECT_3) { copy_v2_v2(isectVCosSS[*tot], v3coSS); (*tot)++; }
2154
2155                 if ((inside_bucket_flag & (ISECT_1 | ISECT_2)) != (ISECT_1 | ISECT_2)) {
2156                         if (line_clip_rect2f(bucket_bounds, v1coSS, v2coSS, v1_clipSS, v2_clipSS)) {
2157                                 if ((inside_bucket_flag & ISECT_1) == 0) { copy_v2_v2(isectVCosSS[*tot], v1_clipSS); (*tot)++; }
2158                                 if ((inside_bucket_flag & ISECT_2) == 0) { copy_v2_v2(isectVCosSS[*tot], v2_clipSS); (*tot)++; }
2159                         }
2160                 }
2161
2162                 if ((inside_bucket_flag & (ISECT_2 | ISECT_3)) != (ISECT_2 | ISECT_3)) {
2163                         if (line_clip_rect2f(bucket_bounds, v2coSS, v3coSS, v1_clipSS, v2_clipSS)) {
2164                                 if ((inside_bucket_flag & ISECT_2) == 0) { copy_v2_v2(isectVCosSS[*tot], v1_clipSS); (*tot)++; }
2165                                 if ((inside_bucket_flag & ISECT_3) == 0) { copy_v2_v2(isectVCosSS[*tot], v2_clipSS); (*tot)++; }
2166                         }
2167                 }
2168
2169                 if ((inside_bucket_flag & (ISECT_3 | ISECT_1)) != (ISECT_3 | ISECT_1)) {
2170                         if (line_clip_rect2f(bucket_bounds, v3coSS, v1coSS, v1_clipSS, v2_clipSS)) {
2171                                 if ((inside_bucket_flag & ISECT_3) == 0) { copy_v2_v2(isectVCosSS[*tot], v1_clipSS); (*tot)++; }
2172                                 if ((inside_bucket_flag & ISECT_1) == 0) { copy_v2_v2(isectVCosSS[*tot], v2_clipSS); (*tot)++; }
2173                         }
2174                 }
2175
2176
2177                 if ((*tot) < 3) { /* no intersections to speak of */
2178                         *tot = 0;
2179                         return;
2180                 }
2181
2182                 /* now we have all points we need, collect their angles and sort them clockwise */
2183
2184                 for (i = 0; i < (*tot); i++) {
2185                         cent[0] += isectVCosSS[i][0];
2186                         cent[1] += isectVCosSS[i][1];
2187                 }
2188                 cent[0] = cent[0] / (float)(*tot);
2189                 cent[1] = cent[1] / (float)(*tot);
2190
2191
2192
2193                 /* Collect angles for every point around the center point */
2194
2195
2196 #if 0   /* uses a few more cycles then the above loop */
2197                 for (i = 0; i < (*tot); i++) {
2198                         isectVCosSS[i][2] = angle_2d_clockwise(up, cent, isectVCosSS[i]);
2199                 }
2200 #endif
2201
2202                 v1_clipSS[0] = cent[0]; /* Abuse this var for the loop below */
2203                 v1_clipSS[1] = cent[1] + 1.0f;
2204
2205                 for (i = 0; i < (*tot); i++) {
2206                         v2_clipSS[0] = isectVCosSS[i][0] - cent[0];
2207                         v2_clipSS[1] = isectVCosSS[i][1] - cent[1];
2208                         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]);
2209                 }
2210
2211                 if (flip) qsort(isectVCosSS, *tot, sizeof(float) * 3, float_z_sort_flip);
2212                 else      qsort(isectVCosSS, *tot, sizeof(float) * 3, float_z_sort);
2213
2214                 doubles = true;
2215                 while (doubles == true) {
2216                         doubles = false;
2217
2218                         for (i = 0; i < (*tot); i++) {
2219                                 if (fabsf(isectVCosSS[(i + 1) % *tot][0] - isectVCosSS[i][0]) < PROJ_PIXEL_TOLERANCE &&
2220                                     fabsf(isectVCosSS[(i + 1) % *tot][1] - isectVCosSS[i][1]) < PROJ_PIXEL_TOLERANCE)
2221                                 {
2222                                         int j;
2223                                         for (j = i; j < (*tot) - 1; j++) {
2224                                                 isectVCosSS[j][0] = isectVCosSS[j + 1][0];
2225                                                 isectVCosSS[j][1] = isectVCosSS[j + 1][1];
2226                                         }
2227                                         doubles = true; /* keep looking for more doubles */
2228                                         (*tot)--;
2229                                 }
2230                         }
2231                         
2232                         /* its possible there is only a few left after remove doubles */
2233                         if ((*tot) < 3) {
2234                                 // printf("removed too many doubles B\n");
2235                                 *tot = 0;
2236                                 return;
2237                         }
2238                 }
2239
2240                 if (is_ortho) {
2241                         for (i = 0; i < (*tot); i++) {
2242                                 barycentric_weights_v2(v1coSS, v2coSS, v3coSS, isectVCosSS[i], w);
2243                                 interp_v2_v2v2v2(bucket_bounds_uv[i], uv1co, uv2co, uv3co, w);
2244                         }
2245                 }
2246                 else {
2247                         for (i = 0; i < (*tot); i++) {
2248                                 barycentric_weights_v2_persp(v1coSS, v2coSS, v3coSS, isectVCosSS[i], w);
2249                                 interp_v2_v2v2v2(bucket_bounds_uv[i], uv1co, uv2co, uv3co, w);
2250                         }
2251                 }
2252         }
2253
2254 #ifdef PROJ_DEBUG_PRINT_CLIP
2255         /* include this at the bottom of the above function to debug the output */
2256
2257         {
2258                 /* If there are ever any problems, */
2259                 float test_uv[4][2];
2260                 int i;
2261                 if (is_ortho) rect_to_uvspace_ortho(bucket_bounds, v1coSS, v2coSS, v3coSS, uv1co, uv2co, uv3co, test_uv, flip);
2262                 else          rect_to_uvspace_persp(bucket_bounds, v1coSS, v2coSS, v3coSS, uv1co, uv2co, uv3co, test_uv, flip);
2263                 printf("(  [(%f,%f), (%f,%f), (%f,%f), (%f,%f)], ", test_uv[0][0], test_uv[0][1],   test_uv[1][0], test_uv[1][1],    test_uv[2][0], test_uv[2][1],    test_uv[3][0], test_uv[3][1]);
2264
2265                 printf("  [(%f,%f), (%f,%f), (%f,%f)], ", uv1co[0], uv1co[1],   uv2co[0], uv2co[1],    uv3co[0], uv3co[1]);
2266
2267                 printf("[");
2268                 for (i = 0; i < (*tot); i++) {
2269                         printf("(%f, %f),", bucket_bounds_uv[i][0], bucket_bounds_uv[i][1]);
2270                 }
2271                 printf("]),\\\n");
2272         }
2273 #endif
2274 }
2275
2276 /*
2277  * # This script creates faces in a blender scene from printed data above.
2278  *
2279  * project_ls = [
2280  * ...(output from above block)...
2281  * ]
2282  *
2283  * from Blender import Scene, Mesh, Window, sys, Mathutils
2284  *
2285  * import bpy
2286  *
2287  * V = Mathutils.Vector
2288  *
2289  * def main():
2290  *     sce = bpy.data.scenes.active
2291  *
2292  *     for item in project_ls:
2293  *         bb = item[0]
2294  *         uv = item[1]
2295  *         poly = item[2]
2296  *
2297  *         me = bpy.data.meshes.new()
2298  *         ob = sce.objects.new(me)
2299  *
2300  *         me.verts.extend([V(bb[0]).xyz, V(bb[1]).xyz, V(bb[2]).xyz, V(bb[3]).xyz])
2301  *         me.faces.extend([(0,1,2,3),])
2302  *         me.verts.extend([V(uv[0]).xyz, V(uv[1]).xyz, V(uv[2]).xyz])
2303  *         me.faces.extend([(4,5,6),])
2304  *
2305  *         vs = [V(p).xyz for p in poly]
2306  *         print len(vs)
2307  *         l = len(me.verts)
2308  *         me.verts.extend(vs)
2309  *
2310  *         i = l
2311  *         while i < len(me.verts):
2312  *             ii = i + 1
2313  *             if ii == len(me.verts):
2314  *                 ii = l
2315  *             me.edges.extend([i, ii])
2316  *             i += 1
2317  *
2318  * if __name__ == '__main__':
2319  *     main()
2320  */
2321
2322
2323 #undef ISECT_1
2324 #undef ISECT_2
2325 #undef ISECT_3
2326 #undef ISECT_4
2327 #undef ISECT_ALL3
2328 #undef ISECT_ALL4
2329
2330
2331 /* checks if pt is inside a convex 2D polyline, the polyline must be ordered rotating clockwise
2332  * otherwise it would have to test for mixed (line_point_side_v2 > 0.0f) cases */
2333 static bool IsectPoly2Df(const float pt[2], float uv[][2], const int tot)
2334 {
2335         int i;
2336         if (line_point_side_v2(uv[tot - 1], uv[0], pt) < 0.0f)
2337                 return 0;
2338
2339         for (i = 1; i < tot; i++) {
2340                 if (line_point_side_v2(uv[i - 1], uv[i], pt) < 0.0f)
2341                         return 0;
2342
2343         }
2344
2345         return 1;
2346 }
2347 static bool IsectPoly2Df_twoside(const float pt[2], float uv[][2], const int tot)
2348 {
2349         int i;
2350         int side = (line_point_side_v2(uv[tot - 1], uv[0], pt) > 0.0f);
2351
2352         for (i = 1; i < tot; i++) {
2353                 if ((line_point_side_v2(uv[i - 1], uv[i], pt) > 0.0f) != side)
2354                         return 0;
2355
2356         }
2357
2358         return 1;
2359 }
2360
2361 /* One of the most important function for projection painting, since it selects the pixels to be added into each bucket.
2362  * initialize pixels from this face where it intersects with the bucket_index, optionally initialize pixels for removing seams */
2363 static void project_paint_face_init(const ProjPaintState *ps, const int thread_index, const int bucket_index, const int face_index, const int image_index, rctf *bucket_bounds, ImBuf *ibuf, ImBuf **tmpibuf, const short clamp_u, const short clamp_v)
2364 {
2365         /* Projection vars, to get the 3D locations into screen space  */
2366         MemArena *arena = ps->arena_mt[thread_index];
2367         LinkNode **bucketPixelNodes = ps->bucketRect + bucket_index;
2368         LinkNode *bucketFaceNodes = ps->bucketFaces[bucket_index];
2369         bool threaded = (ps->thread_tot > 1);
2370
2371         TileInfo tinf = {
2372                 ps->tile_lock,
2373                 ps->do_masking,
2374                 IMAPAINT_TILE_NUMBER(ibuf->x),
2375                 tmpibuf,
2376                 ps->projImages + image_index
2377         };
2378
2379         const MFace *mf = ps->dm_mface + face_index;
2380         const MTFace *tf = ps->dm_mtface[face_index];
2381
2382         /* UV/pixel seeking data */
2383         int x; /* Image X-Pixel */
2384         int y; /* Image Y-Pixel */
2385         float mask;
2386         float uv[2]; /* Image floating point UV - same as x, y but from 0.0-1.0 */
2387
2388         int side;
2389         float *v1coSS, *v2coSS, *v3coSS; /* vert co screen-space, these will be assigned to mf->v1,2,3 or mf->v1,3,4 */
2390
2391         float *vCo[4]; /* vertex screenspace coords */
2392
2393         float w[3], wco[3];
2394
2395         float *uv1co, *uv2co, *uv3co; /* for convenience only, these will be assigned to tf->uv[0],1,2 or tf->uv[0],2,3 */
2396         float pixelScreenCo[4];
2397         bool do_3d_mapping = ps->brush->mtex.brush_map_mode == MTEX_MAP_MODE_3D;
2398
2399         rcti bounds_px; /* ispace bounds */
2400         /* vars for getting uvspace bounds */
2401
2402         float tf_uv_pxoffset[4][2]; /* bucket bounds in UV space so we can init pixels only for this face,  */
2403         float xhalfpx, yhalfpx;
2404         const float ibuf_xf = (float)ibuf->x, ibuf_yf = (float)ibuf->y;
2405
2406         int has_x_isect = 0, has_isect = 0; /* for early loop exit */
2407
2408         int i1, i2, i3;
2409
2410         float uv_clip[8][2];
2411         int uv_clip_tot;
2412         const bool is_ortho = ps->is_ortho;
2413         const bool do_backfacecull = ps->do_backfacecull;
2414         const bool do_clip = ps->rv3d ? ps->rv3d->rflag & RV3D_CLIPPING : 0;
2415
2416         vCo[0] = ps->dm_mvert[mf->v1].co;
2417         vCo[1] = ps->dm_mvert[mf->v2].co;
2418         vCo[2] = ps->dm_mvert[mf->v3].co;
2419
2420
2421         /* Use tf_uv_pxoffset instead of tf->uv so we can offset the UV half a pixel
2422          * this is done so we can avoid offsetting all the pixels by 0.5 which causes
2423          * problems when wrapping negative coords */
2424         xhalfpx = (0.5f + (PROJ_PIXEL_TOLERANCE * (1.0f / 3.0f))) / ibuf_xf;
2425         yhalfpx = (0.5f + (PROJ_PIXEL_TOLERANCE * (1.0f / 4.0f))) / ibuf_yf;
2426
2427         /* Note about (PROJ_GEOM_TOLERANCE/x) above...
2428          * Needed to add this offset since UV coords are often quads aligned to pixels.
2429          * In this case pixels can be exactly between 2 triangles causing nasty
2430          * artifacts.
2431          *
2432          * This workaround can be removed and painting will still work on most cases
2433          * but since the first thing most people try is painting onto a quad- better make it work.
2434          */
2435
2436         tf_uv_pxoffset[0][0] = tf->uv[0][0] - xhalfpx;
2437         tf_uv_pxoffset[0][1] = tf->uv[0][1] - yhalfpx;
2438
2439         tf_uv_pxoffset[1][0] = tf->uv[1][0] - xhalfpx;
2440         tf_uv_pxoffset[1][1] = tf->uv[1][1] - yhalfpx;
2441
2442         tf_uv_pxoffset[2][0] = tf->uv[2][0] - xhalfpx;
2443         tf_uv_pxoffset[2][1] = tf->uv[2][1] - yhalfpx;
2444
2445         if (mf->v4) {
2446                 vCo[3] = ps->dm_mvert[mf->v4].co;
2447
2448                 tf_uv_pxoffset[3][0] = tf->uv[3][0] - xhalfpx;
2449                 tf_uv_pxoffset[3][1] = tf->uv[3][1] - yhalfpx;
2450                 side = 1;
2451         }
2452         else {
2453                 side = 0;
2454         }
2455
2456         do {
2457                 if (side == 1) {
2458                         i1 = 0; i2 = 2; i3 = 3;
2459                 }
2460                 else {
2461                         i1 = 0; i2 = 1; i3 = 2;
2462                 }
2463
2464                 uv1co = tf_uv_pxoffset[i1]; // was tf->uv[i1];
2465                 uv2co = tf_uv_pxoffset[i2]; // was tf->uv[i2];
2466                 uv3co = tf_uv_pxoffset[i3]; // was tf->uv[i3];
2467
2468                 v1coSS = ps->screenCoords[(*(&mf->v1 + i1))];
2469                 v2coSS = ps->screenCoords[(*(&mf->v1 + i2))];
2470                 v3coSS = ps->screenCoords[(*(&mf->v1 + i3))];
2471
2472                 /* This funtion gives is a concave polyline in UV space from the clipped quad and tri*/
2473                 project_bucket_clip_face(
2474                         is_ortho, bucket_bounds,
2475                         v1coSS, v2coSS, v3coSS,
2476                         uv1co, uv2co, uv3co,
2477                         uv_clip, &uv_clip_tot,
2478                         ps->do_backfacecull || ps->do_occlude);
2479
2480                 /* sometimes this happens, better just allow for 8 intersectiosn even though there should be max 6 */
2481 #if 0
2482                 if (uv_clip_tot > 6) {
2483                         printf("this should never happen! %d\n", uv_clip_tot);
2484                 }
2485 #endif
2486
2487                 if (pixel_bounds_array(uv_clip, &bounds_px, ibuf->x, ibuf->y, uv_clip_tot)) {
2488
2489                         if (clamp_u) {
2490                                 CLAMP(bounds_px.xmin, 0, ibuf->x);
2491                                 CLAMP(bounds_px.xmax, 0, ibuf->x);
2492                         }
2493
2494                         if (clamp_v) {
2495                                 CLAMP(bounds_px.ymin, 0, ibuf->y);
2496                                 CLAMP(bounds_px.ymax, 0, ibuf->y);
2497                         }
2498
2499                         /*
2500                         project_paint_undo_tiles_init(&bounds_px, ps->projImages + image_index, tmpibuf,
2501                                                       tile_width, threaded, ps->do_masking);
2502                         */
2503                         /* clip face and */
2504
2505                         has_isect = 0;
2506                         for (y = bounds_px.ymin; y < bounds_px.ymax; y++) {
2507                                 //uv[1] = (((float)y) + 0.5f) / (float)ibuf->y;
2508                                 uv[1] = (float)y / ibuf_yf; /* use pixel offset UV coords instead */
2509
2510                                 has_x_isect = 0;
2511                                 for (x = bounds_px.xmin; x < bounds_px.xmax; x++) {
2512                                         //uv[0] = (((float)x) + 0.5f) / ibuf->x;
2513                                         uv[0] = (float)x / ibuf_xf; /* use pixel offset UV coords instead */
2514
2515                                         /* Note about IsectPoly2Df_twoside, checking the face or uv flipping doesnt work,
2516                                          * could check the poly direction but better to do this */
2517                                         if ((do_backfacecull == true  && IsectPoly2Df(uv, uv_clip, uv_clip_tot)) ||
2518                                             (do_backfacecull == false && IsectPoly2Df_twoside(uv, uv_clip, uv_clip_tot)))
2519                                         {
2520
2521                                                 has_x_isect = has_isect = 1;
2522
2523                                                 if (is_ortho) screen_px_from_ortho(uv, v1coSS, v2coSS, v3coSS, uv1co, uv2co, uv3co, pixelScreenCo, w);
2524                                                 else screen_px_from_persp(uv, v1coSS, v2coSS, v3coSS, uv1co, uv2co, uv3co, pixelScreenCo, w);
2525
2526                                                 /* a pity we need to get the worldspace pixel location here */
2527                                                 if (do_clip || do_3d_mapping) {
2528                                                         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);
2529                                                         if (do_clip && ED_view3d_clipping_test(ps->rv3d, wco, true)) {
2530                                                                 continue; /* Watch out that no code below this needs to run */
2531                                                         }
2532                                                 }
2533
2534                                                 /* Is this UV visible from the view? - raytrace */
2535                                                 /* project_paint_PickFace is less complex, use for testing */
2536                                                 //if (project_paint_PickFace(ps, pixelScreenCo, w, &side) == face_index) {
2537                                                 if ((ps->do_occlude == false) ||
2538                                                     !project_bucket_point_occluded(ps, bucketFaceNodes, face_index, pixelScreenCo))
2539                                                 {
2540                                                         mask = project_paint_uvpixel_mask(ps, face_index, side, w);
2541
2542                                                         if (mask > 0.0f) {
2543                                                                 BLI_linklist_prepend_arena(
2544                                                                         bucketPixelNodes,
2545                                                                         project_paint_uvpixel_init(ps, arena, &tinf, x, y, mask, face_index,
2546                                                                                                    pixelScreenCo, wco, side, w),
2547                                                                         arena
2548                                                                         );
2549                                                         }
2550                                                 }
2551
2552                                         }
2553 //#if 0
2554                                         else if (has_x_isect) {
2555                                                 /* assuming the face is not a bow-tie - we know we cant intersect again on the X */
2556                                                 break;
2557                                         }
2558 //#endif
2559                                 }
2560
2561
2562 #if 0           /* TODO - investigate why this dosnt work sometimes! it should! */
2563                                 /* no intersection for this entire row, after some intersection above means we can quit now */
2564                                 if (has_x_isect == 0 && has_isect) {
2565                                         break;
2566                                 }
2567 #endif
2568                         }
2569                 }
2570         } while (side--);
2571
2572
2573
2574 #ifndef PROJ_DEBUG_NOSEAMBLEED
2575         if (ps->seam_bleed_px > 0.0f) {
2576                 int face_seam_flag;
2577
2578                 if (threaded)
2579                         BLI_lock_thread(LOCK_CUSTOM1);  /* Other threads could be modifying these vars */
2580
2581                 face_seam_flag = ps->faceSeamFlags[face_index];
2582
2583                 /* are any of our edges un-initialized? */
2584                 if ((face_seam_flag & (PROJ_FACE_SEAM1 | PROJ_FACE_NOSEAM1)) == 0 ||
2585                     (face_seam_flag & (PROJ_FACE_SEAM2 | PROJ_FACE_NOSEAM2)) == 0 ||
2586                     (face_seam_flag & (PROJ_FACE_SEAM3 | PROJ_FACE_NOSEAM3)) == 0 ||
2587                     (face_seam_flag & (PROJ_FACE_SEAM4 | PROJ_FACE_NOSEAM4)) == 0)
2588                 {
2589                         project_face_seams_init(ps, face_index, mf->v4);
2590                         face_seam_flag = ps->faceSeamFlags[face_index];
2591                         //printf("seams - %d %d %d %d\n", flag&PROJ_FACE_SEAM1, flag&PROJ_FACE_SEAM2, flag&PROJ_FACE_SEAM3, flag&PROJ_FACE_SEAM4);
2592                 }
2593
2594                 if ((face_seam_flag & (PROJ_FACE_SEAM1 | PROJ_FACE_SEAM2 | PROJ_FACE_SEAM3 | PROJ_FACE_SEAM4)) == 0) {
2595
2596                         if (threaded)
2597                                 BLI_unlock_thread(LOCK_CUSTOM1);  /* Other threads could be modifying these vars */
2598
2599                 }
2600                 else {
2601                         /* we have a seam - deal with it! */
2602
2603                         /* Now create new UV's for the seam face */
2604                         float (*outset_uv)[2] = ps->faceSeamUVs[face_index];
2605                         float insetCos[4][3]; /* inset face coords.  NOTE!!! ScreenSace for ortho, Worldspace in prespective view */
2606
2607                         float *vCoSS[4]; /* vertex screenspace coords */
2608
2609                         float bucket_clip_edges[2][2]; /* store the screenspace coords of the face, clipped by the bucket's screen aligned rectangle */
2610                         float edge_verts_inset_clip[2][3];
2611                         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 */
2612
2613                         float seam_subsection[4][2];
2614                         float fac1, fac2, ftot;
2615
2616                         if (outset_uv[0][0] == FLT_MAX) /* first time initialize */
2617                                 uv_image_outset(tf_uv_pxoffset, outset_uv, ps->seam_bleed_px, ibuf->x, ibuf->y, mf->v4 != 0, (ps->faceWindingFlags[face_index] & PROJ_FACE_WINDING_CW) == 0);
2618
2619                         /* ps->faceSeamUVs cant be modified when threading, now this is done we can unlock */
2620                         if (threaded)
2621                                 BLI_unlock_thread(LOCK_CUSTOM1);  /* Other threads could be modifying these vars */
2622
2623                         vCoSS[0] = ps->screenCoords[mf->v1];
2624                         vCoSS[1] = ps->screenCoords[mf->v2];
2625                         vCoSS[2] = ps->screenCoords[mf->v3];
2626                         if (mf->v4)
2627                                 vCoSS[3] = ps->screenCoords[mf->v4];
2628
2629                         /* PROJ_FACE_SCALE_SEAM must be slightly less then 1.0f */
2630                         if (is_ortho) {
2631                                 if (mf->v4) scale_quad(insetCos, vCoSS, PROJ_FACE_SCALE_SEAM);
2632                                 else        scale_tri(insetCos, vCoSS, PROJ_FACE_SCALE_SEAM);
2633                         }
2634                         else {
2635                                 if (mf->v4) scale_quad(insetCos, vCo, PROJ_FACE_SCALE_SEAM);
2636                                 else        scale_tri(insetCos, vCo, PROJ_FACE_SCALE_SEAM);
2637                         }
2638
2639                         side = 0; /* for triangles this wont need to change */
2640
2641                         for (fidx1 = 0; fidx1 < (mf->v4 ? 4 : 3); fidx1++) {
2642                                 if (mf->v4) fidx2 = (fidx1 == 3) ? 0 : fidx1 + 1;  /* next fidx in the face (0,1,2,3) -> (1,2,3,0) */
2643                                 else        fidx2 = (fidx1 == 2) ? 0 : fidx1 + 1;  /* next fidx in the face (0,1,2) -> (1,2,0) */
2644
2645                                 if ((face_seam_flag & (1 << fidx1)) && /* 1<<fidx1 -> PROJ_FACE_SEAM# */
2646                                     line_clip_rect2f(bucket_bounds, vCoSS[fidx1], vCoSS[fidx2], bucket_clip_edges[0], bucket_clip_edges[1]))
2647                                 {
2648
2649                                         ftot = len_v2v2(vCoSS[fidx1], vCoSS[fidx2]); /* screenspace edge length */
2650
2651                                         if (ftot > 0.0f) { /* avoid div by zero */
2652                                                 if (mf->v4) {
2653                                                         if (fidx1 == 2 || fidx2 == 2) side = 1;
2654                                                         else side = 0;
2655                                                 }
2656
2657                                                 fac1 = len_v2v2(vCoSS[fidx1], bucket_clip_edges[0]) / ftot;
2658                                                 fac2 = len_v2v2(vCoSS[fidx1], bucket_clip_edges[1]) / ftot;
2659
2660                                                 interp_v2_v2v2(seam_subsection[0], tf_uv_pxoffset[fidx1], tf_uv_pxoffset[fidx2], fac1);
2661                                                 interp_v2_v2v2(seam_subsection[1], tf_uv_pxoffset[fidx1], tf_uv_pxoffset[fidx2], fac2);
2662
2663                                                 interp_v2_v2v2(seam_subsection[2], outset_uv[fidx1], outset_uv[fidx2], fac2);
2664                                                 interp_v2_v2v2(seam_subsection[3], outset_uv[fidx1], outset_uv[fidx2], fac1);
2665
2666                                                 /* if the bucket_clip_edges values Z values was kept we could avoid this
2667                                                  * Inset needs to be added so occlusion tests wont hit adjacent faces */
2668                                                 interp_v3_v3v3(edge_verts_inset_clip[0], insetCos[fidx1], insetCos[fidx2], fac1);
2669                                                 interp_v3_v3v3(edge_verts_inset_clip[1], insetCos[fidx1], insetCos[fidx2], fac2);
2670
2671
2672                                                 if (pixel_bounds_uv(seam_subsection[0], seam_subsection[1], seam_subsection[2], seam_subsection[3], &bounds_px, ibuf->x, ibuf->y, true)) {
2673                                                         /* bounds between the seam rect and the uvspace bucket pixels */
2674
2675                                                         has_isect = 0;
2676                                                         for (y = bounds_px.ymin; y < bounds_px.ymax; y++) {
2677                                                                 // uv[1] = (((float)y) + 0.5f) / (float)ibuf->y;
2678                                                                 uv[1] = (float)y / ibuf_yf; /* use offset uvs instead */
2679
2680                                                                 has_x_isect = 0;
2681                                                                 for (x = bounds_px.xmin; x < bounds_px.xmax; x++) {
2682                                                                         //uv[0] = (((float)x) + 0.5f) / (float)ibuf->x;
2683                                                                         uv[0] = (float)x / ibuf_xf; /* use offset uvs instead */
2684
2685                                                                         /* test we're inside uvspace bucket and triangle bounds */
2686                                                                         if (isect_point_quad_v2(uv, seam_subsection[0], seam_subsection[1], seam_subsection[2], seam_subsection[3])) {
2687                                                                                 float fac;
2688
2689                                                                                 /* We need to find the closest point along the face edge,
2690                                                                                  * getting the screen_px_from_*** wont work because our actual location
2691                                                                                  * is not relevant, since we are outside the face, Use VecLerpf to find
2692                                                                                  * our location on the side of the face's UV */
2693 #if 0
2694                                                                                 if (is_ortho) screen_px_from_ortho(ps, uv, v1co, v2co, v3co, uv1co, uv2co, uv3co, pixelScreenCo);
2695                                                                                 else          screen_px_from_persp(ps, uv, v1co, v2co, v3co, uv1co, uv2co, uv3co, pixelScreenCo);
2696 #endif
2697
2698                                                                                 /* Since this is a seam we need to work out where on the line this pixel is */
2699                                                                                 //fac = line_point_factor_v2(uv, uv_seam_quad[0], uv_seam_quad[1]);
2700
2701                                                                                 fac = line_point_factor_v2(uv, seam_subsection[0], seam_subsection[1]);
2702                                                                                 if      (fac < 0.0f) { copy_v3_v3(pixelScreenCo, edge_verts_inset_clip[0]); }
2703                                                                                 else if (fac > 1.0f) { copy_v3_v3(pixelScreenCo, edge_verts_inset_clip[1]); }
2704                                                                                 else                 { interp_v3_v3v3(pixelScreenCo, edge_verts_inset_clip[0], edge_verts_inset_clip[1], fac); }
2705
2706                                                                                 if (!is_ortho) {
2707                                                                                         pixelScreenCo[3] = 1.0f;
2708                                                                                         mul_m4_v4((float(*)[4])ps->projectMat, pixelScreenCo); /* cast because of const */
2709                                                                                         pixelScreenCo[0] = (float)(ps->winx * 0.5f) + (ps->winx * 0.5f) * pixelScreenCo[0] / pixelScreenCo[3];
2710                                                                                         pixelScreenCo[1] = (float)(ps->winy * 0.5f) + (ps->winy * 0.5f) * pixelScreenCo[1] / pixelScreenCo[3];
2711                                                                                         pixelScreenCo[2] = pixelScreenCo[2] / pixelScreenCo[3]; /* Use the depth for bucket point occlusion */
2712                                                                                 }
2713
2714                                                                                 if ((ps->do_occlude == false) ||
2715                                                                                     !project_bucket_point_occluded(ps, bucketFaceNodes, face_index, pixelScreenCo))
2716                                                                                 {
2717                                                                                         /* Only bother calculating the weights if we intersect */
2718                                                                                         if (ps->do_mask_normal || ps->dm_mtface_clone) {
2719 #if 1
2720                                                                                                 /* get the UV on the line since we want to copy the pixels from there for bleeding */
2721                                                                                                 float uv_close[2];
2722                                                                                                 float uv_fac = closest_to_line_v2(uv_close, uv, tf_uv_pxoffset[fidx1], tf_uv_pxoffset[fidx2]);
2723                                                                                                 if      (uv_fac < 0.0f) copy_v2_v2(uv_close, tf_uv_pxoffset[fidx1]);
2724                                                                                                 else if (uv_fac > 1.0f) copy_v2_v2(uv_close, tf_uv_pxoffset[fidx2]);
2725
2726                                                                                                 if (side) {
2727                                                                                                         barycentric_weights_v2(tf_uv_pxoffset[0], tf_uv_pxoffset[2], tf_uv_pxoffset[3], uv_close, w);
2728                                                                                                 }
2729                                                                                                 else {
2730                                                                                                         barycentric_weights_v2(tf_uv_pxoffset[0], tf_uv_pxoffset[1], tf_uv_pxoffset[2], uv_close, w);
2731                                                                                                 }
2732 #else                                                                                   /* this is buggy with quads, don't use for now */
2733
2734                                                                                                 /* Cheat, we know where we are along the edge so work out the weights from that */
2735                                                                                                 uv_fac = fac1 + (uv_fac * (fac2 - fac1));
2736
2737                                                                                                 w[0] = w[1] = w[2] = 0.0;
2738                                                                                                 if (side) {
2739                                                                                                         w[fidx1 ? fidx1 - 1 : 0] = 1.0f - uv_fac;
2740                                                                                                         w[fidx2 ? fidx2 - 1 : 0] = uv_fac;
2741                                                                                                 }
2742                                                                                                 else {
2743                                                                                                         w[fidx1] = 1.0f - uv_fac;
2744                                                                                                         w[fidx2] = uv_fac;
2745                                                                                                 }
2746 #endif
2747                                                                                         }
2748
2749                                                                                         /* a pity we need to get the worldspace pixel location here */
2750                                                                                         if (do_clip || do_3d_mapping) {
2751                                                                                                 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);
2752                                                                                                 else      interp_v3_v3v3v3(wco, ps->dm_mvert[mf->v1].co, ps->dm_mvert[mf->v2].co, ps->dm_mvert[mf->v3].co, w);
2753
2754                                                                                                 if (do_clip && ED_view3d_clipping_test(ps->rv3d, wco, true)) {
2755                                                                                                         continue; /* Watch out that no code below this needs to run */
2756                                                                                                 }
2757                                                                                         }
2758
2759                                                                                         mask = project_paint_uvpixel_mask(ps, face_index, side, w);
2760
2761                                                                                         if (mask > 0.0f) {
2762                                                                                                 BLI_linklist_prepend_arena(
2763                                                                                                         bucketPixelNodes,
2764                                                                                                         project_paint_uvpixel_init(ps, arena, &tinf, x, y, mask, face_index,
2765                                                                                                         pixelScreenCo, wco, side, w),
2766                                                                                                         arena
2767                                                                                                         );
2768                                                                                         }
2769
2770                                                                                 }
2771                                                                         }
2772                                                                         else if (has_x_isect) {
2773                                                                                 /* assuming the face is not a bow-tie - we know we cant intersect again on the X */
2774                                                                                 break;
2775                                                                         }
2776                                                                 }
2777
2778 #if 0                           /* TODO - investigate why this dosnt work sometimes! it should! */
2779                                                                 /* no intersection for this entire row, after some intersection above means we can quit now */
2780                                                                 if (has_x_isect == 0 && has_isect) {
2781                                                                         break;
2782                                                                 }
2783 #endif
2784                                                         }
2785                                                 }
2786                                         }
2787                                 }
2788                         }
2789                 }
2790         }
2791 #endif // PROJ_DEBUG_NOSEAMBLEED
2792 }
2793
2794
2795 /* takes floating point screenspace min/max and returns int min/max to be used as indices for ps->bucketRect, ps->bucketFlags */
2796 static void project_paint_bucket_bounds(const ProjPaintState *ps, const float min[2], const float max[2], int bucketMin[2], int bucketMax[2])
2797 {
2798         /* divide by bucketWidth & bucketHeight so the bounds are offset in bucket grid units */
2799         /* 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 */
2800         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 */
2801         bucketMin[1] = (int)((int)(((float)(min[1] - ps->screenMin[1]) / ps->screen_height) * ps->buckets_y) + 0.5f);
2802
2803         bucketMax[0] = (int)((int)(((float)(max[0] - ps->screenMin[0]) / ps->screen_width) * ps->buckets_x) + 1.5f);
2804         bucketMax[1] = (int)((int)(((float)(max[1] - ps->screenMin[1]) / ps->screen_height) * ps->buckets_y) + 1.5f);
2805
2806         /* in case the rect is outside the mesh 2d bounds */
2807         CLAMP(bucketMin[0], 0, ps->buckets_x);
2808         CLAMP(bucketMin[1], 0, ps->buckets_y);
2809
2810         CLAMP(bucketMax[0], 0, ps->buckets_x);
2811         CLAMP(bucketMax[1], 0, ps->buckets_y);
2812 }
2813
2814 /* set bucket_bounds to a screen space-aligned floating point bound-box */
2815 static void project_bucket_bounds(const ProjPaintState *ps, const int bucket_x, const int bucket_y, rctf *bucket_bounds)
2816 {
2817         bucket_bounds->xmin = ps->screenMin[0] + ((bucket_x) * (ps->screen_width / ps->buckets_x));     /* left */
2818         bucket_bounds->xmax = ps->screenMin[0] + ((bucket_x + 1) * (ps->screen_width / ps->buckets_x)); /* right */
2819
2820         bucket_bounds->ymin = ps->screenMin[1] + ((bucket_y) * (ps->screen_height / ps->buckets_y));      /* bottom */
2821         bucket_bounds->ymax = ps->screenMin[1] + ((bucket_y + 1) * (ps->screen_height  / ps->buckets_y)); /* top */
2822 }
2823
2824 /* Fill this bucket with pixels from the faces that intersect it.
2825  *
2826  * have bucket_bounds as an argument so we don't need to give bucket_x/y the rect function needs */
2827 static void project_bucket_init(const ProjPaintState *ps, const int thread_index, const int bucket_index, rctf *bucket_bounds)
2828 {
2829         LinkNode *node;
2830         int face_index, image_index = 0;
2831         ImBuf *ibuf = NULL;
2832         Image *tpage_last = NULL, *tpage;
2833         Image *ima = NULL;
2834         ImBuf *tmpibuf = NULL;
2835
2836         if (ps->image_tot == 1) {
2837                 /* Simple loop, no context switching */
2838                 ibuf = ps->projImages[0].ibuf;
2839                 ima = ps->projImages[0].ima;
2840
2841                 for (node = ps->bucketFaces[bucket_index]; node; node = node->next) {
2842                         project_paint_face_init(ps, thread_index, bucket_index, GET_INT_FROM_POINTER(node->link), 0, bucket_bounds, ibuf, &tmpibuf, ima->tpageflag & IMA_CLAMP_U, ima->tpageflag & IMA_CLAMP_V);
2843                 }
2844         }
2845         else {
2846
2847                 /* More complicated loop, switch between images */
2848                 for (node = ps->bucketFaces[bucket_index]; node; node = node->next) {
2849                         face_index = GET_INT_FROM_POINTER(node->link);
2850
2851                         /* Image context switching */
2852                         tpage = project_paint_face_paint_image(ps, face_index);
2853                         if (tpage_last != tpage) {
2854                                 tpage_last = tpage;
2855
2856                                 for (image_index = 0; image_index < ps->image_tot; image_index++) {
2857                                         if (ps->projImages[image_index].ima == tpage_last) {
2858                                                 ibuf = ps->projImages[image_index].ibuf;
2859                                                 ima = ps->projImages[image_index].ima;
2860                                                 break;
2861                                         }
2862                                 }
2863                         }
2864                         /* context switching done */
2865
2866                         project_paint_face_init(ps, thread_index, bucket_index, face_index, image_index, bucket_bounds, ibuf, &tmpibuf, ima->tpageflag & IMA_CLAMP_U, ima->tpageflag & IMA_CLAMP_V);
2867                 }
2868         }
2869
2870         if (tmpibuf)
2871                 IMB_freeImBuf(tmpibuf);
2872
2873