Tracking: Cleanup. make code friendly for multi-column editing
[blender-staging.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_bits.h"
47 #include "BLI_math_color_blend.h"
48 #include "BLI_memarena.h"
49 #include "BLI_threads.h"
50 #include "BLI_utildefines.h"
51
52 #include "BLT_translation.h"
53
54
55 #include "IMB_imbuf.h"
56 #include "IMB_imbuf_types.h"
57
58 #include "DNA_brush_types.h"
59 #include "DNA_material_types.h"
60 #include "DNA_mesh_types.h"
61 #include "DNA_node_types.h"
62 #include "DNA_object_types.h"
63
64 #include "BKE_camera.h"
65 #include "BKE_context.h"
66 #include "BKE_colortools.h"
67 #include "BKE_depsgraph.h"
68 #include "BKE_DerivedMesh.h"
69 #include "BKE_idprop.h"
70 #include "BKE_brush.h"
71 #include "BKE_image.h"
72 #include "BKE_library.h"
73 #include "BKE_main.h"
74 #include "BKE_material.h"
75 #include "BKE_mesh.h"
76 #include "BKE_mesh_mapping.h"
77 #include "BKE_node.h"
78 #include "BKE_paint.h"
79 #include "BKE_report.h"
80 #include "BKE_scene.h"
81 #include "BKE_texture.h"
82
83 #include "UI_interface.h"
84
85 #include "ED_mesh.h"
86 #include "ED_node.h"
87 #include "ED_paint.h"
88 #include "ED_screen.h"
89 #include "ED_uvedit.h"
90 #include "ED_view3d.h"
91
92 #include "GPU_extensions.h"
93
94 #include "WM_api.h"
95 #include "WM_types.h"
96
97 #include "RNA_access.h"
98 #include "RNA_define.h"
99 #include "RNA_enum_types.h"
100
101 #include "GPU_draw.h"
102
103 #include "IMB_colormanagement.h"
104
105 #include "bmesh.h"
106 //#include "bmesh_tools.h"
107
108 #include "paint_intern.h"
109
110 static void partial_redraw_array_init(ImagePaintPartialRedraw *pr);
111
112 /* Defines and Structs */
113 /* FTOCHAR as inline function */
114 BLI_INLINE unsigned char f_to_char(const float val)
115 {
116         return FTOCHAR(val);
117 }
118
119 /* ProjectionPaint defines */
120
121 /* approx the number of buckets to have under the brush,
122  * used with the brush size to set the ps->buckets_x and ps->buckets_y value.
123  *
124  * When 3 - a brush should have ~9 buckets under it at once
125  * ...this helps for threading while painting as well as
126  * avoiding initializing pixels that wont touch the brush */
127 #define PROJ_BUCKET_BRUSH_DIV 4
128
129 #define PROJ_BUCKET_RECT_MIN 4
130 #define PROJ_BUCKET_RECT_MAX 256
131
132 #define PROJ_BOUNDBOX_DIV 8
133 #define PROJ_BOUNDBOX_SQUARED  (PROJ_BOUNDBOX_DIV * PROJ_BOUNDBOX_DIV)
134
135 //#define PROJ_DEBUG_PAINT 1
136 //#define PROJ_DEBUG_NOSEAMBLEED 1
137 //#define PROJ_DEBUG_PRINT_CLIP 1
138 #define PROJ_DEBUG_WINCLIP 1
139
140
141 #ifndef PROJ_DEBUG_NOSEAMBLEED
142 /* projectFaceSeamFlags options */
143 //#define PROJ_FACE_IGNORE      (1<<0)  /* When the face is hidden, backfacing or occluded */
144 //#define PROJ_FACE_INIT        (1<<1)  /* When we have initialized the faces data */
145 #define PROJ_FACE_SEAM1 (1 << 0)  /* If this face has a seam on any of its edges */
146 #define PROJ_FACE_SEAM2 (1 << 1)
147 #define PROJ_FACE_SEAM3 (1 << 2)
148
149 #define PROJ_FACE_NOSEAM1   (1 << 4)
150 #define PROJ_FACE_NOSEAM2   (1 << 5)
151 #define PROJ_FACE_NOSEAM3   (1 << 6)
152
153 /* face winding */
154 #define PROJ_FACE_WINDING_INIT 1
155 #define PROJ_FACE_WINDING_CW 2
156
157 /* a slightly scaled down face is used to get fake 3D location for edge pixels in the seams
158  * as this number approaches  1.0f the likelihood increases of float precision errors where
159  * it is occluded by an adjacent face */
160 #define PROJ_FACE_SCALE_SEAM    0.99f
161 #endif  /* PROJ_DEBUG_NOSEAMBLEED */
162
163
164 #define PROJ_SRC_VIEW       1
165 #define PROJ_SRC_IMAGE_CAM  2
166 #define PROJ_SRC_IMAGE_VIEW 3
167 #define PROJ_SRC_VIEW_FILL  4
168
169 #define PROJ_VIEW_DATA_ID "view_data"
170 #define PROJ_VIEW_DATA_SIZE (4 * 4 + 4 * 4 + 3) /* viewmat + winmat + clipsta + clipend + is_ortho */
171
172 #define PROJ_BUCKET_NULL        0
173 #define PROJ_BUCKET_INIT        (1 << 0)
174 // #define PROJ_BUCKET_CLONE_INIT       (1<<1)
175
176 /* used for testing doubles, if a point is on a line etc */
177 #define PROJ_GEOM_TOLERANCE 0.00075f
178 #define PROJ_PIXEL_TOLERANCE 0.01f
179
180 /* vert flags */
181 #define PROJ_VERT_CULL 1
182
183 /* to avoid locking in tile initialization */
184 #define TILE_PENDING SET_INT_IN_POINTER(-1)
185
186 /* This is mainly a convenience struct used so we can keep an array of images we use -
187  * their imbufs, etc, in 1 array, When using threads this array is copied for each thread
188  * because 'partRedrawRect' and 'touch' values would not be thread safe */
189 typedef struct ProjPaintImage {
190         Image *ima;
191         ImBuf *ibuf;
192         ImagePaintPartialRedraw *partRedrawRect;
193         volatile void **undoRect; /* only used to build undo tiles during painting */
194         unsigned short **maskRect; /* the mask accumulation must happen on canvas, not on space screen bucket.
195                                     * Here we store the mask rectangle */
196         bool **valid; /* store flag to enforce validation of undo rectangle */
197         bool touch;
198 } ProjPaintImage;
199
200 /**
201  * Handle for stroke (operator customdata)
202  */
203 typedef struct ProjStrokeHandle {
204         /* Support for painting from multiple views at once,
205          * currently used to implement symmetry painting,
206          * we can assume at least the first is set while painting. */
207         struct ProjPaintState *ps_views[8];
208         int ps_views_tot;
209         int symmetry_flags;
210
211         int orig_brush_size;
212
213         bool need_redraw;
214
215         /* trick to bypass regular paint and allow clone picking */
216         bool is_clone_cursor_pick;
217
218         /* In ProjPaintState, only here for convenience */
219         Scene *scene;
220         Brush *brush;
221 } ProjStrokeHandle;
222
223 /* Main projection painting struct passed to all projection painting functions */
224 typedef struct ProjPaintState {
225         View3D *v3d;
226         RegionView3D *rv3d;
227         ARegion *ar;
228         Scene *scene;
229         int source; /* PROJ_SRC_**** */
230
231         /* the paint color. It can change depending of inverted mode or not */
232         float paint_color[3];
233         float paint_color_linear[3];
234         float dither;
235
236         Brush *brush;
237         short tool, blend, mode;
238
239         float brush_size;
240         Object *ob;
241         /* for symmetry, we need to store modified object matrix */
242         float obmat[4][4];
243         float obmat_imat[4][4];
244         /* end similarities with ImagePaintState */
245
246         Image *stencil_ima;
247         Image *canvas_ima;
248         Image *clone_ima;
249         float stencil_value;
250
251         /* projection painting only */
252         MemArena *arena_mt[BLENDER_MAX_THREADS]; /* for multithreading, the first item is sometimes used for non threaded cases too */
253         LinkNode **bucketRect;              /* screen sized 2D array, each pixel has a linked list of ProjPixel's */
254         LinkNode **bucketFaces;             /* bucketRect aligned array linkList of faces overlapping each bucket */
255         unsigned char *bucketFlags;         /* store if the bucks have been initialized  */
256
257         char *vertFlags;                    /* store options per vert, now only store if the vert is pointing away from the view */
258         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 */
259         int buckets_y;
260
261         int pixel_sizeof;           /* result of project_paint_pixel_sizeof(), constant per stroke */
262
263         int image_tot;              /* size of projectImages array */
264
265         float (*screenCoords)[4];   /* verts projected into floating point screen space */
266         float screenMin[2];         /* 2D bounds for mesh verts on the screen's plane (screenspace) */
267         float screenMax[2];
268         float screen_width;         /* Calculated from screenMin & screenMax */
269         float screen_height;
270         int winx, winy;             /* from the carea or from the projection render */
271
272         /* options for projection painting */
273         bool  do_layer_clone;
274         bool  do_layer_stencil;
275         bool  do_layer_stencil_inv;
276         bool  do_stencil_brush;
277         bool  do_material_slots;
278
279         bool  do_occlude;               /* Use raytraced occlusion? - ortherwise will paint right through to the back*/
280         bool  do_backfacecull;          /* ignore faces with normals pointing away, skips a lot of raycasts if your normals are correctly flipped */
281         bool  do_mask_normal;           /* mask out pixels based on their normals */
282         bool  do_mask_cavity;           /* mask out pixels based on cavity */
283         bool  do_new_shading_nodes;     /* cache BKE_scene_use_new_shading_nodes value */
284         float normal_angle;             /* what angle to mask at */
285         float normal_angle__cos;         /* cos(normal_angle), faster to compare */
286         float normal_angle_inner;
287         float normal_angle_inner__cos;
288         float normal_angle_range;       /* difference between normal_angle and normal_angle_inner, for easy access */
289
290         bool do_face_sel;               /* quick access to (me->editflag & ME_EDIT_PAINT_FACE_SEL) */
291         bool is_ortho;
292         bool is_flip_object;            /* the object is negative scaled */
293         bool do_masking;              /* use masking during painting. Some operations such as airbrush may disable */
294         bool is_texbrush;              /* only to avoid running  */
295         bool is_maskbrush;            /* mask brush is applied before masking */
296 #ifndef PROJ_DEBUG_NOSEAMBLEED
297         float seam_bleed_px;
298 #endif
299         /* clone vars */
300         float cloneOffset[2];
301
302         float projectMat[4][4];     /* Projection matrix, use for getting screen coords */
303         float projectMatInv[4][4];  /* inverse of projectMat */
304         float viewDir[3];           /* View vector, use for do_backfacecull and for ray casting with an ortho viewport  */
305         float viewPos[3];           /* View location in object relative 3D space, so can compare to verts  */
306         float clipsta, clipend;
307
308         /* reproject vars */
309         Image *reproject_image;
310         ImBuf *reproject_ibuf;
311         bool   reproject_ibuf_free_float;
312         bool   reproject_ibuf_free_uchar;
313
314         /* threads */
315         int thread_tot;
316         int bucketMin[2];
317         int bucketMax[2];
318         int context_bucket_x, context_bucket_y; /* must lock threads while accessing these */
319
320         struct CurveMapping *cavity_curve;
321         BlurKernel *blurkernel;
322
323
324
325         /* -------------------------------------------------------------------- */
326         /* Vars shared between multiple views (keep last) */
327         /**
328          * This data is owned by ``ProjStrokeHandle.ps_views[0]``,
329          * all other views re-use the data.
330          */
331
332 #define PROJ_PAINT_STATE_SHARED_MEMCPY(ps_dst, ps_src) \
333         MEMCPY_STRUCT_OFS(ps_dst, ps_src, is_shared_user)
334
335 #define PROJ_PAINT_STATE_SHARED_CLEAR(ps) \
336         MEMSET_STRUCT_OFS(ps, 0, is_shared_user)
337
338         bool is_shared_user;
339
340         ProjPaintImage *projImages;
341         float *cavities;            /* cavity amount for vertices */
342
343 #ifndef PROJ_DEBUG_NOSEAMBLEED
344         char *faceSeamFlags;                /* store info about faces, if they are initialized etc*/
345         char *faceWindingFlags;             /* save the winding of the face in uv space, helps as an extra validation step for seam detection */
346         float (*faceSeamUVs)[3][2];         /* expanded UVs for faces to use as seams */
347         LinkNode **vertFaces;               /* Only needed for when seam_bleed_px is enabled, use to find UV seams */
348 #endif
349
350         SpinLock *tile_lock;
351
352         DerivedMesh    *dm;
353         int  dm_totlooptri;
354         int  dm_totpoly;
355         int  dm_totedge;
356         int  dm_totvert;
357         bool dm_release;
358
359         const MVert    *dm_mvert;
360         const MEdge    *dm_medge;
361         const MPoly    *dm_mpoly;
362         const MLoop    *dm_mloop;
363         const MLoopTri *dm_mlooptri;
364
365         const MLoopUV  *dm_mloopuv_stencil;
366
367         /**
368          * \note These UV layers are aligned to \a dm_mpoly
369          * but each pointer references the start of the layer,
370          * so a loop indirection is needed as well.
371          */
372         const MLoopUV **dm_mloopuv;
373         const MLoopUV **dm_mloopuv_clone;    /* other UV map, use for cloning between layers */
374
375         bool use_colormanagement;
376 } ProjPaintState;
377
378 typedef union pixelPointer {
379         float *f_pt;            /* float buffer */
380         unsigned int *uint_pt; /* 2 ways to access a char buffer */
381         unsigned char *ch_pt;
382 } PixelPointer;
383
384 typedef union pixelStore {
385         unsigned char ch[4];
386         unsigned int uint;
387         float f[4];
388 } PixelStore;
389
390 typedef struct ProjPixel {
391         float projCoSS[2]; /* the floating point screen projection of this pixel */
392         float worldCoSS[3];
393
394         short x_px, y_px;
395
396         unsigned short image_index; /* if anyone wants to paint onto more than 65535 images they can bite me */
397         unsigned char bb_cell_index;
398
399         /* for various reasons we may want to mask out painting onto this pixel */
400         unsigned short mask;
401
402         /* Only used when the airbrush is disabled.
403          * Store the max mask value to avoid painting over an area with a lower opacity
404          * with an advantage that we can avoid touching the pixel at all, if the
405          * new mask value is lower then mask_accum */
406         unsigned short *mask_accum;
407
408         /* horrible hack, store tile valid flag pointer here to re-validate tiles used for anchored and drag-dot strokes */
409         bool *valid;
410
411         PixelPointer origColor;
412         PixelStore newColor;
413         PixelPointer pixel;
414 } ProjPixel;
415
416 typedef struct ProjPixelClone {
417         struct ProjPixel __pp;
418         PixelStore clonepx;
419 } ProjPixelClone;
420
421 /* undo tile pushing */
422 typedef struct {
423         SpinLock *lock;
424         bool masked;
425         unsigned short tile_width;
426         ImBuf **tmpibuf;
427         ProjPaintImage *pjima;
428 } TileInfo;
429
430
431
432 /* -------------------------------------------------------------------- */
433
434 /** \name MLoopTri accessor functions.
435  * \{ */
436
437 BLI_INLINE const MPoly *ps_tri_index_to_mpoly(const ProjPaintState *ps, int tri_index)
438 {
439         return &ps->dm_mpoly[ps->dm_mlooptri[tri_index].poly];
440 }
441
442 #define PS_LOOPTRI_AS_VERT_INDEX_3(ps, lt) \
443         ps->dm_mloop[lt->tri[0]].v, \
444         ps->dm_mloop[lt->tri[1]].v, \
445         ps->dm_mloop[lt->tri[2]].v,
446
447 #define PS_LOOPTRI_AS_UV_3(uvlayer, lt) \
448         uvlayer[lt->poly][lt->tri[0]].uv, \
449         uvlayer[lt->poly][lt->tri[1]].uv, \
450         uvlayer[lt->poly][lt->tri[2]].uv,
451
452 #define PS_LOOPTRI_ASSIGN_UV_3(uv_tri, uvlayer, lt)  { \
453         (uv_tri)[0] = uvlayer[lt->poly][lt->tri[0]].uv; \
454         (uv_tri)[1] = uvlayer[lt->poly][lt->tri[1]].uv; \
455         (uv_tri)[2] = uvlayer[lt->poly][lt->tri[2]].uv; \
456 } ((void)0)
457
458 /** \} */
459
460
461
462 /* Finish projection painting structs */
463
464 static TexPaintSlot *project_paint_face_paint_slot(const ProjPaintState *ps, int tri_index)
465 {
466         const MPoly *mp = ps_tri_index_to_mpoly(ps, tri_index);
467         Material *ma = ps->dm->mat[mp->mat_nr];
468         return ma ? ma->texpaintslot + ma->paint_active_slot : NULL;
469 }
470
471 static Image *project_paint_face_paint_image(const ProjPaintState *ps, int tri_index)
472 {
473         if (ps->do_stencil_brush) {
474                 return ps->stencil_ima;
475         }
476         else {
477                 const MPoly *mp = ps_tri_index_to_mpoly(ps, tri_index);
478                 Material *ma = ps->dm->mat[mp->mat_nr];
479                 TexPaintSlot *slot = ma ? ma->texpaintslot + ma->paint_active_slot : NULL;
480                 return slot ? slot->ima : ps->canvas_ima;
481         }
482 }
483
484 static TexPaintSlot *project_paint_face_clone_slot(const ProjPaintState *ps, int tri_index)
485 {
486         const MPoly *mp = ps_tri_index_to_mpoly(ps, tri_index);
487         Material *ma = ps->dm->mat[mp->mat_nr];
488         return ma ? ma->texpaintslot + ma->paint_clone_slot : NULL;
489 }
490
491 static Image *project_paint_face_clone_image(const ProjPaintState *ps, int tri_index)
492 {
493         const MPoly *mp = ps_tri_index_to_mpoly(ps, tri_index);
494         Material *ma = ps->dm->mat[mp->mat_nr];
495         TexPaintSlot *slot = ma ? ma->texpaintslot + ma->paint_clone_slot : NULL;
496         return slot ? slot->ima : ps->clone_ima;
497 }
498
499 /* fast projection bucket array lookup, use the safe version for bound checking  */
500 static int project_bucket_offset(const ProjPaintState *ps, const float projCoSS[2])
501 {
502         /* If we were not dealing with screenspace 2D coords we could simple do...
503          * ps->bucketRect[x + (y*ps->buckets_y)] */
504
505         /* please explain?
506          * projCoSS[0] - ps->screenMin[0]   : zero origin
507          * ... / ps->screen_width           : range from 0.0 to 1.0
508          * ... * ps->buckets_x              : use as a bucket index
509          *
510          * Second multiplication does similar but for vertical offset
511          */
512         return ( (int)(((projCoSS[0] - ps->screenMin[0]) / ps->screen_width)  * ps->buckets_x)) +
513                (((int)(((projCoSS[1] - ps->screenMin[1]) / ps->screen_height) * ps->buckets_y)) * ps->buckets_x);
514 }
515
516 static int project_bucket_offset_safe(const ProjPaintState *ps, const float projCoSS[2])
517 {
518         int bucket_index = project_bucket_offset(ps, projCoSS);
519
520         if (bucket_index < 0 || bucket_index >= ps->buckets_x * ps->buckets_y) {
521                 return -1;
522         }
523         else {
524                 return bucket_index;
525         }
526 }
527
528 static float VecZDepthOrtho(
529         const float pt[2],
530         const float v1[3], const float v2[3], const float v3[3],
531         float w[3])
532 {
533         barycentric_weights_v2(v1, v2, v3, pt, w);
534         return (v1[2] * w[0]) + (v2[2] * w[1]) + (v3[2] * w[2]);
535 }
536
537 static float VecZDepthPersp(
538         const float pt[2],
539         const float v1[4], const float v2[4], const float v3[4],
540         float w[3])
541 {
542         float wtot_inv, wtot;
543         float w_tmp[3];
544
545         barycentric_weights_v2_persp(v1, v2, v3, pt, w);
546         /* for the depth we need the weights to match what
547          * barycentric_weights_v2 would return, in this case its easiest just to
548          * undo the 4th axis division and make it unit-sum
549          *
550          * don't call barycentric_weights_v2() because our callers expect 'w'
551          * to be weighted from the perspective */
552         w_tmp[0] = w[0] * v1[3];
553         w_tmp[1] = w[1] * v2[3];
554         w_tmp[2] = w[2] * v3[3];
555
556         wtot = w_tmp[0] + w_tmp[1] + w_tmp[2];
557
558         if (wtot != 0.0f) {
559                 wtot_inv = 1.0f / wtot;
560
561                 w_tmp[0] = w_tmp[0] * wtot_inv;
562                 w_tmp[1] = w_tmp[1] * wtot_inv;
563                 w_tmp[2] = w_tmp[2] * wtot_inv;
564         }
565         else /* dummy values for zero area face */
566                 w_tmp[0] = w_tmp[1] = w_tmp[2] = 1.0f / 3.0f;
567         /* done mimicing barycentric_weights_v2() */
568
569         return (v1[2] * w_tmp[0]) + (v2[2] * w_tmp[1]) + (v3[2] * w_tmp[2]);
570 }
571
572
573 /* Return the top-most face index that the screen space coord 'pt' touches (or -1) */
574 static int project_paint_PickFace(
575         const ProjPaintState *ps, const float pt[2],
576         float w[3])
577 {
578         LinkNode *node;
579         float w_tmp[3];
580         int bucket_index;
581         int best_tri_index = -1;
582         float z_depth_best = FLT_MAX, z_depth;
583
584         bucket_index = project_bucket_offset_safe(ps, pt);
585         if (bucket_index == -1)
586                 return -1;
587
588
589
590         /* we could return 0 for 1 face buckets, as long as this function assumes
591          * that the point its testing is only every originated from an existing face */
592
593         for (node = ps->bucketFaces[bucket_index]; node; node = node->next) {
594                 const int tri_index = GET_INT_FROM_POINTER(node->link);
595                 const MLoopTri *lt = &ps->dm_mlooptri[tri_index];
596                 const float *vtri_ss[3] = {
597                     ps->screenCoords[ps->dm_mloop[lt->tri[0]].v],
598                     ps->screenCoords[ps->dm_mloop[lt->tri[1]].v],
599                     ps->screenCoords[ps->dm_mloop[lt->tri[2]].v],
600                 };
601
602
603                 if (isect_point_tri_v2(pt, UNPACK3(vtri_ss))) {
604                         if (ps->is_ortho) {
605                                 z_depth = VecZDepthOrtho(pt, UNPACK3(vtri_ss), w_tmp);
606                         }
607                         else {
608                                 z_depth = VecZDepthPersp(pt, UNPACK3(vtri_ss), w_tmp);
609                         }
610
611                         if (z_depth < z_depth_best) {
612                                 best_tri_index = tri_index;
613                                 z_depth_best = z_depth;
614                                 copy_v3_v3(w, w_tmp);
615                         }
616                 }
617         }
618
619         return best_tri_index; /* will be -1 or a valid face */
620 }
621
622 /* Converts a uv coord into a pixel location wrapping if the uv is outside 0-1 range */
623 static void uvco_to_wrapped_pxco(const float uv[2], int ibuf_x, int ibuf_y, float *x, float *y)
624 {
625         /* use */
626         *x = fmodf(uv[0], 1.0f);
627         *y = fmodf(uv[1], 1.0f);
628
629         if (*x < 0.0f) *x += 1.0f;
630         if (*y < 0.0f) *y += 1.0f;
631
632         *x = *x * ibuf_x - 0.5f;
633         *y = *y * ibuf_y - 0.5f;
634 }
635
636 /* Set the top-most face color that the screen space coord 'pt' touches (or return 0 if none touch) */
637 static bool project_paint_PickColor(
638         const ProjPaintState *ps, const float pt[2],
639         float *rgba_fp, unsigned char *rgba, const bool interp)
640 {
641         const MLoopTri *lt;
642         const float *lt_tri_uv[3];
643         float w[3], uv[2];
644         int tri_index;
645         Image *ima;
646         ImBuf *ibuf;
647         int xi, yi;
648
649         tri_index = project_paint_PickFace(ps, pt, w);
650
651         if (tri_index == -1)
652                 return 0;
653
654         lt = &ps->dm_mlooptri[tri_index];
655         PS_LOOPTRI_ASSIGN_UV_3(lt_tri_uv, ps->dm_mloopuv, lt);
656
657         interp_v2_v2v2v2(uv, UNPACK3(lt_tri_uv), w);
658
659         ima = project_paint_face_paint_image(ps, tri_index);
660         ibuf = BKE_image_get_first_ibuf(ima); /* we must have got the imbuf before getting here */
661         if (!ibuf) return 0;
662
663         if (interp) {
664                 float x, y;
665                 uvco_to_wrapped_pxco(uv, ibuf->x, ibuf->y, &x, &y);
666
667                 if (ibuf->rect_float) {
668                         if (rgba_fp) {
669                                 bilinear_interpolation_color_wrap(ibuf, NULL, rgba_fp, x, y);
670                         }
671                         else {
672                                 float rgba_tmp_f[4];
673                                 bilinear_interpolation_color_wrap(ibuf, NULL, rgba_tmp_f, x, y);
674                                 premul_float_to_straight_uchar(rgba, rgba_tmp_f);
675                         }
676                 }
677                 else {
678                         if (rgba) {
679                                 bilinear_interpolation_color_wrap(ibuf, rgba, NULL, x, y);
680                         }
681                         else {
682                                 unsigned char rgba_tmp[4];
683                                 bilinear_interpolation_color_wrap(ibuf, rgba_tmp, NULL, x, y);
684                                 straight_uchar_to_premul_float(rgba_fp, rgba_tmp);
685                         }
686                 }
687         }
688         else {
689                 //xi = (int)((uv[0]*ibuf->x) + 0.5f);
690                 //yi = (int)((uv[1]*ibuf->y) + 0.5f);
691                 //if (xi < 0 || xi >= ibuf->x  ||  yi < 0 || yi >= ibuf->y) return 0;
692
693                 /* wrap */
694                 xi = mod_i((int)(uv[0] * ibuf->x), ibuf->x);
695                 yi = mod_i((int)(uv[1] * ibuf->y), ibuf->y);
696
697                 if (rgba) {
698                         if (ibuf->rect_float) {
699                                 const float *rgba_tmp_fp = ibuf->rect_float + (xi + yi * ibuf->x * 4);
700                                 premul_float_to_straight_uchar(rgba, rgba_tmp_fp);
701                         }
702                         else {
703                                 *((unsigned int *)rgba) = *(unsigned int *)(((char *)ibuf->rect) + ((xi + yi * ibuf->x) * 4));
704                         }
705                 }
706
707                 if (rgba_fp) {
708                         if (ibuf->rect_float) {
709                                 copy_v4_v4(rgba_fp, (ibuf->rect_float + ((xi + yi * ibuf->x) * 4)));
710                         }
711                         else {
712                                 unsigned char *tmp_ch = ((unsigned char *)ibuf->rect) + ((xi + yi * ibuf->x) * 4);
713                                 straight_uchar_to_premul_float(rgba_fp, tmp_ch);
714                         }
715                 }
716         }
717         BKE_image_release_ibuf(ima, ibuf, NULL);
718         return 1;
719 }
720
721 /**
722  * Check if 'pt' is infront of the 3 verts on the Z axis (used for screenspace occlusion test)
723  * \return
724  * -  `0`:   no occlusion
725  * - `-1`: no occlusion but 2D intersection is true
726  * -  `1`: occluded
727  * -  `2`: occluded with `w[3]` weights set (need to know in some cases)
728  */
729 static int project_paint_occlude_ptv(
730         const float pt[3],
731         const float v1[4], const float v2[4], const float v3[4],
732         float w[3], const bool is_ortho)
733 {
734         /* if all are behind us, return false */
735         if (v1[2] > pt[2] && v2[2] > pt[2] && v3[2] > pt[2])
736                 return 0;
737
738         /* do a 2D point in try intersection */
739         if (!isect_point_tri_v2(pt, v1, v2, v3))
740                 return 0;  /* we know there is  */
741
742
743         /* From here on we know there IS an intersection */
744         /* if ALL of the verts are infront of us then we know it intersects ? */
745         if (v1[2] < pt[2] && v2[2] < pt[2] && v3[2] < pt[2]) {
746                 return 1;
747         }
748         else {
749                 /* we intersect? - find the exact depth at the point of intersection */
750                 /* Is this point is occluded by another face? */
751                 if (is_ortho) {
752                         if (VecZDepthOrtho(pt, v1, v2, v3, w) < pt[2]) return 2;
753                 }
754                 else {
755                         if (VecZDepthPersp(pt, v1, v2, v3, w) < pt[2]) return 2;
756                 }
757         }
758         return -1;
759 }
760
761
762 static int project_paint_occlude_ptv_clip(
763         const float pt[3],
764         const float v1[4], const float v2[4], const float v3[4],
765         const float v1_3d[3], const float v2_3d[3], const float v3_3d[3],
766         float w[3], const bool is_ortho, RegionView3D *rv3d)
767 {
768         float wco[3];
769         int ret = project_paint_occlude_ptv(pt, v1, v2, v3, w, is_ortho);
770
771         if (ret <= 0)
772                 return ret;
773
774         if (ret == 1) { /* weights not calculated */
775                 if (is_ortho) {
776                         barycentric_weights_v2(v1, v2, v3, pt, w);
777                 }
778                 else {
779                         barycentric_weights_v2_persp(v1, v2, v3, pt, w);
780                 }
781         }
782
783         /* Test if we're in the clipped area, */
784         interp_v3_v3v3v3(wco, v1_3d, v2_3d, v3_3d, w);
785
786         if (!ED_view3d_clipping_test(rv3d, wco, true)) {
787                 return 1;
788         }
789
790         return -1;
791 }
792
793
794 /* Check if a screenspace location is occluded by any other faces
795  * check, pixelScreenCo must be in screenspace, its Z-Depth only needs to be used for comparison
796  * and doesn't need to be correct in relation to X and Y coords (this is the case in perspective view) */
797 static bool project_bucket_point_occluded(
798         const ProjPaintState *ps, LinkNode *bucketFace,
799         const int orig_face, const float pixelScreenCo[4])
800 {
801         int isect_ret;
802         const bool do_clip = ps->rv3d ? (ps->rv3d->rflag & RV3D_CLIPPING) != 0 : 0;
803
804         /* we could return 0 for 1 face buckets, as long as this function assumes
805          * that the point its testing is only every originated from an existing face */
806
807         for (; bucketFace; bucketFace = bucketFace->next) {
808                 const int tri_index = GET_INT_FROM_POINTER(bucketFace->link);
809
810                 if (orig_face != tri_index) {
811                         const MLoopTri *lt = &ps->dm_mlooptri[tri_index];
812                         const float *vtri_ss[3] = {
813                             ps->screenCoords[ps->dm_mloop[lt->tri[0]].v],
814                             ps->screenCoords[ps->dm_mloop[lt->tri[1]].v],
815                             ps->screenCoords[ps->dm_mloop[lt->tri[2]].v],
816                         };
817                         float w[3];
818
819                         if (do_clip) {
820                                 const float *vtri_co[3] = {
821                                     ps->dm_mvert[ps->dm_mloop[lt->tri[0]].v].co,
822                                     ps->dm_mvert[ps->dm_mloop[lt->tri[1]].v].co,
823                                     ps->dm_mvert[ps->dm_mloop[lt->tri[2]].v].co,
824                                 };
825                                 isect_ret = project_paint_occlude_ptv_clip(
826                                         pixelScreenCo, UNPACK3(vtri_ss), UNPACK3(vtri_co),
827                                         w, ps->is_ortho, ps->rv3d);
828                         }
829                         else {
830                                 isect_ret = project_paint_occlude_ptv(
831                                         pixelScreenCo, UNPACK3(vtri_ss),
832                                         w, ps->is_ortho);
833                         }
834
835                         if (isect_ret >= 1) {
836                                 /* TODO - we may want to cache the first hit,
837                                  * it is not possible to swap the face order in the list anymore */
838                                 return true;
839                         }
840                 }
841         }
842         return false;
843 }
844
845 /* basic line intersection, could move to math_geom.c, 2 points with a horiz line
846  * 1 for an intersection, 2 if the first point is aligned, 3 if the second point is aligned */
847 #define ISECT_TRUE 1
848 #define ISECT_TRUE_P1 2
849 #define ISECT_TRUE_P2 3
850 static int line_isect_y(const float p1[2], const float p2[2], const float y_level, float *x_isect)
851 {
852         float y_diff;
853
854         if (y_level == p1[1]) { /* are we touching the first point? - no interpolation needed */
855                 *x_isect = p1[0];
856                 return ISECT_TRUE_P1;
857         }
858         if (y_level == p2[1]) { /* are we touching the second point? - no interpolation needed */
859                 *x_isect = p2[0];
860                 return ISECT_TRUE_P2;
861         }
862
863         y_diff = fabsf(p1[1] - p2[1]); /* yuck, horizontal line, we cant do much here */
864
865         if (y_diff < 0.000001f) {
866                 *x_isect = (p1[0] + p2[0]) * 0.5f;
867                 return ISECT_TRUE;
868         }
869
870         if (p1[1] > y_level && p2[1] < y_level) {
871                 *x_isect = (p2[0] * (p1[1] - y_level) + p1[0] * (y_level - p2[1])) / y_diff;  /* (p1[1] - p2[1]); */
872                 return ISECT_TRUE;
873         }
874         else if (p1[1] < y_level && p2[1] > y_level) {
875                 *x_isect = (p2[0] * (y_level - p1[1]) + p1[0] * (p2[1] - y_level)) / y_diff;  /* (p2[1] - p1[1]); */
876                 return ISECT_TRUE;
877         }
878         else {
879                 return 0;
880         }
881 }
882
883 static int line_isect_x(const float p1[2], const float p2[2], const float x_level, float *y_isect)
884 {
885         float x_diff;
886
887         if (x_level == p1[0]) { /* are we touching the first point? - no interpolation needed */
888                 *y_isect = p1[1];
889                 return ISECT_TRUE_P1;
890         }
891         if (x_level == p2[0]) { /* are we touching the second point? - no interpolation needed */
892                 *y_isect = p2[1];
893                 return ISECT_TRUE_P2;
894         }
895
896         x_diff = fabsf(p1[0] - p2[0]); /* yuck, horizontal line, we cant do much here */
897
898         if (x_diff < 0.000001f) { /* yuck, vertical line, we cant do much here */
899                 *y_isect = (p1[0] + p2[0]) * 0.5f;
900                 return ISECT_TRUE;
901         }
902
903         if (p1[0] > x_level && p2[0] < x_level) {
904                 *y_isect = (p2[1] * (p1[0] - x_level) + p1[1] * (x_level - p2[0])) / x_diff;  /* (p1[0] - p2[0]); */
905                 return ISECT_TRUE;
906         }
907         else if (p1[0] < x_level && p2[0] > x_level) {
908                 *y_isect = (p2[1] * (x_level - p1[0]) + p1[1] * (p2[0] - x_level)) / x_diff;  /* (p2[0] - p1[0]); */
909                 return ISECT_TRUE;
910         }
911         else {
912                 return 0;
913         }
914 }
915
916 /* simple func use for comparing UV locations to check if there are seams.
917  * Its possible this gives incorrect results, when the UVs for 1 face go into the next
918  * tile, but do not do this for the adjacent face, it could return a false positive.
919  * This is so unlikely that Id not worry about it. */
920 #ifndef PROJ_DEBUG_NOSEAMBLEED
921 static bool cmp_uv(const float vec2a[2], const float vec2b[2])
922 {
923         /* if the UV's are not between 0.0 and 1.0 */
924         float xa = fmodf(vec2a[0], 1.0f);
925         float ya = fmodf(vec2a[1], 1.0f);
926
927         float xb = fmodf(vec2b[0], 1.0f);
928         float yb = fmodf(vec2b[1], 1.0f);
929
930         if (xa < 0.0f) xa += 1.0f;
931         if (ya < 0.0f) ya += 1.0f;
932
933         if (xb < 0.0f) xb += 1.0f;
934         if (yb < 0.0f) yb += 1.0f;
935
936         return ((fabsf(xa - xb) < PROJ_GEOM_TOLERANCE) && (fabsf(ya - yb) < PROJ_GEOM_TOLERANCE)) ? 1 : 0;
937 }
938 #endif
939
940 /* set min_px and max_px to the image space bounds of the UV coords
941  * return zero if there is no area in the returned rectangle */
942 #ifndef PROJ_DEBUG_NOSEAMBLEED
943 static bool pixel_bounds_uv(
944         const float uv_quad[4][2],
945         rcti *bounds_px,
946         const int ibuf_x, const int ibuf_y
947         )
948 {
949         float min_uv[2], max_uv[2]; /* UV bounds */
950
951         INIT_MINMAX2(min_uv, max_uv);
952
953         minmax_v2v2_v2(min_uv, max_uv, uv_quad[0]);
954         minmax_v2v2_v2(min_uv, max_uv, uv_quad[1]);
955         minmax_v2v2_v2(min_uv, max_uv, uv_quad[2]);
956         minmax_v2v2_v2(min_uv, max_uv, uv_quad[3]);
957
958         bounds_px->xmin = (int)(ibuf_x * min_uv[0]);
959         bounds_px->ymin = (int)(ibuf_y * min_uv[1]);
960
961         bounds_px->xmax = (int)(ibuf_x * max_uv[0]) + 1;
962         bounds_px->ymax = (int)(ibuf_y * max_uv[1]) + 1;
963
964         /*printf("%d %d %d %d\n", min_px[0], min_px[1], max_px[0], max_px[1]);*/
965
966         /* face uses no UV area when quantized to pixels? */
967         return (bounds_px->xmin == bounds_px->xmax || bounds_px->ymin == bounds_px->ymax) ? 0 : 1;
968 }
969 #endif
970
971 static bool pixel_bounds_array(float (*uv)[2], rcti *bounds_px, const int ibuf_x, const int ibuf_y, int tot)
972 {
973         float min_uv[2], max_uv[2]; /* UV bounds */
974
975         if (tot == 0) {
976                 return 0;
977         }
978
979         INIT_MINMAX2(min_uv, max_uv);
980
981         while (tot--) {
982                 minmax_v2v2_v2(min_uv, max_uv, (*uv));
983                 uv++;
984         }
985
986         bounds_px->xmin = (int)(ibuf_x * min_uv[0]);
987         bounds_px->ymin = (int)(ibuf_y * min_uv[1]);
988
989         bounds_px->xmax = (int)(ibuf_x * max_uv[0]) + 1;
990         bounds_px->ymax = (int)(ibuf_y * max_uv[1]) + 1;
991
992         /*printf("%d %d %d %d\n", min_px[0], min_px[1], max_px[0], max_px[1]);*/
993
994         /* face uses no UV area when quantized to pixels? */
995         return (bounds_px->xmin == bounds_px->xmax || bounds_px->ymin == bounds_px->ymax) ? 0 : 1;
996 }
997
998 #ifndef PROJ_DEBUG_NOSEAMBLEED
999
1000 static void project_face_winding_init(const ProjPaintState *ps, const int tri_index)
1001 {
1002         /* detect the winding of faces in uv space */
1003         const MLoopTri *lt = &ps->dm_mlooptri[tri_index];
1004         const float *lt_tri_uv[3] = { PS_LOOPTRI_AS_UV_3(ps->dm_mloopuv, lt) };
1005         float winding = cross_tri_v2(lt_tri_uv[0], lt_tri_uv[1], lt_tri_uv[2]);
1006
1007         if (winding > 0)
1008                 ps->faceWindingFlags[tri_index] |= PROJ_FACE_WINDING_CW;
1009
1010         ps->faceWindingFlags[tri_index] |= PROJ_FACE_WINDING_INIT;
1011 }
1012
1013 /* This function returns 1 if this face has a seam along the 2 face-vert indices
1014  * 'orig_i1_fidx' and 'orig_i2_fidx' */
1015 static bool check_seam(
1016         const ProjPaintState *ps,
1017         const int orig_face, const int orig_i1_fidx, const int orig_i2_fidx,
1018         int *other_face, int *orig_fidx)
1019 {
1020         const MLoopTri *orig_lt = &ps->dm_mlooptri[orig_face];
1021         const float *orig_lt_tri_uv[3] = { PS_LOOPTRI_AS_UV_3(ps->dm_mloopuv, orig_lt) };
1022         /* vert indices from face vert order indices */
1023         const unsigned int i1 = ps->dm_mloop[orig_lt->tri[orig_i1_fidx]].v;
1024         const unsigned int i2 = ps->dm_mloop[orig_lt->tri[orig_i2_fidx]].v;
1025         LinkNode *node;
1026         int i1_fidx = -1, i2_fidx = -1; /* index in face */
1027
1028         for (node = ps->vertFaces[i1]; node; node = node->next) {
1029                 const int tri_index = GET_INT_FROM_POINTER(node->link);
1030
1031                 if (tri_index != orig_face) {
1032                         const MLoopTri *lt = &ps->dm_mlooptri[tri_index];
1033                         const int lt_vtri[3] = { PS_LOOPTRI_AS_VERT_INDEX_3(ps, lt) };
1034                         /* could check if the 2 faces images match here,
1035                          * but then there wouldn't be a way to return the opposite face's info */
1036
1037
1038                         /* We need to know the order of the verts in the adjacent face
1039                          * set the i1_fidx and i2_fidx to (0,1,2,3) */
1040                         i1_fidx = BKE_MESH_TESSTRI_VINDEX_ORDER(lt_vtri, i1);
1041                         i2_fidx = BKE_MESH_TESSTRI_VINDEX_ORDER(lt_vtri, i2);
1042
1043                         /* Only need to check if 'i2_fidx' is valid because we know i1_fidx is the same vert on both faces */
1044                         if (i2_fidx != -1) {
1045                                 const float *lt_tri_uv[3] = { PS_LOOPTRI_AS_UV_3(ps->dm_mloopuv, lt) };
1046                                 Image *tpage = project_paint_face_paint_image(ps, tri_index);
1047                                 Image *orig_tpage = project_paint_face_paint_image(ps, orig_face);
1048
1049                                 BLI_assert(i1_fidx != -1);
1050
1051                                 /* This IS an adjacent face!, now lets check if the UVs are ok */
1052
1053                                 /* set up the other face */
1054                                 *other_face = tri_index;
1055                                 
1056                                 /* we check if difference is 1 here, else we might have a case of edge 2-0 for a tri */
1057                                 *orig_fidx = (i1_fidx < i2_fidx && (i2_fidx - i1_fidx == 1)) ? i1_fidx : i2_fidx;
1058
1059                                 /* initialize face winding if needed */
1060                                 if ((ps->faceWindingFlags[tri_index] & PROJ_FACE_WINDING_INIT) == 0)
1061                                         project_face_winding_init(ps, tri_index);
1062
1063                                 /* first test if they have the same image */
1064                                 if ((orig_tpage == tpage) &&
1065                                     cmp_uv(orig_lt_tri_uv[orig_i1_fidx], lt_tri_uv[i1_fidx]) &&
1066                                     cmp_uv(orig_lt_tri_uv[orig_i2_fidx], lt_tri_uv[i2_fidx]))
1067                                 {
1068                                         /* if faces don't have the same winding in uv space,
1069                                          * they are on the same side so edge is boundary */
1070                                         if ((ps->faceWindingFlags[tri_index] & PROJ_FACE_WINDING_CW) !=
1071                                             (ps->faceWindingFlags[orig_face] & PROJ_FACE_WINDING_CW))
1072                                         {
1073                                                 return 1;
1074                                         }
1075
1076                                         // printf("SEAM (NONE)\n");
1077                                         return 0;
1078
1079                                 }
1080                                 else {
1081                                         // printf("SEAM (UV GAP)\n");
1082                                         return 1;
1083                                 }
1084                         }
1085                 }
1086         }
1087         // printf("SEAM (NO FACE)\n");
1088         *other_face = -1;
1089         return 1;
1090 }
1091
1092 #define SMALL_NUMBER  1.e-6f
1093 BLI_INLINE float shell_v2v2_normal_dir_to_dist(float n[2], float d[2])
1094 {
1095         const float angle_cos = (normalize_v2(n) < SMALL_NUMBER) ? fabsf(dot_v2v2(d, n)) : 0.0f;
1096         return (UNLIKELY(angle_cos < SMALL_NUMBER)) ? 1.0f : (1.0f / angle_cos);
1097 }
1098 #undef SMALL_NUMBER
1099
1100 /* Calculate outset UV's, this is not the same as simply scaling the UVs,
1101  * since the outset coords are a margin that keep an even distance from the original UV's,
1102  * note that the image aspect is taken into account */
1103 static void uv_image_outset(
1104         float (*orig_uv)[2], float (*outset_uv)[2], const float scaler,
1105         const int ibuf_x, const int ibuf_y, const bool cw)
1106 {
1107         /* disallow shell-thickness to outset extreme values,
1108          * otherwise near zero area UV's may extend thousands of pixels. */
1109         const float scale_clamp = 5.0f;
1110
1111         float a1, a2, a3;
1112         float puv[3][2]; /* pixelspace uv's */
1113         float no1[2], no2[2], no3[2]; /* normals */
1114         float dir1[2], dir2[2], dir3[2];
1115         float ibuf_inv[2];
1116
1117         ibuf_inv[0] = 1.0f / (float)ibuf_x;
1118         ibuf_inv[1] = 1.0f / (float)ibuf_y;
1119
1120         /* make UV's in pixel space so we can */
1121         puv[0][0] = orig_uv[0][0] * ibuf_x;
1122         puv[0][1] = orig_uv[0][1] * ibuf_y;
1123
1124         puv[1][0] = orig_uv[1][0] * ibuf_x;
1125         puv[1][1] = orig_uv[1][1] * ibuf_y;
1126
1127         puv[2][0] = orig_uv[2][0] * ibuf_x;
1128         puv[2][1] = orig_uv[2][1] * ibuf_y;
1129
1130         /* face edge directions */
1131         sub_v2_v2v2(dir1, puv[1], puv[0]);
1132         sub_v2_v2v2(dir2, puv[2], puv[1]);
1133         sub_v2_v2v2(dir3, puv[0], puv[2]);
1134         normalize_v2(dir1);
1135         normalize_v2(dir2);
1136         normalize_v2(dir3);
1137
1138         /* here we just use the orthonormality property (a1, a2) dot (a2, -a1) = 0
1139          * to get normals from the edge directions based on the winding */
1140         if (cw) {
1141                 no1[0] = -dir3[1] - dir1[1];
1142                 no1[1] =  dir3[0] + dir1[0];
1143                 no2[0] = -dir1[1] - dir2[1];
1144                 no2[1] =  dir1[0] + dir2[0];
1145                 no3[0] = -dir2[1] - dir3[1];
1146                 no3[1] =  dir2[0] + dir3[0];
1147         }
1148         else {
1149                 no1[0] =  dir3[1] + dir1[1];
1150                 no1[1] = -dir3[0] - dir1[0];
1151                 no2[0] =  dir1[1] + dir2[1];
1152                 no2[1] = -dir1[0] - dir2[0];
1153                 no3[0] =  dir2[1] + dir3[1];
1154                 no3[1] = -dir2[0] - dir3[0];
1155         }
1156
1157         a1 = shell_v2v2_normal_dir_to_dist(no1, dir3);
1158         a2 = shell_v2v2_normal_dir_to_dist(no2, dir1);
1159         a3 = shell_v2v2_normal_dir_to_dist(no3, dir2);
1160
1161         CLAMP_MAX(a1, scale_clamp);
1162         CLAMP_MAX(a2, scale_clamp);
1163         CLAMP_MAX(a3, scale_clamp);
1164
1165         mul_v2_fl(no1, a1 * scaler);
1166         mul_v2_fl(no2, a2 * scaler);
1167         mul_v2_fl(no3, a3 * scaler);
1168         add_v2_v2v2(outset_uv[0], puv[0], no1);
1169         add_v2_v2v2(outset_uv[1], puv[1], no2);
1170         add_v2_v2v2(outset_uv[2], puv[2], no3);
1171
1172         mul_v2_v2(outset_uv[0], ibuf_inv);
1173         mul_v2_v2(outset_uv[1], ibuf_inv);
1174         mul_v2_v2(outset_uv[2], ibuf_inv);
1175 }
1176
1177 /*
1178  * Be tricky with flags, first 4 bits are PROJ_FACE_SEAM1 to 4, last 4 bits are PROJ_FACE_NOSEAM1 to 4
1179  * 1<<i - where i is (0-3)
1180  *
1181  * If we're multithreadng, make sure threads are locked when this is called
1182  */
1183 static void project_face_seams_init(const ProjPaintState *ps, const int tri_index)
1184 {
1185         int other_face, other_fidx; /* vars for the other face, we also set its flag */
1186         int fidx1 = 2;
1187         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 */
1188
1189         /* initialize face winding if needed */
1190         if ((ps->faceWindingFlags[tri_index] & PROJ_FACE_WINDING_INIT) == 0)
1191                 project_face_winding_init(ps, tri_index);
1192
1193         do {
1194                 if ((ps->faceSeamFlags[tri_index] & (1 << fidx1 | 16 << fidx1)) == 0) {
1195                         if (check_seam(ps, tri_index, fidx1, fidx2, &other_face, &other_fidx)) {
1196                                 ps->faceSeamFlags[tri_index] |= 1 << fidx1;
1197                                 if (other_face != -1)
1198                                         ps->faceSeamFlags[other_face] |= 1 << other_fidx;
1199                         }
1200                         else {
1201                                 ps->faceSeamFlags[tri_index] |= 16 << fidx1;
1202                                 if (other_face != -1)
1203                                         ps->faceSeamFlags[other_face] |= 16 << other_fidx;  /* second 4 bits for disabled */
1204                         }
1205                 }
1206
1207                 fidx2 = fidx1;
1208         } while (fidx1--);
1209 }
1210 #endif // PROJ_DEBUG_NOSEAMBLEED
1211
1212
1213 /* Converts a UV location to a 3D screenspace location
1214  * Takes a 'uv' and 3 UV coords, and sets the values of pixelScreenCo
1215  *
1216  * This is used for finding a pixels location in screenspace for painting */
1217 static void screen_px_from_ortho(
1218         const float uv[2],
1219         const float v1co[3], const float v2co[3], const float v3co[3],  /* Screenspace coords */
1220         const float uv1co[2], const float uv2co[2], const float uv3co[2],
1221         float pixelScreenCo[4],
1222         float w[3])
1223 {
1224         barycentric_weights_v2(uv1co, uv2co, uv3co, uv, w);
1225         interp_v3_v3v3v3(pixelScreenCo, v1co, v2co, v3co, w);
1226 }
1227
1228 /* same as screen_px_from_ortho except we
1229  * do perspective correction on the pixel coordinate */
1230 static void screen_px_from_persp(
1231         const float uv[2],
1232         const float v1co[4], const float v2co[4], const float v3co[4],  /* screenspace coords */
1233         const float uv1co[2], const float uv2co[2], const float uv3co[2],
1234         float pixelScreenCo[4],
1235         float w[3])
1236 {
1237         float w_int[3];
1238         float wtot_inv, wtot;
1239         barycentric_weights_v2(uv1co, uv2co, uv3co, uv, w);
1240
1241         /* re-weight from the 4th coord of each screen vert */
1242         w_int[0] = w[0] * v1co[3];
1243         w_int[1] = w[1] * v2co[3];
1244         w_int[2] = w[2] * v3co[3];
1245
1246         wtot = w_int[0] + w_int[1] + w_int[2];
1247
1248         if (wtot > 0.0f) {
1249                 wtot_inv = 1.0f / wtot;
1250                 w_int[0] *= wtot_inv;
1251                 w_int[1] *= wtot_inv;
1252                 w_int[2] *= wtot_inv;
1253         }
1254         else {
1255                 w[0] = w[1] = w[2] =
1256                 w_int[0] = w_int[1] = w_int[2] = 1.0f / 3.0f;  /* dummy values for zero area face */
1257         }
1258         /* done re-weighting */
1259
1260         /* do interpolation based on projected weight */
1261         interp_v3_v3v3v3(pixelScreenCo, v1co, v2co, v3co, w_int);
1262 }
1263
1264
1265 /**
1266  * Set a direction vector based on a screen location.
1267  * (use for perspective view, else we can simply use `ps->viewDir`)
1268  *
1269  * Similar functionality to #ED_view3d_win_to_vector
1270  *
1271  * \param r_dir: Resulting direction (length is undefined).
1272  */
1273 static void screen_px_to_vector_persp(
1274         int winx, int winy, const float projmat_inv[4][4], const float view_pos[3],
1275         const float co_px[2],
1276         float r_dir[3])
1277 {
1278         r_dir[0] = 2.0f * (co_px[0] / winx) - 1.0f;
1279         r_dir[1] = 2.0f * (co_px[1] / winy) - 1.0f;
1280         r_dir[2] = -0.5f;
1281         mul_project_m4_v3((float(*)[4])projmat_inv, r_dir);
1282         sub_v3_v3(r_dir, view_pos);
1283 }
1284
1285 /**
1286  * Special function to return the factor to a point along a line in pixel space.
1287  *
1288  * This is needed since we can't use #line_point_factor_v2 for perspective screen-space coords.
1289  *
1290  * \param p: 2D screen-space location.
1291  * \param v1, v2: 3D object-space locations.
1292  */
1293 static float screen_px_line_point_factor_v2_persp(
1294         const ProjPaintState *ps,
1295         const float p[2],
1296         const float v1[3], const float v2[3])
1297 {
1298         const float zero[3] = {0};
1299         float v1_proj[3], v2_proj[3];
1300         float dir[3];
1301
1302         screen_px_to_vector_persp(ps->winx, ps->winy, ps->projectMatInv, ps->viewPos, p, dir);
1303
1304         sub_v3_v3v3(v1_proj, v1, ps->viewPos);
1305         sub_v3_v3v3(v2_proj, v2, ps->viewPos);
1306
1307         project_plane_v3_v3v3(v1_proj, v1_proj, dir);
1308         project_plane_v3_v3v3(v2_proj, v2_proj, dir);
1309
1310         return line_point_factor_v2(zero, v1_proj, v2_proj);
1311 }
1312
1313
1314 static void project_face_pixel(
1315         const float *lt_tri_uv[3], ImBuf *ibuf_other, const float w[3],
1316         unsigned char rgba_ub[4], float rgba_f[4])
1317 {
1318         float uv_other[2], x, y;
1319
1320         interp_v2_v2v2v2(uv_other, UNPACK3(lt_tri_uv), w);
1321
1322         /* use */
1323         uvco_to_wrapped_pxco(uv_other, ibuf_other->x, ibuf_other->y, &x, &y);
1324
1325         if (ibuf_other->rect_float) { /* from float to float */
1326                 bilinear_interpolation_color_wrap(ibuf_other, NULL, rgba_f, x, y);
1327         }
1328         else { /* from char to float */
1329                 bilinear_interpolation_color_wrap(ibuf_other, rgba_ub, NULL, x, y);
1330         }
1331
1332 }
1333
1334 /* run this outside project_paint_uvpixel_init since pixels with mask 0 don't need init */
1335 static float project_paint_uvpixel_mask(
1336         const ProjPaintState *ps,
1337         const int tri_index,
1338         const float w[3])
1339 {
1340         float mask;
1341
1342         /* Image Mask */
1343         if (ps->do_layer_stencil) {
1344                 /* another UV maps image is masking this one's */
1345                 ImBuf *ibuf_other;
1346                 Image *other_tpage = ps->stencil_ima;
1347
1348                 if (other_tpage && (ibuf_other = BKE_image_acquire_ibuf(other_tpage, NULL, NULL))) {
1349                         const MLoopTri *lt_other = &ps->dm_mlooptri[tri_index];
1350                         const float *lt_other_tri_uv[3] = { PS_LOOPTRI_AS_UV_3(ps->dm_mloopuv, lt_other) };
1351
1352                         /* BKE_image_acquire_ibuf - TODO - this may be slow */
1353                         unsigned char rgba_ub[4];
1354                         float rgba_f[4];
1355
1356                         project_face_pixel(lt_other_tri_uv, ibuf_other, w, rgba_ub, rgba_f);
1357
1358                         if (ibuf_other->rect_float) { /* from float to float */
1359                                 mask = ((rgba_f[0] + rgba_f[1] + rgba_f[2]) * (1.0f / 3.0f)) * rgba_f[3];
1360                         }
1361                         else { /* from char to float */
1362                                 mask = ((rgba_ub[0] + rgba_ub[1] + rgba_ub[2]) * (1.0f / (255.0f * 3.0f))) * (rgba_ub[3] * (1.0f / 255.0f));
1363                         }
1364
1365                         BKE_image_release_ibuf(other_tpage, ibuf_other, NULL);
1366
1367                         if (!ps->do_layer_stencil_inv) /* matching the gimps layer mask black/white rules, white==full opacity */
1368                                 mask = (1.0f - mask);
1369
1370                         if (mask == 0.0f) {
1371                                 return 0.0f;
1372                         }
1373                 }
1374                 else {
1375                         return 0.0f;
1376                 }
1377         }
1378         else {
1379                 mask = 1.0f;
1380         }
1381
1382         if (ps->do_mask_cavity) {
1383                 const MLoopTri *lt = &ps->dm_mlooptri[tri_index];
1384                 const int lt_vtri[3] = { PS_LOOPTRI_AS_VERT_INDEX_3(ps, lt) };
1385                 float ca1, ca2, ca3, ca_mask;
1386                 ca1 = ps->cavities[lt_vtri[0]];
1387                 ca2 = ps->cavities[lt_vtri[1]];
1388                 ca3 = ps->cavities[lt_vtri[2]];
1389
1390                 ca_mask = w[0] * ca1 + w[1] * ca2 + w[2] * ca3;
1391                 ca_mask = curvemapping_evaluateF(ps->cavity_curve, 0, ca_mask);
1392                 CLAMP(ca_mask, 0.0f, 1.0f);
1393                 mask *= ca_mask;
1394         }
1395
1396         /* calculate mask */
1397         if (ps->do_mask_normal) {
1398                 const MLoopTri *lt = &ps->dm_mlooptri[tri_index];
1399                 const int lt_vtri[3] = { PS_LOOPTRI_AS_VERT_INDEX_3(ps, lt) };
1400                 const MPoly *mp = &ps->dm_mpoly[lt->poly];
1401                 float no[3], angle_cos;
1402
1403                 if (mp->flag & ME_SMOOTH) {
1404                         const short *no1, *no2, *no3;
1405                         no1 = ps->dm_mvert[lt_vtri[0]].no;
1406                         no2 = ps->dm_mvert[lt_vtri[1]].no;
1407                         no3 = ps->dm_mvert[lt_vtri[2]].no;
1408
1409                         no[0] = w[0] * no1[0] + w[1] * no2[0] + w[2] * no3[0];
1410                         no[1] = w[0] * no1[1] + w[1] * no2[1] + w[2] * no3[1];
1411                         no[2] = w[0] * no1[2] + w[1] * no2[2] + w[2] * no3[2];
1412                         normalize_v3(no);
1413                 }
1414                 else {
1415                         /* incase the */
1416 #if 1
1417                         /* normalizing per pixel isn't optimal, we could cache or check ps->*/
1418                         normal_tri_v3(no,
1419                                       ps->dm_mvert[lt_vtri[0]].co,
1420                                       ps->dm_mvert[lt_vtri[1]].co,
1421                                       ps->dm_mvert[lt_vtri[2]].co);
1422 #else
1423                         /* don't use because some modifiers dont have normal data (subsurf for eg) */
1424                         copy_v3_v3(no, (float *)ps->dm->getTessFaceData(ps->dm, tri_index, CD_NORMAL));
1425 #endif
1426                 }
1427
1428                 if (UNLIKELY(ps->is_flip_object)) {
1429                         negate_v3(no);
1430                 }
1431
1432                 /* now we can use the normal as a mask */
1433                 if (ps->is_ortho) {
1434                         angle_cos = dot_v3v3(ps->viewDir, no);
1435                 }
1436                 else {
1437                         /* Annoying but for the perspective view we need to get the pixels location in 3D space :/ */
1438                         float viewDirPersp[3];
1439                         const float *co1, *co2, *co3;
1440                         co1 = ps->dm_mvert[lt_vtri[0]].co;
1441                         co2 = ps->dm_mvert[lt_vtri[1]].co;
1442                         co3 = ps->dm_mvert[lt_vtri[2]].co;
1443
1444                         /* Get the direction from the viewPoint to the pixel and normalize */
1445                         viewDirPersp[0] = (ps->viewPos[0] - (w[0] * co1[0] + w[1] * co2[0] + w[2] * co3[0]));
1446                         viewDirPersp[1] = (ps->viewPos[1] - (w[0] * co1[1] + w[1] * co2[1] + w[2] * co3[1]));
1447                         viewDirPersp[2] = (ps->viewPos[2] - (w[0] * co1[2] + w[1] * co2[2] + w[2] * co3[2]));
1448                         normalize_v3(viewDirPersp);
1449                         if (UNLIKELY(ps->is_flip_object)) {
1450                                 negate_v3(viewDirPersp);
1451                         }
1452
1453                         angle_cos = dot_v3v3(viewDirPersp, no);
1454                 }
1455
1456                 if (angle_cos <= ps->normal_angle__cos) {
1457                         return 0.0f; /* outsize the normal limit*/
1458                 }
1459                 else if (angle_cos < ps->normal_angle_inner__cos) {
1460                         mask *= (ps->normal_angle - acosf(angle_cos)) / ps->normal_angle_range;
1461                 } /* otherwise no mask normal is needed, were within the limit */
1462         }
1463
1464         /* This only works when the opacity dosnt change while painting, stylus pressure messes with this
1465          * so don't use it. */
1466         // if (ps->is_airbrush == 0) mask *= BKE_brush_alpha_get(ps->brush);
1467
1468         return mask;
1469 }
1470
1471 static int project_paint_pixel_sizeof(const short tool)
1472 {
1473         if ((tool == PAINT_TOOL_CLONE) || (tool == PAINT_TOOL_SMEAR)) {
1474                 return sizeof(ProjPixelClone);
1475         }
1476         else {
1477                 return sizeof(ProjPixel);
1478         }
1479 }
1480
1481 static int project_paint_undo_subtiles(const TileInfo *tinf, int tx, int ty)
1482 {
1483         ProjPaintImage *pjIma = tinf->pjima;
1484         int tile_index = tx + ty * tinf->tile_width;
1485         bool generate_tile = false;
1486
1487         /* double check lock to avoid locking */
1488         if (UNLIKELY(!pjIma->undoRect[tile_index])) {
1489                 if (tinf->lock)
1490                         BLI_spin_lock(tinf->lock);
1491                 if (LIKELY(!pjIma->undoRect[tile_index])) {
1492                         pjIma->undoRect[tile_index] = TILE_PENDING;
1493                         generate_tile = true;
1494                 }
1495                 if (tinf->lock)
1496                         BLI_spin_unlock(tinf->lock);
1497         }
1498
1499
1500         if (generate_tile) {
1501                 volatile void *undorect;
1502                 if (tinf->masked) {
1503                         undorect = image_undo_push_tile(
1504                                 pjIma->ima, pjIma->ibuf, tinf->tmpibuf,
1505                                 tx, ty, &pjIma->maskRect[tile_index], &pjIma->valid[tile_index], true, false);
1506                 }
1507                 else {
1508                         undorect = image_undo_push_tile(
1509                                 pjIma->ima, pjIma->ibuf, tinf->tmpibuf,
1510                                 tx, ty, NULL, &pjIma->valid[tile_index], true, false);
1511                 }
1512
1513                 pjIma->ibuf->userflags |= IB_BITMAPDIRTY;
1514                 /* tile ready, publish */
1515                 if (tinf->lock)
1516                         BLI_spin_lock(tinf->lock);
1517                 pjIma->undoRect[tile_index] = undorect;
1518                 if (tinf->lock)
1519                         BLI_spin_unlock(tinf->lock);
1520
1521         }
1522
1523         return tile_index;
1524 }
1525
1526 /* run this function when we know a bucket's, face's pixel can be initialized,
1527  * return the ProjPixel which is added to 'ps->bucketRect[bucket_index]' */
1528 static ProjPixel *project_paint_uvpixel_init(
1529         const ProjPaintState *ps,
1530         MemArena *arena,
1531         const TileInfo *tinf,
1532         int x_px, int y_px,
1533         const float mask,
1534         const int tri_index,
1535         const float pixelScreenCo[4],
1536         const float world_spaceCo[3],
1537         const float w[3])
1538 {
1539         ProjPixel *projPixel;
1540         int x_tile, y_tile;
1541         int x_round, y_round;
1542         int tile_offset;
1543         /* volatile is important here to ensure pending check is not optimized away by compiler*/
1544         volatile int tile_index;
1545
1546         ProjPaintImage *projima = tinf->pjima;
1547         ImBuf *ibuf = projima->ibuf;
1548         /* wrap pixel location */
1549
1550         x_px = mod_i(x_px, ibuf->x);
1551         y_px = mod_i(y_px, ibuf->y);
1552
1553         BLI_assert(ps->pixel_sizeof == project_paint_pixel_sizeof(ps->tool));
1554         projPixel = BLI_memarena_alloc(arena, ps->pixel_sizeof);
1555
1556         /* calculate the undo tile offset of the pixel, used to store the original
1557          * pixel color and accumulated mask if any */
1558         x_tile =  x_px >> IMAPAINT_TILE_BITS;
1559         y_tile =  y_px >> IMAPAINT_TILE_BITS;
1560
1561         x_round = x_tile * IMAPAINT_TILE_SIZE;
1562         y_round = y_tile * IMAPAINT_TILE_SIZE;
1563         //memset(projPixel, 0, size);
1564
1565         tile_offset = (x_px - x_round) + (y_px - y_round) * IMAPAINT_TILE_SIZE;
1566         tile_index = project_paint_undo_subtiles(tinf, x_tile, y_tile);
1567
1568         /* other thread may be initializing the tile so wait here */
1569         while (projima->undoRect[tile_index] == TILE_PENDING)
1570                 ;
1571
1572         BLI_assert(tile_index < (IMAPAINT_TILE_NUMBER(ibuf->x) * IMAPAINT_TILE_NUMBER(ibuf->y)));
1573         BLI_assert(tile_offset < (IMAPAINT_TILE_SIZE * IMAPAINT_TILE_SIZE));
1574
1575         projPixel->valid = projima->valid[tile_index];
1576
1577         if (ibuf->rect_float) {
1578                 projPixel->pixel.f_pt = ibuf->rect_float + ((x_px + y_px * ibuf->x) * 4);
1579                 projPixel->origColor.f_pt = (float *)projima->undoRect[tile_index] + 4 * tile_offset;
1580                 zero_v4(projPixel->newColor.f);
1581         }
1582         else {
1583                 projPixel->pixel.ch_pt = (unsigned char *)(ibuf->rect + (x_px + y_px * ibuf->x));
1584                 projPixel->origColor.uint_pt = (unsigned int *)projima->undoRect[tile_index] + tile_offset;
1585                 projPixel->newColor.uint = 0;
1586         }
1587
1588         /* screenspace unclamped, we could keep its z and w values but don't need them at the moment */
1589         if (ps->brush->mtex.brush_map_mode == MTEX_MAP_MODE_3D) {
1590                 copy_v3_v3(projPixel->worldCoSS, world_spaceCo);
1591         }
1592
1593         copy_v2_v2(projPixel->projCoSS, pixelScreenCo);
1594
1595         projPixel->x_px = x_px;
1596         projPixel->y_px = y_px;
1597
1598         projPixel->mask = (unsigned short)(mask * 65535);
1599         if (ps->do_masking)
1600                 projPixel->mask_accum = projima->maskRect[tile_index] + tile_offset;
1601         else
1602                 projPixel->mask_accum = NULL;
1603
1604         /* which bounding box cell are we in?, needed for undo */
1605         projPixel->bb_cell_index = ((int)(((float)x_px / (float)ibuf->x) * PROJ_BOUNDBOX_DIV)) +
1606                                    ((int)(((float)y_px / (float)ibuf->y) * PROJ_BOUNDBOX_DIV)) * PROJ_BOUNDBOX_DIV;
1607
1608         /* done with view3d_project_float inline */
1609         if (ps->tool == PAINT_TOOL_CLONE) {
1610                 if (ps->dm_mloopuv_clone) {
1611                         ImBuf *ibuf_other;
1612                         Image *other_tpage = project_paint_face_clone_image(ps, tri_index);
1613
1614                         if (other_tpage && (ibuf_other = BKE_image_acquire_ibuf(other_tpage, NULL, NULL))) {
1615                                 const MLoopTri *lt_other = &ps->dm_mlooptri[tri_index];
1616                                 const float *lt_other_tri_uv[3] = { PS_LOOPTRI_AS_UV_3(ps->dm_mloopuv_clone, lt_other) };
1617
1618                                 /* BKE_image_acquire_ibuf - TODO - this may be slow */
1619
1620                                 if (ibuf->rect_float) {
1621                                         if (ibuf_other->rect_float) { /* from float to float */
1622                                                 project_face_pixel(lt_other_tri_uv, ibuf_other, w, NULL, ((ProjPixelClone *)projPixel)->clonepx.f);
1623                                         }
1624                                         else { /* from char to float */
1625                                                 unsigned char rgba_ub[4];
1626                                                 float rgba[4];
1627                                                 project_face_pixel(lt_other_tri_uv, ibuf_other, w, rgba_ub, NULL);
1628                                                 if (ps->use_colormanagement) {
1629                                                         srgb_to_linearrgb_uchar4(rgba, rgba_ub);
1630                                                 }
1631                                                 else {
1632                                                         rgba_uchar_to_float(rgba, rgba_ub);
1633                                                 }
1634                                                 straight_to_premul_v4_v4(((ProjPixelClone *)projPixel)->clonepx.f, rgba);
1635                                         }
1636                                 }
1637                                 else {
1638                                         if (ibuf_other->rect_float) { /* float to char */
1639                                                 float rgba[4];
1640                                                 project_face_pixel(lt_other_tri_uv, ibuf_other, w, NULL, rgba);
1641                                                 premul_to_straight_v4(rgba);
1642                                                 if (ps->use_colormanagement) {
1643                                                         linearrgb_to_srgb_uchar3(((ProjPixelClone *)projPixel)->clonepx.ch, rgba);
1644                                                 }
1645                                                 else {
1646                                                         rgb_float_to_uchar(((ProjPixelClone *)projPixel)->clonepx.ch, rgba);
1647                                                 }
1648                                                 ((ProjPixelClone *)projPixel)->clonepx.ch[3] =  rgba[3] * 255;
1649                                         }
1650                                         else { /* char to char */
1651                                                 project_face_pixel(lt_other_tri_uv, ibuf_other, w, ((ProjPixelClone *)projPixel)->clonepx.ch, NULL);
1652                                         }
1653                                 }
1654
1655                                 BKE_image_release_ibuf(other_tpage, ibuf_other, NULL);
1656                         }
1657                         else {
1658                                 if (ibuf->rect_float) {
1659                                         ((ProjPixelClone *)projPixel)->clonepx.f[3] = 0;
1660                                 }
1661                                 else {
1662                                         ((ProjPixelClone *)projPixel)->clonepx.ch[3] = 0;
1663                                 }
1664                         }
1665
1666                 }
1667                 else {
1668                         float co[2];
1669                         sub_v2_v2v2(co, projPixel->projCoSS, ps->cloneOffset);
1670
1671                         /* no need to initialize the bucket, we're only checking buckets faces and for this
1672                          * the faces are already initialized in project_paint_delayed_face_init(...) */
1673                         if (ibuf->rect_float) {
1674                                 if (!project_paint_PickColor(ps, co, ((ProjPixelClone *)projPixel)->clonepx.f, NULL, 1)) {
1675                                         ((ProjPixelClone *)projPixel)->clonepx.f[3] = 0; /* zero alpha - ignore */
1676                                 }
1677                         }
1678                         else {
1679                                 if (!project_paint_PickColor(ps, co, NULL, ((ProjPixelClone *)projPixel)->clonepx.ch, 1)) {
1680                                         ((ProjPixelClone *)projPixel)->clonepx.ch[3] = 0; /* zero alpha - ignore */
1681                                 }
1682                         }
1683                 }
1684         }
1685
1686 #ifdef PROJ_DEBUG_PAINT
1687         if (ibuf->rect_float) projPixel->pixel.f_pt[0] = 0;
1688         else                  projPixel->pixel.ch_pt[0] = 0;
1689 #endif
1690         /* pointer arithmetics */
1691         projPixel->image_index = projima - ps->projImages;
1692
1693         return projPixel;
1694 }
1695
1696 static bool line_clip_rect2f(
1697         const rctf *cliprect,
1698         const rctf *rect,
1699         const float l1[2], const float l2[2],
1700         float l1_clip[2], float l2_clip[2])
1701 {
1702         /* first account for horizontal, then vertical lines */
1703         /* horiz */
1704         if (fabsf(l1[1] - l2[1]) < PROJ_PIXEL_TOLERANCE) {
1705                 /* is the line out of range on its Y axis? */
1706                 if (l1[1] < rect->ymin || l1[1] > rect->ymax) {
1707                         return 0;
1708                 }
1709                 /* line is out of range on its X axis */
1710                 if ((l1[0] < rect->xmin && l2[0] < rect->xmin) || (l1[0] > rect->xmax && l2[0] > rect->xmax)) {
1711                         return 0;
1712                 }
1713
1714
1715                 if (fabsf(l1[0] - l2[0]) < PROJ_PIXEL_TOLERANCE) { /* this is a single point  (or close to)*/
1716                         if (BLI_rctf_isect_pt_v(rect, l1)) {
1717                                 copy_v2_v2(l1_clip, l1);
1718                                 copy_v2_v2(l2_clip, l2);
1719                                 return 1;
1720                         }
1721                         else {
1722                                 return 0;
1723                         }
1724                 }
1725
1726                 copy_v2_v2(l1_clip, l1);
1727                 copy_v2_v2(l2_clip, l2);
1728                 CLAMP(l1_clip[0], rect->xmin, rect->xmax);
1729                 CLAMP(l2_clip[0], rect->xmin, rect->xmax);
1730                 return 1;
1731         }
1732         else if (fabsf(l1[0] - l2[0]) < PROJ_PIXEL_TOLERANCE) {
1733                 /* is the line out of range on its X axis? */
1734                 if (l1[0] < rect->xmin || l1[0] > rect->xmax) {
1735                         return 0;
1736                 }
1737
1738                 /* line is out of range on its Y axis */
1739                 if ((l1[1] < rect->ymin && l2[1] < rect->ymin) || (l1[1] > rect->ymax && l2[1] > rect->ymax)) {
1740                         return 0;
1741                 }
1742
1743                 if (fabsf(l1[1] - l2[1]) < PROJ_PIXEL_TOLERANCE) { /* this is a single point  (or close to)*/
1744                         if (BLI_rctf_isect_pt_v(rect, l1)) {
1745                                 copy_v2_v2(l1_clip, l1);
1746                                 copy_v2_v2(l2_clip, l2);
1747                                 return 1;
1748                         }
1749                         else {
1750                                 return 0;
1751                         }
1752                 }
1753
1754                 copy_v2_v2(l1_clip, l1);
1755                 copy_v2_v2(l2_clip, l2);
1756                 CLAMP(l1_clip[1], rect->ymin, rect->ymax);
1757                 CLAMP(l2_clip[1], rect->ymin, rect->ymax);
1758                 return 1;
1759         }
1760         else {
1761                 float isect;
1762                 short ok1 = 0;
1763                 short ok2 = 0;
1764
1765                 /* Done with vertical lines */
1766
1767                 /* are either of the points inside the rectangle ? */
1768                 if (BLI_rctf_isect_pt_v(rect, l1)) {
1769                         copy_v2_v2(l1_clip, l1);
1770                         ok1 = 1;
1771                 }
1772
1773                 if (BLI_rctf_isect_pt_v(rect, l2)) {
1774                         copy_v2_v2(l2_clip, l2);
1775                         ok2 = 1;
1776                 }
1777
1778                 /* line inside rect */
1779                 if (ok1 && ok2) return 1;
1780
1781                 /* top/bottom */
1782                 if (line_isect_y(l1, l2, rect->ymin, &isect) && (isect >= cliprect->xmin) && (isect <= cliprect->xmax)) {
1783                         if (l1[1] < l2[1]) { /* line 1 is outside */
1784                                 l1_clip[0] = isect;
1785                                 l1_clip[1] = rect->ymin;
1786                                 ok1 = 1;
1787                         }
1788                         else {
1789                                 l2_clip[0] = isect;
1790                                 l2_clip[1] = rect->ymin;
1791                                 ok2 = 2;
1792                         }
1793                 }
1794
1795                 if (ok1 && ok2) return 1;
1796
1797                 if (line_isect_y(l1, l2, rect->ymax, &isect) && (isect >= cliprect->xmin) && (isect <= cliprect->xmax)) {
1798                         if (l1[1] > l2[1]) { /* line 1 is outside */
1799                                 l1_clip[0] = isect;
1800                                 l1_clip[1] = rect->ymax;
1801                                 ok1 = 1;
1802                         }
1803                         else {
1804                                 l2_clip[0] = isect;
1805                                 l2_clip[1] = rect->ymax;
1806                                 ok2 = 2;
1807                         }
1808                 }
1809
1810                 if (ok1 && ok2) return 1;
1811
1812                 /* left/right */
1813                 if (line_isect_x(l1, l2, rect->xmin, &isect) && (isect >= cliprect->ymin) && (isect <= cliprect->ymax)) {
1814                         if (l1[0] < l2[0]) { /* line 1 is outside */
1815                                 l1_clip[0] = rect->xmin;
1816                                 l1_clip[1] = isect;
1817                                 ok1 = 1;
1818                         }
1819                         else {
1820                                 l2_clip[0] = rect->xmin;
1821                                 l2_clip[1] = isect;
1822                                 ok2 = 2;
1823                         }
1824                 }
1825
1826                 if (ok1 && ok2) return 1;
1827
1828                 if (line_isect_x(l1, l2, rect->xmax, &isect) && (isect >= cliprect->ymin) && (isect <= cliprect->ymax)) {
1829                         if (l1[0] > l2[0]) { /* line 1 is outside */
1830                                 l1_clip[0] = rect->xmax;
1831                                 l1_clip[1] = isect;
1832                                 ok1 = 1;
1833                         }
1834                         else {
1835                                 l2_clip[0] = rect->xmax;
1836                                 l2_clip[1] = isect;
1837                                 ok2 = 2;
1838                         }
1839                 }
1840
1841                 if (ok1 && ok2) {
1842                         return 1;
1843                 }
1844                 else {
1845                         return 0;
1846                 }
1847         }
1848 }
1849
1850
1851
1852 /**
1853  * Scale the tri about its center
1854  * scaling by #PROJ_FACE_SCALE_SEAM (0.99x) is used for getting fake UV pixel coords that are on the
1855  * edge of the face but slightly inside it occlusion tests don't return hits on adjacent faces
1856  */
1857 #ifndef PROJ_DEBUG_NOSEAMBLEED
1858
1859 static void scale_tri(float insetCos[3][3], const float *origCos[4], const float inset)
1860 {
1861         float cent[3];
1862         cent[0] = (origCos[0][0] + origCos[1][0] + origCos[2][0]) * (1.0f / 3.0f);
1863         cent[1] = (origCos[0][1] + origCos[1][1] + origCos[2][1]) * (1.0f / 3.0f);
1864         cent[2] = (origCos[0][2] + origCos[1][2] + origCos[2][2]) * (1.0f / 3.0f);
1865
1866         sub_v3_v3v3(insetCos[0], origCos[0], cent);
1867         sub_v3_v3v3(insetCos[1], origCos[1], cent);
1868         sub_v3_v3v3(insetCos[2], origCos[2], cent);
1869
1870         mul_v3_fl(insetCos[0], inset);
1871         mul_v3_fl(insetCos[1], inset);
1872         mul_v3_fl(insetCos[2], inset);
1873
1874         add_v3_v3(insetCos[0], cent);
1875         add_v3_v3(insetCos[1], cent);
1876         add_v3_v3(insetCos[2], cent);
1877 }
1878 #endif //PROJ_DEBUG_NOSEAMBLEED
1879
1880 static float len_squared_v2v2_alt(const float v1[2], const float v2_1, const float v2_2)
1881 {
1882         float x, y;
1883
1884         x = v1[0] - v2_1;
1885         y = v1[1] - v2_2;
1886         return x * x + y * y;
1887 }
1888
1889 /* note, use a squared value so we can use len_squared_v2v2
1890  * be sure that you have done a bounds check first or this may fail */
1891 /* only give bucket_bounds as an arg because we need it elsewhere */
1892 static bool project_bucket_isect_circle(const float cent[2], const float radius_squared, const rctf *bucket_bounds)
1893 {
1894
1895         /* Would normally to a simple intersection test, however we know the bounds of these 2 already intersect
1896          * so we only need to test if the center is inside the vertical or horizontal bounds on either axis,
1897          * this is even less work then an intersection test
1898          */
1899 #if 0
1900         if (BLI_rctf_isect_pt_v(bucket_bounds, cent))
1901                 return 1;
1902 #endif
1903
1904         if ((bucket_bounds->xmin <= cent[0] && bucket_bounds->xmax >= cent[0]) ||
1905             (bucket_bounds->ymin <= cent[1] && bucket_bounds->ymax >= cent[1]))
1906         {
1907                 return 1;
1908         }
1909
1910         /* out of bounds left */
1911         if (cent[0] < bucket_bounds->xmin) {
1912                 /* lower left out of radius test */
1913                 if (cent[1] < bucket_bounds->ymin) {
1914                         return (len_squared_v2v2_alt(cent, bucket_bounds->xmin, bucket_bounds->ymin) < radius_squared) ? 1 : 0;
1915                 }
1916                 /* top left test */
1917                 else if (cent[1] > bucket_bounds->ymax) {
1918                         return (len_squared_v2v2_alt(cent, bucket_bounds->xmin, bucket_bounds->ymax) < radius_squared) ? 1 : 0;
1919                 }
1920         }
1921         else if (cent[0] > bucket_bounds->xmax) {
1922                 /* lower right out of radius test */
1923                 if (cent[1] < bucket_bounds->ymin) {
1924                         return (len_squared_v2v2_alt(cent, bucket_bounds->xmax, bucket_bounds->ymin) < radius_squared) ? 1 : 0;
1925                 }
1926                 /* top right test */
1927                 else if (cent[1] > bucket_bounds->ymax) {
1928                         return (len_squared_v2v2_alt(cent, bucket_bounds->xmax, bucket_bounds->ymax) < radius_squared) ? 1 : 0;
1929                 }
1930         }
1931
1932         return 0;
1933 }
1934
1935
1936
1937 /* Note for rect_to_uvspace_ortho() and rect_to_uvspace_persp()
1938  * in ortho view this function gives good results when bucket_bounds are outside the triangle
1939  * however in some cases, perspective view will mess up with faces that have minimal screenspace area
1940  * (viewed from the side)
1941  *
1942  * for this reason its not reliable in this case so we'll use the Simple Barycentric'
1943  * funcs that only account for points inside the triangle.
1944  * however switching back to this for ortho is always an option */
1945
1946 static void rect_to_uvspace_ortho(
1947         const rctf *bucket_bounds,
1948         const float *v1coSS, const float *v2coSS, const float *v3coSS,
1949         const float *uv1co, const float *uv2co, const float *uv3co,
1950         float bucket_bounds_uv[4][2],
1951         const int flip)
1952 {
1953         float uv[2];
1954         float w[3];
1955
1956         /* get the UV space bounding box */
1957         uv[0] = bucket_bounds->xmax;
1958         uv[1] = bucket_bounds->ymin;
1959         barycentric_weights_v2(v1coSS, v2coSS, v3coSS, uv, w);
1960         interp_v2_v2v2v2(bucket_bounds_uv[flip ? 3 : 0], uv1co, uv2co, uv3co, w);
1961
1962         //uv[0] = bucket_bounds->xmax; // set above
1963         uv[1] = bucket_bounds->ymax;
1964         barycentric_weights_v2(v1coSS, v2coSS, v3coSS, uv, w);
1965         interp_v2_v2v2v2(bucket_bounds_uv[flip ? 2 : 1], uv1co, uv2co, uv3co, w);
1966
1967         uv[0] = bucket_bounds->xmin;
1968         //uv[1] = bucket_bounds->ymax; // set above
1969         barycentric_weights_v2(v1coSS, v2coSS, v3coSS, uv, w);
1970         interp_v2_v2v2v2(bucket_bounds_uv[flip ? 1 : 2], uv1co, uv2co, uv3co, w);
1971
1972         //uv[0] = bucket_bounds->xmin; // set above
1973         uv[1] = bucket_bounds->ymin;
1974         barycentric_weights_v2(v1coSS, v2coSS, v3coSS, uv, w);
1975         interp_v2_v2v2v2(bucket_bounds_uv[flip ? 0 : 3], uv1co, uv2co, uv3co, w);
1976 }
1977
1978 /* same as above but use barycentric_weights_v2_persp */
1979 static void rect_to_uvspace_persp(
1980         const rctf *bucket_bounds,
1981         const float *v1coSS, const float *v2coSS, const float *v3coSS,
1982         const float *uv1co, const float *uv2co, const float *uv3co,
1983         float bucket_bounds_uv[4][2],
1984         const int flip
1985         )
1986 {
1987         float uv[2];
1988         float w[3];
1989
1990         /* get the UV space bounding box */
1991         uv[0] = bucket_bounds->xmax;
1992         uv[1] = bucket_bounds->ymin;
1993         barycentric_weights_v2_persp(v1coSS, v2coSS, v3coSS, uv, w);
1994         interp_v2_v2v2v2(bucket_bounds_uv[flip ? 3 : 0], uv1co, uv2co, uv3co, w);
1995
1996         //uv[0] = bucket_bounds->xmax; // set above
1997         uv[1] = bucket_bounds->ymax;
1998         barycentric_weights_v2_persp(v1coSS, v2coSS, v3coSS, uv, w);
1999         interp_v2_v2v2v2(bucket_bounds_uv[flip ? 2 : 1], uv1co, uv2co, uv3co, w);
2000
2001         uv[0] = bucket_bounds->xmin;
2002         //uv[1] = bucket_bounds->ymax; // set above
2003         barycentric_weights_v2_persp(v1coSS, v2coSS, v3coSS, uv, w);
2004         interp_v2_v2v2v2(bucket_bounds_uv[flip ? 1 : 2], uv1co, uv2co, uv3co, w);
2005
2006         //uv[0] = bucket_bounds->xmin; // set above
2007         uv[1] = bucket_bounds->ymin;
2008         barycentric_weights_v2_persp(v1coSS, v2coSS, v3coSS, uv, w);
2009         interp_v2_v2v2v2(bucket_bounds_uv[flip ? 0 : 3], uv1co, uv2co, uv3co, w);
2010 }
2011
2012 /* This works as we need it to but we can save a few steps and not use it */
2013
2014 #if 0
2015 static float angle_2d_clockwise(const float p1[2], const float p2[2], const float p3[2])
2016 {
2017         float v1[2], v2[2];
2018
2019         v1[0] = p1[0] - p2[0];    v1[1] = p1[1] - p2[1];
2020         v2[0] = p3[0] - p2[0];    v2[1] = p3[1] - p2[1];
2021
2022         return -atan2f(v1[0] * v2[1] - v1[1] * v2[0], v1[0] * v2[0] + v1[1] * v2[1]);
2023 }
2024 #endif
2025
2026 #define ISECT_1 (1)
2027 #define ISECT_2 (1 << 1)
2028 #define ISECT_3 (1 << 2)
2029 #define ISECT_4 (1 << 3)
2030 #define ISECT_ALL3 ((1 << 3) - 1)
2031 #define ISECT_ALL4 ((1 << 4) - 1)
2032
2033 /* limit must be a fraction over 1.0f */
2034 static bool IsectPT2Df_limit(
2035         const float pt[2],
2036         const float v1[2], const float v2[2], const float v3[2],
2037         const float limit)
2038 {
2039         return ((area_tri_v2(pt, v1, v2) +
2040                  area_tri_v2(pt, v2, v3) +
2041                  area_tri_v2(pt, v3, v1)) / (area_tri_v2(v1, v2, v3))) < limit;
2042 }
2043
2044 /* Clip the face by a bucket and set the uv-space bucket_bounds_uv
2045  * so we have the clipped UV's to do pixel intersection tests with
2046  * */
2047 static int float_z_sort_flip(const void *p1, const void *p2)
2048 {
2049         return (((float *)p1)[2] < ((float *)p2)[2] ? 1 : -1);
2050 }
2051
2052 static int float_z_sort(const void *p1, const void *p2)
2053 {
2054         return (((float *)p1)[2] < ((float *)p2)[2] ? -1 : 1);
2055 }
2056
2057 /* assumes one point is within the rectangle */
2058 static bool line_rect_clip(
2059         const rctf *rect,
2060         const float l1[4], const float l2[4],
2061         const float uv1[2], const float uv2[2],
2062         float uv[2], bool is_ortho)
2063 {
2064         float min = FLT_MAX, tmp;
2065         float xlen = l2[0] - l1[0];
2066         float ylen = l2[1] - l1[1];
2067
2068         /* 0.1 might seem too much, but remember, this is pixels! */
2069         if (xlen > 0.1f) {
2070                 if ((l1[0] - rect->xmin) * (l2[0] - rect->xmin) <= 0) {
2071                         tmp = rect->xmin;
2072                         min = min_ff((tmp - l1[0]) / xlen, min);
2073                 }
2074                 else if ((l1[0] - rect->xmax) * (l2[0] - rect->xmax) < 0) {
2075                         tmp = rect->xmax;
2076                         min = min_ff((tmp - l1[0]) / xlen, min);
2077                 }
2078         }
2079
2080         if (ylen > 0.1f) {
2081                 if ((l1[1] - rect->ymin) * (l2[1] - rect->ymin) <= 0) {
2082                         tmp = rect->ymin;
2083                         min = min_ff((tmp - l1[1]) / ylen, min);
2084                 }
2085                 else if ((l1[1] - rect->ymax) * (l2[1] - rect->ymax) < 0) {
2086                         tmp = rect->ymax;
2087                         min = min_ff((tmp - l1[1]) / ylen, min);
2088                 }
2089         }
2090
2091         if (min == FLT_MAX)
2092                 return false;
2093
2094         tmp = (is_ortho) ? 1.0f : (l1[3] + min * (l2[3] - l1[3]));
2095
2096         uv[0] = (uv1[0] + min / tmp * (uv2[0] - uv1[0]));
2097         uv[1] = (uv1[1] + min / tmp * (uv2[1] - uv1[1]));
2098
2099         return true;
2100 }
2101
2102
2103 static void project_bucket_clip_face(
2104         const bool is_ortho, const bool is_flip_object,
2105         const rctf *cliprect,
2106         const rctf *bucket_bounds,
2107         const float *v1coSS, const float *v2coSS, const float *v3coSS,
2108         const float *uv1co, const float *uv2co, const float *uv3co,
2109         float bucket_bounds_uv[8][2],
2110         int *tot, bool cull)
2111 {
2112         int inside_bucket_flag = 0;
2113         int inside_face_flag = 0;
2114         int flip;
2115         bool collinear = false;
2116         
2117         float bucket_bounds_ss[4][2];
2118
2119         /* detect pathological case where face the three vertices are almost collinear in screen space.
2120          * mostly those will be culled but when flood filling or with smooth shading it's a possibility */
2121         if (min_fff(dist_squared_to_line_v2(v1coSS, v2coSS, v3coSS),
2122                     dist_squared_to_line_v2(v2coSS, v3coSS, v1coSS),
2123                     dist_squared_to_line_v2(v3coSS, v1coSS, v2coSS)) < PROJ_PIXEL_TOLERANCE)
2124         {
2125                 collinear = true;
2126         }
2127         
2128         /* get the UV space bounding box */
2129         inside_bucket_flag |= BLI_rctf_isect_pt_v(bucket_bounds, v1coSS);
2130         inside_bucket_flag |= BLI_rctf_isect_pt_v(bucket_bounds, v2coSS) << 1;
2131         inside_bucket_flag |= BLI_rctf_isect_pt_v(bucket_bounds, v3coSS) << 2;
2132         
2133         if (inside_bucket_flag == ISECT_ALL3) {
2134                 /* is_flip_object is used here because we use the face winding */
2135                 flip = (((line_point_side_v2(v1coSS, v2coSS, v3coSS) > 0.0f) != is_flip_object) !=
2136                         (line_point_side_v2(uv1co, uv2co, uv3co) > 0.0f));
2137
2138                 /* all screenspace points are inside the bucket bounding box,
2139                  * this means we don't need to clip and can simply return the UVs */
2140                 if (flip) { /* facing the back? */
2141                         copy_v2_v2(bucket_bounds_uv[0], uv3co);
2142                         copy_v2_v2(bucket_bounds_uv[1], uv2co);
2143                         copy_v2_v2(bucket_bounds_uv[2], uv1co);
2144                 }
2145                 else {
2146                         copy_v2_v2(bucket_bounds_uv[0], uv1co);
2147                         copy_v2_v2(bucket_bounds_uv[1], uv2co);
2148                         copy_v2_v2(bucket_bounds_uv[2], uv3co);
2149                 }               
2150                 
2151                 *tot = 3;
2152                 return;
2153         }
2154         /* handle pathological case here, no need for further intersections below since tringle area is almost zero */
2155         if (collinear) {
2156                 int flag;
2157                 
2158                 (*tot) = 0;
2159
2160                 if (cull)
2161                         return;
2162                 
2163                 if (inside_bucket_flag & ISECT_1) { copy_v2_v2(bucket_bounds_uv[*tot], uv1co); (*tot)++; }
2164
2165                 flag = inside_bucket_flag & (ISECT_1 | ISECT_2);
2166                 if (flag && flag != (ISECT_1 | ISECT_2)) {
2167                         if (line_rect_clip(bucket_bounds, v1coSS, v2coSS, uv1co, uv2co, bucket_bounds_uv[*tot], is_ortho))
2168                                 (*tot)++;
2169                 }
2170                 
2171                 if (inside_bucket_flag & ISECT_2) { copy_v2_v2(bucket_bounds_uv[*tot], uv2co); (*tot)++; }
2172                 
2173                 flag = inside_bucket_flag & (ISECT_2 | ISECT_3);
2174                 if (flag && flag != (ISECT_2 | ISECT_3)) {
2175                         if (line_rect_clip(bucket_bounds, v2coSS, v3coSS, uv2co, uv3co, bucket_bounds_uv[*tot], is_ortho))
2176                                 (*tot)++;
2177                 }
2178
2179                 if (inside_bucket_flag & ISECT_3) { copy_v2_v2(bucket_bounds_uv[*tot], uv3co); (*tot)++; }
2180
2181                 flag = inside_bucket_flag & (ISECT_3 | ISECT_1);
2182                 if (flag && flag != (ISECT_3 | ISECT_1)) {
2183                         if (line_rect_clip(bucket_bounds, v3coSS, v1coSS, uv3co, uv1co, bucket_bounds_uv[*tot], is_ortho))
2184                                 (*tot)++;
2185                 }
2186                 
2187                 if ((*tot) < 3) {
2188                         /* no intersections to speak of, but more probable is that all face is just outside the
2189                          * rectangle and culled due to float precision issues. Since above tests have failed,
2190                          * just dump triangle as is for painting */
2191                         *tot = 0;
2192                         copy_v2_v2(bucket_bounds_uv[*tot], uv1co); (*tot)++;
2193                         copy_v2_v2(bucket_bounds_uv[*tot], uv2co); (*tot)++;
2194                         copy_v2_v2(bucket_bounds_uv[*tot], uv3co); (*tot)++;
2195                         return;
2196                 }
2197
2198                 return;
2199         }
2200
2201         /* get the UV space bounding box */
2202         /* use IsectPT2Df_limit here so we catch points are are touching the tri edge (or a small fraction over) */
2203         bucket_bounds_ss[0][0] = bucket_bounds->xmax;
2204         bucket_bounds_ss[0][1] = bucket_bounds->ymin;
2205         inside_face_flag |= (IsectPT2Df_limit(bucket_bounds_ss[0], v1coSS, v2coSS, v3coSS, 1 + PROJ_GEOM_TOLERANCE) ? ISECT_1 : 0);
2206
2207         bucket_bounds_ss[1][0] = bucket_bounds->xmax;
2208         bucket_bounds_ss[1][1] = bucket_bounds->ymax;
2209         inside_face_flag |= (IsectPT2Df_limit(bucket_bounds_ss[1], v1coSS, v2coSS, v3coSS, 1 + PROJ_GEOM_TOLERANCE) ? ISECT_2 : 0);
2210
2211         bucket_bounds_ss[2][0] = bucket_bounds->xmin;
2212         bucket_bounds_ss[2][1] = bucket_bounds->ymax;
2213         inside_face_flag |= (IsectPT2Df_limit(bucket_bounds_ss[2], v1coSS, v2coSS, v3coSS, 1 + PROJ_GEOM_TOLERANCE) ? ISECT_3 : 0);
2214
2215         bucket_bounds_ss[3][0] = bucket_bounds->xmin;
2216         bucket_bounds_ss[3][1] = bucket_bounds->ymin;
2217         inside_face_flag |= (IsectPT2Df_limit(bucket_bounds_ss[3], v1coSS, v2coSS, v3coSS, 1 + PROJ_GEOM_TOLERANCE) ? ISECT_4 : 0);
2218
2219         flip = ((line_point_side_v2(v1coSS, v2coSS, v3coSS) > 0.0f) !=
2220                 (line_point_side_v2(uv1co, uv2co, uv3co) > 0.0f));
2221
2222         if (inside_face_flag == ISECT_ALL4) {
2223                 /* bucket is totally inside the screenspace face, we can safely use weights */
2224
2225                 if (is_ortho) {
2226                         rect_to_uvspace_ortho(bucket_bounds, v1coSS, v2coSS, v3coSS, uv1co, uv2co, uv3co, bucket_bounds_uv, flip);
2227                 }
2228                 else {
2229                         rect_to_uvspace_persp(bucket_bounds, v1coSS, v2coSS, v3coSS, uv1co, uv2co, uv3co, bucket_bounds_uv, flip);
2230                 }
2231
2232                 *tot = 4;
2233                 return;
2234         }
2235         else {
2236                 /* The Complicated Case!
2237                  *
2238                  * The 2 cases above are where the face is inside the bucket or the bucket is inside the face.
2239                  *
2240                  * we need to make a convex polyline from the intersection between the screenspace face
2241                  * and the bucket bounds.
2242                  *
2243                  * There are a number of ways this could be done, currently it just collects all intersecting verts,
2244                  * and line intersections,  then sorts them clockwise, this is a lot easier then evaluating the geometry to
2245                  * do a correct clipping on both shapes. */
2246
2247
2248                 /* add a bunch of points, we know must make up the convex hull which is the clipped rect and triangle */
2249
2250
2251
2252                 /* Maximum possible 6 intersections when using a rectangle and triangle */
2253                 float isectVCosSS[8][3]; /* The 3rd float is used to store angle for qsort(), NOT as a Z location */
2254                 float v1_clipSS[2], v2_clipSS[2];
2255                 float w[3];
2256
2257                 /* calc center */
2258                 float cent[2] = {0.0f, 0.0f};
2259                 /*float up[2] = {0.0f, 1.0f};*/
2260                 int i;
2261                 bool doubles;
2262
2263                 (*tot) = 0;
2264
2265                 if (inside_face_flag & ISECT_1) { copy_v2_v2(isectVCosSS[*tot], bucket_bounds_ss[0]); (*tot)++; }
2266                 if (inside_face_flag & ISECT_2) { copy_v2_v2(isectVCosSS[*tot], bucket_bounds_ss[1]); (*tot)++; }
2267                 if (inside_face_flag & ISECT_3) { copy_v2_v2(isectVCosSS[*tot], bucket_bounds_ss[2]); (*tot)++; }
2268                 if (inside_face_flag & ISECT_4) { copy_v2_v2(isectVCosSS[*tot], bucket_bounds_ss[3]); (*tot)++; }
2269
2270                 if (inside_bucket_flag & ISECT_1) { copy_v2_v2(isectVCosSS[*tot], v1coSS); (*tot)++; }
2271                 if (inside_bucket_flag & ISECT_2) { copy_v2_v2(isectVCosSS[*tot], v2coSS); (*tot)++; }
2272                 if (inside_bucket_flag & ISECT_3) { copy_v2_v2(isectVCosSS[*tot], v3coSS); (*tot)++; }
2273
2274                 if ((inside_bucket_flag & (ISECT_1 | ISECT_2)) != (ISECT_1 | ISECT_2)) {
2275                         if (line_clip_rect2f(cliprect, bucket_bounds, v1coSS, v2coSS, v1_clipSS, v2_clipSS)) {
2276                                 if ((inside_bucket_flag & ISECT_1) == 0) { copy_v2_v2(isectVCosSS[*tot], v1_clipSS); (*tot)++; }
2277                                 if ((inside_bucket_flag & ISECT_2) == 0) { copy_v2_v2(isectVCosSS[*tot], v2_clipSS); (*tot)++; }
2278                         }
2279                 }
2280
2281                 if ((inside_bucket_flag & (ISECT_2 | ISECT_3)) != (ISECT_2 | ISECT_3)) {
2282                         if (line_clip_rect2f(cliprect, bucket_bounds, v2coSS, v3coSS, v1_clipSS, v2_clipSS)) {
2283                                 if ((inside_bucket_flag & ISECT_2) == 0) { copy_v2_v2(isectVCosSS[*tot], v1_clipSS); (*tot)++; }
2284                                 if ((inside_bucket_flag & ISECT_3) == 0) { copy_v2_v2(isectVCosSS[*tot], v2_clipSS); (*tot)++; }
2285                         }
2286                 }
2287
2288                 if ((inside_bucket_flag & (ISECT_3 | ISECT_1)) != (ISECT_3 | ISECT_1)) {
2289                         if (line_clip_rect2f(cliprect, bucket_bounds, v3coSS, v1coSS, v1_clipSS, v2_clipSS)) {
2290                                 if ((inside_bucket_flag & ISECT_3) == 0) { copy_v2_v2(isectVCosSS[*tot], v1_clipSS); (*tot)++; }
2291                                 if ((inside_bucket_flag & ISECT_1) == 0) { copy_v2_v2(isectVCosSS[*tot], v2_clipSS); (*tot)++; }
2292                         }
2293                 }
2294
2295
2296                 if ((*tot) < 3) { /* no intersections to speak of */
2297                         *tot = 0;
2298                         return;
2299                 }
2300
2301                 /* now we have all points we need, collect their angles and sort them clockwise */
2302
2303                 for (i = 0; i < (*tot); i++) {
2304                         cent[0] += isectVCosSS[i][0];
2305                         cent[1] += isectVCosSS[i][1];
2306                 }
2307                 cent[0] = cent[0] / (float)(*tot);
2308                 cent[1] = cent[1] / (float)(*tot);
2309
2310
2311
2312                 /* Collect angles for every point around the center point */
2313
2314
2315 #if 0   /* uses a few more cycles then the above loop */
2316                 for (i = 0; i < (*tot); i++) {
2317                         isectVCosSS[i][2] = angle_2d_clockwise(up, cent, isectVCosSS[i]);
2318                 }
2319 #endif
2320
2321                 v1_clipSS[0] = cent[0]; /* Abuse this var for the loop below */
2322                 v1_clipSS[1] = cent[1] + 1.0f;
2323
2324                 for (i = 0; i < (*tot); i++) {
2325                         v2_clipSS[0] = isectVCosSS[i][0] - cent[0];
2326                         v2_clipSS[1] = isectVCosSS[i][1] - cent[1];
2327                         isectVCosSS[i][2] = atan2f(v1_clipSS[0] * v2_clipSS[1] - v1_clipSS[1] * v2_clipSS[0],
2328                                                    v1_clipSS[0] * v2_clipSS[0] + v1_clipSS[1] * v2_clipSS[1]);
2329                 }
2330
2331                 if (flip) qsort(isectVCosSS, *tot, sizeof(float) * 3, float_z_sort_flip);
2332                 else      qsort(isectVCosSS, *tot, sizeof(float) * 3, float_z_sort);
2333
2334                 doubles = true;
2335                 while (doubles == true) {
2336                         doubles = false;
2337
2338                         for (i = 0; i < (*tot); i++) {
2339                                 if (fabsf(isectVCosSS[(i + 1) % *tot][0] - isectVCosSS[i][0]) < PROJ_PIXEL_TOLERANCE &&
2340                                     fabsf(isectVCosSS[(i + 1) % *tot][1] - isectVCosSS[i][1]) < PROJ_PIXEL_TOLERANCE)
2341                                 {
2342                                         int j;
2343                                         for (j = i; j < (*tot) - 1; j++) {
2344                                                 isectVCosSS[j][0] = isectVCosSS[j + 1][0];
2345                                                 isectVCosSS[j][1] = isectVCosSS[j + 1][1];
2346                                         }
2347                                         doubles = true; /* keep looking for more doubles */
2348                                         (*tot)--;
2349                                 }
2350                         }
2351                         
2352                         /* its possible there is only a few left after remove doubles */
2353                         if ((*tot) < 3) {
2354                                 // printf("removed too many doubles B\n");
2355                                 *tot = 0;
2356                                 return;
2357                         }
2358                 }
2359
2360                 if (is_ortho) {
2361                         for (i = 0; i < (*tot); i++) {
2362                                 barycentric_weights_v2(v1coSS, v2coSS, v3coSS, isectVCosSS[i], w);
2363                                 interp_v2_v2v2v2(bucket_bounds_uv[i], uv1co, uv2co, uv3co, w);
2364                         }
2365                 }
2366                 else {
2367                         for (i = 0; i < (*tot); i++) {
2368                                 barycentric_weights_v2_persp(v1coSS, v2coSS, v3coSS, isectVCosSS[i], w);
2369                                 interp_v2_v2v2v2(bucket_bounds_uv[i], uv1co, uv2co, uv3co, w);
2370                         }
2371                 }
2372         }
2373
2374 #ifdef PROJ_DEBUG_PRINT_CLIP
2375         /* include this at the bottom of the above function to debug the output */
2376
2377         {
2378                 /* If there are ever any problems, */
2379                 float test_uv[4][2];
2380                 int i;
2381                 if (is_ortho) rect_to_uvspace_ortho(bucket_bounds, v1coSS, v2coSS, v3coSS, uv1co, uv2co, uv3co, test_uv, flip);
2382                 else          rect_to_uvspace_persp(bucket_bounds, v1coSS, v2coSS, v3coSS, uv1co, uv2co, uv3co, test_uv, flip);
2383                 printf("(  [(%f,%f), (%f,%f), (%f,%f), (%f,%f)], ",
2384                        test_uv[0][0], test_uv[0][1],   test_uv[1][0], test_uv[1][1],
2385                        test_uv[2][0], test_uv[2][1],    test_uv[3][0], test_uv[3][1]);
2386
2387                 printf("  [(%f,%f), (%f,%f), (%f,%f)], ", uv1co[0], uv1co[1],   uv2co[0], uv2co[1],    uv3co[0], uv3co[1]);
2388
2389                 printf("[");
2390                 for (i = 0; i < (*tot); i++) {
2391                         printf("(%f, %f),", bucket_bounds_uv[i][0], bucket_bounds_uv[i][1]);
2392                 }
2393                 printf("]),\\\n");
2394         }
2395 #endif
2396 }
2397
2398 /*
2399  * # This script creates faces in a blender scene from printed data above.
2400  *
2401  * project_ls = [
2402  * ...(output from above block)...
2403  * ]
2404  *
2405  * from Blender import Scene, Mesh, Window, sys, Mathutils
2406  *
2407  * import bpy
2408  *
2409  * V = Mathutils.Vector
2410  *
2411  * def main():
2412  *     sce = bpy.data.scenes.active
2413  *
2414  *     for item in project_ls:
2415  *         bb = item[0]
2416  *         uv = item[1]
2417  *         poly = item[2]
2418  *
2419  *         me = bpy.data.meshes.new()
2420  *         ob = sce.objects.new(me)
2421  *
2422  *         me.verts.extend([V(bb[0]).xyz, V(bb[1]).xyz, V(bb[2]).xyz, V(bb[3]).xyz])
2423  *         me.faces.extend([(0,1,2,3),])
2424  *         me.verts.extend([V(uv[0]).xyz, V(uv[1]).xyz, V(uv[2]).xyz])
2425  *         me.faces.extend([(4,5,6),])
2426  *
2427  *         vs = [V(p).xyz for p in poly]
2428  *         print len(vs)
2429  *         l = len(me.verts)
2430  *         me.verts.extend(vs)
2431  *
2432  *         i = l
2433  *         while i < len(me.verts):
2434  *             ii = i + 1
2435  *             if ii == len(me.verts):
2436  *                 ii = l
2437  *             me.edges.extend([i, ii])
2438  *             i += 1
2439  *
2440  * if __name__ == '__main__':
2441  *     main()
2442  */
2443
2444
2445 #undef ISECT_1
2446 #undef ISECT_2
2447 #undef ISECT_3
2448 #undef ISECT_4
2449 #undef ISECT_ALL3
2450 #undef ISECT_ALL4
2451
2452
2453 /* checks if pt is inside a convex 2D polyline, the polyline must be ordered rotating clockwise
2454  * otherwise it would have to test for mixed (line_point_side_v2 > 0.0f) cases */
2455 static bool IsectPoly2Df(const float pt[2], float uv[][2], const int tot)
2456 {
2457         int i;
2458         if (line_point_side_v2(uv[tot - 1], uv[0], pt) < 0.0f)
2459                 return 0;
2460
2461         for (i = 1; i < tot; i++) {
2462                 if (line_point_side_v2(uv[i - 1], uv[i], pt) < 0.0f)
2463                         return 0;
2464
2465         }
2466
2467         return 1;
2468 }
2469 static bool IsectPoly2Df_twoside(const float pt[2], float uv[][2], const int tot)
2470 {
2471         int i;
2472         bool side = (line_point_side_v2(uv[tot - 1], uv[0], pt) > 0.0f);
2473
2474         for (i = 1; i < tot; i++) {
2475                 if ((line_point_side_v2(uv[i - 1], uv[i], pt) > 0.0f) != side)
2476                         return 0;
2477
2478         }
2479
2480         return 1;
2481 }
2482
2483 /* One of the most important function for projection painting,
2484  * since it selects the pixels to be added into each bucket.
2485  *
2486  * initialize pixels from this face where it intersects with the bucket_index,
2487  * optionally initialize pixels for removing seams */
2488 static void project_paint_face_init(
2489         const ProjPaintState *ps,
2490         const int thread_index, const int bucket_index, const int tri_index, const int image_index,
2491         const rctf *clip_rect, const rctf *bucket_bounds, ImBuf *ibuf, ImBuf **tmpibuf,
2492         const bool clamp_u, const bool clamp_v)
2493 {
2494         /* Projection vars, to get the 3D locations into screen space  */
2495         MemArena *arena = ps->arena_mt[thread_index];
2496         LinkNode **bucketPixelNodes = ps->bucketRect + bucket_index;
2497         LinkNode *bucketFaceNodes = ps->bucketFaces[bucket_index];
2498         bool threaded = (ps->thread_tot > 1);
2499
2500         TileInfo tinf = {
2501                 ps->tile_lock,
2502                 ps->do_masking,
2503                 IMAPAINT_TILE_NUMBER(ibuf->x),
2504                 tmpibuf,
2505                 ps->projImages + image_index
2506         };
2507
2508         const MLoopTri *lt = &ps->dm_mlooptri[tri_index];
2509         const int lt_vtri[3] = { PS_LOOPTRI_AS_VERT_INDEX_3(ps, lt) };
2510         const float *lt_tri_uv[3] = { PS_LOOPTRI_AS_UV_3(ps->dm_mloopuv, lt) };
2511
2512         /* UV/pixel seeking data */
2513         int x; /* Image X-Pixel */
2514         int y; /* Image Y-Pixel */
2515         float mask;
2516         float uv[2]; /* Image floating point UV - same as x, y but from 0.0-1.0 */
2517
2518         const float *v1coSS, *v2coSS, *v3coSS; /* vert co screen-space, these will be assigned to lt_vtri[0-2] */
2519
2520         const float *vCo[3]; /* vertex screenspace coords */
2521
2522         float w[3], wco[3];
2523
2524         float *uv1co, *uv2co, *uv3co; /* for convenience only, these will be assigned to lt_tri_uv[0],1,2 or lt_tri_uv[0],2,3 */
2525         float pixelScreenCo[4];
2526         bool do_3d_mapping = ps->brush->mtex.brush_map_mode == MTEX_MAP_MODE_3D;
2527
2528         rcti bounds_px; /* ispace bounds */
2529         /* vars for getting uvspace bounds */
2530
2531         float lt_uv_pxoffset[3][2]; /* bucket bounds in UV space so we can init pixels only for this face,  */
2532         float xhalfpx, yhalfpx;
2533         const float ibuf_xf = (float)ibuf->x, ibuf_yf = (float)ibuf->y;
2534
2535         int has_x_isect = 0, has_isect = 0; /* for early loop exit */
2536
2537         float uv_clip[8][2];
2538         int uv_clip_tot;
2539         const bool is_ortho = ps->is_ortho;
2540         const bool is_flip_object = ps->is_flip_object;
2541         const bool do_backfacecull = ps->do_backfacecull;
2542         const bool do_clip = ps->rv3d ? ps->rv3d->rflag & RV3D_CLIPPING : 0;
2543
2544         vCo[0] = ps->dm_mvert[lt_vtri[0]].co;
2545         vCo[1] = ps->dm_mvert[lt_vtri[1]].co;
2546         vCo[2] = ps->dm_mvert[lt_vtri[2]].co;
2547
2548
2549         /* Use lt_uv_pxoffset instead of lt_tri_uv so we can offset the UV half a pixel
2550          * this is done so we can avoid offsetting all the pixels by 0.5 which causes
2551          * problems when wrapping negative coords */
2552         xhalfpx = (0.5f + (PROJ_PIXEL_TOLERANCE * (1.0f / 3.0f))) / ibuf_xf;
2553         yhalfpx = (0.5f + (PROJ_PIXEL_TOLERANCE * (1.0f / 4.0f))) / ibuf_yf;
2554
2555         /* Note about (PROJ_GEOM_TOLERANCE/x) above...
2556          * Needed to add this offset since UV coords are often quads aligned to pixels.
2557          * In this case pixels can be exactly between 2 triangles causing nasty
2558          * artifacts.
2559          *
2560          * This workaround can be removed and painting will still work on most cases
2561          * but since the first thing most people try is painting onto a quad- better make it work.
2562          */
2563
2564         lt_uv_pxoffset[0][0] = lt_tri_uv[0][0] - xhalfpx;
2565         lt_uv_pxoffset[0][1] = lt_tri_uv[0][1] - yhalfpx;
2566
2567         lt_uv_pxoffset[1][0] = lt_tri_uv[1][0] - xhalfpx;
2568         lt_uv_pxoffset[1][1] = lt_tri_uv[1][1] - yhalfpx;
2569
2570         lt_uv_pxoffset[2][0] = lt_tri_uv[2][0] - xhalfpx;
2571         lt_uv_pxoffset[2][1] = lt_tri_uv[2][1] - yhalfpx;
2572
2573         {
2574                 uv1co = lt_uv_pxoffset[0]; // was lt_tri_uv[i1];
2575                 uv2co = lt_uv_pxoffset[1]; // was lt_tri_uv[i2];
2576                 uv3co = lt_uv_pxoffset[2]; // was lt_tri_uv[i3];
2577
2578                 v1coSS = ps->screenCoords[lt_vtri[0]];
2579                 v2coSS = ps->screenCoords[lt_vtri[1]];
2580                 v3coSS = ps->screenCoords[lt_vtri[2]];
2581
2582                 /* This funtion gives is a concave polyline in UV space from the clipped tri*/
2583                 project_bucket_clip_face(
2584                         is_ortho, is_flip_object,
2585                         clip_rect, bucket_bounds,
2586                         v1coSS, v2coSS, v3coSS,
2587                         uv1co, uv2co, uv3co,
2588                         uv_clip, &uv_clip_tot,
2589                         do_backfacecull || ps->do_occlude);
2590
2591                 /* sometimes this happens, better just allow for 8 intersectiosn even though there should be max 6 */
2592 #if 0
2593                 if (uv_clip_tot > 6) {
2594                         printf("this should never happen! %d\n", uv_clip_tot);
2595                 }
2596 #endif
2597
2598                 if (pixel_bounds_array(uv_clip, &bounds_px, ibuf->x, ibuf->y, uv_clip_tot)) {
2599
2600                         if (clamp_u) {
2601                                 CLAMP(bounds_px.xmin, 0, ibuf->x);
2602                                 CLAMP(bounds_px.xmax, 0, ibuf->x);
2603                         }
2604
2605                         if (clamp_v) {
2606                                 CLAMP(bounds_px.ymin, 0, ibuf->y);
2607                                 CLAMP(bounds_px.ymax, 0, ibuf->y);
2608                         }
2609
2610 #if 0
2611                         project_paint_undo_tiles_init(&bounds_px, ps->projImages + image_index, tmpibuf,
2612                                                       tile_width, threaded, ps->do_masking);
2613 #endif
2614                         /* clip face and */
2615
2616                         has_isect = 0;
2617                         for (y = bounds_px.ymin; y < bounds_px.ymax; y++) {
2618                                 //uv[1] = (((float)y) + 0.5f) / (float)ibuf->y;
2619                                 uv[1] = (float)y / ibuf_yf; /* use pixel offset UV coords instead */
2620
2621                                 has_x_isect = 0;
2622                                 for (x = bounds_px.xmin; x < bounds_px.xmax; x++) {
2623                                         //uv[0] = (((float)x) + 0.5f) / ibuf->x;
2624                                         uv[0] = (float)x / ibuf_xf; /* use pixel offset UV coords instead */
2625
2626                                         /* Note about IsectPoly2Df_twoside, checking the face or uv flipping doesnt work,
2627                                          * could check the poly direction but better to do this */
2628                                         if ((do_backfacecull == true  && IsectPoly2Df(uv, uv_clip, uv_clip_tot)) ||
2629                                             (do_backfacecull == false && IsectPoly2Df_twoside(uv, uv_clip, uv_clip_tot)))
2630                                         {
2631
2632                                                 has_x_isect = has_isect = 1;
2633
2634                                                 if (is_ortho) screen_px_from_ortho(uv, v1coSS, v2coSS, v3coSS, uv1co, uv2co, uv3co, pixelScreenCo, w);
2635                                                 else screen_px_from_persp(uv, v1coSS, v2coSS, v3coSS, uv1co, uv2co, uv3co, pixelScreenCo, w);
2636
2637                                                 /* a pity we need to get the worldspace pixel location here */
2638                                                 if (do_clip || do_3d_mapping) {
2639                                                         interp_v3_v3v3v3(
2640                                                                 wco,
2641                                                                 ps->dm_mvert[lt_vtri[0]].co,
2642                                                                 ps->dm_mvert[lt_vtri[1]].co,
2643                                                                 ps->dm_mvert[lt_vtri[2]].co,
2644                                                                 w);
2645                                                         if (do_clip && ED_view3d_clipping_test(ps->rv3d, wco, true)) {
2646                                                                 continue; /* Watch out that no code below this needs to run */
2647                                                         }
2648                                                 }
2649
2650                                                 /* Is this UV visible from the view? - raytrace */
2651                                                 /* project_paint_PickFace is less complex, use for testing */
2652                                                 //if (project_paint_PickFace(ps, pixelScreenCo, w, &side) == tri_index) {
2653                                                 if ((ps->do_occlude == false) ||
2654                                                     !project_bucket_point_occluded(ps, bucketFaceNodes, tri_index, pixelScreenCo))
2655                                                 {
2656                                                         mask = project_paint_uvpixel_mask(ps, tri_index, w);
2657
2658                                                         if (mask > 0.0f) {
2659                                                                 BLI_linklist_prepend_arena(
2660                                                                         bucketPixelNodes,
2661                                                                         project_paint_uvpixel_init(ps, arena, &tinf, x, y, mask, tri_index,
2662                                                                                                    pixelScreenCo, wco, w),
2663                                                                         arena
2664                                                                         );
2665                                                         }
2666                                                 }
2667
2668                                         }
2669 //#if 0
2670                                         else if (has_x_isect) {
2671                                                 /* assuming the face is not a bow-tie - we know we cant intersect again on the X */
2672                                                 break;
2673                                         }
2674 //#endif
2675                                 }
2676
2677
2678 #if 0           /* TODO - investigate why this dosnt work sometimes! it should! */
2679                                 /* no intersection for this entire row, after some intersection above means we can quit now */
2680                                 if (has_x_isect == 0 && has_isect) {
2681                                         break;
2682                                 }
2683 #endif
2684                         }
2685                 }
2686         }
2687
2688
2689 #ifndef PROJ_DEBUG_NOSEAMBLEED
2690         if (ps->seam_bleed_px > 0.0f) {
2691                 int face_seam_flag;
2692
2693                 if (threaded)
2694                         BLI_lock_thread(LOCK_CUSTOM1);  /* Other threads could be modifying these vars */
2695
2696                 face_seam_flag = ps->faceSeamFlags[tri_index];
2697
2698                 /* are any of our edges un-initialized? */
2699                 if ((face_seam_flag & (PROJ_FACE_SEAM1 | PROJ_FACE_NOSEAM1)) == 0 ||
2700                     (face_seam_flag & (PROJ_FACE_SEAM2 | PROJ_FACE_NOSEAM2)) == 0 ||
2701                     (face_seam_flag & (PROJ_FACE_SEAM3 | PROJ_FACE_NOSEAM3)) == 0)
2702                 {
2703                         project_face_seams_init(ps, tri_index);
2704                         face_seam_flag = ps->faceSeamFlags[tri_index];
2705                         //printf("seams - %d %d %d %d\n", flag&PROJ_FACE_SEAM1, flag&PROJ_FACE_SEAM2, flag&PROJ_FACE_SEAM3);
2706                 }
2707
2708                 if ((face_seam_flag & (PROJ_FACE_SEAM1 | PROJ_FACE_SEAM2 | PROJ_FACE_SEAM3)) == 0) {
2709
2710                         if (threaded)
2711                                 BLI_unlock_thread(LOCK_CUSTOM1);  /* Other threads could be modifying these vars */
2712
2713                 }
2714                 else {
2715                         /* we have a seam - deal with it! */
2716
2717                         /* Now create new UV's for the seam face */
2718                         float (*outset_uv)[2] = ps->faceSeamUVs[tri_index];
2719                         float insetCos[3][3]; /* inset face coords.  NOTE!!! ScreenSace for ortho, Worldspace in prespective view */
2720
2721                         const float *vCoSS[3]; /* vertex screenspace coords */
2722
2723                         float bucket_clip_edges[2][2]; /* store the screenspace coords of the face, clipped by the bucket's screen aligned rectangle */
2724                         float edge_verts_inset_clip[2][3];
2725                         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 */
2726
2727                         float seam_subsection[4][2];
2728                         float fac1, fac2;
2729
2730                         if (outset_uv[0][0] == FLT_MAX) /* first time initialize */
2731                                 uv_image_outset(
2732                                         lt_uv_pxoffset, outset_uv, ps->seam_bleed_px,
2733                                         ibuf->x, ibuf->y, (ps->faceWindingFlags[tri_index] & PROJ_FACE_WINDING_CW) == 0);
2734
2735                         /* ps->faceSeamUVs cant be modified when threading, now this is done we can unlock */
2736                         if (threaded)
2737                                 BLI_unlock_thread(LOCK_CUSTOM1);  /* Other threads could be modifying these vars */
2738
2739                         vCoSS[0] = ps->screenCoords[lt_vtri[0]];
2740                         vCoSS[1] = ps->screenCoords[lt_vtri[1]];
2741                         vCoSS[2] = ps->screenCoords[lt_vtri[2]];
2742
2743                         /* PROJ_FACE_SCALE_SEAM must be slightly less then 1.0f */
2744                         if (is_ortho) {
2745                                 scale_tri(insetCos, vCoSS, PROJ_FACE_SCALE_SEAM);
2746                         }
2747                         else {
2748                                 scale_tri(insetCos, vCo, PROJ_FACE_SCALE_SEAM);
2749                         }
2750
2751                         for (fidx1 = 0; fidx1 < 3; fidx1++) {
2752                                 fidx2 = (fidx1 == 2) ? 0 : fidx1 + 1;  /* next fidx in the face (0,1,2) -> (1,2,0) */
2753
2754                                 if ((face_seam_flag & (1 << fidx1)) && /* 1<<fidx1 -> PROJ_FACE_SEAM# */
2755                                     line_clip_rect2f(clip_rect, bucket_bounds, vCoSS[fidx1], vCoSS[fidx2], bucket_clip_edges[0], bucket_clip_edges[1]))
2756                                 {
2757                                         if (len_squared_v2v2(vCoSS[fidx1], vCoSS[fidx2]) > FLT_EPSILON) { /* avoid div by zero */
2758
2759                                                 if (is_ortho) {
2760                                                         fac1 = line_point_factor_v2(bucket_clip_edges[0], vCoSS[fidx1], vCoSS[fidx2]);
2761                                                         fac2 = line_point_factor_v2(bucket_clip_edges[1], vCoSS[fidx1], vCoSS[fidx2]);
2762                                                 }
2763                                                 else {
2764                                                         fac1 = screen_px_line_point_factor_v2_persp(ps, bucket_clip_edges[0], vCo[fidx1], vCo[fidx2]);
2765                                                         fac2 = screen_px_line_point_factor_v2_persp(ps, bucket_clip_edges[1], vCo[fidx1], vCo[fidx2]);
2766                                                 }
2767
2768                                                 interp_v2_v2v2(seam_subsection[0], lt_uv_pxoffset[fidx1], lt_uv_pxoffset[fidx2], fac1);
2769                                                 interp_v2_v2v2(seam_subsection[1], lt_uv_pxoffset[fidx1], lt_uv_pxoffset[fidx2], fac2);
2770
2771                                                 interp_v2_v2v2(seam_subsection[2], outset_uv[fidx1], outset_uv[fidx2], fac2);
2772                                                 interp_v2_v2v2(seam_subsection[3], outset_uv[fidx1], outset_uv[fidx2], fac1);
2773
2774                                                 /* if the bucket_clip_edges values Z values was kept we could avoid this
2775                                                  * Inset needs to be added so occlusion tests wont hit adjacent faces */
2776                                                 interp_v3_v3v3(edge_verts_inset_clip[0], insetCos[fidx1], insetCos[fidx2], fac1);
2777                                                 interp_v3_v3v3(edge_verts_inset_clip[1], insetCos[fidx1], insetCos[fidx2], fac2);
2778
2779
2780                                                 if (pixel_bounds_uv(seam_subsection, &bounds_px, ibuf->x, ibuf->y)) {
2781                                                         /* bounds between the seam rect and the uvspace bucket pixels */
2782
2783                                                         has_isect = 0;
2784                                                         for (y = bounds_px.ymin; y < bounds_px.ymax; y++) {
2785                                                                 // uv[1] = (((float)y) + 0.5f) / (float)ibuf->y;
2786                                                                 uv[1] = (float)y / ibuf_yf; /* use offset uvs instead */
2787
2788                                                                 has_x_isect = 0;
2789                                                                 for (x = bounds_px.xmin; x < bounds_px.xmax; x++) {
2790                                                                         //uv[0] = (((float)x) + 0.5f) / (float)ibuf->x;
2791                                                                         uv[0] = (float)x / ibuf_xf; /* use offset uvs instead */
2792
2793                                                                         /* test we're inside uvspace bucket and triangle bounds */
2794                                                                         if (isect_point_quad_v2(uv, UNPACK4(seam_subsection))) {
2795                                                                                 float fac;
2796
2797                                                                                 /* We need to find the closest point along the face edge,
2798                                                                                  * getting the screen_px_from_*** wont work because our actual location
2799                                                                                  * is not relevant, since we are outside the face, Use VecLerpf to find
2800                                                                                  * our location on the side of the face's UV */
2801 #if 0
2802                                                                                 if (is_ortho) screen_px_from_ortho(ps, uv, v1co, v2co, v3co, uv1co, uv2co, uv3co, pixelScreenCo);
2803                                                                                 else          screen_px_from_persp(ps, uv, v1co, v2co, v3co, uv1co, uv2co, uv3co, pixelScreenCo);
2804 #endif
2805
2806                                                                                 /* Since this is a seam we need to work out where on the line this pixel is */
2807                                                                                 //fac = line_point_factor_v2(uv, uv_seam_quad[0], uv_seam_quad[1]);
2808                                                                                 fac = resolve_quad_u_v2(uv, UNPACK4(seam_subsection));
2809                                                                                 interp_v3_v3v3(pixelScreenCo, edge_verts_inset_clip[0], edge_verts_inset_clip[1], fac);
2810
2811                                                                                 if (!is_ortho) {
2812                                                                                         pixelScreenCo[3] = 1.0f;
2813                                                                                         mul_m4_v4((float(*)[4])ps->projectMat, pixelScreenCo); /* cast because of const */
2814                                                                                         pixelScreenCo[0] = (float)(ps->winx * 0.5f) + (ps->winx * 0.5f) * pixelScreenCo[0] / pixelScreenCo[3];
2815                                                                                         pixelScreenCo[1] = (float)(ps->winy * 0.5f) + (ps->winy * 0.5f) * pixelScreenCo[1] / pixelScreenCo[3];
2816                                                                                         pixelScreenCo[2] = pixelScreenCo[2] / pixelScreenCo[3]; /* Use the depth for bucket point occlusion */
2817                                                                                 }
2818
2819                                                                                 if ((ps->do_occlude == false) ||
2820                                                                                     !project_bucket_point_occluded(ps, bucketFaceNodes, tri_index, pixelScreenCo))
2821                                                                                 {
2822                                                                                         /* Only bother calculating the weights if we intersect */
2823                                                                                         if (ps->do_mask_normal || ps->dm_mloopuv_clone) {
2824                                                                                                 const float uv_fac = fac1 + (fac * (fac2 - fac1));
2825 #if 0
2826                                                                                                 /* get the UV on the line since we want to copy the pixels from there for bleeding */
2827                                                                                                 float uv_close[2];
2828                                                                                                 interp_v2_v2v2(uv_close, lt_uv_pxoffset[fidx1], lt_uv_pxoffset[fidx2], uv_fac);
2829                                                                                                 barycentric_weights_v2(lt_uv_pxoffset[0], lt_uv_pxoffset[1], lt_uv_pxoffset[2], uv_close, w);
2830 #else
2831
2832                                                                                                 /* Cheat, we know where we are along the edge so work out the weights from that */
2833                                                                                                 w[0] = w[1] = w[2] = 0.0;
2834                                                                                                 w[fidx1] = 1.0f - uv_fac;
2835                                                                                                 w[fidx2] = uv_fac;
2836 #endif
2837                                                                                         }
2838
2839                                                                                         /* a pity we need to get the worldspace pixel location here */
2840                                                                                         if (do_clip || do_3d_mapping) {
2841                                                                                                 interp_v3_v3v3v3(wco, vCo[0], vCo[1], vCo[2], w);
2842
2843                                                                                                 if (do_clip && ED_view3d_clipping_test(ps->rv3d, wco, true)) {
2844                                                                                                         continue; /* Watch out that no code below this needs to run */
2845                                                                                                 }
2846                                                                                         }
2847
2848                                                                                         mask = project_paint_uvpixel_mask(ps, tri_index, w);
2849
2850                                                                                         if (mask > 0.0f) {
2851                                                                                                 BLI_linklist_prepend_arena(
2852                                                                                                         bucketPixelNodes,
2853                                                                                                         project_paint_uvpixel_init(ps, arena, &tinf, x, y, mask, tri_index,
2854                                                                                                         pixelScreenCo, wco, w),
2855                                                                                                         arena
2856                                                                                                         );
2857                                                                                         }
2858
2859                                                                                 }
2860                                                                         }
2861                                                                         else if (has_x_isect) {
2862                                                                                 /* assuming the face is not a bow-tie - we know we cant intersect again on the X */
2863                                                                                 break;
2864                                                                         }
2865                                                                 }
2866
2867 #if 0                           /* TODO - investigate why this dosnt work sometimes! it should! */
2868                                                                 /* no intersection for this entire row, after some intersection above means we can quit now */
2869                                                                 if (has_x_isect == 0 && has_isect) {