Workbench: API Changes
[blender.git] / source / blender / editors / sculpt_paint / paint_image_proj.c
1 /*
2  * ***** BEGIN GPL LICENSE BLOCK *****
3  *
4  * This program is free software; you can redistribute it and/or
5  * modify it under the terms of the GNU General Public License
6  * as published by the Free Software Foundation; either version 2
7  * of the License, or (at your option) any later version.
8  *
9  * This program is distributed in the hope that it will be useful,
10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
12  * GNU General Public License for more details.
13  *
14  * along with this program; if not, write to the Free Software Foundation,
15  * Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
16  *
17  * The Original Code is Copyright (C) 2001-2002 by NaN Holding BV.
18  * All rights reserved.
19  *
20  * The Original Code is: some of this file.
21  *
22  * Contributor(s): Jens Ole Wund (bjornmose), Campbell Barton (ideasman42)
23  *
24  * ***** END GPL LICENSE BLOCK *****
25  */
26
27 /** \file blender/editors/sculpt_paint/paint_image_proj.c
28  *  \ingroup edsculpt
29  *  \brief Functions to paint images in 2D and 3D.
30  */
31
32 #include <float.h>
33 #include <string.h>
34 #include <stdio.h>
35 #include <math.h>
36
37 #include "MEM_guardedalloc.h"
38
39 #ifdef WIN32
40 #  include "BLI_winstuff.h"
41 #endif
42
43 #include "BLI_blenlib.h"
44 #include "BLI_linklist.h"
45 #include "BLI_math.h"
46 #include "BLI_math_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_colorband.h"
66 #include "BKE_context.h"
67 #include "BKE_colortools.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_mesh_runtime.h"
78 #include "BKE_node.h"
79 #include "BKE_paint.h"
80 #include "BKE_report.h"
81 #include "BKE_scene.h"
82 #include "BKE_texture.h"
83
84 #include "DEG_depsgraph.h"
85 #include "DEG_depsgraph_query.h"
86
87 #include "UI_interface.h"
88
89 #include "ED_object.h"
90 #include "ED_mesh.h"
91 #include "ED_node.h"
92 #include "ED_paint.h"
93 #include "ED_screen.h"
94 #include "ED_uvedit.h"
95 #include "ED_view3d.h"
96
97 #include "GPU_extensions.h"
98
99 #include "WM_api.h"
100 #include "WM_types.h"
101
102 #include "RNA_access.h"
103 #include "RNA_define.h"
104 #include "RNA_enum_types.h"
105
106 #include "GPU_draw.h"
107
108 #include "IMB_colormanagement.h"
109
110 #include "bmesh.h"
111 //#include "bmesh_tools.h"
112
113 #include "paint_intern.h"
114
115 static void partial_redraw_array_init(ImagePaintPartialRedraw *pr);
116
117 /* Defines and Structs */
118 /* unit_float_to_uchar_clamp as inline function */
119 BLI_INLINE unsigned char f_to_char(const float val)
120 {
121         return unit_float_to_uchar_clamp(val);
122 }
123
124 /* ProjectionPaint defines */
125
126 /* approx the number of buckets to have under the brush,
127  * used with the brush size to set the ps->buckets_x and ps->buckets_y value.
128  *
129  * When 3 - a brush should have ~9 buckets under it at once
130  * ...this helps for threading while painting as well as
131  * avoiding initializing pixels that wont touch the brush */
132 #define PROJ_BUCKET_BRUSH_DIV 4
133
134 #define PROJ_BUCKET_RECT_MIN 4
135 #define PROJ_BUCKET_RECT_MAX 256
136
137 #define PROJ_BOUNDBOX_DIV 8
138 #define PROJ_BOUNDBOX_SQUARED  (PROJ_BOUNDBOX_DIV * PROJ_BOUNDBOX_DIV)
139
140 //#define PROJ_DEBUG_PAINT 1
141 //#define PROJ_DEBUG_NOSEAMBLEED 1
142 //#define PROJ_DEBUG_PRINT_CLIP 1
143 #define PROJ_DEBUG_WINCLIP 1
144
145
146 #ifndef PROJ_DEBUG_NOSEAMBLEED
147 /* projectFaceSeamFlags options */
148 //#define PROJ_FACE_IGNORE      (1<<0)  /* When the face is hidden, backfacing or occluded */
149 //#define PROJ_FACE_INIT        (1<<1)  /* When we have initialized the faces data */
150 #define PROJ_FACE_SEAM1 (1 << 0)  /* If this face has a seam on any of its edges */
151 #define PROJ_FACE_SEAM2 (1 << 1)
152 #define PROJ_FACE_SEAM3 (1 << 2)
153
154 #define PROJ_FACE_NOSEAM1   (1 << 4)
155 #define PROJ_FACE_NOSEAM2   (1 << 5)
156 #define PROJ_FACE_NOSEAM3   (1 << 6)
157
158 /* face winding */
159 #define PROJ_FACE_WINDING_INIT 1
160 #define PROJ_FACE_WINDING_CW 2
161
162 /* a slightly scaled down face is used to get fake 3D location for edge pixels in the seams
163  * as this number approaches  1.0f the likelihood increases of float precision errors where
164  * it is occluded by an adjacent face */
165 #define PROJ_FACE_SCALE_SEAM    0.99f
166 #endif  /* PROJ_DEBUG_NOSEAMBLEED */
167
168
169 #define PROJ_SRC_VIEW       1
170 #define PROJ_SRC_IMAGE_CAM  2
171 #define PROJ_SRC_IMAGE_VIEW 3
172 #define PROJ_SRC_VIEW_FILL  4
173
174 #define PROJ_VIEW_DATA_ID "view_data"
175 #define PROJ_VIEW_DATA_SIZE (4 * 4 + 4 * 4 + 3) /* viewmat + winmat + clipsta + clipend + is_ortho */
176
177 #define PROJ_BUCKET_NULL        0
178 #define PROJ_BUCKET_INIT        (1 << 0)
179 // #define PROJ_BUCKET_CLONE_INIT       (1<<1)
180
181 /* used for testing doubles, if a point is on a line etc */
182 #define PROJ_GEOM_TOLERANCE 0.00075f
183 #define PROJ_PIXEL_TOLERANCE 0.01f
184
185 /* vert flags */
186 #define PROJ_VERT_CULL 1
187
188 /* to avoid locking in tile initialization */
189 #define TILE_PENDING SET_INT_IN_POINTER(-1)
190
191 /* This is mainly a convenience struct used so we can keep an array of images we use -
192  * their imbufs, etc, in 1 array, When using threads this array is copied for each thread
193  * because 'partRedrawRect' and 'touch' values would not be thread safe */
194 typedef struct ProjPaintImage {
195         Image *ima;
196         ImBuf *ibuf;
197         ImagePaintPartialRedraw *partRedrawRect;
198         volatile void **undoRect; /* only used to build undo tiles during painting */
199         unsigned short **maskRect; /* the mask accumulation must happen on canvas, not on space screen bucket.
200                                     * Here we store the mask rectangle */
201         bool **valid; /* store flag to enforce validation of undo rectangle */
202         bool touch;
203 } ProjPaintImage;
204
205 /**
206  * Handle for stroke (operator customdata)
207  */
208 typedef struct ProjStrokeHandle {
209         /* Support for painting from multiple views at once,
210          * currently used to implement symmetry painting,
211          * we can assume at least the first is set while painting. */
212         struct ProjPaintState *ps_views[8];
213         int ps_views_tot;
214         int symmetry_flags;
215
216         int orig_brush_size;
217
218         bool need_redraw;
219
220         /* trick to bypass regular paint and allow clone picking */
221         bool is_clone_cursor_pick;
222
223         /* In ProjPaintState, only here for convenience */
224         Scene *scene;
225         Brush *brush;
226 } ProjStrokeHandle;
227
228 /* Main projection painting struct passed to all projection painting functions */
229 typedef struct ProjPaintState {
230         View3D *v3d;
231         RegionView3D *rv3d;
232         ARegion *ar;
233         Depsgraph *depsgraph;
234         Scene *scene;
235         int source; /* PROJ_SRC_**** */
236
237         /* the paint color. It can change depending of inverted mode or not */
238         float paint_color[3];
239         float paint_color_linear[3];
240         float dither;
241
242         Brush *brush;
243         short tool, blend, mode;
244
245         float brush_size;
246         Object *ob;
247         /* for symmetry, we need to store modified object matrix */
248         float obmat[4][4];
249         float obmat_imat[4][4];
250         /* end similarities with ImagePaintState */
251
252         Image *stencil_ima;
253         Image *canvas_ima;
254         Image *clone_ima;
255         float stencil_value;
256
257         /* projection painting only */
258         MemArena *arena_mt[BLENDER_MAX_THREADS]; /* for multithreading, the first item is sometimes used for non threaded cases too */
259         LinkNode **bucketRect;              /* screen sized 2D array, each pixel has a linked list of ProjPixel's */
260         LinkNode **bucketFaces;             /* bucketRect aligned array linkList of faces overlapping each bucket */
261         unsigned char *bucketFlags;         /* store if the bucks have been initialized  */
262
263         char *vertFlags;                    /* store options per vert, now only store if the vert is pointing away from the view */
264         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 */
265         int buckets_y;
266
267         int pixel_sizeof;           /* result of project_paint_pixel_sizeof(), constant per stroke */
268
269         int image_tot;              /* size of projectImages array */
270
271         float (*screenCoords)[4];   /* verts projected into floating point screen space */
272         float screenMin[2];         /* 2D bounds for mesh verts on the screen's plane (screenspace) */
273         float screenMax[2];
274         float screen_width;         /* Calculated from screenMin & screenMax */
275         float screen_height;
276         int winx, winy;             /* from the carea or from the projection render */
277
278         /* options for projection painting */
279         bool  do_layer_clone;
280         bool  do_layer_stencil;
281         bool  do_layer_stencil_inv;
282         bool  do_stencil_brush;
283         bool  do_material_slots;
284
285         bool  do_occlude;               /* Use raytraced occlusion? - ortherwise will paint right through to the back*/
286         bool  do_backfacecull;          /* ignore faces with normals pointing away, skips a lot of raycasts if your normals are correctly flipped */
287         bool  do_mask_normal;           /* mask out pixels based on their normals */
288         bool  do_mask_cavity;           /* mask out pixels based on cavity */
289         float normal_angle;             /* what angle to mask at */
290         float normal_angle__cos;         /* cos(normal_angle), faster to compare */
291         float normal_angle_inner;
292         float normal_angle_inner__cos;
293         float normal_angle_range;       /* difference between normal_angle and normal_angle_inner, for easy access */
294
295         bool do_face_sel;               /* quick access to (me->editflag & ME_EDIT_PAINT_FACE_SEL) */
296         bool is_ortho;
297         bool is_flip_object;            /* the object is negative scaled */
298         bool do_masking;              /* use masking during painting. Some operations such as airbrush may disable */
299         bool is_texbrush;              /* only to avoid running  */
300         bool is_maskbrush;            /* mask brush is applied before masking */
301 #ifndef PROJ_DEBUG_NOSEAMBLEED
302         float seam_bleed_px;
303 #endif
304         /* clone vars */
305         float cloneOffset[2];
306
307         float projectMat[4][4];     /* Projection matrix, use for getting screen coords */
308         float projectMatInv[4][4];  /* inverse of projectMat */
309         float viewDir[3];           /* View vector, use for do_backfacecull and for ray casting with an ortho viewport  */
310         float viewPos[3];           /* View location in object relative 3D space, so can compare to verts  */
311         float clipsta, clipend;
312
313         /* reproject vars */
314         Image *reproject_image;
315         ImBuf *reproject_ibuf;
316         bool   reproject_ibuf_free_float;
317         bool   reproject_ibuf_free_uchar;
318
319         /* threads */
320         int thread_tot;
321         int bucketMin[2];
322         int bucketMax[2];
323         int context_bucket_x, context_bucket_y; /* must lock threads while accessing these */
324
325         struct CurveMapping *cavity_curve;
326         BlurKernel *blurkernel;
327
328
329
330         /* -------------------------------------------------------------------- */
331         /* Vars shared between multiple views (keep last) */
332         /**
333          * This data is owned by ``ProjStrokeHandle.ps_views[0]``,
334          * all other views re-use the data.
335          */
336
337 #define PROJ_PAINT_STATE_SHARED_MEMCPY(ps_dst, ps_src) \
338         MEMCPY_STRUCT_OFS(ps_dst, ps_src, is_shared_user)
339
340 #define PROJ_PAINT_STATE_SHARED_CLEAR(ps) \
341         MEMSET_STRUCT_OFS(ps, 0, is_shared_user)
342
343         bool is_shared_user;
344
345         ProjPaintImage *projImages;
346         float *cavities;            /* cavity amount for vertices */
347
348 #ifndef PROJ_DEBUG_NOSEAMBLEED
349         char *faceSeamFlags;                /* store info about faces, if they are initialized etc*/
350         char *faceWindingFlags;             /* save the winding of the face in uv space, helps as an extra validation step for seam detection */
351         float (*faceSeamUVs)[3][2];         /* expanded UVs for faces to use as seams */
352         LinkNode **vertFaces;               /* Only needed for when seam_bleed_px is enabled, use to find UV seams */
353 #endif
354
355         SpinLock *tile_lock;
356
357         DerivedMesh    *dm;
358         int  dm_totlooptri;
359         int  dm_totpoly;
360         int  dm_totedge;
361         int  dm_totvert;
362         bool dm_release;
363
364         const MVert    *dm_mvert;
365         const MEdge    *dm_medge;
366         const MPoly    *dm_mpoly;
367         const MLoop    *dm_mloop;
368         const MLoopTri *dm_mlooptri;
369
370         const MLoopUV  *dm_mloopuv_stencil;
371
372         /**
373          * \note These UV layers are aligned to \a dm_mpoly
374          * but each pointer references the start of the layer,
375          * so a loop indirection is needed as well.
376          */
377         const MLoopUV **dm_mloopuv;
378         const MLoopUV **dm_mloopuv_clone;    /* other UV map, use for cloning between layers */
379
380         bool use_colormanagement;
381 } ProjPaintState;
382
383 typedef union pixelPointer {
384         float *f_pt;            /* float buffer */
385         unsigned int *uint_pt; /* 2 ways to access a char buffer */
386         unsigned char *ch_pt;
387 } PixelPointer;
388
389 typedef union pixelStore {
390         unsigned char ch[4];
391         unsigned int uint;
392         float f[4];
393 } PixelStore;
394
395 typedef struct ProjPixel {
396         float projCoSS[2]; /* the floating point screen projection of this pixel */
397         float worldCoSS[3];
398
399         short x_px, y_px;
400
401         unsigned short image_index; /* if anyone wants to paint onto more than 65535 images they can bite me */
402         unsigned char bb_cell_index;
403
404         /* for various reasons we may want to mask out painting onto this pixel */
405         unsigned short mask;
406
407         /* Only used when the airbrush is disabled.
408          * Store the max mask value to avoid painting over an area with a lower opacity
409          * with an advantage that we can avoid touching the pixel at all, if the
410          * new mask value is lower then mask_accum */
411         unsigned short *mask_accum;
412
413         /* horrible hack, store tile valid flag pointer here to re-validate tiles used for anchored and drag-dot strokes */
414         bool *valid;
415
416         PixelPointer origColor;
417         PixelStore newColor;
418         PixelPointer pixel;
419 } ProjPixel;
420
421 typedef struct ProjPixelClone {
422         struct ProjPixel __pp;
423         PixelStore clonepx;
424 } ProjPixelClone;
425
426 /* undo tile pushing */
427 typedef struct {
428         SpinLock *lock;
429         bool masked;
430         unsigned short tile_width;
431         ImBuf **tmpibuf;
432         ProjPaintImage *pjima;
433 } TileInfo;
434
435
436
437 /* -------------------------------------------------------------------- */
438
439 /** \name MLoopTri accessor functions.
440  * \{ */
441
442 BLI_INLINE const MPoly *ps_tri_index_to_mpoly(const ProjPaintState *ps, int tri_index)
443 {
444         return &ps->dm_mpoly[ps->dm_mlooptri[tri_index].poly];
445 }
446
447 #define PS_LOOPTRI_AS_VERT_INDEX_3(ps, lt) \
448         ps->dm_mloop[lt->tri[0]].v, \
449         ps->dm_mloop[lt->tri[1]].v, \
450         ps->dm_mloop[lt->tri[2]].v,
451
452 #define PS_LOOPTRI_AS_UV_3(uvlayer, lt) \
453         uvlayer[lt->poly][lt->tri[0]].uv, \
454         uvlayer[lt->poly][lt->tri[1]].uv, \
455         uvlayer[lt->poly][lt->tri[2]].uv,
456
457 #define PS_LOOPTRI_ASSIGN_UV_3(uv_tri, uvlayer, lt)  { \
458         (uv_tri)[0] = uvlayer[lt->poly][lt->tri[0]].uv; \
459         (uv_tri)[1] = uvlayer[lt->poly][lt->tri[1]].uv; \
460         (uv_tri)[2] = uvlayer[lt->poly][lt->tri[2]].uv; \
461 } ((void)0)
462
463 /** \} */
464
465
466
467 /* Finish projection painting structs */
468
469 static TexPaintSlot *project_paint_face_paint_slot(const ProjPaintState *ps, int tri_index)
470 {
471         const MPoly *mp = ps_tri_index_to_mpoly(ps, tri_index);
472         Material *ma = ps->dm->mat[mp->mat_nr];
473         return ma ? ma->texpaintslot + ma->paint_active_slot : NULL;
474 }
475
476 static Image *project_paint_face_paint_image(const ProjPaintState *ps, int tri_index)
477 {
478         if (ps->do_stencil_brush) {
479                 return ps->stencil_ima;
480         }
481         else {
482                 const MPoly *mp = ps_tri_index_to_mpoly(ps, tri_index);
483                 Material *ma = ps->dm->mat[mp->mat_nr];
484                 TexPaintSlot *slot = ma ? ma->texpaintslot + ma->paint_active_slot : NULL;
485                 return slot ? slot->ima : ps->canvas_ima;
486         }
487 }
488
489 static TexPaintSlot *project_paint_face_clone_slot(const ProjPaintState *ps, int tri_index)
490 {
491         const MPoly *mp = ps_tri_index_to_mpoly(ps, tri_index);
492         Material *ma = ps->dm->mat[mp->mat_nr];
493         return ma ? ma->texpaintslot + ma->paint_clone_slot : NULL;
494 }
495
496 static Image *project_paint_face_clone_image(const ProjPaintState *ps, int tri_index)
497 {
498         const MPoly *mp = ps_tri_index_to_mpoly(ps, tri_index);
499         Material *ma = ps->dm->mat[mp->mat_nr];
500         TexPaintSlot *slot = ma ? ma->texpaintslot + ma->paint_clone_slot : NULL;
501         return slot ? slot->ima : ps->clone_ima;
502 }
503
504 /* fast projection bucket array lookup, use the safe version for bound checking  */
505 static int project_bucket_offset(const ProjPaintState *ps, const float projCoSS[2])
506 {
507         /* If we were not dealing with screenspace 2D coords we could simple do...
508          * ps->bucketRect[x + (y*ps->buckets_y)] */
509
510         /* please explain?
511          * projCoSS[0] - ps->screenMin[0]   : zero origin
512          * ... / ps->screen_width           : range from 0.0 to 1.0
513          * ... * ps->buckets_x              : use as a bucket index
514          *
515          * Second multiplication does similar but for vertical offset
516          */
517         return ( (int)(((projCoSS[0] - ps->screenMin[0]) / ps->screen_width)  * ps->buckets_x)) +
518                (((int)(((projCoSS[1] - ps->screenMin[1]) / ps->screen_height) * ps->buckets_y)) * ps->buckets_x);
519 }
520
521 static int project_bucket_offset_safe(const ProjPaintState *ps, const float projCoSS[2])
522 {
523         int bucket_index = project_bucket_offset(ps, projCoSS);
524
525         if (bucket_index < 0 || bucket_index >= ps->buckets_x * ps->buckets_y) {
526                 return -1;
527         }
528         else {
529                 return bucket_index;
530         }
531 }
532
533 static float VecZDepthOrtho(
534         const float pt[2],
535         const float v1[3], const float v2[3], const float v3[3],
536         float w[3])
537 {
538         barycentric_weights_v2(v1, v2, v3, pt, w);
539         return (v1[2] * w[0]) + (v2[2] * w[1]) + (v3[2] * w[2]);
540 }
541
542 static float VecZDepthPersp(
543         const float pt[2],
544         const float v1[4], const float v2[4], const float v3[4],
545         float w[3])
546 {
547         float wtot_inv, wtot;
548         float w_tmp[3];
549
550         barycentric_weights_v2_persp(v1, v2, v3, pt, w);
551         /* for the depth we need the weights to match what
552          * barycentric_weights_v2 would return, in this case its easiest just to
553          * undo the 4th axis division and make it unit-sum
554          *
555          * don't call barycentric_weights_v2() because our callers expect 'w'
556          * to be weighted from the perspective */
557         w_tmp[0] = w[0] * v1[3];
558         w_tmp[1] = w[1] * v2[3];
559         w_tmp[2] = w[2] * v3[3];
560
561         wtot = w_tmp[0] + w_tmp[1] + w_tmp[2];
562
563         if (wtot != 0.0f) {
564                 wtot_inv = 1.0f / wtot;
565
566                 w_tmp[0] = w_tmp[0] * wtot_inv;
567                 w_tmp[1] = w_tmp[1] * wtot_inv;
568                 w_tmp[2] = w_tmp[2] * wtot_inv;
569         }
570         else /* dummy values for zero area face */
571                 w_tmp[0] = w_tmp[1] = w_tmp[2] = 1.0f / 3.0f;
572         /* done mimicing barycentric_weights_v2() */
573
574         return (v1[2] * w_tmp[0]) + (v2[2] * w_tmp[1]) + (v3[2] * w_tmp[2]);
575 }
576
577
578 /* Return the top-most face index that the screen space coord 'pt' touches (or -1) */
579 static int project_paint_PickFace(
580         const ProjPaintState *ps, const float pt[2],
581         float w[3])
582 {
583         LinkNode *node;
584         float w_tmp[3];
585         int bucket_index;
586         int best_tri_index = -1;
587         float z_depth_best = FLT_MAX, z_depth;
588
589         bucket_index = project_bucket_offset_safe(ps, pt);
590         if (bucket_index == -1)
591                 return -1;
592
593
594
595         /* we could return 0 for 1 face buckets, as long as this function assumes
596          * that the point its testing is only every originated from an existing face */
597
598         for (node = ps->bucketFaces[bucket_index]; node; node = node->next) {
599                 const int tri_index = GET_INT_FROM_POINTER(node->link);
600                 const MLoopTri *lt = &ps->dm_mlooptri[tri_index];
601                 const float *vtri_ss[3] = {
602                     ps->screenCoords[ps->dm_mloop[lt->tri[0]].v],
603                     ps->screenCoords[ps->dm_mloop[lt->tri[1]].v],
604                     ps->screenCoords[ps->dm_mloop[lt->tri[2]].v],
605                 };
606
607
608                 if (isect_point_tri_v2(pt, UNPACK3(vtri_ss))) {
609                         if (ps->is_ortho) {
610                                 z_depth = VecZDepthOrtho(pt, UNPACK3(vtri_ss), w_tmp);
611                         }
612                         else {
613                                 z_depth = VecZDepthPersp(pt, UNPACK3(vtri_ss), w_tmp);
614                         }
615
616                         if (z_depth < z_depth_best) {
617                                 best_tri_index = tri_index;
618                                 z_depth_best = z_depth;
619                                 copy_v3_v3(w, w_tmp);
620                         }
621                 }
622         }
623
624         return best_tri_index; /* will be -1 or a valid face */
625 }
626
627 /* Converts a uv coord into a pixel location wrapping if the uv is outside 0-1 range */
628 static void uvco_to_wrapped_pxco(const float uv[2], int ibuf_x, int ibuf_y, float *x, float *y)
629 {
630         /* use */
631         *x = fmodf(uv[0], 1.0f);
632         *y = fmodf(uv[1], 1.0f);
633
634         if (*x < 0.0f) *x += 1.0f;
635         if (*y < 0.0f) *y += 1.0f;
636
637         *x = *x * ibuf_x - 0.5f;
638         *y = *y * ibuf_y - 0.5f;
639 }
640
641 /* Set the top-most face color that the screen space coord 'pt' touches (or return 0 if none touch) */
642 static bool project_paint_PickColor(
643         const ProjPaintState *ps, const float pt[2],
644         float *rgba_fp, unsigned char *rgba, const bool interp)
645 {
646         const MLoopTri *lt;
647         const float *lt_tri_uv[3];
648         float w[3], uv[2];
649         int tri_index;
650         Image *ima;
651         ImBuf *ibuf;
652         int xi, yi;
653
654         tri_index = project_paint_PickFace(ps, pt, w);
655
656         if (tri_index == -1)
657                 return 0;
658
659         lt = &ps->dm_mlooptri[tri_index];
660         PS_LOOPTRI_ASSIGN_UV_3(lt_tri_uv, ps->dm_mloopuv, lt);
661
662         interp_v2_v2v2v2(uv, UNPACK3(lt_tri_uv), w);
663
664         ima = project_paint_face_paint_image(ps, tri_index);
665         ibuf = BKE_image_get_first_ibuf(ima); /* we must have got the imbuf before getting here */
666         if (!ibuf) return 0;
667
668         if (interp) {
669                 float x, y;
670                 uvco_to_wrapped_pxco(uv, ibuf->x, ibuf->y, &x, &y);
671
672                 if (ibuf->rect_float) {
673                         if (rgba_fp) {
674                                 bilinear_interpolation_color_wrap(ibuf, NULL, rgba_fp, x, y);
675                         }
676                         else {
677                                 float rgba_tmp_f[4];
678                                 bilinear_interpolation_color_wrap(ibuf, NULL, rgba_tmp_f, x, y);
679                                 premul_float_to_straight_uchar(rgba, rgba_tmp_f);
680                         }
681                 }
682                 else {
683                         if (rgba) {
684                                 bilinear_interpolation_color_wrap(ibuf, rgba, NULL, x, y);
685                         }
686                         else {
687                                 unsigned char rgba_tmp[4];
688                                 bilinear_interpolation_color_wrap(ibuf, rgba_tmp, NULL, x, y);
689                                 straight_uchar_to_premul_float(rgba_fp, rgba_tmp);
690                         }
691                 }
692         }
693         else {
694                 //xi = (int)((uv[0]*ibuf->x) + 0.5f);
695                 //yi = (int)((uv[1]*ibuf->y) + 0.5f);
696                 //if (xi < 0 || xi >= ibuf->x  ||  yi < 0 || yi >= ibuf->y) return 0;
697
698                 /* wrap */
699                 xi = mod_i((int)(uv[0] * ibuf->x), ibuf->x);
700                 yi = mod_i((int)(uv[1] * ibuf->y), ibuf->y);
701
702                 if (rgba) {
703                         if (ibuf->rect_float) {
704                                 const float *rgba_tmp_fp = ibuf->rect_float + (xi + yi * ibuf->x * 4);
705                                 premul_float_to_straight_uchar(rgba, rgba_tmp_fp);
706                         }
707                         else {
708                                 *((unsigned int *)rgba) = *(unsigned int *)(((char *)ibuf->rect) + ((xi + yi * ibuf->x) * 4));
709                         }
710                 }
711
712                 if (rgba_fp) {
713                         if (ibuf->rect_float) {
714                                 copy_v4_v4(rgba_fp, (ibuf->rect_float + ((xi + yi * ibuf->x) * 4)));
715                         }
716                         else {
717                                 unsigned char *tmp_ch = ((unsigned char *)ibuf->rect) + ((xi + yi * ibuf->x) * 4);
718                                 straight_uchar_to_premul_float(rgba_fp, tmp_ch);
719                         }
720                 }
721         }
722         BKE_image_release_ibuf(ima, ibuf, NULL);
723         return 1;
724 }
725
726 /**
727  * Check if 'pt' is infront of the 3 verts on the Z axis (used for screenspace occlusion test)
728  * \return
729  * -  `0`:   no occlusion
730  * - `-1`: no occlusion but 2D intersection is true
731  * -  `1`: occluded
732  * -  `2`: occluded with `w[3]` weights set (need to know in some cases)
733  */
734 static int project_paint_occlude_ptv(
735         const float pt[3],
736         const float v1[4], const float v2[4], const float v3[4],
737         float w[3], const bool is_ortho)
738 {
739         /* if all are behind us, return false */
740         if (v1[2] > pt[2] && v2[2] > pt[2] && v3[2] > pt[2])
741                 return 0;
742
743         /* do a 2D point in try intersection */
744         if (!isect_point_tri_v2(pt, v1, v2, v3))
745                 return 0;  /* we know there is  */
746
747
748         /* From here on we know there IS an intersection */
749         /* if ALL of the verts are infront of us then we know it intersects ? */
750         if (v1[2] < pt[2] && v2[2] < pt[2] && v3[2] < pt[2]) {
751                 return 1;
752         }
753         else {
754                 /* we intersect? - find the exact depth at the point of intersection */
755                 /* Is this point is occluded by another face? */
756                 if (is_ortho) {
757                         if (VecZDepthOrtho(pt, v1, v2, v3, w) < pt[2]) return 2;
758                 }
759                 else {
760                         if (VecZDepthPersp(pt, v1, v2, v3, w) < pt[2]) return 2;
761                 }
762         }
763         return -1;
764 }
765
766
767 static int project_paint_occlude_ptv_clip(
768         const float pt[3],
769         const float v1[4], const float v2[4], const float v3[4],
770         const float v1_3d[3], const float v2_3d[3], const float v3_3d[3],
771         float w[3], const bool is_ortho, RegionView3D *rv3d)
772 {
773         float wco[3];
774         int ret = project_paint_occlude_ptv(pt, v1, v2, v3, w, is_ortho);
775
776         if (ret <= 0)
777                 return ret;
778
779         if (ret == 1) { /* weights not calculated */
780                 if (is_ortho) {
781                         barycentric_weights_v2(v1, v2, v3, pt, w);
782                 }
783                 else {
784                         barycentric_weights_v2_persp(v1, v2, v3, pt, w);
785                 }
786         }
787
788         /* Test if we're in the clipped area, */
789         interp_v3_v3v3v3(wco, v1_3d, v2_3d, v3_3d, w);
790
791         if (!ED_view3d_clipping_test(rv3d, wco, true)) {
792                 return 1;
793         }
794
795         return -1;
796 }
797
798
799 /* Check if a screenspace location is occluded by any other faces
800  * check, pixelScreenCo must be in screenspace, its Z-Depth only needs to be used for comparison
801  * and doesn't need to be correct in relation to X and Y coords (this is the case in perspective view) */
802 static bool project_bucket_point_occluded(
803         const ProjPaintState *ps, LinkNode *bucketFace,
804         const int orig_face, const float pixelScreenCo[4])
805 {
806         int isect_ret;
807         const bool do_clip = ps->rv3d ? (ps->rv3d->rflag & RV3D_CLIPPING) != 0 : 0;
808
809         /* we could return 0 for 1 face buckets, as long as this function assumes
810          * that the point its testing is only every originated from an existing face */
811
812         for (; bucketFace; bucketFace = bucketFace->next) {
813                 const int tri_index = GET_INT_FROM_POINTER(bucketFace->link);
814
815                 if (orig_face != tri_index) {
816                         const MLoopTri *lt = &ps->dm_mlooptri[tri_index];
817                         const float *vtri_ss[3] = {
818                             ps->screenCoords[ps->dm_mloop[lt->tri[0]].v],
819                             ps->screenCoords[ps->dm_mloop[lt->tri[1]].v],
820                             ps->screenCoords[ps->dm_mloop[lt->tri[2]].v],
821                         };
822                         float w[3];
823
824                         if (do_clip) {
825                                 const float *vtri_co[3] = {
826                                     ps->dm_mvert[ps->dm_mloop[lt->tri[0]].v].co,
827                                     ps->dm_mvert[ps->dm_mloop[lt->tri[1]].v].co,
828                                     ps->dm_mvert[ps->dm_mloop[lt->tri[2]].v].co,
829                                 };
830                                 isect_ret = project_paint_occlude_ptv_clip(
831                                         pixelScreenCo, UNPACK3(vtri_ss), UNPACK3(vtri_co),
832                                         w, ps->is_ortho, ps->rv3d);
833                         }
834                         else {
835                                 isect_ret = project_paint_occlude_ptv(
836                                         pixelScreenCo, UNPACK3(vtri_ss),
837                                         w, ps->is_ortho);
838                         }
839
840                         if (isect_ret >= 1) {
841                                 /* TODO - we may want to cache the first hit,
842                                  * it is not possible to swap the face order in the list anymore */
843                                 return true;
844                         }
845                 }
846         }
847         return false;
848 }
849
850 /* basic line intersection, could move to math_geom.c, 2 points with a horiz line
851  * 1 for an intersection, 2 if the first point is aligned, 3 if the second point is aligned */
852 #define ISECT_TRUE 1
853 #define ISECT_TRUE_P1 2
854 #define ISECT_TRUE_P2 3
855 static int line_isect_y(const float p1[2], const float p2[2], const float y_level, float *x_isect)
856 {
857         float y_diff;
858
859         if (y_level == p1[1]) { /* are we touching the first point? - no interpolation needed */
860                 *x_isect = p1[0];
861                 return ISECT_TRUE_P1;
862         }
863         if (y_level == p2[1]) { /* are we touching the second point? - no interpolation needed */
864                 *x_isect = p2[0];
865                 return ISECT_TRUE_P2;
866         }
867
868         y_diff = fabsf(p1[1] - p2[1]); /* yuck, horizontal line, we cant do much here */
869
870         if (y_diff < 0.000001f) {
871                 *x_isect = (p1[0] + p2[0]) * 0.5f;
872                 return ISECT_TRUE;
873         }
874
875         if (p1[1] > y_level && p2[1] < y_level) {
876                 *x_isect = (p2[0] * (p1[1] - y_level) + p1[0] * (y_level - p2[1])) / y_diff;  /* (p1[1] - p2[1]); */
877                 return ISECT_TRUE;
878         }
879         else if (p1[1] < y_level && p2[1] > y_level) {
880                 *x_isect = (p2[0] * (y_level - p1[1]) + p1[0] * (p2[1] - y_level)) / y_diff;  /* (p2[1] - p1[1]); */
881                 return ISECT_TRUE;
882         }
883         else {
884                 return 0;
885         }
886 }
887
888 static int line_isect_x(const float p1[2], const float p2[2], const float x_level, float *y_isect)
889 {
890         float x_diff;
891
892         if (x_level == p1[0]) { /* are we touching the first point? - no interpolation needed */
893                 *y_isect = p1[1];
894                 return ISECT_TRUE_P1;
895         }
896         if (x_level == p2[0]) { /* are we touching the second point? - no interpolation needed */
897                 *y_isect = p2[1];
898                 return ISECT_TRUE_P2;
899         }
900
901         x_diff = fabsf(p1[0] - p2[0]); /* yuck, horizontal line, we cant do much here */
902
903         if (x_diff < 0.000001f) { /* yuck, vertical line, we cant do much here */
904                 *y_isect = (p1[0] + p2[0]) * 0.5f;
905                 return ISECT_TRUE;
906         }
907
908         if (p1[0] > x_level && p2[0] < x_level) {
909                 *y_isect = (p2[1] * (p1[0] - x_level) + p1[1] * (x_level - p2[0])) / x_diff;  /* (p1[0] - p2[0]); */
910                 return ISECT_TRUE;
911         }
912         else if (p1[0] < x_level && p2[0] > x_level) {
913                 *y_isect = (p2[1] * (x_level - p1[0]) + p1[1] * (p2[0] - x_level)) / x_diff;  /* (p2[0] - p1[0]); */
914                 return ISECT_TRUE;
915         }
916         else {
917                 return 0;
918         }
919 }
920
921 /* simple func use for comparing UV locations to check if there are seams.
922  * Its possible this gives incorrect results, when the UVs for 1 face go into the next
923  * tile, but do not do this for the adjacent face, it could return a false positive.
924  * This is so unlikely that Id not worry about it. */
925 #ifndef PROJ_DEBUG_NOSEAMBLEED
926 static bool cmp_uv(const float vec2a[2], const float vec2b[2])
927 {
928         /* if the UV's are not between 0.0 and 1.0 */
929         float xa = fmodf(vec2a[0], 1.0f);
930         float ya = fmodf(vec2a[1], 1.0f);
931
932         float xb = fmodf(vec2b[0], 1.0f);
933         float yb = fmodf(vec2b[1], 1.0f);
934
935         if (xa < 0.0f) xa += 1.0f;
936         if (ya < 0.0f) ya += 1.0f;
937
938         if (xb < 0.0f) xb += 1.0f;
939         if (yb < 0.0f) yb += 1.0f;
940
941         return ((fabsf(xa - xb) < PROJ_GEOM_TOLERANCE) && (fabsf(ya - yb) < PROJ_GEOM_TOLERANCE)) ? 1 : 0;
942 }
943 #endif
944
945 /* set min_px and max_px to the image space bounds of the UV coords
946  * return zero if there is no area in the returned rectangle */
947 #ifndef PROJ_DEBUG_NOSEAMBLEED
948 static bool pixel_bounds_uv(
949         const float uv_quad[4][2],
950         rcti *bounds_px,
951         const int ibuf_x, const int ibuf_y
952         )
953 {
954         float min_uv[2], max_uv[2]; /* UV bounds */
955
956         INIT_MINMAX2(min_uv, max_uv);
957
958         minmax_v2v2_v2(min_uv, max_uv, uv_quad[0]);
959         minmax_v2v2_v2(min_uv, max_uv, uv_quad[1]);
960         minmax_v2v2_v2(min_uv, max_uv, uv_quad[2]);
961         minmax_v2v2_v2(min_uv, max_uv, uv_quad[3]);
962
963         bounds_px->xmin = (int)(ibuf_x * min_uv[0]);
964         bounds_px->ymin = (int)(ibuf_y * min_uv[1]);
965
966         bounds_px->xmax = (int)(ibuf_x * max_uv[0]) + 1;
967         bounds_px->ymax = (int)(ibuf_y * max_uv[1]) + 1;
968
969         /*printf("%d %d %d %d\n", min_px[0], min_px[1], max_px[0], max_px[1]);*/
970
971         /* face uses no UV area when quantized to pixels? */
972         return (bounds_px->xmin == bounds_px->xmax || bounds_px->ymin == bounds_px->ymax) ? 0 : 1;
973 }
974 #endif
975
976 static bool pixel_bounds_array(float (*uv)[2], rcti *bounds_px, const int ibuf_x, const int ibuf_y, int tot)
977 {
978         float min_uv[2], max_uv[2]; /* UV bounds */
979
980         if (tot == 0) {
981                 return 0;
982         }
983
984         INIT_MINMAX2(min_uv, max_uv);
985
986         while (tot--) {
987                 minmax_v2v2_v2(min_uv, max_uv, (*uv));
988                 uv++;
989         }
990
991         bounds_px->xmin = (int)(ibuf_x * min_uv[0]);
992         bounds_px->ymin = (int)(ibuf_y * min_uv[1]);
993
994         bounds_px->xmax = (int)(ibuf_x * max_uv[0]) + 1;
995         bounds_px->ymax = (int)(ibuf_y * max_uv[1]) + 1;
996
997         /*printf("%d %d %d %d\n", min_px[0], min_px[1], max_px[0], max_px[1]);*/
998
999         /* face uses no UV area when quantized to pixels? */
1000         return (bounds_px->xmin == bounds_px->xmax || bounds_px->ymin == bounds_px->ymax) ? 0 : 1;
1001 }
1002
1003 #ifndef PROJ_DEBUG_NOSEAMBLEED
1004
1005 static void project_face_winding_init(const ProjPaintState *ps, const int tri_index)
1006 {
1007         /* detect the winding of faces in uv space */
1008         const MLoopTri *lt = &ps->dm_mlooptri[tri_index];
1009         const float *lt_tri_uv[3] = { PS_LOOPTRI_AS_UV_3(ps->dm_mloopuv, lt) };
1010         float winding = cross_tri_v2(lt_tri_uv[0], lt_tri_uv[1], lt_tri_uv[2]);
1011
1012         if (winding > 0)
1013                 ps->faceWindingFlags[tri_index] |= PROJ_FACE_WINDING_CW;
1014
1015         ps->faceWindingFlags[tri_index] |= PROJ_FACE_WINDING_INIT;
1016 }
1017
1018 /* This function returns 1 if this face has a seam along the 2 face-vert indices
1019  * 'orig_i1_fidx' and 'orig_i2_fidx' */
1020 static bool check_seam(
1021         const ProjPaintState *ps,
1022         const int orig_face, const int orig_i1_fidx, const int orig_i2_fidx,
1023         int *other_face, int *orig_fidx)
1024 {
1025         const MLoopTri *orig_lt = &ps->dm_mlooptri[orig_face];
1026         const float *orig_lt_tri_uv[3] = { PS_LOOPTRI_AS_UV_3(ps->dm_mloopuv, orig_lt) };
1027         /* vert indices from face vert order indices */
1028         const unsigned int i1 = ps->dm_mloop[orig_lt->tri[orig_i1_fidx]].v;
1029         const unsigned int i2 = ps->dm_mloop[orig_lt->tri[orig_i2_fidx]].v;
1030         LinkNode *node;
1031         int i1_fidx = -1, i2_fidx = -1; /* index in face */
1032
1033         for (node = ps->vertFaces[i1]; node; node = node->next) {
1034                 const int tri_index = GET_INT_FROM_POINTER(node->link);
1035
1036                 if (tri_index != orig_face) {
1037                         const MLoopTri *lt = &ps->dm_mlooptri[tri_index];
1038                         const int lt_vtri[3] = { PS_LOOPTRI_AS_VERT_INDEX_3(ps, lt) };
1039                         /* could check if the 2 faces images match here,
1040                          * but then there wouldn't be a way to return the opposite face's info */
1041
1042
1043                         /* We need to know the order of the verts in the adjacent face
1044                          * set the i1_fidx and i2_fidx to (0,1,2,3) */
1045                         i1_fidx = BKE_MESH_TESSTRI_VINDEX_ORDER(lt_vtri, i1);
1046                         i2_fidx = BKE_MESH_TESSTRI_VINDEX_ORDER(lt_vtri, i2);
1047
1048                         /* Only need to check if 'i2_fidx' is valid because we know i1_fidx is the same vert on both faces */
1049                         if (i2_fidx != -1) {
1050                                 const float *lt_tri_uv[3] = { PS_LOOPTRI_AS_UV_3(ps->dm_mloopuv, lt) };
1051                                 Image *tpage = project_paint_face_paint_image(ps, tri_index);
1052                                 Image *orig_tpage = project_paint_face_paint_image(ps, orig_face);
1053
1054                                 BLI_assert(i1_fidx != -1);
1055
1056                                 /* This IS an adjacent face!, now lets check if the UVs are ok */
1057
1058                                 /* set up the other face */
1059                                 *other_face = tri_index;
1060
1061                                 /* we check if difference is 1 here, else we might have a case of edge 2-0 for a tri */
1062                                 *orig_fidx = (i1_fidx < i2_fidx && (i2_fidx - i1_fidx == 1)) ? i1_fidx : i2_fidx;
1063
1064                                 /* initialize face winding if needed */
1065                                 if ((ps->faceWindingFlags[tri_index] & PROJ_FACE_WINDING_INIT) == 0)
1066                                         project_face_winding_init(ps, tri_index);
1067
1068                                 /* first test if they have the same image */
1069                                 if ((orig_tpage == tpage) &&
1070                                     cmp_uv(orig_lt_tri_uv[orig_i1_fidx], lt_tri_uv[i1_fidx]) &&
1071                                     cmp_uv(orig_lt_tri_uv[orig_i2_fidx], lt_tri_uv[i2_fidx]))
1072                                 {
1073                                         /* if faces don't have the same winding in uv space,
1074                                          * they are on the same side so edge is boundary */
1075                                         if ((ps->faceWindingFlags[tri_index] & PROJ_FACE_WINDING_CW) !=
1076                                             (ps->faceWindingFlags[orig_face] & PROJ_FACE_WINDING_CW))
1077                                         {
1078                                                 return 1;
1079                                         }
1080
1081                                         // printf("SEAM (NONE)\n");
1082                                         return 0;
1083
1084                                 }
1085                                 else {
1086                                         // printf("SEAM (UV GAP)\n");
1087                                         return 1;
1088                                 }
1089                         }
1090                 }
1091         }
1092         // printf("SEAM (NO FACE)\n");
1093         *other_face = -1;
1094         return 1;
1095 }
1096
1097 #define SMALL_NUMBER  1.e-6f
1098 BLI_INLINE float shell_v2v2_normal_dir_to_dist(float n[2], float d[2])
1099 {
1100         const float angle_cos = (normalize_v2(n) < SMALL_NUMBER) ? fabsf(dot_v2v2(d, n)) : 0.0f;
1101         return (UNLIKELY(angle_cos < SMALL_NUMBER)) ? 1.0f : (1.0f / angle_cos);
1102 }
1103 #undef SMALL_NUMBER
1104
1105 /* Calculate outset UV's, this is not the same as simply scaling the UVs,
1106  * since the outset coords are a margin that keep an even distance from the original UV's,
1107  * note that the image aspect is taken into account */
1108 static void uv_image_outset(
1109         float (*orig_uv)[2], float (*outset_uv)[2], const float scaler,
1110         const int ibuf_x, const int ibuf_y, const bool cw)
1111 {
1112         /* disallow shell-thickness to outset extreme values,
1113          * otherwise near zero area UV's may extend thousands of pixels. */
1114         const float scale_clamp = 5.0f;
1115
1116         float a1, a2, a3;
1117         float puv[3][2]; /* pixelspace uv's */
1118         float no1[2], no2[2], no3[2]; /* normals */
1119         float dir1[2], dir2[2], dir3[2];
1120         float ibuf_inv[2];
1121
1122         ibuf_inv[0] = 1.0f / (float)ibuf_x;
1123         ibuf_inv[1] = 1.0f / (float)ibuf_y;
1124
1125         /* make UV's in pixel space so we can */
1126         puv[0][0] = orig_uv[0][0] * ibuf_x;
1127         puv[0][1] = orig_uv[0][1] * ibuf_y;
1128
1129         puv[1][0] = orig_uv[1][0] * ibuf_x;
1130         puv[1][1] = orig_uv[1][1] * ibuf_y;
1131
1132         puv[2][0] = orig_uv[2][0] * ibuf_x;
1133         puv[2][1] = orig_uv[2][1] * ibuf_y;
1134
1135         /* face edge directions */
1136         sub_v2_v2v2(dir1, puv[1], puv[0]);
1137         sub_v2_v2v2(dir2, puv[2], puv[1]);
1138         sub_v2_v2v2(dir3, puv[0], puv[2]);
1139         normalize_v2(dir1);
1140         normalize_v2(dir2);
1141         normalize_v2(dir3);
1142
1143         /* here we just use the orthonormality property (a1, a2) dot (a2, -a1) = 0
1144          * to get normals from the edge directions based on the winding */
1145         if (cw) {
1146                 no1[0] = -dir3[1] - dir1[1];
1147                 no1[1] =  dir3[0] + dir1[0];
1148                 no2[0] = -dir1[1] - dir2[1];
1149                 no2[1] =  dir1[0] + dir2[0];
1150                 no3[0] = -dir2[1] - dir3[1];
1151                 no3[1] =  dir2[0] + dir3[0];
1152         }
1153         else {
1154                 no1[0] =  dir3[1] + dir1[1];
1155                 no1[1] = -dir3[0] - dir1[0];
1156                 no2[0] =  dir1[1] + dir2[1];
1157                 no2[1] = -dir1[0] - dir2[0];
1158                 no3[0] =  dir2[1] + dir3[1];
1159                 no3[1] = -dir2[0] - dir3[0];
1160         }
1161
1162         a1 = shell_v2v2_normal_dir_to_dist(no1, dir3);
1163         a2 = shell_v2v2_normal_dir_to_dist(no2, dir1);
1164         a3 = shell_v2v2_normal_dir_to_dist(no3, dir2);
1165
1166         CLAMP_MAX(a1, scale_clamp);
1167         CLAMP_MAX(a2, scale_clamp);
1168         CLAMP_MAX(a3, scale_clamp);
1169
1170         mul_v2_fl(no1, a1 * scaler);
1171         mul_v2_fl(no2, a2 * scaler);
1172         mul_v2_fl(no3, a3 * scaler);
1173         add_v2_v2v2(outset_uv[0], puv[0], no1);
1174         add_v2_v2v2(outset_uv[1], puv[1], no2);
1175         add_v2_v2v2(outset_uv[2], puv[2], no3);
1176
1177         mul_v2_v2(outset_uv[0], ibuf_inv);
1178         mul_v2_v2(outset_uv[1], ibuf_inv);
1179         mul_v2_v2(outset_uv[2], ibuf_inv);
1180 }
1181
1182 /*
1183  * Be tricky with flags, first 4 bits are PROJ_FACE_SEAM1 to 4, last 4 bits are PROJ_FACE_NOSEAM1 to 4
1184  * 1<<i - where i is (0-3)
1185  *
1186  * If we're multithreadng, make sure threads are locked when this is called
1187  */
1188 static void project_face_seams_init(const ProjPaintState *ps, const int tri_index)
1189 {
1190         int other_face, other_fidx; /* vars for the other face, we also set its flag */
1191         int fidx1 = 2;
1192         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 */
1193
1194         /* initialize face winding if needed */
1195         if ((ps->faceWindingFlags[tri_index] & PROJ_FACE_WINDING_INIT) == 0)
1196                 project_face_winding_init(ps, tri_index);
1197
1198         do {
1199                 if ((ps->faceSeamFlags[tri_index] & (1 << fidx1 | 16 << fidx1)) == 0) {
1200                         if (check_seam(ps, tri_index, fidx1, fidx2, &other_face, &other_fidx)) {
1201                                 ps->faceSeamFlags[tri_index] |= 1 << fidx1;
1202                                 if (other_face != -1)
1203                                         ps->faceSeamFlags[other_face] |= 1 << other_fidx;
1204                         }
1205                         else {
1206                                 ps->faceSeamFlags[tri_index] |= 16 << fidx1;
1207                                 if (other_face != -1)
1208                                         ps->faceSeamFlags[other_face] |= 16 << other_fidx;  /* second 4 bits for disabled */
1209                         }
1210                 }
1211
1212                 fidx2 = fidx1;
1213         } while (fidx1--);
1214 }
1215 #endif // PROJ_DEBUG_NOSEAMBLEED
1216
1217
1218 /* Converts a UV location to a 3D screenspace location
1219  * Takes a 'uv' and 3 UV coords, and sets the values of pixelScreenCo
1220  *
1221  * This is used for finding a pixels location in screenspace for painting */
1222 static void screen_px_from_ortho(
1223         const float uv[2],
1224         const float v1co[3], const float v2co[3], const float v3co[3],  /* Screenspace coords */
1225         const float uv1co[2], const float uv2co[2], const float uv3co[2],
1226         float pixelScreenCo[4],
1227         float w[3])
1228 {
1229         barycentric_weights_v2(uv1co, uv2co, uv3co, uv, w);
1230         interp_v3_v3v3v3(pixelScreenCo, v1co, v2co, v3co, w);
1231 }
1232
1233 /* same as screen_px_from_ortho except we
1234  * do perspective correction on the pixel coordinate */
1235 static void screen_px_from_persp(
1236         const float uv[2],
1237         const float v1co[4], const float v2co[4], const float v3co[4],  /* screenspace coords */
1238         const float uv1co[2], const float uv2co[2], const float uv3co[2],
1239         float pixelScreenCo[4],
1240         float w[3])
1241 {
1242         float w_int[3];
1243         float wtot_inv, wtot;
1244         barycentric_weights_v2(uv1co, uv2co, uv3co, uv, w);
1245
1246         /* re-weight from the 4th coord of each screen vert */
1247         w_int[0] = w[0] * v1co[3];
1248         w_int[1] = w[1] * v2co[3];
1249         w_int[2] = w[2] * v3co[3];
1250
1251         wtot = w_int[0] + w_int[1] + w_int[2];
1252
1253         if (wtot > 0.0f) {
1254                 wtot_inv = 1.0f / wtot;
1255                 w_int[0] *= wtot_inv;
1256                 w_int[1] *= wtot_inv;
1257                 w_int[2] *= wtot_inv;
1258         }
1259         else {
1260                 w[0] = w[1] = w[2] =
1261                 w_int[0] = w_int[1] = w_int[2] = 1.0f / 3.0f;  /* dummy values for zero area face */
1262         }
1263         /* done re-weighting */
1264
1265         /* do interpolation based on projected weight */
1266         interp_v3_v3v3v3(pixelScreenCo, v1co, v2co, v3co, w_int);
1267 }
1268
1269
1270 /**
1271  * Set a direction vector based on a screen location.
1272  * (use for perspective view, else we can simply use `ps->viewDir`)
1273  *
1274  * Similar functionality to #ED_view3d_win_to_vector
1275  *
1276  * \param r_dir: Resulting direction (length is undefined).
1277  */
1278 static void screen_px_to_vector_persp(
1279         int winx, int winy, const float projmat_inv[4][4], const float view_pos[3],
1280         const float co_px[2],
1281         float r_dir[3])
1282 {
1283         r_dir[0] = 2.0f * (co_px[0] / winx) - 1.0f;
1284         r_dir[1] = 2.0f * (co_px[1] / winy) - 1.0f;
1285         r_dir[2] = -0.5f;
1286         mul_project_m4_v3((float(*)[4])projmat_inv, r_dir);
1287         sub_v3_v3(r_dir, view_pos);
1288 }
1289
1290 /**
1291  * Special function to return the factor to a point along a line in pixel space.
1292  *
1293  * This is needed since we can't use #line_point_factor_v2 for perspective screen-space coords.
1294  *
1295  * \param p: 2D screen-space location.
1296  * \param v1, v2: 3D object-space locations.
1297  */
1298 static float screen_px_line_point_factor_v2_persp(
1299         const ProjPaintState *ps,
1300         const float p[2],
1301         const float v1[3], const float v2[3])
1302 {
1303         const float zero[3] = {0};
1304         float v1_proj[3], v2_proj[3];
1305         float dir[3];
1306
1307         screen_px_to_vector_persp(ps->winx, ps->winy, ps->projectMatInv, ps->viewPos, p, dir);
1308
1309         sub_v3_v3v3(v1_proj, v1, ps->viewPos);
1310         sub_v3_v3v3(v2_proj, v2, ps->viewPos);
1311
1312         project_plane_v3_v3v3(v1_proj, v1_proj, dir);
1313         project_plane_v3_v3v3(v2_proj, v2_proj, dir);
1314
1315         return line_point_factor_v2(zero, v1_proj, v2_proj);
1316 }
1317
1318
1319 static void project_face_pixel(
1320         const float *lt_tri_uv[3], ImBuf *ibuf_other, const float w[3],
1321         unsigned char rgba_ub[4], float rgba_f[4])
1322 {
1323         float uv_other[2], x, y;
1324
1325         interp_v2_v2v2v2(uv_other, UNPACK3(lt_tri_uv), w);
1326
1327         /* use */
1328         uvco_to_wrapped_pxco(uv_other, ibuf_other->x, ibuf_other->y, &x, &y);
1329
1330         if (ibuf_other->rect_float) { /* from float to float */
1331                 bilinear_interpolation_color_wrap(ibuf_other, NULL, rgba_f, x, y);
1332         }
1333         else { /* from char to float */
1334                 bilinear_interpolation_color_wrap(ibuf_other, rgba_ub, NULL, x, y);
1335         }
1336
1337 }
1338
1339 /* run this outside project_paint_uvpixel_init since pixels with mask 0 don't need init */
1340 static float project_paint_uvpixel_mask(
1341         const ProjPaintState *ps,
1342         const int tri_index,
1343         const float w[3])
1344 {
1345         float mask;
1346
1347         /* Image Mask */
1348         if (ps->do_layer_stencil) {
1349                 /* another UV maps image is masking this one's */
1350                 ImBuf *ibuf_other;
1351                 Image *other_tpage = ps->stencil_ima;
1352
1353                 if (other_tpage && (ibuf_other = BKE_image_acquire_ibuf(other_tpage, NULL, NULL))) {
1354                         const MLoopTri *lt_other = &ps->dm_mlooptri[tri_index];
1355                         const float *lt_other_tri_uv[3] = { PS_LOOPTRI_AS_UV_3(ps->dm_mloopuv, lt_other) };
1356
1357                         /* BKE_image_acquire_ibuf - TODO - this may be slow */
1358                         unsigned char rgba_ub[4];
1359                         float rgba_f[4];
1360
1361                         project_face_pixel(lt_other_tri_uv, ibuf_other, w, rgba_ub, rgba_f);
1362
1363                         if (ibuf_other->rect_float) { /* from float to float */
1364                                 mask = ((rgba_f[0] + rgba_f[1] + rgba_f[2]) * (1.0f / 3.0f)) * rgba_f[3];
1365                         }
1366                         else { /* from char to float */
1367                                 mask = ((rgba_ub[0] + rgba_ub[1] + rgba_ub[2]) * (1.0f / (255.0f * 3.0f))) * (rgba_ub[3] * (1.0f / 255.0f));
1368                         }
1369
1370                         BKE_image_release_ibuf(other_tpage, ibuf_other, NULL);
1371
1372                         if (!ps->do_layer_stencil_inv) /* matching the gimps layer mask black/white rules, white==full opacity */
1373                                 mask = (1.0f - mask);
1374
1375                         if (mask == 0.0f) {
1376                                 return 0.0f;
1377                         }
1378                 }
1379                 else {
1380                         return 0.0f;
1381                 }
1382         }
1383         else {
1384                 mask = 1.0f;
1385         }
1386
1387         if (ps->do_mask_cavity) {
1388                 const MLoopTri *lt = &ps->dm_mlooptri[tri_index];
1389                 const int lt_vtri[3] = { PS_LOOPTRI_AS_VERT_INDEX_3(ps, lt) };
1390                 float ca1, ca2, ca3, ca_mask;
1391                 ca1 = ps->cavities[lt_vtri[0]];
1392                 ca2 = ps->cavities[lt_vtri[1]];
1393                 ca3 = ps->cavities[lt_vtri[2]];
1394
1395                 ca_mask = w[0] * ca1 + w[1] * ca2 + w[2] * ca3;
1396                 ca_mask = curvemapping_evaluateF(ps->cavity_curve, 0, ca_mask);
1397                 CLAMP(ca_mask, 0.0f, 1.0f);
1398                 mask *= ca_mask;
1399         }
1400
1401         /* calculate mask */
1402         if (ps->do_mask_normal) {
1403                 const MLoopTri *lt = &ps->dm_mlooptri[tri_index];
1404                 const int lt_vtri[3] = { PS_LOOPTRI_AS_VERT_INDEX_3(ps, lt) };
1405                 const MPoly *mp = &ps->dm_mpoly[lt->poly];
1406                 float no[3], angle_cos;
1407
1408                 if (mp->flag & ME_SMOOTH) {
1409                         const short *no1, *no2, *no3;
1410                         no1 = ps->dm_mvert[lt_vtri[0]].no;
1411                         no2 = ps->dm_mvert[lt_vtri[1]].no;
1412                         no3 = ps->dm_mvert[lt_vtri[2]].no;
1413
1414                         no[0] = w[0] * no1[0] + w[1] * no2[0] + w[2] * no3[0];
1415                         no[1] = w[0] * no1[1] + w[1] * no2[1] + w[2] * no3[1];
1416                         no[2] = w[0] * no1[2] + w[1] * no2[2] + w[2] * no3[2];
1417                         normalize_v3(no);
1418                 }
1419                 else {
1420                         /* incase the */
1421 #if 1
1422                         /* normalizing per pixel isn't optimal, we could cache or check ps->*/
1423                         normal_tri_v3(no,
1424                                       ps->dm_mvert[lt_vtri[0]].co,
1425                                       ps->dm_mvert[lt_vtri[1]].co,
1426                                       ps->dm_mvert[lt_vtri[2]].co);
1427 #else
1428                         /* don't use because some modifiers dont have normal data (subsurf for eg) */
1429                         copy_v3_v3(no, (float *)ps->dm->getTessFaceData(ps->dm, tri_index, CD_NORMAL));
1430 #endif
1431                 }
1432
1433                 if (UNLIKELY(ps->is_flip_object)) {
1434                         negate_v3(no);
1435                 }
1436
1437                 /* now we can use the normal as a mask */
1438                 if (ps->is_ortho) {
1439                         angle_cos = dot_v3v3(ps->viewDir, no);
1440                 }
1441                 else {
1442                         /* Annoying but for the perspective view we need to get the pixels location in 3D space :/ */
1443                         float viewDirPersp[3];
1444                         const float *co1, *co2, *co3;
1445                         co1 = ps->dm_mvert[lt_vtri[0]].co;
1446                         co2 = ps->dm_mvert[lt_vtri[1]].co;
1447                         co3 = ps->dm_mvert[lt_vtri[2]].co;
1448
1449                         /* Get the direction from the viewPoint to the pixel and normalize */
1450                         viewDirPersp[0] = (ps->viewPos[0] - (w[0] * co1[0] + w[1] * co2[0] + w[2] * co3[0]));
1451                         viewDirPersp[1] = (ps->viewPos[1] - (w[0] * co1[1] + w[1] * co2[1] + w[2] * co3[1]));
1452                         viewDirPersp[2] = (ps->viewPos[2] - (w[0] * co1[2] + w[1] * co2[2] + w[2] * co3[2]));
1453                         normalize_v3(viewDirPersp);
1454                         if (UNLIKELY(ps->is_flip_object)) {
1455                                 negate_v3(viewDirPersp);
1456                         }
1457
1458                         angle_cos = dot_v3v3(viewDirPersp, no);
1459                 }
1460
1461                 if (angle_cos <= ps->normal_angle__cos) {
1462                         return 0.0f; /* outsize the normal limit*/
1463                 }
1464                 else if (angle_cos < ps->normal_angle_inner__cos) {
1465                         mask *= (ps->normal_angle - acosf(angle_cos)) / ps->normal_angle_range;
1466                 } /* otherwise no mask normal is needed, were within the limit */
1467         }
1468
1469         /* This only works when the opacity dosnt change while painting, stylus pressure messes with this
1470          * so don't use it. */
1471         // if (ps->is_airbrush == 0) mask *= BKE_brush_alpha_get(ps->brush);
1472
1473         return mask;
1474 }
1475
1476 static int project_paint_pixel_sizeof(const short tool)
1477 {
1478         if ((tool == PAINT_TOOL_CLONE) || (tool == PAINT_TOOL_SMEAR)) {
1479                 return sizeof(ProjPixelClone);
1480         }
1481         else {
1482                 return sizeof(ProjPixel);
1483         }
1484 }
1485
1486 static int project_paint_undo_subtiles(const TileInfo *tinf, int tx, int ty)
1487 {
1488         ProjPaintImage *pjIma = tinf->pjima;
1489         int tile_index = tx + ty * tinf->tile_width;
1490         bool generate_tile = false;
1491
1492         /* double check lock to avoid locking */
1493         if (UNLIKELY(!pjIma->undoRect[tile_index])) {
1494                 if (tinf->lock)
1495                         BLI_spin_lock(tinf->lock);
1496                 if (LIKELY(!pjIma->undoRect[tile_index])) {
1497                         pjIma->undoRect[tile_index] = TILE_PENDING;
1498                         generate_tile = true;
1499                 }
1500                 if (tinf->lock)
1501                         BLI_spin_unlock(tinf->lock);
1502         }
1503
1504
1505         if (generate_tile) {
1506                 ListBase *undo_tiles = ED_image_undo_get_tiles();
1507                 volatile void *undorect;
1508                 if (tinf->masked) {
1509                         undorect = image_undo_push_tile(
1510                                 undo_tiles, pjIma->ima, pjIma->ibuf, tinf->tmpibuf,
1511                                 tx, ty, &pjIma->maskRect[tile_index], &pjIma->valid[tile_index], true, false);
1512                 }
1513                 else {
1514                         undorect = image_undo_push_tile(
1515                                 undo_tiles, pjIma->ima, pjIma->ibuf, tinf->tmpibuf,
1516                                 tx, ty, NULL, &pjIma->valid[tile_index], true, false);
1517                 }
1518
1519                 pjIma->ibuf->userflags |= IB_BITMAPDIRTY;
1520                 /* tile ready, publish */
1521                 if (tinf->lock)
1522                         BLI_spin_lock(tinf->lock);
1523                 pjIma->undoRect[tile_index] = undorect;
1524                 if (tinf->lock)
1525                         BLI_spin_unlock(tinf->lock);
1526
1527         }
1528
1529         return tile_index;
1530 }
1531
1532 /* run this function when we know a bucket's, face's pixel can be initialized,
1533  * return the ProjPixel which is added to 'ps->bucketRect[bucket_index]' */
1534 static ProjPixel *project_paint_uvpixel_init(
1535         const ProjPaintState *ps,
1536         MemArena *arena,
1537         const TileInfo *tinf,
1538         int x_px, int y_px,
1539         const float mask,
1540         const int tri_index,
1541         const float pixelScreenCo[4],
1542         const float world_spaceCo[3],
1543         const float w[3])
1544 {
1545         ProjPixel *projPixel;
1546         int x_tile, y_tile;
1547         int x_round, y_round;
1548         int tile_offset;
1549         /* volatile is important here to ensure pending check is not optimized away by compiler*/
1550         volatile int tile_index;
1551
1552         ProjPaintImage *projima = tinf->pjima;
1553         ImBuf *ibuf = projima->ibuf;
1554         /* wrap pixel location */
1555
1556         x_px = mod_i(x_px, ibuf->x);
1557         y_px = mod_i(y_px, ibuf->y);
1558
1559         BLI_assert(ps->pixel_sizeof == project_paint_pixel_sizeof(ps->tool));
1560         projPixel = BLI_memarena_alloc(arena, ps->pixel_sizeof);
1561
1562         /* calculate the undo tile offset of the pixel, used to store the original
1563          * pixel color and accumulated mask if any */
1564         x_tile =  x_px >> IMAPAINT_TILE_BITS;
1565         y_tile =  y_px >> IMAPAINT_TILE_BITS;
1566
1567         x_round = x_tile * IMAPAINT_TILE_SIZE;
1568         y_round = y_tile * IMAPAINT_TILE_SIZE;
1569         //memset(projPixel, 0, size);
1570
1571         tile_offset = (x_px - x_round) + (y_px - y_round) * IMAPAINT_TILE_SIZE;
1572         tile_index = project_paint_undo_subtiles(tinf, x_tile, y_tile);
1573
1574         /* other thread may be initializing the tile so wait here */
1575         while (projima->undoRect[tile_index] == TILE_PENDING)
1576                 ;
1577
1578         BLI_assert(tile_index < (IMAPAINT_TILE_NUMBER(ibuf->x) * IMAPAINT_TILE_NUMBER(ibuf->y)));
1579         BLI_assert(tile_offset < (IMAPAINT_TILE_SIZE * IMAPAINT_TILE_SIZE));
1580
1581         projPixel->valid = projima->valid[tile_index];
1582
1583         if (ibuf->rect_float) {
1584                 projPixel->pixel.f_pt = ibuf->rect_float + ((x_px + y_px * ibuf->x) * 4);
1585                 projPixel->origColor.f_pt = (float *)projima->undoRect[tile_index] + 4 * tile_offset;
1586                 zero_v4(projPixel->newColor.f);
1587         }
1588         else {
1589                 projPixel->pixel.ch_pt = (unsigned char *)(ibuf->rect + (x_px + y_px * ibuf->x));
1590                 projPixel->origColor.uint_pt = (unsigned int *)projima->undoRect[tile_index] + tile_offset;
1591                 projPixel->newColor.uint = 0;
1592         }
1593
1594         /* screenspace unclamped, we could keep its z and w values but don't need them at the moment */
1595         if (ps->brush->mtex.brush_map_mode == MTEX_MAP_MODE_3D) {
1596                 copy_v3_v3(projPixel->worldCoSS, world_spaceCo);
1597         }
1598
1599         copy_v2_v2(projPixel->projCoSS, pixelScreenCo);
1600
1601         projPixel->x_px = x_px;
1602         projPixel->y_px = y_px;
1603
1604         projPixel->mask = (unsigned short)(mask * 65535);
1605         if (ps->do_masking)
1606                 projPixel->mask_accum = projima->maskRect[tile_index] + tile_offset;
1607         else
1608                 projPixel->mask_accum = NULL;
1609
1610         /* which bounding box cell are we in?, needed for undo */
1611         projPixel->bb_cell_index = ((int)(((float)x_px / (float)ibuf->x) * PROJ_BOUNDBOX_DIV)) +
1612                                    ((int)(((float)y_px / (float)ibuf->y) * PROJ_BOUNDBOX_DIV)) * PROJ_BOUNDBOX_DIV;
1613
1614         /* done with view3d_project_float inline */
1615         if (ps->tool == PAINT_TOOL_CLONE) {
1616                 if (ps->dm_mloopuv_clone) {
1617                         ImBuf *ibuf_other;
1618                         Image *other_tpage = project_paint_face_clone_image(ps, tri_index);
1619
1620                         if (other_tpage && (ibuf_other = BKE_image_acquire_ibuf(other_tpage, NULL, NULL))) {
1621                                 const MLoopTri *lt_other = &ps->dm_mlooptri[tri_index];
1622                                 const float *lt_other_tri_uv[3] = { PS_LOOPTRI_AS_UV_3(ps->dm_mloopuv_clone, lt_other) };
1623
1624                                 /* BKE_image_acquire_ibuf - TODO - this may be slow */
1625
1626                                 if (ibuf->rect_float) {
1627                                         if (ibuf_other->rect_float) { /* from float to float */
1628                                                 project_face_pixel(lt_other_tri_uv, ibuf_other, w, NULL, ((ProjPixelClone *)projPixel)->clonepx.f);
1629                                         }
1630                                         else { /* from char to float */
1631                                                 unsigned char rgba_ub[4];
1632                                                 float rgba[4];
1633                                                 project_face_pixel(lt_other_tri_uv, ibuf_other, w, rgba_ub, NULL);
1634                                                 if (ps->use_colormanagement) {
1635                                                         srgb_to_linearrgb_uchar4(rgba, rgba_ub);
1636                                                 }
1637                                                 else {
1638                                                         rgba_uchar_to_float(rgba, rgba_ub);
1639                                                 }
1640                                                 straight_to_premul_v4_v4(((ProjPixelClone *)projPixel)->clonepx.f, rgba);
1641                                         }
1642                                 }
1643                                 else {
1644                                         if (ibuf_other->rect_float) { /* float to char */
1645                                                 float rgba[4];
1646                                                 project_face_pixel(lt_other_tri_uv, ibuf_other, w, NULL, rgba);
1647                                                 premul_to_straight_v4(rgba);
1648                                                 if (ps->use_colormanagement) {
1649                                                         linearrgb_to_srgb_uchar3(((ProjPixelClone *)projPixel)->clonepx.ch, rgba);
1650                                                 }
1651                                                 else {
1652                                                         rgb_float_to_uchar(((ProjPixelClone *)projPixel)->clonepx.ch, rgba);
1653                                                 }
1654                                                 ((ProjPixelClone *)projPixel)->clonepx.ch[3] =  rgba[3] * 255;
1655                                         }
1656                                         else { /* char to char */
1657                                                 project_face_pixel(lt_other_tri_uv, ibuf_other, w, ((ProjPixelClone *)projPixel)->clonepx.ch, NULL);
1658                                         }
1659                                 }
1660
1661                                 BKE_image_release_ibuf(other_tpage, ibuf_other, NULL);
1662                         }
1663                         else {
1664                                 if (ibuf->rect_float) {
1665                                         ((ProjPixelClone *)projPixel)->clonepx.f[3] = 0;
1666                                 }
1667                                 else {
1668                                         ((ProjPixelClone *)projPixel)->clonepx.ch[3] = 0;
1669                                 }
1670                         }
1671
1672                 }
1673                 else {
1674                         float co[2];
1675                         sub_v2_v2v2(co, projPixel->projCoSS, ps->cloneOffset);
1676
1677                         /* no need to initialize the bucket, we're only checking buckets faces and for this
1678                          * the faces are already initialized in project_paint_delayed_face_init(...) */
1679                         if (ibuf->rect_float) {
1680                                 if (!project_paint_PickColor(ps, co, ((ProjPixelClone *)projPixel)->clonepx.f, NULL, 1)) {
1681                                         ((ProjPixelClone *)projPixel)->clonepx.f[3] = 0; /* zero alpha - ignore */
1682                                 }
1683                         }
1684                         else {
1685                                 if (!project_paint_PickColor(ps, co, NULL, ((ProjPixelClone *)projPixel)->clonepx.ch, 1)) {
1686                                         ((ProjPixelClone *)projPixel)->clonepx.ch[3] = 0; /* zero alpha - ignore */
1687                                 }
1688                         }
1689                 }
1690         }
1691
1692 #ifdef PROJ_DEBUG_PAINT
1693         if (ibuf->rect_float) projPixel->pixel.f_pt[0] = 0;
1694         else                  projPixel->pixel.ch_pt[0] = 0;
1695 #endif
1696         /* pointer arithmetics */
1697         projPixel->image_index = projima - ps->projImages;
1698
1699         return projPixel;
1700 }
1701
1702 static bool line_clip_rect2f(
1703         const rctf *cliprect,
1704         const rctf *rect,
1705         const float l1[2], const float l2[2],
1706         float l1_clip[2], float l2_clip[2])
1707 {
1708         /* first account for horizontal, then vertical lines */
1709         /* horiz */
1710         if (fabsf(l1[1] - l2[1]) < PROJ_PIXEL_TOLERANCE) {
1711                 /* is the line out of range on its Y axis? */
1712                 if (l1[1] < rect->ymin || l1[1] > rect->ymax) {
1713                         return 0;
1714                 }
1715                 /* line is out of range on its X axis */
1716                 if ((l1[0] < rect->xmin && l2[0] < rect->xmin) || (l1[0] > rect->xmax && l2[0] > rect->xmax)) {
1717                         return 0;
1718                 }
1719
1720
1721                 if (fabsf(l1[0] - l2[0]) < PROJ_PIXEL_TOLERANCE) { /* this is a single point  (or close to)*/
1722                         if (BLI_rctf_isect_pt_v(rect, l1)) {
1723                                 copy_v2_v2(l1_clip, l1);
1724                                 copy_v2_v2(l2_clip, l2);
1725                                 return 1;
1726                         }
1727                         else {
1728                                 return 0;
1729                         }
1730                 }
1731
1732                 copy_v2_v2(l1_clip, l1);
1733                 copy_v2_v2(l2_clip, l2);
1734                 CLAMP(l1_clip[0], rect->xmin, rect->xmax);
1735                 CLAMP(l2_clip[0], rect->xmin, rect->xmax);
1736                 return 1;
1737         }
1738         else if (fabsf(l1[0] - l2[0]) < PROJ_PIXEL_TOLERANCE) {
1739                 /* is the line out of range on its X axis? */
1740                 if (l1[0] < rect->xmin || l1[0] > rect->xmax) {
1741                         return 0;
1742                 }
1743
1744                 /* line is out of range on its Y axis */
1745                 if ((l1[1] < rect->ymin && l2[1] < rect->ymin) || (l1[1] > rect->ymax && l2[1] > rect->ymax)) {
1746                         return 0;
1747                 }
1748
1749                 if (fabsf(l1[1] - l2[1]) < PROJ_PIXEL_TOLERANCE) { /* this is a single point  (or close to)*/
1750                         if (BLI_rctf_isect_pt_v(rect, l1)) {
1751                                 copy_v2_v2(l1_clip, l1);
1752                                 copy_v2_v2(l2_clip, l2);
1753                                 return 1;
1754                         }
1755                         else {
1756                                 return 0;
1757                         }
1758                 }
1759
1760                 copy_v2_v2(l1_clip, l1);
1761                 copy_v2_v2(l2_clip, l2);
1762                 CLAMP(l1_clip[1], rect->ymin, rect->ymax);
1763                 CLAMP(l2_clip[1], rect->ymin, rect->ymax);
1764                 return 1;
1765         }
1766         else {
1767                 float isect;
1768                 short ok1 = 0;
1769                 short ok2 = 0;
1770
1771                 /* Done with vertical lines */
1772
1773                 /* are either of the points inside the rectangle ? */
1774                 if (BLI_rctf_isect_pt_v(rect, l1)) {
1775                         copy_v2_v2(l1_clip, l1);
1776                         ok1 = 1;
1777                 }
1778
1779                 if (BLI_rctf_isect_pt_v(rect, l2)) {
1780                         copy_v2_v2(l2_clip, l2);
1781                         ok2 = 1;
1782                 }
1783
1784                 /* line inside rect */
1785                 if (ok1 && ok2) return 1;
1786
1787                 /* top/bottom */
1788                 if (line_isect_y(l1, l2, rect->ymin, &isect) && (isect >= cliprect->xmin) && (isect <= cliprect->xmax)) {
1789                         if (l1[1] < l2[1]) { /* line 1 is outside */
1790                                 l1_clip[0] = isect;
1791                                 l1_clip[1] = rect->ymin;
1792                                 ok1 = 1;
1793                         }
1794                         else {
1795                                 l2_clip[0] = isect;
1796                                 l2_clip[1] = rect->ymin;
1797                                 ok2 = 2;
1798                         }
1799                 }
1800
1801                 if (ok1 && ok2) return 1;
1802
1803                 if (line_isect_y(l1, l2, rect->ymax, &isect) && (isect >= cliprect->xmin) && (isect <= cliprect->xmax)) {
1804                         if (l1[1] > l2[1]) { /* line 1 is outside */
1805                                 l1_clip[0] = isect;
1806                                 l1_clip[1] = rect->ymax;
1807                                 ok1 = 1;
1808                         }
1809                         else {
1810                                 l2_clip[0] = isect;
1811                                 l2_clip[1] = rect->ymax;
1812                                 ok2 = 2;
1813                         }
1814                 }
1815
1816                 if (ok1 && ok2) return 1;
1817
1818                 /* left/right */
1819                 if (line_isect_x(l1, l2, rect->xmin, &isect) && (isect >= cliprect->ymin) && (isect <= cliprect->ymax)) {
1820                         if (l1[0] < l2[0]) { /* line 1 is outside */
1821                                 l1_clip[0] = rect->xmin;
1822                                 l1_clip[1] = isect;
1823                                 ok1 = 1;
1824                         }
1825                         else {
1826                                 l2_clip[0] = rect->xmin;
1827                                 l2_clip[1] = isect;
1828                                 ok2 = 2;
1829                         }
1830                 }
1831
1832                 if (ok1 && ok2) return 1;
1833
1834                 if (line_isect_x(l1, l2, rect->xmax, &isect) && (isect >= cliprect->ymin) && (isect <= cliprect->ymax)) {
1835                         if (l1[0] > l2[0]) { /* line 1 is outside */
1836                                 l1_clip[0] = rect->xmax;
1837                                 l1_clip[1] = isect;
1838                                 ok1 = 1;
1839                         }
1840                         else {
1841                                 l2_clip[0] = rect->xmax;
1842                                 l2_clip[1] = isect;
1843                                 ok2 = 2;
1844                         }
1845                 }
1846
1847                 if (ok1 && ok2) {
1848                         return 1;
1849                 }
1850                 else {
1851                         return 0;
1852                 }
1853         }
1854 }
1855
1856
1857
1858 /**
1859  * Scale the tri about its center
1860  * scaling by #PROJ_FACE_SCALE_SEAM (0.99x) is used for getting fake UV pixel coords that are on the
1861  * edge of the face but slightly inside it occlusion tests don't return hits on adjacent faces
1862  */
1863 #ifndef PROJ_DEBUG_NOSEAMBLEED
1864
1865 static void scale_tri(float insetCos[3][3], const float *origCos[4], const float inset)
1866 {
1867         float cent[3];
1868         cent[0] = (origCos[0][0] + origCos[1][0] + origCos[2][0]) * (1.0f / 3.0f);
1869         cent[1] = (origCos[0][1] + origCos[1][1] + origCos[2][1]) * (1.0f / 3.0f);
1870         cent[2] = (origCos[0][2] + origCos[1][2] + origCos[2][2]) * (1.0f / 3.0f);
1871
1872         sub_v3_v3v3(insetCos[0], origCos[0], cent);
1873         sub_v3_v3v3(insetCos[1], origCos[1], cent);
1874         sub_v3_v3v3(insetCos[2], origCos[2], cent);
1875
1876         mul_v3_fl(insetCos[0], inset);
1877         mul_v3_fl(insetCos[1], inset);
1878         mul_v3_fl(insetCos[2], inset);
1879
1880         add_v3_v3(insetCos[0], cent);
1881         add_v3_v3(insetCos[1], cent);
1882         add_v3_v3(insetCos[2], cent);
1883 }
1884 #endif //PROJ_DEBUG_NOSEAMBLEED
1885
1886 static float len_squared_v2v2_alt(const float v1[2], const float v2_1, const float v2_2)
1887 {
1888         float x, y;
1889
1890         x = v1[0] - v2_1;
1891         y = v1[1] - v2_2;
1892         return x * x + y * y;
1893 }
1894
1895 /* note, use a squared value so we can use len_squared_v2v2
1896  * be sure that you have done a bounds check first or this may fail */
1897 /* only give bucket_bounds as an arg because we need it elsewhere */
1898 static bool project_bucket_isect_circle(const float cent[2], const float radius_squared, const rctf *bucket_bounds)
1899 {
1900
1901         /* Would normally to a simple intersection test, however we know the bounds of these 2 already intersect
1902          * so we only need to test if the center is inside the vertical or horizontal bounds on either axis,
1903          * this is even less work then an intersection test
1904          */
1905 #if 0
1906         if (BLI_rctf_isect_pt_v(bucket_bounds, cent))
1907                 return 1;
1908 #endif
1909
1910         if ((bucket_bounds->xmin <= cent[0] && bucket_bounds->xmax >= cent[0]) ||
1911             (bucket_bounds->ymin <= cent[1] && bucket_bounds->ymax >= cent[1]))
1912         {
1913                 return 1;
1914         }
1915
1916         /* out of bounds left */
1917         if (cent[0] < bucket_bounds->xmin) {
1918                 /* lower left out of radius test */
1919                 if (cent[1] < bucket_bounds->ymin) {
1920                         return (len_squared_v2v2_alt(cent, bucket_bounds->xmin, bucket_bounds->ymin) < radius_squared) ? 1 : 0;
1921                 }
1922                 /* top left test */
1923                 else if (cent[1] > bucket_bounds->ymax) {
1924                         return (len_squared_v2v2_alt(cent, bucket_bounds->xmin, bucket_bounds->ymax) < radius_squared) ? 1 : 0;
1925                 }
1926         }
1927         else if (cent[0] > bucket_bounds->xmax) {
1928                 /* lower right out of radius test */
1929                 if (cent[1] < bucket_bounds->ymin) {
1930                         return (len_squared_v2v2_alt(cent, bucket_bounds->xmax, bucket_bounds->ymin) < radius_squared) ? 1 : 0;
1931                 }
1932                 /* top right test */
1933                 else if (cent[1] > bucket_bounds->ymax) {
1934                         return (len_squared_v2v2_alt(cent, bucket_bounds->xmax, bucket_bounds->ymax) < radius_squared) ? 1 : 0;
1935                 }
1936         }
1937
1938         return 0;
1939 }
1940
1941
1942
1943 /* Note for rect_to_uvspace_ortho() and rect_to_uvspace_persp()
1944  * in ortho view this function gives good results when bucket_bounds are outside the triangle
1945  * however in some cases, perspective view will mess up with faces that have minimal screenspace area
1946  * (viewed from the side)
1947  *
1948  * for this reason its not reliable in this case so we'll use the Simple Barycentric'
1949  * funcs that only account for points inside the triangle.
1950  * however switching back to this for ortho is always an option */
1951
1952 static void rect_to_uvspace_ortho(
1953         const rctf *bucket_bounds,
1954         const float *v1coSS, const float *v2coSS, const float *v3coSS,
1955         const float *uv1co, const float *uv2co, const float *uv3co,
1956         float bucket_bounds_uv[4][2],
1957         const int flip)
1958 {
1959         float uv[2];
1960         float w[3];
1961
1962         /* get the UV space bounding box */
1963         uv[0] = bucket_bounds->xmax;
1964         uv[1] = bucket_bounds->ymin;
1965         barycentric_weights_v2(v1coSS, v2coSS, v3coSS, uv, w);
1966         interp_v2_v2v2v2(bucket_bounds_uv[flip ? 3 : 0], uv1co, uv2co, uv3co, w);
1967
1968         //uv[0] = bucket_bounds->xmax; // set above
1969         uv[1] = bucket_bounds->ymax;
1970         barycentric_weights_v2(v1coSS, v2coSS, v3coSS, uv, w);
1971         interp_v2_v2v2v2(bucket_bounds_uv[flip ? 2 : 1], uv1co, uv2co, uv3co, w);
1972
1973         uv[0] = bucket_bounds->xmin;
1974         //uv[1] = bucket_bounds->ymax; // set above
1975         barycentric_weights_v2(v1coSS, v2coSS, v3coSS, uv, w);
1976         interp_v2_v2v2v2(bucket_bounds_uv[flip ? 1 : 2], uv1co, uv2co, uv3co, w);
1977
1978         //uv[0] = bucket_bounds->xmin; // set above
1979         uv[1] = bucket_bounds->ymin;
1980         barycentric_weights_v2(v1coSS, v2coSS, v3coSS, uv, w);
1981         interp_v2_v2v2v2(bucket_bounds_uv[flip ? 0 : 3], uv1co, uv2co, uv3co, w);
1982 }
1983
1984 /* same as above but use barycentric_weights_v2_persp */
1985 static void rect_to_uvspace_persp(
1986         const rctf *bucket_bounds,
1987         const float *v1coSS, const float *v2coSS, const float *v3coSS,
1988         const float *uv1co, const float *uv2co, const float *uv3co,
1989         float bucket_bounds_uv[4][2],
1990         const int flip
1991         )
1992 {
1993         float uv[2];
1994         float w[3];
1995
1996         /* get the UV space bounding box */
1997         uv[0] = bucket_bounds->xmax;
1998         uv[1] = bucket_bounds->ymin;
1999         barycentric_weights_v2_persp(v1coSS, v2coSS, v3coSS, uv, w);
2000         interp_v2_v2v2v2(bucket_bounds_uv[flip ? 3 : 0], uv1co, uv2co, uv3co, w);
2001
2002         //uv[0] = bucket_bounds->xmax; // set above
2003         uv[1] = bucket_bounds->ymax;
2004         barycentric_weights_v2_persp(v1coSS, v2coSS, v3coSS, uv, w);
2005         interp_v2_v2v2v2(bucket_bounds_uv[flip ? 2 : 1], uv1co, uv2co, uv3co, w);
2006
2007         uv[0] = bucket_bounds->xmin;
2008         //uv[1] = bucket_bounds->ymax; // set above
2009         barycentric_weights_v2_persp(v1coSS, v2coSS, v3coSS, uv, w);
2010         interp_v2_v2v2v2(bucket_bounds_uv[flip ? 1 : 2], uv1co, uv2co, uv3co, w);
2011
2012         //uv[0] = bucket_bounds->xmin; // set above
2013         uv[1] = bucket_bounds->ymin;
2014         barycentric_weights_v2_persp(v1coSS, v2coSS, v3coSS, uv, w);
2015         interp_v2_v2v2v2(bucket_bounds_uv[flip ? 0 : 3], uv1co, uv2co, uv3co, w);
2016 }
2017
2018 /* This works as we need it to but we can save a few steps and not use it */
2019
2020 #if 0
2021 static float angle_2d_clockwise(const float p1[2], const float p2[2], const float p3[2])
2022 {
2023         float v1[2], v2[2];
2024
2025         v1[0] = p1[0] - p2[0];    v1[1] = p1[1] - p2[1];
2026         v2[0] = p3[0] - p2[0];    v2[1] = p3[1] - p2[1];
2027
2028         return -atan2f(v1[0] * v2[1] - v1[1] * v2[0], v1[0] * v2[0] + v1[1] * v2[1]);
2029 }
2030 #endif
2031
2032 #define ISECT_1 (1)
2033 #define ISECT_2 (1 << 1)
2034 #define ISECT_3 (1 << 2)
2035 #define ISECT_4 (1 << 3)
2036 #define ISECT_ALL3 ((1 << 3) - 1)
2037 #define ISECT_ALL4 ((1 << 4) - 1)
2038
2039 /* limit must be a fraction over 1.0f */
2040 static bool IsectPT2Df_limit(
2041         const float pt[2],
2042         const float v1[2], const float v2[2], const float v3[2],
2043         const float limit)
2044 {
2045         return ((area_tri_v2(pt, v1, v2) +
2046                  area_tri_v2(pt, v2, v3) +
2047                  area_tri_v2(pt, v3, v1)) / (area_tri_v2(v1, v2, v3))) < limit;
2048 }
2049
2050 /* Clip the face by a bucket and set the uv-space bucket_bounds_uv
2051  * so we have the clipped UV's to do pixel intersection tests with
2052  * */
2053 static int float_z_sort_flip(const void *p1, const void *p2)
2054 {
2055         return (((float *)p1)[2] < ((float *)p2)[2] ? 1 : -1);
2056 }
2057
2058 static int float_z_sort(const void *p1, const void *p2)
2059 {
2060         return (((float *)p1)[2] < ((float *)p2)[2] ? -1 : 1);
2061 }
2062
2063 /* assumes one point is within the rectangle */
2064 static bool line_rect_clip(
2065         const rctf *rect,
2066         const float l1[4], const float l2[4],
2067         const float uv1[2], const float uv2[2],
2068         float uv[2], bool is_ortho)
2069 {
2070         float min = FLT_MAX, tmp;
2071         float xlen = l2[0] - l1[0];
2072         float ylen = l2[1] - l1[1];
2073
2074         /* 0.1 might seem too much, but remember, this is pixels! */
2075         if (xlen > 0.1f) {
2076                 if ((l1[0] - rect->xmin) * (l2[0] - rect->xmin) <= 0) {
2077                         tmp = rect->xmin;
2078                         min = min_ff((tmp - l1[0]) / xlen, min);
2079                 }
2080                 else if ((l1[0] - rect->xmax) * (l2[0] - rect->xmax) < 0) {
2081                         tmp = rect->xmax;
2082                         min = min_ff((tmp - l1[0]) / xlen, min);
2083                 }
2084         }
2085
2086         if (ylen > 0.1f) {
2087                 if ((l1[1] - rect->ymin) * (l2[1] - rect->ymin) <= 0) {
2088                         tmp = rect->ymin;
2089                         min = min_ff((tmp - l1[1]) / ylen, min);
2090                 }
2091                 else if ((l1[1] - rect->ymax) * (l2[1] - rect->ymax) < 0) {
2092                         tmp = rect->ymax;
2093                         min = min_ff((tmp - l1[1]) / ylen, min);
2094                 }
2095         }
2096
2097         if (min == FLT_MAX)
2098                 return false;
2099
2100         tmp = (is_ortho) ? 1.0f : (l1[3] + min * (l2[3] - l1[3]));
2101
2102         uv[0] = (uv1[0] + min / tmp * (uv2[0] - uv1[0]));
2103         uv[1] = (uv1[1] + min / tmp * (uv2[1] - uv1[1]));
2104
2105         return true;
2106 }
2107
2108
2109 static void project_bucket_clip_face(
2110         const bool is_ortho, const bool is_flip_object,
2111         const rctf *cliprect,
2112         const rctf *bucket_bounds,
2113         const float *v1coSS, const float *v2coSS, const float *v3coSS,
2114         const float *uv1co, const float *uv2co, const float *uv3co,
2115         float bucket_bounds_uv[8][2],
2116         int *tot, bool cull)
2117 {
2118         int inside_bucket_flag = 0;
2119         int inside_face_flag = 0;
2120         int flip;
2121         bool collinear = false;
2122
2123         float bucket_bounds_ss[4][2];
2124
2125         /* detect pathological case where face the three vertices are almost collinear in screen space.
2126          * mostly those will be culled but when flood filling or with smooth shading it's a possibility */
2127         if (min_fff(dist_squared_to_line_v2(v1coSS, v2coSS, v3coSS),
2128                     dist_squared_to_line_v2(v2coSS, v3coSS, v1coSS),
2129                     dist_squared_to_line_v2(v3coSS, v1coSS, v2coSS)) < PROJ_PIXEL_TOLERANCE)
2130         {
2131                 collinear = true;
2132         }
2133
2134         /* get the UV space bounding box */
2135         inside_bucket_flag |= BLI_rctf_isect_pt_v(bucket_bounds, v1coSS);
2136         inside_bucket_flag |= BLI_rctf_isect_pt_v(bucket_bounds, v2coSS) << 1;
2137         inside_bucket_flag |= BLI_rctf_isect_pt_v(bucket_bounds, v3coSS) << 2;
2138
2139         if (inside_bucket_flag == ISECT_ALL3) {
2140                 /* is_flip_object is used here because we use the face winding */
2141                 flip = (((line_point_side_v2(v1coSS, v2coSS, v3coSS) > 0.0f) != is_flip_object) !=
2142                         (line_point_side_v2(uv1co, uv2co, uv3co) > 0.0f));
2143
2144                 /* all screenspace points are inside the bucket bounding box,
2145                  * this means we don't need to clip and can simply return the UVs */
2146                 if (flip) { /* facing the back? */
2147                         copy_v2_v2(bucket_bounds_uv[0], uv3co);
2148                         copy_v2_v2(bucket_bounds_uv[1], uv2co);
2149                         copy_v2_v2(bucket_bounds_uv[2], uv1co);
2150                 }
2151                 else {
2152                         copy_v2_v2(bucket_bounds_uv[0], uv1co);
2153                         copy_v2_v2(bucket_bounds_uv[1], uv2co);
2154                         copy_v2_v2(bucket_bounds_uv[2], uv3co);
2155                 }
2156
2157                 *tot = 3;
2158                 return;
2159         }
2160         /* handle pathological case here, no need for further intersections below since tringle area is almost zero */
2161         if (collinear) {
2162                 int flag;
2163
2164                 (*tot) = 0;
2165
2166                 if (cull)
2167                         return;
2168
2169                 if (inside_bucket_flag & ISECT_1) { copy_v2_v2(bucket_bounds_uv[*tot], uv1co); (*tot)++; }
2170
2171                 flag = inside_bucket_flag & (ISECT_1 | ISECT_2);
2172                 if (flag && flag != (ISECT_1 | ISECT_2)) {
2173                         if (line_rect_clip(bucket_bounds, v1coSS, v2coSS, uv1co, uv2co, bucket_bounds_uv[*tot], is_ortho))
2174                                 (*tot)++;
2175                 }
2176
2177                 if (inside_bucket_flag & ISECT_2) { copy_v2_v2(bucket_bounds_uv[*tot], uv2co); (*tot)++; }
2178
2179                 flag = inside_bucket_flag & (ISECT_2 | ISECT_3);
2180                 if (flag && flag != (ISECT_2 | ISECT_3)) {
2181                         if (line_rect_clip(bucket_bounds, v2coSS, v3coSS, uv2co, uv3co, bucket_bounds_uv[*tot], is_ortho))
2182                                 (*tot)++;
2183                 }
2184
2185                 if (inside_bucket_flag & ISECT_3) { copy_v2_v2(bucket_bounds_uv[*tot], uv3co); (*tot)++; }
2186
2187                 flag = inside_bucket_flag & (ISECT_3 | ISECT_1);
2188                 if (flag && flag != (ISECT_3 | ISECT_1)) {
2189                         if (line_rect_clip(bucket_bounds, v3coSS, v1coSS, uv3co, uv1co, bucket_bounds_uv[*tot], is_ortho))
2190                                 (*tot)++;
2191                 }
2192
2193                 if ((*tot) < 3) {
2194                         /* no intersections to speak of, but more probable is that all face is just outside the
2195                          * rectangle and culled due to float precision issues. Since above tests have failed,
2196                          * just dump triangle as is for painting */
2197                         *tot = 0;
2198                         copy_v2_v2(bucket_bounds_uv[*tot], uv1co); (*tot)++;
2199                         copy_v2_v2(bucket_bounds_uv[*tot], uv2co); (*tot)++;
2200                         copy_v2_v2(bucket_bounds_uv[*tot], uv3co); (*tot)++;
2201                         return;
2202                 }
2203
2204                 return;
2205         }
2206
2207         /* get the UV space bounding box */
2208         /* use IsectPT2Df_limit here so we catch points are are touching the tri edge (or a small fraction over) */
2209         bucket_bounds_ss[0][0] = bucket_bounds->xmax;
2210         bucket_bounds_ss[0][1] = bucket_bounds->ymin;
2211         inside_face_flag |= (IsectPT2Df_limit(bucket_bounds_ss[0], v1coSS, v2coSS, v3coSS, 1 + PROJ_GEOM_TOLERANCE) ? ISECT_1 : 0);
2212
2213         bucket_bounds_ss[1][0] = bucket_bounds->xmax;
2214         bucket_bounds_ss[1][1] = bucket_bounds->ymax;
2215         inside_face_flag |= (IsectPT2Df_limit(bucket_bounds_ss[1], v1coSS, v2coSS, v3coSS, 1 + PROJ_GEOM_TOLERANCE) ? ISECT_2 : 0);
2216
2217         bucket_bounds_ss[2][0] = bucket_bounds->xmin;
2218         bucket_bounds_ss[2][1] = bucket_bounds->ymax;
2219         inside_face_flag |= (IsectPT2Df_limit(bucket_bounds_ss[2], v1coSS, v2coSS, v3coSS, 1 + PROJ_GEOM_TOLERANCE) ? ISECT_3 : 0);
2220
2221         bucket_bounds_ss[3][0] = bucket_bounds->xmin;
2222         bucket_bounds_ss[3][1] = bucket_bounds->ymin;
2223         inside_face_flag |= (IsectPT2Df_limit(bucket_bounds_ss[3], v1coSS, v2coSS, v3coSS, 1 + PROJ_GEOM_TOLERANCE) ? ISECT_4 : 0);
2224
2225         flip = ((line_point_side_v2(v1coSS, v2coSS, v3coSS) > 0.0f) !=
2226                 (line_point_side_v2(uv1co, uv2co, uv3co) > 0.0f));
2227
2228         if (inside_face_flag == ISECT_ALL4) {
2229                 /* bucket is totally inside the screenspace face, we can safely use weights */
2230
2231                 if (is_ortho) {
2232                         rect_to_uvspace_ortho(bucket_bounds, v1coSS, v2coSS, v3coSS, uv1co, uv2co, uv3co, bucket_bounds_uv, flip);
2233                 }
2234                 else {
2235                         rect_to_uvspace_persp(bucket_bounds, v1coSS, v2coSS, v3coSS, uv1co, uv2co, uv3co, bucket_bounds_uv, flip);
2236                 }
2237
2238                 *tot = 4;
2239                 return;
2240         }
2241         else {
2242                 /* The Complicated Case!
2243                  *
2244                  * The 2 cases above are where the face is inside the bucket or the bucket is inside the face.
2245                  *
2246                  * we need to make a convex polyline from the intersection between the screenspace face
2247                  * and the bucket bounds.
2248                  *
2249                  * There are a number of ways this could be done, currently it just collects all intersecting verts,
2250                  * and line intersections,  then sorts them clockwise, this is a lot easier then evaluating the geometry to
2251                  * do a correct clipping on both shapes. */
2252
2253
2254                 /* add a bunch of points, we know must make up the convex hull which is the clipped rect and triangle */
2255
2256
2257
2258                 /* Maximum possible 6 intersections when using a rectangle and triangle */
2259                 float isectVCosSS[8][3]; /* The 3rd float is used to store angle for qsort(), NOT as a Z location */
2260                 float v1_clipSS[2], v2_clipSS[2];
2261                 float w[3];
2262
2263                 /* calc center */
2264                 float cent[2] = {0.0f, 0.0f};
2265                 /*float up[2] = {0.0f, 1.0f};*/
2266                 int i;
2267                 bool doubles;
2268
2269                 (*tot) = 0;
2270
2271                 if (inside_face_flag & ISECT_1) { copy_v2_v2(isectVCosSS[*tot], bucket_bounds_ss[0]); (*tot)++; }
2272                 if (inside_face_flag & ISECT_2) { copy_v2_v2(isectVCosSS[*tot], bucket_bounds_ss[1]); (*tot)++; }
2273                 if (inside_face_flag & ISECT_3) { copy_v2_v2(isectVCosSS[*tot], bucket_bounds_ss[2]); (*tot)++; }
2274                 if (inside_face_flag & ISECT_4) { copy_v2_v2(isectVCosSS[*tot], bucket_bounds_ss[3]); (*tot)++; }
2275
2276                 if (inside_bucket_flag & ISECT_1) { copy_v2_v2(isectVCosSS[*tot], v1coSS); (*tot)++; }
2277                 if (inside_bucket_flag & ISECT_2) { copy_v2_v2(isectVCosSS[*tot], v2coSS); (*tot)++; }
2278                 if (inside_bucket_flag & ISECT_3) { copy_v2_v2(isectVCosSS[*tot], v3coSS); (*tot)++; }
2279
2280                 if ((inside_bucket_flag & (ISECT_1 | ISECT_2)) != (ISECT_1 | ISECT_2)) {
2281                         if (line_clip_rect2f(cliprect, bucket_bounds, v1coSS, v2coSS, v1_clipSS, v2_clipSS)) {
2282                                 if ((inside_bucket_flag & ISECT_1) == 0) { copy_v2_v2(isectVCosSS[*tot], v1_clipSS); (*tot)++; }
2283                                 if ((inside_bucket_flag & ISECT_2) == 0) { copy_v2_v2(isectVCosSS[*tot], v2_clipSS); (*tot)++; }
2284                         }
2285                 }
2286
2287                 if ((inside_bucket_flag & (ISECT_2 | ISECT_3)) != (ISECT_2 | ISECT_3)) {
2288                         if (line_clip_rect2f(cliprect, bucket_bounds, v2coSS, v3coSS, v1_clipSS, v2_clipSS)) {
2289                                 if ((inside_bucket_flag & ISECT_2) == 0) { copy_v2_v2(isectVCosSS[*tot], v1_clipSS); (*tot)++; }
2290                                 if ((inside_bucket_flag & ISECT_3) == 0) { copy_v2_v2(isectVCosSS[*tot], v2_clipSS); (*tot)++; }
2291                         }
2292                 }
2293
2294                 if ((inside_bucket_flag & (ISECT_3 | ISECT_1)) != (ISECT_3 | ISECT_1)) {
2295                         if (line_clip_rect2f(cliprect, bucket_bounds, v3coSS, v1coSS, v1_clipSS, v2_clipSS)) {
2296                                 if ((inside_bucket_flag & ISECT_3) == 0) { copy_v2_v2(isectVCosSS[*tot], v1_clipSS); (*tot)++; }
2297                                 if ((inside_bucket_flag & ISECT_1) == 0) { copy_v2_v2(isectVCosSS[*tot], v2_clipSS); (*tot)++; }
2298                         }
2299                 }
2300
2301
2302                 if ((*tot) < 3) { /* no intersections to speak of */
2303                         *tot = 0;
2304                         return;
2305                 }
2306
2307                 /* now we have all points we need, collect their angles and sort them clockwise */
2308
2309                 for (i = 0; i < (*tot); i++) {
2310                         cent[0] += isectVCosSS[i][0];
2311                         cent[1] += isectVCosSS[i][1];
2312                 }
2313                 cent[0] = cent[0] / (float)(*tot);
2314                 cent[1] = cent[1] / (float)(*tot);
2315
2316
2317
2318                 /* Collect angles for every point around the center point */
2319
2320
2321 #if 0   /* uses a few more cycles then the above loop */
2322                 for (i = 0; i < (*tot); i++) {
2323                         isectVCosSS[i][2] = angle_2d_clockwise(up, cent, isectVCosSS[i]);
2324                 }
2325 #endif
2326
2327                 v1_clipSS[0] = cent[0]; /* Abuse this var for the loop below */
2328                 v1_clipSS[1] = cent[1] + 1.0f;
2329
2330                 for (i = 0; i < (*tot); i++) {
2331                         v2_clipSS[0] = isectVCosSS[i][0] - cent[0];
2332                         v2_clipSS[1] = isectVCosSS[i][1] - cent[1];
2333                         isectVCosSS[i][2] = atan2f(v1_clipSS[0] * v2_clipSS[1] - v1_clipSS[1] * v2_clipSS[0],
2334                                                    v1_clipSS[0] * v2_clipSS[0] + v1_clipSS[1] * v2_clipSS[1]);
2335                 }
2336
2337                 if (flip) qsort(isectVCosSS, *tot, sizeof(float) * 3, float_z_sort_flip);
2338                 else      qsort(isectVCosSS, *tot, sizeof(float) * 3, float_z_sort);
2339
2340                 doubles = true;
2341                 while (doubles == true) {
2342                         doubles = false;
2343
2344                         for (i = 0; i < (*tot); i++) {
2345                                 if (fabsf(isectVCosSS[(i + 1) % *tot][0] - isectVCosSS[i][0]) < PROJ_PIXEL_TOLERANCE &&
2346                                     fabsf(isectVCosSS[(i + 1) % *tot][1] - isectVCosSS[i][1]) < PROJ_PIXEL_TOLERANCE)
2347                                 {
2348                                         int j;
2349                                         for (j = i; j < (*tot) - 1; j++) {
2350                                                 isectVCosSS[j][0] = isectVCosSS[j + 1][0];
2351                                                 isectVCosSS[j][1] = isectVCosSS[j + 1][1];
2352                                         }
2353                                         doubles = true; /* keep looking for more doubles */
2354                                         (*tot)--;
2355                                 }
2356                         }
2357
2358                         /* its possible there is only a few left after remove doubles */
2359                         if ((*tot) < 3) {
2360                                 // printf("removed too many doubles B\n");
2361                                 *tot = 0;
2362                                 return;
2363                         }
2364                 }
2365
2366                 if (is_ortho) {
2367                         for (i = 0; i < (*tot); i++) {
2368                                 barycentric_weights_v2(v1coSS, v2coSS, v3coSS, isectVCosSS[i], w);
2369                                 interp_v2_v2v2v2(bucket_bounds_uv[i], uv1co, uv2co, uv3co, w);
2370                         }
2371                 }
2372                 else {
2373                         for (i = 0; i < (*tot); i++) {
2374                                 barycentric_weights_v2_persp(v1coSS, v2coSS, v3coSS, isectVCosSS[i], w);
2375                                 interp_v2_v2v2v2(bucket_bounds_uv[i], uv1co, uv2co, uv3co, w);
2376                         }
2377                 }
2378         }
2379
2380 #ifdef PROJ_DEBUG_PRINT_CLIP
2381         /* include this at the bottom of the above function to debug the output */
2382
2383         {
2384                 /* If there are ever any problems, */
2385                 float test_uv[4][2];
2386                 int i;
2387                 if (is_ortho) rect_to_uvspace_ortho(bucket_bounds, v1coSS, v2coSS, v3coSS, uv1co, uv2co, uv3co, test_uv, flip);
2388                 else          rect_to_uvspace_persp(bucket_bounds, v1coSS, v2coSS, v3coSS, uv1co, uv2co, uv3co, test_uv, flip);
2389                 printf("(  [(%f,%f), (%f,%f), (%f,%f), (%f,%f)], ",
2390                        test_uv[0][0], test_uv[0][1],   test_uv[1][0], test_uv[1][1],
2391                        test_uv[2][0], test_uv[2][1],    test_uv[3][0], test_uv[3][1]);
2392
2393                 printf("  [(%f,%f), (%f,%f), (%f,%f)], ", uv1co[0], uv1co[1],   uv2co[0], uv2co[1],    uv3co[0], uv3co[1]);
2394
2395                 printf("[");
2396                 for (i = 0; i < (*tot); i++) {
2397                         printf("(%f, %f),", bucket_bounds_uv[i][0], bucket_bounds_uv[i][1]);
2398                 }
2399                 printf("]),\\\n");
2400         }
2401 #endif
2402 }
2403
2404 /*
2405  * # This script creates faces in a blender scene from printed data above.
2406  *
2407  * project_ls = [
2408  * ...(output from above block)...
2409  * ]
2410  *
2411  * from Blender import Scene, Mesh, Window, sys, Mathutils
2412  *
2413  * import bpy
2414  *
2415  * V = Mathutils.Vector
2416  *
2417  * def main():
2418  *     sce = bpy.data.scenes.active
2419  *
2420  *     for item in project_ls:
2421  *         bb = item[0]
2422  *         uv = item[1]
2423  *         poly = item[2]
2424  *
2425  *         me = bpy.data.meshes.new()
2426  *         ob = sce.objects.new(me)
2427  *
2428  *         me.verts.extend([V(bb[0]).xyz, V(bb[1]).xyz, V(bb[2]).xyz, V(bb[3]).xyz])
2429  *         me.faces.extend([(0,1,2,3),])
2430  *         me.verts.extend([V(uv[0]).xyz, V(uv[1]).xyz, V(uv[2]).xyz])
2431  *         me.faces.extend([(4,5,6),])
2432  *
2433  *         vs = [V(p).xyz for p in poly]
2434  *         print len(vs)
2435  *         l = len(me.verts)
2436  *         me.verts.extend(vs)
2437  *
2438  *         i = l
2439  *         while i < len(me.verts):
2440  *             ii = i + 1
2441  *             if ii == len(me.verts):
2442  *                 ii = l
2443  *             me.edges.extend([i, ii])
2444  *             i += 1
2445  *
2446  * if __name__ == '__main__':
2447  *     main()
2448  */
2449
2450
2451 #undef ISECT_1
2452 #undef ISECT_2
2453 #undef ISECT_3
2454 #undef ISECT_4
2455 #undef ISECT_ALL3
2456 #undef ISECT_ALL4
2457
2458
2459 /* checks if pt is inside a convex 2D polyline, the polyline must be ordered rotating clockwise
2460  * otherwise it would have to test for mixed (line_point_side_v2 > 0.0f) cases */
2461 static bool IsectPoly2Df(const float pt[2], float uv[][2], const int tot)
2462 {
2463         int i;
2464         if (line_point_side_v2(uv[tot - 1], uv[0], pt) < 0.0f)
2465                 return 0;
2466
2467         for (i = 1; i < tot; i++) {
2468                 if (line_point_side_v2(uv[i - 1], uv[i], pt) < 0.0f)
2469                         return 0;
2470
2471         }
2472
2473         return 1;
2474 }
2475 static bool IsectPoly2Df_twoside(const float pt[2], float uv[][2], const int tot)
2476 {
2477         int i;
2478         bool side = (line_point_side_v2(uv[tot - 1], uv[0], pt) > 0.0f);
2479
2480         for (i = 1; i < tot; i++) {
2481                 if ((line_point_side_v2(uv[i - 1], uv[i], pt) > 0.0f) != side)
2482                         return 0;
2483
2484         }
2485
2486         return 1;
2487 }
2488
2489 /* One of the most important function for projection painting,
2490  * since it selects the pixels to be added into each bucket.
2491  *
2492  * initialize pixels from this face where it intersects with the bucket_index,
2493  * optionally initialize pixels for removing seams */
2494 static void project_paint_face_init(
2495         const ProjPaintState *ps,
2496         const int thread_index, const int bucket_index, const int tri_index, const int image_index,
2497         const rctf *clip_rect, const rctf *bucket_bounds, ImBuf *ibuf, ImBuf **tmpibuf)
2498 {
2499         /* Projection vars, to get the 3D locations into screen space  */
2500         MemArena *arena = ps->arena_mt[thread_index];
2501         LinkNode **bucketPixelNodes = ps->bucketRect + bucket_index;
2502         LinkNode *bucketFaceNodes = ps->bucketFaces[bucket_index];
2503         bool threaded = (ps->thread_tot > 1);
2504
2505         TileInfo tinf = {
2506                 ps->tile_lock,
2507                 ps->do_masking,
2508                 IMAPAINT_TILE_NUMBER(ibuf->x),
2509                 tmpibuf,
2510                 ps->projImages + image_index
2511         };
2512
2513         const MLoopTri *lt = &ps->dm_mlooptri[tri_index];
2514         const int lt_vtri[3] = { PS_LOOPTRI_AS_VERT_INDEX_3(ps, lt) };
2515         const float *lt_tri_uv[3] = { PS_LOOPTRI_AS_UV_3(ps->dm_mloopuv, lt) };
2516
2517         /* UV/pixel seeking data */
2518         int x; /* Image X-Pixel */
2519         int y; /* Image Y-Pixel */
2520         float mask;
2521         float uv[2]; /* Image floating point UV - same as x, y but from 0.0-1.0 */
2522
2523         const float *v1coSS, *v2coSS, *v3coSS; /* vert co screen-space, these will be assigned to lt_vtri[0-2] */
2524
2525         const float *vCo[3]; /* vertex screenspace coords */
2526
2527         float w[3], wco[3];
2528
2529         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 */
2530         float pixelScreenCo[4];
2531         bool do_3d_mapping = ps->brush->mtex.brush_map_mode == MTEX_MAP_MODE_3D;
2532
2533         rcti bounds_px; /* ispace bounds */
2534         /* vars for getting uvspace bounds */
2535
2536         float lt_uv_pxoffset[3][2]; /* bucket bounds in UV space so we can init pixels only for this face,  */
2537         float xhalfpx, yhalfpx;
2538         const float ibuf_xf = (float)ibuf->x, ibuf_yf = (float)ibuf->y;
2539
2540         int has_x_isect = 0, has_isect = 0; /* for early loop exit */
2541
2542         float uv_clip[8][2];
2543         int uv_clip_tot;
2544         const bool is_ortho = ps->is_ortho;
2545         const bool is_flip_object = ps->is_flip_object;
2546         const bool do_backfacecull = ps->do_backfacecull;
2547         const bool do_clip = ps->rv3d ? ps->rv3d->rflag & RV3D_CLIPPING : 0;
2548
2549         vCo[0] = ps->dm_mvert[lt_vtri[0]].co;
2550         vCo[1] = ps->dm_mvert[lt_vtri[1]].co;
2551         vCo[2] = ps->dm_mvert[lt_vtri[2]].co;
2552
2553
2554         /* Use lt_uv_pxoffset instead of lt_tri_uv so we can offset the UV half a pixel
2555          * this is done so we can avoid offsetting all the pixels by 0.5 which causes
2556          * problems when wrapping negative coords */
2557         xhalfpx = (0.5f + (PROJ_PIXEL_TOLERANCE * (1.0f / 3.0f))) / ibuf_xf;
2558         yhalfpx = (0.5f + (PROJ_PIXEL_TOLERANCE * (1.0f / 4.0f))) / ibuf_yf;
2559
2560         /* Note about (PROJ_GEOM_TOLERANCE/x) above...
2561          * Needed to add this offset since UV coords are often quads aligned to pixels.
2562          * In this case pixels can be exactly between 2 triangles causing nasty
2563          * artifacts.
2564          *
2565          * This workaround can be removed and painting will still work on most cases
2566          * but since the first thing most people try is painting onto a quad- better make it work.
2567          */
2568
2569         lt_uv_pxoffset[0][0] = lt_tri_uv[0][0] - xhalfpx;
2570         lt_uv_pxoffset[0][1] = lt_tri_uv[0][1] - yhalfpx;
2571
2572         lt_uv_pxoffset[1][0] = lt_tri_uv[1][0] - xhalfpx;
2573         lt_uv_pxoffset[1][1] = lt_tri_uv[1][1] - yhalfpx;
2574
2575         lt_uv_pxoffset[2][0] = lt_tri_uv[2][0] - xhalfpx;
2576         lt_uv_pxoffset[2][1] = lt_tri_uv[2][1] - yhalfpx;
2577
2578         {
2579                 uv1co = lt_uv_pxoffset[0]; // was lt_tri_uv[i1];
2580                 uv2co = lt_uv_pxoffset[1]; // was lt_tri_uv[i2];
2581                 uv3co = lt_uv_pxoffset[2]; // was lt_tri_uv[i3];
2582
2583                 v1coSS = ps->screenCoords[lt_vtri[0]];
2584                 v2coSS = ps->screenCoords[lt_vtri[1]];
2585                 v3coSS = ps->screenCoords[lt_vtri[2]];
2586
2587                 /* This funtion gives is a concave polyline in UV space from the clipped tri*/
2588                 project_bucket_clip_face(
2589                         is_ortho, is_flip_object,
2590                         clip_rect, bucket_bounds,
2591                         v1coSS, v2coSS, v3coSS,
2592                         uv1co, uv2co, uv3co,
2593                         uv_clip, &uv_clip_tot,
2594                         do_backfacecull || ps->do_occlude);
2595
2596                 /* sometimes this happens, better just allow for 8 intersectiosn even though there should be max 6 */
2597 #if 0
2598                 if (uv_clip_tot > 6) {
2599                         printf("this should never happen! %d\n", uv_clip_tot);
2600                 }
2601 #endif
2602
2603                 if (pixel_bounds_array(uv_clip, &bounds_px, ibuf->x, ibuf->y, uv_clip_tot)) {
2604 #if 0
2605                         project_paint_undo_tiles_init(&bounds_px, ps->projImages + image_index, tmpibuf,
2606                                                       tile_width, threaded, ps->do_masking);
2607 #endif
2608                         /* clip face and */
2609
2610                         has_isect = 0;
2611                         for (y = bounds_px.ymin; y < bounds_px.ymax; y++) {
2612                                 //uv[1] = (((float)y) + 0.5f) / (float)ibuf->y;
2613                                 uv[1] = (float)y / ibuf_yf; /* use pixel offset UV coords instead */
2614
2615                                 has_x_isect = 0;
2616                                 for (x = bounds_px.xmin; x < bounds_px.xmax; x++) {
2617                                         //uv[0] = (((float)x) + 0.5f) / ibuf->x;
2618                                         uv[0] = (float)x / ibuf_xf; /* use pixel offset UV coords instead */
2619
2620                                         /* Note about IsectPoly2Df_twoside, checking the face or uv flipping doesnt work,
2621                                          * could check the poly direction but better to do this */
2622                                         if ((do_backfacecull == true  && IsectPoly2Df(uv, uv_clip, uv_clip_tot)) ||
2623                                             (do_backfacecull == false && IsectPoly2Df_twoside(uv, uv_clip, uv_clip_tot)))
2624                                         {
2625
2626                                                 has_x_isect = has_isect = 1;
2627
2628                                                 if (is_ortho) screen_px_from_ortho(uv, v1coSS, v2coSS, v3coSS, uv1co, uv2co, uv3co, pixelScreenCo, w);
2629                                                 else screen_px_from_persp(uv, v1coSS, v2coSS, v3coSS, uv1co, uv2co, uv3co, pixelScreenCo, w);
2630
2631                                                 /* a pity we need to get the worldspace pixel location here */
2632                                                 if (do_clip || do_3d_mapping) {
2633                                                         interp_v3_v3v3v3(
2634                                                                 wco,
2635                                                                 ps->dm_mvert[lt_vtri[0]].co,
2636                                                                 ps->dm_mvert[lt_vtri[1]].co,
2637                                                                 ps->dm_mvert[lt_vtri[2]].co,
2638                                                                 w);
2639                                                         if (do_clip && ED_view3d_clipping_test(ps->rv3d, wco, true)) {
2640                                                                 continue; /* Watch out that no code below this needs to run */
2641                                                         }
2642                                                 }
2643
2644                                                 /* Is this UV visible from the view? - raytrace */
2645                                                 /* project_paint_PickFace is less complex, use for testing */
2646                                                 //if (project_paint_PickFace(ps, pixelScreenCo, w, &side) == tri_index) {
2647                                                 if ((ps->do_occlude == false) ||
2648                                                     !project_bucket_point_occluded(ps, bucketFaceNodes, tri_index, pixelScreenCo))
2649                                                 {
2650                                                         mask = project_paint_uvpixel_mask(ps, tri_index, w);
2651
2652                                                         if (mask > 0.0f) {
2653                                                                 BLI_linklist_prepend_arena(
2654                                                                         bucketPixelNodes,
2655                                                                         project_paint_uvpixel_init(ps, arena, &tinf, x, y, mask, tri_index,
2656                                                                                                    pixelScreenCo, wco, w),
2657                                                                         arena
2658                                                                         );
2659                                                         }
2660                                                 }
2661
2662                                         }
2663 //#if 0
2664                                         else if (has_x_isect) {
2665                                                 /* assuming the face is not a bow-tie - we know we cant intersect again on the X */
2666                                                 break;
2667                                         }
2668 //#endif
2669                                 }
2670
2671
2672 #if 0           /* TODO - investigate why this dosnt work sometimes! it should! */
2673                                 /* no intersection for this entire row, after some intersection above means we can quit now */
2674                                 if (has_x_isect == 0 && has_isect) {
2675                                         break;
2676                                 }
2677 #endif
2678                         }
2679                 }
2680         }
2681
2682
2683 #ifndef PROJ_DEBUG_NOSEAMBLEED
2684         if (ps->seam_bleed_px > 0.0f) {
2685                 int face_seam_flag;
2686
2687                 if (threaded)
2688                         BLI_thread_lock(LOCK_CUSTOM1);  /* Other threads could be modifying these vars */
2689
2690                 face_seam_flag = ps->faceSeamFlags[tri_index];
2691
2692                 /* are any of our edges un-initialized? */
2693                 if ((face_seam_flag & (PROJ_FACE_SEAM1 | PROJ_FACE_NOSEAM1)) == 0 ||
2694                     (face_seam_flag & (PROJ_FACE_SEAM2 | PROJ_FACE_NOSEAM2)) == 0 ||
2695                     (face_seam_flag & (PROJ_FACE_SEAM3 | PROJ_FACE_NOSEAM3)) == 0)
2696                 {
2697                         project_face_seams_init(ps, tri_index);
2698                         face_seam_flag = ps->faceSeamFlags[tri_index];
2699                         //printf("seams - %d %d %d %d\n", flag&PROJ_FACE_SEAM1, flag&PROJ_FACE_SEAM2, flag&PROJ_FACE_SEAM3);
2700                 }
2701
2702                 if ((face_seam_flag & (PROJ_FACE_SEAM1 | PROJ_FACE_SEAM2 | PROJ_FACE_SEAM3)) == 0) {
2703
2704                         if (threaded)
2705                                 BLI_thread_unlock(LOCK_CUSTOM1);  /* Other threads could be modifying these vars */
2706
2707                 }
2708                 else {
2709                         /* we have a seam - deal with it! */
2710
2711                         /* Now create new UV's for the seam face */
2712                         float (*outset_uv)[2] = ps->faceSeamUVs[tri_index];
2713                         float insetCos[3][3]; /* inset face coords.  NOTE!!! ScreenSace for ortho, Worldspace in prespective view */
2714
2715                         const float *vCoSS[3]; /* vertex screenspace coords */
2716
2717                         float bucket_clip_edges[2][2]; /* store the screenspace coords of the face, clipped by the bucket's screen aligned rectangle */
2718                         float edge_verts_inset_clip[2][3];
2719                         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 */
2720
2721                         float seam_subsection[4][2];
2722                         float fac1, fac2;
2723
2724                         if (outset_uv[0][0] == FLT_MAX) /* first time initialize */
2725                                 uv_image_outset(
2726                                         lt_uv_pxoffset, outset_uv, ps->seam_bleed_px,
2727                                         ibuf->x, ibuf->y, (ps->faceWindingFlags[tri_index] & PROJ_FACE_WINDING_CW) == 0);
2728
2729                         /* ps->faceSeamUVs cant be modified when threading, now this is done we can unlock */
2730                         if (threaded)
2731                                 BLI_thread_unlock(LOCK_CUSTOM1);  /* Other threads could be modifying these vars */
2732
2733                         vCoSS[0] = ps->screenCoords[lt_vtri[0]];
2734                         vCoSS[1] = ps->screenCoords[lt_vtri[1]];
2735                         vCoSS[2] = ps->screenCoords[lt_vtri[2]];
2736
2737                         /* PROJ_FACE_SCALE_SEAM must be slightly less then 1.0f */
2738                         if (is_ortho) {
2739                                 scale_tri(insetCos, vCoSS, PROJ_FACE_SCALE_SEAM);
2740                         }
2741                         else {
2742                                 scale_tri(insetCos, vCo, PROJ_FACE_SCALE_SEAM);
2743                         }
2744
2745                         for (fidx1 = 0; fidx1 < 3; fidx1++) {
2746                                 fidx2 = (fidx1 == 2) ? 0 : fidx1 + 1;  /* next fidx in the face (0,1,2) -> (1,2,0) */
2747
2748                                 if ((face_seam_flag & (1 << fidx1)) && /* 1<<fidx1 -> PROJ_FACE_SEAM# */
2749                                     line_clip_rect2f(clip_rect, bucket_bounds, vCoSS[fidx1], vCoSS[fidx2], bucket_clip_edges[0], bucket_clip_edges[1]))
2750                                 {
2751                                         if (len_squared_v2v2(vCoSS[fidx1], vCoSS[fidx2]) > FLT_EPSILON) { /* avoid div by zero */
2752
2753                                                 if (is_ortho) {
2754                                                         fac1 = line_point_factor_v2(bucket_clip_edges[0], vCoSS[fidx1], vCoSS[fidx2]);
2755                                                         fac2 = line_point_factor_v2(bucket_clip_edges[1], vCoSS[fidx1], vCoSS[fidx2]);
2756                                                 }
2757                                                 else {
2758                                                         fac1 = screen_px_line_point_factor_v2_persp(ps, bucket_clip_edges[0], vCo[fidx1], vCo[fidx2]);
2759                                                         fac2 = screen_px_line_point_factor_v2_persp(ps, bucket_clip_edges[1], vCo[fidx1], vCo[fidx2]);
2760                                                 }
2761
2762                                                 interp_v2_v2v2(seam_subsection[0], lt_uv_pxoffset[fidx1], lt_uv_pxoffset[fidx2], fac1);
2763                                                 interp_v2_v2v2(seam_subsection[1], lt_uv_pxoffset[fidx1], lt_uv_pxoffset[fidx2], fac2);
2764
2765                                                 interp_v2_v2v2(seam_subsection[2], outset_uv[fidx1], outset_uv[fidx2], fac2);
2766                                                 interp_v2_v2v2(seam_subsection[3], outset_uv[fidx1], outset_uv[fidx2], fac1);
2767
2768                                                 /* if the bucket_clip_edges values Z values was kept we could avoid this
2769                                                  * Inset needs to be added so occlusion tests wont hit adjacent faces */
2770                                                 interp_v3_v3v3(edge_verts_inset_clip[0], insetCos[fidx1], insetCos[fidx2], fac1);
2771                                                 interp_v3_v3v3(edge_verts_inset_clip[1], insetCos[fidx1], insetCos[fidx2], fac2);
2772
2773
2774                                                 if (pixel_bounds_uv(seam_subsection, &bounds_px, ibuf->x, ibuf->y)) {
2775                                                         /* bounds between the seam rect and the uvspace bucket pixels */
2776
2777                                                         has_isect = 0;
2778                                                         for (y = bounds_px.ymin; y < bounds_px.ymax; y++) {
2779                                                                 // uv[1] = (((float)y) + 0.5f) / (float)ibuf->y;
2780                                                                 uv[1] = (float)y / ibuf_yf; /* use offset uvs instead */
2781
2782                                                                 has_x_isect = 0;
2783                                                                 for (x = bounds_px.xmin; x < bounds_px.xmax; x++) {
2784                                                                         //uv[0] = (((float)x) + 0.5f) / (float)ibuf->x;
2785                                                                         uv[0] = (float)x / ibuf_xf; /* use offset uvs instead */
2786
2787                                                                         /* test we're inside uvspace bucket and triangle bounds */
2788                                                                         if (isect_point_quad_v2(uv, UNPACK4(seam_subsection))) {
2789                                                                                 float fac;
2790
2791                                                                                 /* We need to find the closest point along the face edge,
2792                                                                                  * getting the screen_px_from_*** wont work because our actual location
2793                                                                                  * is not relevant, since we are outside the face, Use VecLerpf to find
2794                                                                                  * our location on the side of the face's UV */
2795 #if 0
2796                                                                                 if (is_ortho) screen_px_from_ortho(ps, uv, v1co, v2co, v3co, uv1co, uv2co, uv3co, pixelScreenCo);
2797                                                                                 else          screen_px_from_persp(ps, uv, v1co, v2co, v3co, uv1co, uv2co, uv3co, pixelScreenCo);
2798 #endif
2799
2800                                                                                 /* Since this is a seam we need to work out where on the line this pixel is */
2801                                                                                 //fac = line_point_factor_v2(uv, uv_seam_quad[0], uv_seam_quad[1]);
2802                                                                                 fac = resolve_quad_u_v2(uv, UNPACK4(seam_subsection));
2803                                                                                 interp_v3_v3v3(pixelScreenCo, edge_verts_inset_clip[0], edge_verts_inset_clip[1], fac);
2804
2805                                                                                 if (!is_ortho) {
2806                                                                                         pixelScreenCo[3] = 1.0f;
2807                                                                                         mul_m4_v4((float(*)[4])ps->projectMat, pixelScreenCo); /* cast because of const */
2808                                                                                         pixelScreenCo[0] = (float)(ps->winx * 0.5f) + (ps->winx * 0.5f) * pixelScreenCo[0] / pixelScreenCo[3];
2809                                                                                         pixelScreenCo[1] = (float)(ps->winy * 0.5f) + (ps->winy * 0.5f) * pixelScreenCo[1] / pixelScreenCo[3];
2810                                                                                         pixelScreenCo[2] = pixelScreenCo[2] / pixelScreenCo[3]; /* Use the depth for bucket point occlusion */
2811                                                                                 }
2812
2813                                                                                 if ((ps->do_occlude == false) ||
2814                                                                                     !project_bucket_point_occluded(ps, bucketFaceNodes, tri_index, pixelScreenCo))
2815                                                                                 {
2816                                                                                         /* Only bother calculating the weights if we intersect */
2817                                                                                         if (ps->do_mask_normal || ps->dm_mloopuv_clone) {
2818                                                                                                 const float uv_fac = fac1 + (fac * (fac2 - fac1));
2819 #if 0
2820                                                                                                 /* get the UV on the line since we want to copy the pixels from there for bleeding */
2821                                                                                                 float uv_close[2];
2822                                                                                                 interp_v2_v2v2(uv_close, lt_uv_pxoffset[fidx1], lt_uv_pxoffset[fidx2], uv_fac);
2823                                                                                                 barycentric_weights_v2(lt_uv_pxoffset[0], lt_uv_pxoffset[1], lt_uv_pxoffset[2], uv_close, w);
2824 #else
2825
2826                                                                                                 /* Cheat, we know where we are along the edge so work out the weights from that */
2827                                                                                                 w[0] = w[1] = w[2] = 0.0;
2828                                                                                                 w[fidx1] = 1.0f - uv_fac;
2829                                                                                                 w[fidx2] = uv_fac;
2830 #endif
2831                                                                                         }
2832
2833                                                                                         /* a pity we need to get the worldspace pixel location here */
2834                                                                                         if (do_clip || do_3d_mapping) {
2835                                                                                                 interp_v3_v3v3v3(wco, vCo[0], vCo[1], vCo[2], w);
2836
2837                                                                                                 if (do_clip && ED_view3d_clipping_test(ps->rv3d, wco, true)) {
2838                                                                                                         continue; /* Watch out that no code below this needs to run */
2839                                                                                                 }
2840                                                                                         }
2841
2842                                                                                         mask = project_paint_uvpixel_mask(ps, tri_index, w);
2843
2844                                                                                         if (mask > 0.0f) {
2845                                                                                                 BLI_linklist_prepend_arena(
2846                                                                                                         bucketPixelNodes,
2847                                                                                                         project_paint_uvpixel_init(ps, arena, &tinf, x, y, mask, tri_index,
2848                                                                                                         pixelScreenCo, wco, w),
2849                                                                                                         arena
2850                                                                                                         );
2851                                                                                         }
2852
2853                                                                                 }
2854                                                                         }
2855                                                                         else if (has_x_isect) {
2856                                                                                 /* assuming the face is not a bow-tie - we know we cant intersect again on the X */
2857                                                                                 break;
2858                                                                         }
2859                                                                 }
2860
2861 #if 0                           /* TODO - investigate why this dosnt work sometimes! it should! */
2862                                                                 /* no intersection for this entire row, after some intersection above means we can quit now */
2863                                                                 if (has_x_isect == 0 && has_isect) {
2864                                                                         break;
2865                                                                 }
2866 #endif
2867                                                         }
2868                                                 }
2869                                         }
2870                                 }
2871                         }
2872                 }
2873         }
2874 #else
2875         UNUSED_VARS(vCo, threaded);
2876 #endif // PROJ_DEBUG_NOSEAMBLEED
2877 }
2878
2879
2880 /* takes floating point screenspace min/max and returns int min/max to be used as indices for ps->bucketRect, ps->bucketFlags */
2881 static void project_paint_bucket_bounds(const ProjPaintState *ps, const float min[2], const float max[2], int bucketMin[2], int bucketMax[2])
2882 {
2883         /* divide by bucketWidth & bucketHeight so the bounds are offset in bucket grid units */
2884         /* XXX: the offset of 0.5 is always truncated to zero and the offset of 1.5f is always truncated to 1, is this really correct?? - jwilkins */
2885         bucketMin[0] = (int)((int)(((float)(min[0] - ps->screenMin[0]) / ps->screen_width) * ps->buckets_x) + 0.5f); /* these offsets of 0.5 and 1.5 seem odd but they are correct */
2886         bucketMin[1] = (int)((int)(((float)(min[1] - ps->screenMin[1]) / ps->screen_height) * ps->buckets_y) + 0.5f);
2887
2888         bucketMax[0] = (int)((int)(((float)(max[0] - ps->screenMin[0]) / ps->screen_width) * ps->buckets_x) + 1.5f);
2889         bucketMax[1] = (int)((int)(((float)(max[1] - ps->screenMin[1]) / ps->screen_height) * ps->buckets_y) + 1.5f);
2890
2891         /* in case the rect is outside the mesh 2d bounds */
2892         CLAMP(bucketMin[0], 0, ps->buckets_x);
2893         CLAMP(bucketMin[1], 0, ps->buckets_y);
2894
2895         CLAMP(bucketMax[0], 0, ps->buckets_x);
2896         CLAMP(bucketMax[1], 0, ps->buckets_y);
2897 }
2898
2899 /* set bucket_bounds to a screen space-aligned floating point bound-box */
2900 static void project_bucket_bounds(const ProjPaintState *ps, const int bucket_x, const int bucket_y, rctf *bucket_bounds)
2901 {
2902         bucket_bounds->xmin = ps->screenMin[0] + ((bucket_x) * (ps->screen_width / ps->buckets_x));     /* left */
2903         bucket_bounds->xmax = ps->screenMin[0] + ((bucket_x + 1) * (ps->screen_width / ps->buckets_x)); /* right */
2904
2905         bucket_bounds->ymin = ps->screenMin[1] + ((bucket_y) * (ps->screen_height / ps->buckets_y));      /* bottom */
2906         bucket_bounds->ymax = ps->screenMin[1] + ((bucket_y + 1) * (ps->screen_height  / ps->buckets_y)); /* top */
2907 }
2908
2909 /* Fill this bucket with pixels from the faces that intersect it.
2910  *
2911  * have bucket_bounds as an argument so we don't need to give bucket_x/y the rect function needs */
2912 static void project_bucket_init(
2913         const ProjPaintState *ps, const int thread_index, const int bucket_index,
2914         const rctf *clip_rect, const rctf *bucket_bounds)
2915 {
2916         LinkNode *node;
2917         int tri_index, image_index = 0;
2918         ImBuf *ibuf = NULL;
2919         Image *tpage_last = NULL, *tpage;
2920         ImBuf *tmpibuf = NULL;
2921
2922         if (ps->image_tot == 1) {
2923                 /* Simple loop, no context switching */
2924                 ibuf = ps->projImages[0].ibuf;
2925
2926                 for (node = ps->bucketFaces[bucket_index]; node; node = node->next) {
2927                         project_paint_face_init(
2928                                 ps, thread_index, bucket_index, GET_INT_FROM_POINTER(node->link), 0,
2929                                 clip_rect, bucket_bounds, ibuf, &tmpibuf);
2930                 }
2931         }
2932         else {
2933
2934                 /* More complicated loop, switch between images */
2935                 for (node = ps->bucketFaces[bucket_index]; node; node = node->next) {
2936                         tri_index = GET_INT_FROM_POINTER(node->link);
2937
2938                         /* Image context switching */
2939                       &