Cleanup: spelling
[blender-staging.git] / source / blender / editors / sculpt_paint / paint_image_proj.c
1 /*
2  * ***** BEGIN GPL LICENSE BLOCK *****
3  *
4  * This program is free software; you can redistribute it and/or
5  * modify it under the terms of the GNU General Public License
6  * as published by the Free Software Foundation; either version 2
7  * of the License, or (at your option) any later version.
8  *
9  * This program is distributed in the hope that it will be useful,
10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
12  * GNU General Public License for more details.
13  *
14  * along with this program; if not, write to the Free Software Foundation,
15  * Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
16  *
17  * The Original Code is Copyright (C) 2001-2002 by NaN Holding BV.
18  * All rights reserved.
19  *
20  * The Original Code is: some of this file.
21  *
22  * Contributor(s): Jens Ole Wund (bjornmose), Campbell Barton (ideasman42)
23  *
24  * ***** END GPL LICENSE BLOCK *****
25  */
26
27 /** \file blender/editors/sculpt_paint/paint_image_proj.c
28  *  \ingroup edsculpt
29  *  \brief Functions to paint images in 2D and 3D.
30  */
31
32 #include <float.h>
33 #include <string.h>
34 #include <stdio.h>
35 #include <math.h>
36
37 #include "MEM_guardedalloc.h"
38
39 #ifdef WIN32
40 #  include "BLI_winstuff.h"
41 #endif
42
43 #include "BLI_blenlib.h"
44 #include "BLI_linklist.h"
45 #include "BLI_math.h"
46 #include "BLI_math_bits.h"
47 #include "BLI_math_color_blend.h"
48 #include "BLI_memarena.h"
49 #include "BLI_threads.h"
50 #include "BLI_utildefines.h"
51
52 #include "BLT_translation.h"
53
54
55 #include "IMB_imbuf.h"
56 #include "IMB_imbuf_types.h"
57
58 #include "DNA_brush_types.h"
59 #include "DNA_material_types.h"
60 #include "DNA_mesh_types.h"
61 #include "DNA_node_types.h"
62 #include "DNA_object_types.h"
63
64 #include "BKE_camera.h"
65 #include "BKE_context.h"
66 #include "BKE_colortools.h"
67 #include "BKE_depsgraph.h"
68 #include "BKE_DerivedMesh.h"
69 #include "BKE_idprop.h"
70 #include "BKE_brush.h"
71 #include "BKE_image.h"
72 #include "BKE_library.h"
73 #include "BKE_main.h"
74 #include "BKE_material.h"
75 #include "BKE_mesh.h"
76 #include "BKE_mesh_mapping.h"
77 #include "BKE_node.h"
78 #include "BKE_paint.h"
79 #include "BKE_report.h"
80 #include "BKE_scene.h"
81 #include "BKE_texture.h"
82
83 #include "UI_interface.h"
84
85 #include "ED_mesh.h"
86 #include "ED_node.h"
87 #include "ED_paint.h"
88 #include "ED_screen.h"
89 #include "ED_uvedit.h"
90 #include "ED_view3d.h"
91
92 #include "GPU_extensions.h"
93
94 #include "WM_api.h"
95 #include "WM_types.h"
96
97 #include "RNA_access.h"
98 #include "RNA_define.h"
99 #include "RNA_enum_types.h"
100
101 #include "GPU_draw.h"
102
103 #include "IMB_colormanagement.h"
104
105 #include "bmesh.h"
106 //#include "bmesh_tools.h"
107
108 #include "paint_intern.h"
109
110 /* Defines and Structs */
111 /* FTOCHAR as inline function */
112 BLI_INLINE unsigned char f_to_char(const float val)
113 {
114         return FTOCHAR(val);
115 }
116
117 /* ProjectionPaint defines */
118
119 /* approx the number of buckets to have under the brush,
120  * used with the brush size to set the ps->buckets_x and ps->buckets_y value.
121  *
122  * When 3 - a brush should have ~9 buckets under it at once
123  * ...this helps for threading while painting as well as
124  * avoiding initializing pixels that wont touch the brush */
125 #define PROJ_BUCKET_BRUSH_DIV 4
126
127 #define PROJ_BUCKET_RECT_MIN 4
128 #define PROJ_BUCKET_RECT_MAX 256
129
130 #define PROJ_BOUNDBOX_DIV 8
131 #define PROJ_BOUNDBOX_SQUARED  (PROJ_BOUNDBOX_DIV * PROJ_BOUNDBOX_DIV)
132
133 //#define PROJ_DEBUG_PAINT 1
134 //#define PROJ_DEBUG_NOSEAMBLEED 1
135 //#define PROJ_DEBUG_PRINT_CLIP 1
136 #define PROJ_DEBUG_WINCLIP 1
137
138
139 #ifndef PROJ_DEBUG_NOSEAMBLEED
140 /* projectFaceSeamFlags options */
141 //#define PROJ_FACE_IGNORE      (1<<0)  /* When the face is hidden, backfacing or occluded */
142 //#define PROJ_FACE_INIT        (1<<1)  /* When we have initialized the faces data */
143 #define PROJ_FACE_SEAM1 (1 << 0)  /* If this face has a seam on any of its edges */
144 #define PROJ_FACE_SEAM2 (1 << 1)
145 #define PROJ_FACE_SEAM3 (1 << 2)
146
147 #define PROJ_FACE_NOSEAM1   (1 << 4)
148 #define PROJ_FACE_NOSEAM2   (1 << 5)
149 #define PROJ_FACE_NOSEAM3   (1 << 6)
150
151 /* face winding */
152 #define PROJ_FACE_WINDING_INIT 1
153 #define PROJ_FACE_WINDING_CW 2
154
155 /* a slightly scaled down face is used to get fake 3D location for edge pixels in the seams
156  * as this number approaches  1.0f the likelihood increases of float precision errors where
157  * it is occluded by an adjacent face */
158 #define PROJ_FACE_SCALE_SEAM    0.99f
159 #endif  /* PROJ_DEBUG_NOSEAMBLEED */
160
161
162 #define PROJ_SRC_VIEW       1
163 #define PROJ_SRC_IMAGE_CAM  2
164 #define PROJ_SRC_IMAGE_VIEW 3
165 #define PROJ_SRC_VIEW_FILL  4
166
167 #define PROJ_VIEW_DATA_ID "view_data"
168 #define PROJ_VIEW_DATA_SIZE (4 * 4 + 4 * 4 + 3) /* viewmat + winmat + clipsta + clipend + is_ortho */
169
170 #define PROJ_BUCKET_NULL        0
171 #define PROJ_BUCKET_INIT        (1 << 0)
172 // #define PROJ_BUCKET_CLONE_INIT       (1<<1)
173
174 /* used for testing doubles, if a point is on a line etc */
175 #define PROJ_GEOM_TOLERANCE 0.00075f
176 #define PROJ_PIXEL_TOLERANCE 0.01f
177
178 /* vert flags */
179 #define PROJ_VERT_CULL 1
180
181 /* to avoid locking in tile initialization */
182 #define TILE_PENDING SET_INT_IN_POINTER(-1)
183
184 /* This is mainly a convenience struct used so we can keep an array of images we use
185  * Thir imbufs, etc, in 1 array, When using threads this array is copied for each thread
186  * because 'partRedrawRect' and 'touch' values would not be thread safe */
187 typedef struct ProjPaintImage {
188         Image *ima;
189         ImBuf *ibuf;
190         ImagePaintPartialRedraw *partRedrawRect;
191         volatile void **undoRect; /* only used to build undo tiles during painting */
192         unsigned short **maskRect; /* the mask accumulation must happen on canvas, not on space screen bucket.
193                                     * Here we store the mask rectangle */
194         bool **valid; /* store flag to enforce validation of undo rectangle */
195         bool touch;
196 } ProjPaintImage;
197
198 /**
199  * Handle for stroke (operator customdata)
200  */
201 typedef struct ProjStrokeHandle {
202         /* Support for painting from multiple views at once,
203          * currently used to impliment summetry painting,
204          * we can assume at least the first is set while painting. */
205         struct ProjPaintState *ps_views[8];
206         int ps_views_tot;
207         int symmetry_flags;
208
209         int orig_brush_size;
210
211         bool need_redraw;
212
213         /* trick to bypass regular paint and allow clone picking */
214         bool is_clone_cursor_pick;
215
216         /* In ProjPaintState, only here for convenience */
217         Scene *scene;
218         Brush *brush;
219 } ProjStrokeHandle;
220
221 /* Main projection painting struct passed to all projection painting functions */
222 typedef struct ProjPaintState {
223         View3D *v3d;
224         RegionView3D *rv3d;
225         ARegion *ar;
226         Scene *scene;
227         int source; /* PROJ_SRC_**** */
228
229         /* the paint color. It can change depending of inverted mode or not */
230         float paint_color[3];
231         float paint_color_linear[3];
232         float dither;
233
234         Brush *brush;
235         short tool, blend, mode;
236
237         float brush_size;
238         Object *ob;
239         /* for symmetry, we need to store modified object matrix */
240         float obmat[4][4];
241         float obmat_imat[4][4];
242         /* end similarities with ImagePaintState */
243
244         Image *stencil_ima;
245         Image *canvas_ima;
246         Image *clone_ima;
247         float stencil_value;
248
249         /* projection painting only */
250         MemArena *arena_mt[BLENDER_MAX_THREADS]; /* for multithreading, the first item is sometimes used for non threaded cases too */
251         LinkNode **bucketRect;              /* screen sized 2D array, each pixel has a linked list of ProjPixel's */
252         LinkNode **bucketFaces;             /* bucketRect aligned array linkList of faces overlapping each bucket */
253         unsigned char *bucketFlags;         /* store if the bucks have been initialized  */
254
255         char *vertFlags;                    /* store options per vert, now only store if the vert is pointing away from the view */
256         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 */
257         int buckets_y;
258
259         int pixel_sizeof;           /* result of project_paint_pixel_sizeof(), constant per stroke */
260
261         int image_tot;              /* size of projectImages array */
262
263         float (*screenCoords)[4];   /* verts projected into floating point screen space */
264         float screenMin[2];         /* 2D bounds for mesh verts on the screen's plane (screenspace) */
265         float screenMax[2];
266         float screen_width;         /* Calculated from screenMin & screenMax */
267         float screen_height;
268         int winx, winy;             /* from the carea or from the projection render */
269
270         /* options for projection painting */
271         bool  do_layer_clone;
272         bool  do_layer_stencil;
273         bool  do_layer_stencil_inv;
274         bool  do_stencil_brush;
275         bool  do_material_slots;
276
277         bool  do_occlude;               /* Use raytraced occlusion? - ortherwise will paint right through to the back*/
278         bool  do_backfacecull;          /* ignore faces with normals pointing away, skips a lot of raycasts if your normals are correctly flipped */
279         bool  do_mask_normal;           /* mask out pixels based on their normals */
280         bool  do_mask_cavity;           /* mask out pixels based on cavity */
281         bool  do_new_shading_nodes;     /* cache BKE_scene_use_new_shading_nodes value */
282         float normal_angle;             /* what angle to mask at */
283         float normal_angle__cos;         /* cos(normal_angle), faster to compare */
284         float normal_angle_inner;
285         float normal_angle_inner__cos;
286         float normal_angle_range;       /* difference between normal_angle and normal_angle_inner, for easy access */
287
288         bool do_face_sel;               /* quick access to (me->editflag & ME_EDIT_PAINT_FACE_SEL) */
289         bool is_ortho;
290         bool is_flip_object;            /* the object is negative scaled */
291         bool do_masking;              /* use masking during painting. Some operations such as airbrush may disable */
292         bool is_texbrush;              /* only to avoid running  */
293         bool is_maskbrush;            /* mask brush is applied before masking */
294 #ifndef PROJ_DEBUG_NOSEAMBLEED
295         float seam_bleed_px;
296 #endif
297         /* clone vars */
298         float cloneOffset[2];
299
300         float projectMat[4][4];     /* Projection matrix, use for getting screen coords */
301         float projectMatInv[4][4];  /* inverse of projectMat */
302         float viewDir[3];           /* View vector, use for do_backfacecull and for ray casting with an ortho viewport  */
303         float viewPos[3];           /* View location in object relative 3D space, so can compare to verts  */
304         float clipsta, clipend;
305
306         /* reproject vars */
307         Image *reproject_image;
308         ImBuf *reproject_ibuf;
309
310         /* threads */
311         int thread_tot;
312         int bucketMin[2];
313         int bucketMax[2];
314         int context_bucket_x, context_bucket_y; /* must lock threads while accessing these */
315
316         struct CurveMapping *cavity_curve;
317         BlurKernel *blurkernel;
318
319
320
321         /* -------------------------------------------------------------------- */
322         /* Vars shared between multiple views (keep last) */
323         /**
324          * This data is owned by ``ProjStrokeHandle.ps_views[0]``,
325          * all other views re-use the data.
326          */
327
328 #define PROJ_PAINT_STATE_SHARED_MEMCPY(ps_dst, ps_src) \
329         MEMCPY_STRUCT_OFS(ps_dst, ps_src, is_shared_user)
330
331 #define PROJ_PAINT_STATE_SHARED_CLEAR(ps) \
332         MEMSET_STRUCT_OFS(ps, 0, is_shared_user)
333
334         bool is_shared_user;
335
336         ProjPaintImage *projImages;
337         float *cavities;            /* cavity amount for vertices */
338
339 #ifndef PROJ_DEBUG_NOSEAMBLEED
340         char *faceSeamFlags;                /* store info about faces, if they are initialized etc*/
341         char *faceWindingFlags;             /* save the winding of the face in uv space, helps as an extra validation step for seam detection */
342         float (*faceSeamUVs)[3][2];         /* expanded UVs for faces to use as seams */
343         LinkNode **vertFaces;               /* Only needed for when seam_bleed_px is enabled, use to find UV seams */
344 #endif
345
346         SpinLock *tile_lock;
347
348         DerivedMesh    *dm;
349         int  dm_totlooptri;
350         int  dm_totpoly;
351         int  dm_totedge;
352         int  dm_totvert;
353         bool dm_release;
354
355         const MVert    *dm_mvert;
356         const MEdge    *dm_medge;
357         const MPoly    *dm_mpoly;
358         const MLoop    *dm_mloop;
359         const MLoopTri *dm_mlooptri;
360
361         const MLoopUV  *dm_mloopuv_stencil;
362
363         /**
364          * \note These UV layers are aligned to \a dm_mpoly
365          * but each pointer references the start of the layer,
366          * so a loop indirection is needed as well.
367          */
368         const MLoopUV **dm_mloopuv;
369         const MLoopUV **dm_mloopuv_clone;    /* other UV map, use for cloning between layers */
370 } ProjPaintState;
371
372 typedef union pixelPointer {
373         float *f_pt;            /* float buffer */
374         unsigned int *uint_pt; /* 2 ways to access a char buffer */
375         unsigned char *ch_pt;
376 } PixelPointer;
377
378 typedef union pixelStore {
379         unsigned char ch[4];
380         unsigned int uint;
381         float f[4];
382 } PixelStore;
383
384 typedef struct ProjPixel {
385         float projCoSS[2]; /* the floating point screen projection of this pixel */
386         float worldCoSS[3];
387
388         short x_px, y_px;
389
390         unsigned short image_index; /* if anyone wants to paint onto more than 65535 images they can bite me */
391         unsigned char bb_cell_index;
392
393         /* for various reasons we may want to mask out painting onto this pixel */
394         unsigned short mask;
395
396         /* Only used when the airbrush is disabled.
397          * Store the max mask value to avoid painting over an area with a lower opacity
398          * with an advantage that we can avoid touching the pixel at all, if the
399          * new mask value is lower then mask_accum */
400         unsigned short *mask_accum;
401
402         /* horrible hack, store tile valid flag pointer here to re-validate tiles used for anchored and drag-dot strokes */
403         bool *valid;
404
405         PixelPointer origColor;
406         PixelStore newColor;
407         PixelPointer pixel;
408 } ProjPixel;
409
410 typedef struct ProjPixelClone {
411         struct ProjPixel __pp;
412         PixelStore clonepx;
413 } ProjPixelClone;
414
415 /* undo tile pushing */
416 typedef struct {
417         SpinLock *lock;
418         bool masked;
419         unsigned short tile_width;
420         ImBuf **tmpibuf;
421         ProjPaintImage *pjima;
422 } TileInfo;
423
424
425
426 /* -------------------------------------------------------------------- */
427
428 /** \name MLoopTri accessor functions.
429  * \{ */
430
431 BLI_INLINE const MPoly *ps_tri_index_to_mpoly(const ProjPaintState *ps, int tri_index)
432 {
433         return &ps->dm_mpoly[ps->dm_mlooptri[tri_index].poly];
434 }
435
436 #define PS_LOOPTRI_AS_VERT_INDEX_3(ps, lt) \
437         ps->dm_mloop[lt->tri[0]].v, \
438         ps->dm_mloop[lt->tri[1]].v, \
439         ps->dm_mloop[lt->tri[2]].v,
440
441 #define PS_LOOPTRI_AS_UV_3(uvlayer, lt) \
442         uvlayer[lt->poly][lt->tri[0]].uv, \
443         uvlayer[lt->poly][lt->tri[1]].uv, \
444         uvlayer[lt->poly][lt->tri[2]].uv,
445
446 #define PS_LOOPTRI_ASSIGN_UV_3(uv_tri, uvlayer, lt)  { \
447         (uv_tri)[0] = uvlayer[lt->poly][lt->tri[0]].uv; \
448         (uv_tri)[1] = uvlayer[lt->poly][lt->tri[1]].uv; \
449         (uv_tri)[2] = uvlayer[lt->poly][lt->tri[2]].uv; \
450 } ((void)0)
451
452 /** \} */
453
454
455
456 /* Finish projection painting structs */
457
458 static TexPaintSlot *project_paint_face_paint_slot(const ProjPaintState *ps, int tri_index)
459 {
460         const MPoly *mp = ps_tri_index_to_mpoly(ps, tri_index);
461         Material *ma = ps->dm->mat[mp->mat_nr];
462         return ma ? ma->texpaintslot + ma->paint_active_slot : NULL;
463 }
464
465 static Image *project_paint_face_paint_image(const ProjPaintState *ps, int tri_index)
466 {
467         if (ps->do_stencil_brush) {
468                 return ps->stencil_ima;
469         }
470         else {
471                 const MPoly *mp = ps_tri_index_to_mpoly(ps, tri_index);
472                 Material *ma = ps->dm->mat[mp->mat_nr];
473                 TexPaintSlot *slot = ma ? ma->texpaintslot + ma->paint_active_slot : NULL;
474                 return slot ? slot->ima : ps->canvas_ima;
475         }
476 }
477
478 static TexPaintSlot *project_paint_face_clone_slot(const ProjPaintState *ps, int tri_index)
479 {
480         const MPoly *mp = ps_tri_index_to_mpoly(ps, tri_index);
481         Material *ma = ps->dm->mat[mp->mat_nr];
482         return ma ? ma->texpaintslot + ma->paint_clone_slot : NULL;
483 }
484
485 static Image *project_paint_face_clone_image(const ProjPaintState *ps, int tri_index)
486 {
487         const MPoly *mp = ps_tri_index_to_mpoly(ps, tri_index);
488         Material *ma = ps->dm->mat[mp->mat_nr];
489         TexPaintSlot *slot = ma ? ma->texpaintslot + ma->paint_clone_slot : NULL;
490         return slot ? slot->ima : ps->clone_ima;
491 }
492
493 /* fast projection bucket array lookup, use the safe version for bound checking  */
494 static int project_bucket_offset(const ProjPaintState *ps, const float projCoSS[2])
495 {
496         /* If we were not dealing with screenspace 2D coords we could simple do...
497          * ps->bucketRect[x + (y*ps->buckets_y)] */
498
499         /* please explain?
500          * projCoSS[0] - ps->screenMin[0]   : zero origin
501          * ... / ps->screen_width           : range from 0.0 to 1.0
502          * ... * ps->buckets_x              : use as a bucket index
503          *
504          * Second multiplication does similar but for vertical offset
505          */
506         return ( (int)(((projCoSS[0] - ps->screenMin[0]) / ps->screen_width)  * ps->buckets_x)) +
507                (((int)(((projCoSS[1] - ps->screenMin[1]) / ps->screen_height) * ps->buckets_y)) * ps->buckets_x);
508 }
509
510 static int project_bucket_offset_safe(const ProjPaintState *ps, const float projCoSS[2])
511 {
512         int bucket_index = project_bucket_offset(ps, projCoSS);
513
514         if (bucket_index < 0 || bucket_index >= ps->buckets_x * ps->buckets_y) {
515                 return -1;
516         }
517         else {
518                 return bucket_index;
519         }
520 }
521
522 static float VecZDepthOrtho(
523         const float pt[2],
524         const float v1[3], const float v2[3], const float v3[3],
525         float w[3])
526 {
527         barycentric_weights_v2(v1, v2, v3, pt, w);
528         return (v1[2] * w[0]) + (v2[2] * w[1]) + (v3[2] * w[2]);
529 }
530
531 static float VecZDepthPersp(
532         const float pt[2],
533         const float v1[4], const float v2[4], const float v3[4],
534         float w[3])
535 {
536         float wtot_inv, wtot;
537         float w_tmp[3];
538
539         barycentric_weights_v2_persp(v1, v2, v3, pt, w);
540         /* for the depth we need the weights to match what
541          * barycentric_weights_v2 would return, in this case its easiest just to
542          * undo the 4th axis division and make it unit-sum
543          *
544          * don't call barycentric_weights_v2() because our callers expect 'w'
545          * to be weighted from the perspective */
546         w_tmp[0] = w[0] * v1[3];
547         w_tmp[1] = w[1] * v2[3];
548         w_tmp[2] = w[2] * v3[3];
549
550         wtot = w_tmp[0] + w_tmp[1] + w_tmp[2];
551
552         if (wtot != 0.0f) {
553                 wtot_inv = 1.0f / wtot;
554
555                 w_tmp[0] = w_tmp[0] * wtot_inv;
556                 w_tmp[1] = w_tmp[1] * wtot_inv;
557                 w_tmp[2] = w_tmp[2] * wtot_inv;
558         }
559         else /* dummy values for zero area face */
560                 w_tmp[0] = w_tmp[1] = w_tmp[2] = 1.0f / 3.0f;
561         /* done mimicing barycentric_weights_v2() */
562
563         return (v1[2] * w_tmp[0]) + (v2[2] * w_tmp[1]) + (v3[2] * w_tmp[2]);
564 }
565
566
567 /* Return the top-most face index that the screen space coord 'pt' touches (or -1) */
568 static int project_paint_PickFace(
569         const ProjPaintState *ps, const float pt[2],
570         float w[3])
571 {
572         LinkNode *node;
573         float w_tmp[3];
574         int bucket_index;
575         int best_tri_index = -1;
576         float z_depth_best = FLT_MAX, z_depth;
577
578         bucket_index = project_bucket_offset_safe(ps, pt);
579         if (bucket_index == -1)
580                 return -1;
581
582
583
584         /* we could return 0 for 1 face buckets, as long as this function assumes
585          * that the point its testing is only every originated from an existing face */
586
587         for (node = ps->bucketFaces[bucket_index]; node; node = node->next) {
588                 const int tri_index = GET_INT_FROM_POINTER(node->link);
589                 const MLoopTri *lt = &ps->dm_mlooptri[tri_index];
590                 const float *vtri_ss[3] = {
591                     ps->screenCoords[ps->dm_mloop[lt->tri[0]].v],
592                     ps->screenCoords[ps->dm_mloop[lt->tri[1]].v],
593                     ps->screenCoords[ps->dm_mloop[lt->tri[2]].v],
594                 };
595
596
597                 if (isect_point_tri_v2(pt, UNPACK3(vtri_ss))) {
598                         if (ps->is_ortho) {
599                                 z_depth = VecZDepthOrtho(pt, UNPACK3(vtri_ss), w_tmp);
600                         }
601                         else {
602                                 z_depth = VecZDepthPersp(pt, UNPACK3(vtri_ss), w_tmp);
603                         }
604
605                         if (z_depth < z_depth_best) {
606                                 best_tri_index = tri_index;
607                                 z_depth_best = z_depth;
608                                 copy_v3_v3(w, w_tmp);
609                         }
610                 }
611         }
612
613         return best_tri_index; /* will be -1 or a valid face */
614 }
615
616 /* Converts a uv coord into a pixel location wrapping if the uv is outside 0-1 range */
617 static void uvco_to_wrapped_pxco(const float uv[2], int ibuf_x, int ibuf_y, float *x, float *y)
618 {
619         /* use */
620         *x = fmodf(uv[0], 1.0f);
621         *y = fmodf(uv[1], 1.0f);
622
623         if (*x < 0.0f) *x += 1.0f;
624         if (*y < 0.0f) *y += 1.0f;
625
626         *x = *x * ibuf_x - 0.5f;
627         *y = *y * ibuf_y - 0.5f;
628 }
629
630 /* Set the top-most face color that the screen space coord 'pt' touches (or return 0 if none touch) */
631 static bool project_paint_PickColor(
632         const ProjPaintState *ps, const float pt[2],
633         float *rgba_fp, unsigned char *rgba, const bool interp)
634 {
635         const MLoopTri *lt;
636         const float *lt_tri_uv[3];
637         float w[3], uv[2];
638         int tri_index;
639         Image *ima;
640         ImBuf *ibuf;
641         int xi, yi;
642
643         tri_index = project_paint_PickFace(ps, pt, w);
644
645         if (tri_index == -1)
646                 return 0;
647
648         lt = &ps->dm_mlooptri[tri_index];
649         PS_LOOPTRI_ASSIGN_UV_3(lt_tri_uv, ps->dm_mloopuv, lt);
650
651         interp_v2_v2v2v2(uv, UNPACK3(lt_tri_uv), w);
652
653         ima = project_paint_face_paint_image(ps, tri_index);
654         ibuf = BKE_image_get_first_ibuf(ima); /* we must have got the imbuf before getting here */
655         if (!ibuf) return 0;
656
657         if (interp) {
658                 float x, y;
659                 uvco_to_wrapped_pxco(uv, ibuf->x, ibuf->y, &x, &y);
660
661                 if (ibuf->rect_float) {
662                         if (rgba_fp) {
663                                 bilinear_interpolation_color_wrap(ibuf, NULL, rgba_fp, x, y);
664                         }
665                         else {
666                                 float rgba_tmp_f[4];
667                                 bilinear_interpolation_color_wrap(ibuf, NULL, rgba_tmp_f, x, y);
668                                 premul_float_to_straight_uchar(rgba, rgba_tmp_f);
669                         }
670                 }
671                 else {
672                         if (rgba) {
673                                 bilinear_interpolation_color_wrap(ibuf, rgba, NULL, x, y);
674                         }
675                         else {
676                                 unsigned char rgba_tmp[4];
677                                 bilinear_interpolation_color_wrap(ibuf, rgba_tmp, NULL, x, y);
678                                 straight_uchar_to_premul_float(rgba_fp, rgba_tmp);
679                         }
680                 }
681         }
682         else {
683                 //xi = (int)((uv[0]*ibuf->x) + 0.5f);
684                 //yi = (int)((uv[1]*ibuf->y) + 0.5f);
685                 //if (xi < 0 || xi >= ibuf->x  ||  yi < 0 || yi >= ibuf->y) return 0;
686
687                 /* wrap */
688                 xi = mod_i((int)(uv[0] * ibuf->x), ibuf->x);
689                 yi = mod_i((int)(uv[1] * ibuf->y), ibuf->y);
690
691                 if (rgba) {
692                         if (ibuf->rect_float) {
693                                 const float *rgba_tmp_fp = ibuf->rect_float + (xi + yi * ibuf->x * 4);
694                                 premul_float_to_straight_uchar(rgba, rgba_tmp_fp);
695                         }
696                         else {
697                                 *((unsigned int *)rgba) = *(unsigned int *)(((char *)ibuf->rect) + ((xi + yi * ibuf->x) * 4));
698                         }
699                 }
700
701                 if (rgba_fp) {
702                         if (ibuf->rect_float) {
703                                 copy_v4_v4(rgba_fp, (ibuf->rect_float + ((xi + yi * ibuf->x) * 4)));
704                         }
705                         else {
706                                 unsigned char *tmp_ch = ((unsigned char *)ibuf->rect) + ((xi + yi * ibuf->x) * 4);
707                                 straight_uchar_to_premul_float(rgba_fp, tmp_ch);
708                         }
709                 }
710         }
711         BKE_image_release_ibuf(ima, ibuf, NULL);
712         return 1;
713 }
714
715 /**
716  * Check if 'pt' is infront of the 3 verts on the Z axis (used for screenspace occlusuion test)
717  * \return
718  * -  `0`:   no occlusion
719  * - `-1`: no occlusion but 2D intersection is true
720  * -  `1`: occluded
721  * -  `2`: occluded with `w[3]` weights set (need to know in some cases)
722  */
723 static int project_paint_occlude_ptv(
724         const float pt[3],
725         const float v1[4], const float v2[4], const float v3[4],
726         float w[3], const bool is_ortho)
727 {
728         /* if all are behind us, return false */
729         if (v1[2] > pt[2] && v2[2] > pt[2] && v3[2] > pt[2])
730                 return 0;
731
732         /* do a 2D point in try intersection */
733         if (!isect_point_tri_v2(pt, v1, v2, v3))
734                 return 0;  /* we know there is  */
735
736
737         /* From here on we know there IS an intersection */
738         /* if ALL of the verts are infront of us then we know it intersects ? */
739         if (v1[2] < pt[2] && v2[2] < pt[2] && v3[2] < pt[2]) {
740                 return 1;
741         }
742         else {
743                 /* we intersect? - find the exact depth at the point of intersection */
744                 /* Is this point is occluded by another face? */
745                 if (is_ortho) {
746                         if (VecZDepthOrtho(pt, v1, v2, v3, w) < pt[2]) return 2;
747                 }
748                 else {
749                         if (VecZDepthPersp(pt, v1, v2, v3, w) < pt[2]) return 2;
750                 }
751         }
752         return -1;
753 }
754
755
756 static int project_paint_occlude_ptv_clip(
757         const float pt[3],
758         const float v1[4], const float v2[4], const float v3[4],
759         const float v1_3d[3], const float v2_3d[3], const float v3_3d[3],
760         float w[3], const bool is_ortho, RegionView3D *rv3d)
761 {
762         float wco[3];
763         int ret = project_paint_occlude_ptv(pt, v1, v2, v3, w, is_ortho);
764
765         if (ret <= 0)
766                 return ret;
767
768         if (ret == 1) { /* weights not calculated */
769                 if (is_ortho) {
770                         barycentric_weights_v2(v1, v2, v3, pt, w);
771                 }
772                 else {
773                         barycentric_weights_v2_persp(v1, v2, v3, pt, w);
774                 }
775         }
776
777         /* Test if we're in the clipped area, */
778         interp_v3_v3v3v3(wco, v1_3d, v2_3d, v3_3d, w);
779
780         if (!ED_view3d_clipping_test(rv3d, wco, true)) {
781                 return 1;
782         }
783
784         return -1;
785 }
786
787
788 /* Check if a screenspace location is occluded by any other faces
789  * check, pixelScreenCo must be in screenspace, its Z-Depth only needs to be used for comparison
790  * and doesn't need to be correct in relation to X and Y coords (this is the case in perspective view) */
791 static bool project_bucket_point_occluded(
792         const ProjPaintState *ps, LinkNode *bucketFace,
793         const int orig_face, const float pixelScreenCo[4])
794 {
795         int isect_ret;
796         const bool do_clip = ps->rv3d ? (ps->rv3d->rflag & RV3D_CLIPPING) != 0 : 0;
797
798         /* we could return 0 for 1 face buckets, as long as this function assumes
799          * that the point its testing is only every originated from an existing face */
800
801         for (; bucketFace; bucketFace = bucketFace->next) {
802                 const int tri_index = GET_INT_FROM_POINTER(bucketFace->link);
803
804                 if (orig_face != tri_index) {
805                         const MLoopTri *lt = &ps->dm_mlooptri[tri_index];
806                         const float *vtri_ss[3] = {
807                             ps->screenCoords[ps->dm_mloop[lt->tri[0]].v],
808                             ps->screenCoords[ps->dm_mloop[lt->tri[1]].v],
809                             ps->screenCoords[ps->dm_mloop[lt->tri[2]].v],
810                         };
811                         float w[3];
812
813                         if (do_clip) {
814                                 const float *vtri_co[3] = {
815                                     ps->dm_mvert[ps->dm_mloop[lt->tri[0]].v].co,
816                                     ps->dm_mvert[ps->dm_mloop[lt->tri[1]].v].co,
817                                     ps->dm_mvert[ps->dm_mloop[lt->tri[2]].v].co,
818                                 };
819                                 isect_ret = project_paint_occlude_ptv_clip(
820                                         pixelScreenCo, UNPACK3(vtri_ss), UNPACK3(vtri_co),
821                                         w, ps->is_ortho, ps->rv3d);
822                         }
823                         else {
824                                 isect_ret = project_paint_occlude_ptv(
825                                         pixelScreenCo, UNPACK3(vtri_ss),
826                                         w, ps->is_ortho);
827                         }
828
829                         if (isect_ret >= 1) {
830                                 /* TODO - we may want to cache the first hit,
831                                  * it is not possible to swap the face order in the list anymore */
832                                 return true;
833                         }
834                 }
835         }
836         return false;
837 }
838
839 /* basic line intersection, could move to math_geom.c, 2 points with a horiz line
840  * 1 for an intersection, 2 if the first point is aligned, 3 if the second point is aligned */
841 #define ISECT_TRUE 1
842 #define ISECT_TRUE_P1 2
843 #define ISECT_TRUE_P2 3
844 static int line_isect_y(const float p1[2], const float p2[2], const float y_level, float *x_isect)
845 {
846         float y_diff;
847
848         if (y_level == p1[1]) { /* are we touching the first point? - no interpolation needed */
849                 *x_isect = p1[0];
850                 return ISECT_TRUE_P1;
851         }
852         if (y_level == p2[1]) { /* are we touching the second point? - no interpolation needed */
853                 *x_isect = p2[0];
854                 return ISECT_TRUE_P2;
855         }
856
857         y_diff = fabsf(p1[1] - p2[1]); /* yuck, horizontal line, we cant do much here */
858
859         if (y_diff < 0.000001f) {
860                 *x_isect = (p1[0] + p2[0]) * 0.5f;
861                 return ISECT_TRUE;
862         }
863
864         if (p1[1] > y_level && p2[1] < y_level) {
865                 *x_isect = (p2[0] * (p1[1] - y_level) + p1[0] * (y_level - p2[1])) / y_diff;  /* (p1[1] - p2[1]); */
866                 return ISECT_TRUE;
867         }
868         else if (p1[1] < y_level && p2[1] > y_level) {
869                 *x_isect = (p2[0] * (y_level - p1[1]) + p1[0] * (p2[1] - y_level)) / y_diff;  /* (p2[1] - p1[1]); */
870                 return ISECT_TRUE;
871         }
872         else {
873                 return 0;
874         }
875 }
876
877 static int line_isect_x(const float p1[2], const float p2[2], const float x_level, float *y_isect)
878 {
879         float x_diff;
880
881         if (x_level == p1[0]) { /* are we touching the first point? - no interpolation needed */
882                 *y_isect = p1[1];
883                 return ISECT_TRUE_P1;
884         }
885         if (x_level == p2[0]) { /* are we touching the second point? - no interpolation needed */
886                 *y_isect = p2[1];
887                 return ISECT_TRUE_P2;
888         }
889
890         x_diff = fabsf(p1[0] - p2[0]); /* yuck, horizontal line, we cant do much here */
891
892         if (x_diff < 0.000001f) { /* yuck, vertical line, we cant do much here */
893                 *y_isect = (p1[0] + p2[0]) * 0.5f;
894                 return ISECT_TRUE;
895         }
896
897         if (p1[0] > x_level && p2[0] < x_level) {
898                 *y_isect = (p2[1] * (p1[0] - x_level) + p1[1] * (x_level - p2[0])) / x_diff;  /* (p1[0] - p2[0]); */
899                 return ISECT_TRUE;
900         }
901         else if (p1[0] < x_level && p2[0] > x_level) {
902                 *y_isect = (p2[1] * (x_level - p1[0]) + p1[1] * (p2[0] - x_level)) / x_diff;  /* (p2[0] - p1[0]); */
903                 return ISECT_TRUE;
904         }
905         else {
906                 return 0;
907         }
908 }
909
910 /* simple func use for comparing UV locations to check if there are seams.
911  * Its possible this gives incorrect results, when the UVs for 1 face go into the next
912  * tile, but do not do this for the adjacent face, it could return a false positive.
913  * This is so unlikely that Id not worry about it. */
914 #ifndef PROJ_DEBUG_NOSEAMBLEED
915 static bool cmp_uv(const float vec2a[2], const float vec2b[2])
916 {
917         /* if the UV's are not between 0.0 and 1.0 */
918         float xa = fmodf(vec2a[0], 1.0f);
919         float ya = fmodf(vec2a[1], 1.0f);
920
921         float xb = fmodf(vec2b[0], 1.0f);
922         float yb = fmodf(vec2b[1], 1.0f);
923
924         if (xa < 0.0f) xa += 1.0f;
925         if (ya < 0.0f) ya += 1.0f;
926
927         if (xb < 0.0f) xb += 1.0f;
928         if (yb < 0.0f) yb += 1.0f;
929
930         return ((fabsf(xa - xb) < PROJ_GEOM_TOLERANCE) && (fabsf(ya - yb) < PROJ_GEOM_TOLERANCE)) ? 1 : 0;
931 }
932 #endif
933
934 /* set min_px and max_px to the image space bounds of the UV coords
935  * return zero if there is no area in the returned rectangle */
936 #ifndef PROJ_DEBUG_NOSEAMBLEED
937 static bool pixel_bounds_uv(
938         const float uv_quad[4][2],
939         rcti *bounds_px,
940         const int ibuf_x, const int ibuf_y
941         )
942 {
943         float min_uv[2], max_uv[2]; /* UV bounds */
944
945         INIT_MINMAX2(min_uv, max_uv);
946
947         minmax_v2v2_v2(min_uv, max_uv, uv_quad[0]);
948         minmax_v2v2_v2(min_uv, max_uv, uv_quad[1]);
949         minmax_v2v2_v2(min_uv, max_uv, uv_quad[2]);
950         minmax_v2v2_v2(min_uv, max_uv, uv_quad[3]);
951
952         bounds_px->xmin = (int)(ibuf_x * min_uv[0]);
953         bounds_px->ymin = (int)(ibuf_y * min_uv[1]);
954
955         bounds_px->xmax = (int)(ibuf_x * max_uv[0]) + 1;
956         bounds_px->ymax = (int)(ibuf_y * max_uv[1]) + 1;
957
958         /*printf("%d %d %d %d\n", min_px[0], min_px[1], max_px[0], max_px[1]);*/
959
960         /* face uses no UV area when quantized to pixels? */
961         return (bounds_px->xmin == bounds_px->xmax || bounds_px->ymin == bounds_px->ymax) ? 0 : 1;
962 }
963 #endif
964
965 static bool pixel_bounds_array(float (*uv)[2], rcti *bounds_px, const int ibuf_x, const int ibuf_y, int tot)
966 {
967         float min_uv[2], max_uv[2]; /* UV bounds */
968
969         if (tot == 0) {
970                 return 0;
971         }
972
973         INIT_MINMAX2(min_uv, max_uv);
974
975         while (tot--) {
976                 minmax_v2v2_v2(min_uv, max_uv, (*uv));
977                 uv++;
978         }
979
980         bounds_px->xmin = (int)(ibuf_x * min_uv[0]);
981         bounds_px->ymin = (int)(ibuf_y * min_uv[1]);
982
983         bounds_px->xmax = (int)(ibuf_x * max_uv[0]) + 1;
984         bounds_px->ymax = (int)(ibuf_y * max_uv[1]) + 1;
985
986         /*printf("%d %d %d %d\n", min_px[0], min_px[1], max_px[0], max_px[1]);*/
987
988         /* face uses no UV area when quantized to pixels? */
989         return (bounds_px->xmin == bounds_px->xmax || bounds_px->ymin == bounds_px->ymax) ? 0 : 1;
990 }
991
992 #ifndef PROJ_DEBUG_NOSEAMBLEED
993
994 static void project_face_winding_init(const ProjPaintState *ps, const int tri_index)
995 {
996         /* detect the winding of faces in uv space */
997         const MLoopTri *lt = &ps->dm_mlooptri[tri_index];
998         const float *lt_tri_uv[3] = { PS_LOOPTRI_AS_UV_3(ps->dm_mloopuv, lt) };
999         float winding = cross_tri_v2(lt_tri_uv[0], lt_tri_uv[1], lt_tri_uv[2]);
1000
1001         if (winding > 0)
1002                 ps->faceWindingFlags[tri_index] |= PROJ_FACE_WINDING_CW;
1003
1004         ps->faceWindingFlags[tri_index] |= PROJ_FACE_WINDING_INIT;
1005 }
1006
1007 /* This function returns 1 if this face has a seam along the 2 face-vert indices
1008  * 'orig_i1_fidx' and 'orig_i2_fidx' */
1009 static bool check_seam(
1010         const ProjPaintState *ps,
1011         const int orig_face, const int orig_i1_fidx, const int orig_i2_fidx,
1012         int *other_face, int *orig_fidx)
1013 {
1014         const MLoopTri *orig_lt = &ps->dm_mlooptri[orig_face];
1015         const float *orig_lt_tri_uv[3] = { PS_LOOPTRI_AS_UV_3(ps->dm_mloopuv, orig_lt) };
1016         /* vert indices from face vert order indices */
1017         const unsigned int i1 = ps->dm_mloop[orig_lt->tri[orig_i1_fidx]].v;
1018         const unsigned int i2 = ps->dm_mloop[orig_lt->tri[orig_i2_fidx]].v;
1019         LinkNode *node;
1020         int i1_fidx = -1, i2_fidx = -1; /* index in face */
1021
1022         for (node = ps->vertFaces[i1]; node; node = node->next) {
1023                 const int tri_index = GET_INT_FROM_POINTER(node->link);
1024
1025                 if (tri_index != orig_face) {
1026                         const MLoopTri *lt = &ps->dm_mlooptri[tri_index];
1027                         const int lt_vtri[3] = { PS_LOOPTRI_AS_VERT_INDEX_3(ps, lt) };
1028                         /* could check if the 2 faces images match here,
1029                          * but then there wouldn't be a way to return the opposite face's info */
1030
1031
1032                         /* We need to know the order of the verts in the adjacent face
1033                          * set the i1_fidx and i2_fidx to (0,1,2,3) */
1034                         i1_fidx = BKE_MESH_TESSTRI_VINDEX_ORDER(lt_vtri, i1);
1035                         i2_fidx = BKE_MESH_TESSTRI_VINDEX_ORDER(lt_vtri, i2);
1036
1037                         /* Only need to check if 'i2_fidx' is valid because we know i1_fidx is the same vert on both faces */
1038                         if (i2_fidx != -1) {
1039                                 const float *lt_tri_uv[3] = { PS_LOOPTRI_AS_UV_3(ps->dm_mloopuv, lt) };
1040                                 Image *tpage = project_paint_face_paint_image(ps, tri_index);
1041                                 Image *orig_tpage = project_paint_face_paint_image(ps, orig_face);
1042
1043                                 BLI_assert(i1_fidx != -1);
1044
1045                                 /* This IS an adjacent face!, now lets check if the UVs are ok */
1046
1047                                 /* set up the other face */
1048                                 *other_face = tri_index;
1049                                 
1050                                 /* we check if difference is 1 here, else we might have a case of edge 2-0 for a tri */
1051                                 *orig_fidx = (i1_fidx < i2_fidx && (i2_fidx - i1_fidx == 1)) ? i1_fidx : i2_fidx;
1052
1053                                 /* initialize face winding if needed */
1054                                 if ((ps->faceWindingFlags[tri_index] & PROJ_FACE_WINDING_INIT) == 0)
1055                                         project_face_winding_init(ps, tri_index);
1056
1057                                 /* first test if they have the same image */
1058                                 if ((orig_tpage == tpage) &&
1059                                     cmp_uv(orig_lt_tri_uv[orig_i1_fidx], lt_tri_uv[i1_fidx]) &&
1060                                     cmp_uv(orig_lt_tri_uv[orig_i2_fidx], lt_tri_uv[i2_fidx]))
1061                                 {
1062                                         /* if faces don't have the same winding in uv space,
1063                                          * they are on the same side so edge is boundary */
1064                                         if ((ps->faceWindingFlags[tri_index] & PROJ_FACE_WINDING_CW) !=
1065                                             (ps->faceWindingFlags[orig_face] & PROJ_FACE_WINDING_CW))
1066                                         {
1067                                                 return 1;
1068                                         }
1069
1070                                         // printf("SEAM (NONE)\n");
1071                                         return 0;
1072
1073                                 }
1074                                 else {
1075                                         // printf("SEAM (UV GAP)\n");
1076                                         return 1;
1077                                 }
1078                         }
1079                 }
1080         }
1081         // printf("SEAM (NO FACE)\n");
1082         *other_face = -1;
1083         return 1;
1084 }
1085
1086 #define SMALL_NUMBER  1.e-6f
1087 BLI_INLINE float shell_v2v2_normal_dir_to_dist(float n[2], float d[2])
1088 {
1089         const float angle_cos = (normalize_v2(n) < SMALL_NUMBER) ? fabsf(dot_v2v2(d, n)) : 0.0f;
1090         return (UNLIKELY(angle_cos < SMALL_NUMBER)) ? 1.0f : (1.0f / angle_cos);
1091 }
1092 #undef SMALL_NUMBER
1093
1094 /* Calculate outset UV's, this is not the same as simply scaling the UVs,
1095  * since the outset coords are a margin that keep an even distance from the original UV's,
1096  * note that the image aspect is taken into account */
1097 static void uv_image_outset(
1098         float (*orig_uv)[2], float (*outset_uv)[2], const float scaler,
1099         const int ibuf_x, const int ibuf_y, const bool cw)
1100 {
1101         float a1, a2, a3;
1102         float puv[3][2]; /* pixelspace uv's */
1103         float no1[2], no2[2], no3[2]; /* normals */
1104         float dir1[2], dir2[2], dir3[2];
1105         float ibuf_inv[2];
1106
1107         ibuf_inv[0] = 1.0f / (float)ibuf_x;
1108         ibuf_inv[1] = 1.0f / (float)ibuf_y;
1109
1110         /* make UV's in pixel space so we can */
1111         puv[0][0] = orig_uv[0][0] * ibuf_x;
1112         puv[0][1] = orig_uv[0][1] * ibuf_y;
1113
1114         puv[1][0] = orig_uv[1][0] * ibuf_x;
1115         puv[1][1] = orig_uv[1][1] * ibuf_y;
1116
1117         puv[2][0] = orig_uv[2][0] * ibuf_x;
1118         puv[2][1] = orig_uv[2][1] * ibuf_y;
1119
1120         /* face edge directions */
1121         sub_v2_v2v2(dir1, puv[1], puv[0]);
1122         sub_v2_v2v2(dir2, puv[2], puv[1]);
1123         sub_v2_v2v2(dir3, puv[0], puv[2]);
1124         normalize_v2(dir1);
1125         normalize_v2(dir2);
1126         normalize_v2(dir3);
1127
1128         /* here we just use the orthonormality property (a1, a2) dot (a2, -a1) = 0
1129          * to get normals from the edge directions based on the winding */
1130         if (cw) {
1131                 no1[0] = -dir3[1] - dir1[1];
1132                 no1[1] =  dir3[0] + dir1[0];
1133                 no2[0] = -dir1[1] - dir2[1];
1134                 no2[1] =  dir1[0] + dir2[0];
1135                 no3[0] = -dir2[1] - dir3[1];
1136                 no3[1] =  dir2[0] + dir3[0];
1137         }
1138         else {
1139                 no1[0] =  dir3[1] + dir1[1];
1140                 no1[1] = -dir3[0] - dir1[0];
1141                 no2[0] =  dir1[1] + dir2[1];
1142                 no2[1] = -dir1[0] - dir2[0];
1143                 no3[0] =  dir2[1] + dir3[1];
1144                 no3[1] = -dir2[0] - dir3[0];
1145         }
1146
1147         a1 = shell_v2v2_normal_dir_to_dist(no1, dir3);
1148         a2 = shell_v2v2_normal_dir_to_dist(no2, dir1);
1149         a3 = shell_v2v2_normal_dir_to_dist(no3, dir2);
1150
1151         mul_v2_fl(no1, a1 * scaler);
1152         mul_v2_fl(no2, a2 * scaler);
1153         mul_v2_fl(no3, a3 * scaler);
1154         add_v2_v2v2(outset_uv[0], puv[0], no1);
1155         add_v2_v2v2(outset_uv[1], puv[1], no2);
1156         add_v2_v2v2(outset_uv[2], puv[2], no3);
1157
1158         mul_v2_v2(outset_uv[0], ibuf_inv);
1159         mul_v2_v2(outset_uv[1], ibuf_inv);
1160         mul_v2_v2(outset_uv[2], ibuf_inv);
1161 }
1162
1163 /*
1164  * Be tricky with flags, first 4 bits are PROJ_FACE_SEAM1 to 4, last 4 bits are PROJ_FACE_NOSEAM1 to 4
1165  * 1<<i - where i is (0-3)
1166  *
1167  * If we're multithreadng, make sure threads are locked when this is called
1168  */
1169 static void project_face_seams_init(const ProjPaintState *ps, const int tri_index)
1170 {
1171         int other_face, other_fidx; /* vars for the other face, we also set its flag */
1172         int fidx1 = 2;
1173         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 */
1174
1175         /* initialize face winding if needed */
1176         if ((ps->faceWindingFlags[tri_index] & PROJ_FACE_WINDING_INIT) == 0)
1177                 project_face_winding_init(ps, tri_index);
1178
1179         do {
1180                 if ((ps->faceSeamFlags[tri_index] & (1 << fidx1 | 16 << fidx1)) == 0) {
1181                         if (check_seam(ps, tri_index, fidx1, fidx2, &other_face, &other_fidx)) {
1182                                 ps->faceSeamFlags[tri_index] |= 1 << fidx1;
1183                                 if (other_face != -1)
1184                                         ps->faceSeamFlags[other_face] |= 1 << other_fidx;
1185                         }
1186                         else {
1187                                 ps->faceSeamFlags[tri_index] |= 16 << fidx1;
1188                                 if (other_face != -1)
1189                                         ps->faceSeamFlags[other_face] |= 16 << other_fidx;  /* second 4 bits for disabled */
1190                         }
1191                 }
1192
1193                 fidx2 = fidx1;
1194         } while (fidx1--);
1195 }
1196 #endif // PROJ_DEBUG_NOSEAMBLEED
1197
1198
1199 /* Converts a UV location to a 3D screenspace location
1200  * Takes a 'uv' and 3 UV coords, and sets the values of pixelScreenCo
1201  *
1202  * This is used for finding a pixels location in screenspace for painting */
1203 static void screen_px_from_ortho(
1204         const float uv[2],
1205         const float v1co[3], const float v2co[3], const float v3co[3],  /* Screenspace coords */
1206         const float uv1co[2], const float uv2co[2], const float uv3co[2],
1207         float pixelScreenCo[4],
1208         float w[3])
1209 {
1210         barycentric_weights_v2(uv1co, uv2co, uv3co, uv, w);
1211         interp_v3_v3v3v3(pixelScreenCo, v1co, v2co, v3co, w);
1212 }
1213
1214 /* same as screen_px_from_ortho except we
1215  * do perspective correction on the pixel coordinate */
1216 static void screen_px_from_persp(
1217         const float uv[2],
1218         const float v1co[4], const float v2co[4], const float v3co[4],  /* screenspace coords */
1219         const float uv1co[2], const float uv2co[2], const float uv3co[2],
1220         float pixelScreenCo[4],
1221         float w[3])
1222 {
1223         float w_int[3];
1224         float wtot_inv, wtot;
1225         barycentric_weights_v2(uv1co, uv2co, uv3co, uv, w);
1226
1227         /* re-weight from the 4th coord of each screen vert */
1228         w_int[0] = w[0] * v1co[3];
1229         w_int[1] = w[1] * v2co[3];
1230         w_int[2] = w[2] * v3co[3];
1231
1232         wtot = w_int[0] + w_int[1] + w_int[2];
1233
1234         if (wtot > 0.0f) {
1235                 wtot_inv = 1.0f / wtot;
1236                 w_int[0] *= wtot_inv;
1237                 w_int[1] *= wtot_inv;
1238                 w_int[2] *= wtot_inv;
1239         }
1240         else {
1241                 w[0] = w[1] = w[2] =
1242                 w_int[0] = w_int[1] = w_int[2] = 1.0f / 3.0f;  /* dummy values for zero area face */
1243         }
1244         /* done re-weighting */
1245
1246         /* do interpolation based on projected weight */
1247         interp_v3_v3v3v3(pixelScreenCo, v1co, v2co, v3co, w_int);
1248 }
1249
1250
1251 /**
1252  * Set a direction vector based on a screen location.
1253  * (use for perspective view, else we can simply use `ps->viewDir`)
1254  *
1255  * Similar functionality to #ED_view3d_win_to_vector
1256  *
1257  * \param r_dir: Resulting direction (length is undefined).
1258  */
1259 static void screen_px_to_vector_persp(
1260         int winx, int winy, const float projmat_inv[4][4], const float view_pos[3],
1261         const float co_px[2],
1262         float r_dir[3])
1263 {
1264         r_dir[0] = 2.0f * (co_px[0] / winx) - 1.0f;
1265         r_dir[1] = 2.0f * (co_px[1] / winy) - 1.0f;
1266         r_dir[2] = -0.5f;
1267         mul_project_m4_v3((float(*)[4])projmat_inv, r_dir);
1268         sub_v3_v3(r_dir, view_pos);
1269 }
1270
1271 /**
1272  * Special function to return the factor to a point along a line in pixel space.
1273  *
1274  * This is needed since we can't use #line_point_factor_v2 for perspective screen-space coords.
1275  *
1276  * \param p: 2D screen-space location.
1277  * \param v1, v2: 3D object-space locations.
1278  */
1279 static float screen_px_line_point_factor_v2_persp(
1280         const ProjPaintState *ps,
1281         const float p[2],
1282         const float v1[3], const float v2[3])
1283 {
1284         const float zero[3] = {0};
1285         float v1_proj[3], v2_proj[3];
1286         float dir[3];
1287
1288         screen_px_to_vector_persp(ps->winx, ps->winy, ps->projectMatInv, ps->viewPos, p, dir);
1289
1290         sub_v3_v3v3(v1_proj, v1, ps->viewPos);
1291         sub_v3_v3v3(v2_proj, v2, ps->viewPos);
1292
1293         project_plane_v3_v3v3(v1_proj, v1_proj, dir);
1294         project_plane_v3_v3v3(v2_proj, v2_proj, dir);
1295
1296         return line_point_factor_v2(zero, v1_proj, v2_proj);
1297 }
1298
1299
1300 static void project_face_pixel(
1301         const float *lt_tri_uv[3], ImBuf *ibuf_other, const float w[3],
1302         unsigned char rgba_ub[4], float rgba_f[4])
1303 {
1304         float uv_other[2], x, y;
1305
1306         interp_v2_v2v2v2(uv_other, UNPACK3(lt_tri_uv), w);
1307
1308         /* use */
1309         uvco_to_wrapped_pxco(uv_other, ibuf_other->x, ibuf_other->y, &x, &y);
1310
1311         if (ibuf_other->rect_float) { /* from float to float */
1312                 bilinear_interpolation_color_wrap(ibuf_other, NULL, rgba_f, x, y);
1313         }
1314         else { /* from char to float */
1315                 bilinear_interpolation_color_wrap(ibuf_other, rgba_ub, NULL, x, y);
1316         }
1317
1318 }
1319
1320 /* run this outside project_paint_uvpixel_init since pixels with mask 0 don't need init */
1321 static float project_paint_uvpixel_mask(
1322         const ProjPaintState *ps,
1323         const int tri_index,
1324         const float w[3])
1325 {
1326         float mask;
1327
1328         /* Image Mask */
1329         if (ps->do_layer_stencil) {
1330                 /* another UV maps image is masking this one's */
1331                 ImBuf *ibuf_other;
1332                 Image *other_tpage = ps->stencil_ima;
1333
1334                 if (other_tpage && (ibuf_other = BKE_image_acquire_ibuf(other_tpage, NULL, NULL))) {
1335                         const MLoopTri *lt_other = &ps->dm_mlooptri[tri_index];
1336                         const float *lt_other_tri_uv[3] = { PS_LOOPTRI_AS_UV_3(ps->dm_mloopuv, lt_other) };
1337
1338                         /* BKE_image_acquire_ibuf - TODO - this may be slow */
1339                         unsigned char rgba_ub[4];
1340                         float rgba_f[4];
1341
1342                         project_face_pixel(lt_other_tri_uv, ibuf_other, w, rgba_ub, rgba_f);
1343
1344                         if (ibuf_other->rect_float) { /* from float to float */
1345                                 mask = ((rgba_f[0] + rgba_f[1] + rgba_f[2]) * (1.0f / 3.0f)) * rgba_f[3];
1346                         }
1347                         else { /* from char to float */
1348                                 mask = ((rgba_ub[0] + rgba_ub[1] + rgba_ub[2]) * (1.0f / (255.0f * 3.0f))) * (rgba_ub[3] * (1.0f / 255.0f));
1349                         }
1350
1351                         BKE_image_release_ibuf(other_tpage, ibuf_other, NULL);
1352
1353                         if (!ps->do_layer_stencil_inv) /* matching the gimps layer mask black/white rules, white==full opacity */
1354                                 mask = (1.0f - mask);
1355
1356                         if (mask == 0.0f) {
1357                                 return 0.0f;
1358                         }
1359                 }
1360                 else {
1361                         return 0.0f;
1362                 }
1363         }
1364         else {
1365                 mask = 1.0f;
1366         }
1367
1368         if (ps->do_mask_cavity) {
1369                 const MLoopTri *lt = &ps->dm_mlooptri[tri_index];
1370                 const int lt_vtri[3] = { PS_LOOPTRI_AS_VERT_INDEX_3(ps, lt) };
1371                 float ca1, ca2, ca3, ca_mask;
1372                 ca1 = ps->cavities[lt_vtri[0]];
1373                 ca2 = ps->cavities[lt_vtri[1]];
1374                 ca3 = ps->cavities[lt_vtri[2]];
1375
1376                 ca_mask = w[0] * ca1 + w[1] * ca2 + w[2] * ca3;
1377                 ca_mask = curvemapping_evaluateF(ps->cavity_curve, 0, ca_mask);
1378                 CLAMP(ca_mask, 0.0f, 1.0f);
1379                 mask *= ca_mask;
1380         }
1381
1382         /* calculate mask */
1383         if (ps->do_mask_normal) {
1384                 const MLoopTri *lt = &ps->dm_mlooptri[tri_index];
1385                 const int lt_vtri[3] = { PS_LOOPTRI_AS_VERT_INDEX_3(ps, lt) };
1386                 const MPoly *mp = &ps->dm_mpoly[lt->poly];
1387                 float no[3], angle_cos;
1388
1389                 if (mp->flag & ME_SMOOTH) {
1390                         const short *no1, *no2, *no3;
1391                         no1 = ps->dm_mvert[lt_vtri[0]].no;
1392                         no2 = ps->dm_mvert[lt_vtri[1]].no;
1393                         no3 = ps->dm_mvert[lt_vtri[2]].no;
1394
1395                         no[0] = w[0] * no1[0] + w[1] * no2[0] + w[2] * no3[0];
1396                         no[1] = w[0] * no1[1] + w[1] * no2[1] + w[2] * no3[1];
1397                         no[2] = w[0] * no1[2] + w[1] * no2[2] + w[2] * no3[2];
1398                         normalize_v3(no);
1399                 }
1400                 else {
1401                         /* incase the */
1402 #if 1
1403                         /* normalizing per pixel isn't optimal, we could cache or check ps->*/
1404                         normal_tri_v3(no,
1405                                       ps->dm_mvert[lt_vtri[0]].co,
1406                                       ps->dm_mvert[lt_vtri[1]].co,
1407                                       ps->dm_mvert[lt_vtri[2]].co);
1408 #else
1409                         /* don't use because some modifiers dont have normal data (subsurf for eg) */
1410                         copy_v3_v3(no, (float *)ps->dm->getTessFaceData(ps->dm, tri_index, CD_NORMAL));
1411 #endif
1412                 }
1413
1414                 if (UNLIKELY(ps->is_flip_object)) {
1415                         negate_v3(no);
1416                 }
1417
1418                 /* now we can use the normal as a mask */
1419                 if (ps->is_ortho) {
1420                         angle_cos = dot_v3v3(ps->viewDir, no);
1421                 }
1422                 else {
1423                         /* Annoying but for the perspective view we need to get the pixels location in 3D space :/ */
1424                         float viewDirPersp[3];
1425                         const float *co1, *co2, *co3;
1426                         co1 = ps->dm_mvert[lt_vtri[0]].co;
1427                         co2 = ps->dm_mvert[lt_vtri[1]].co;
1428                         co3 = ps->dm_mvert[lt_vtri[2]].co;
1429
1430                         /* Get the direction from the viewPoint to the pixel and normalize */
1431                         viewDirPersp[0] = (ps->viewPos[0] - (w[0] * co1[0] + w[1] * co2[0] + w[2] * co3[0]));
1432                         viewDirPersp[1] = (ps->viewPos[1] - (w[0] * co1[1] + w[1] * co2[1] + w[2] * co3[1]));
1433                         viewDirPersp[2] = (ps->viewPos[2] - (w[0] * co1[2] + w[1] * co2[2] + w[2] * co3[2]));
1434                         normalize_v3(viewDirPersp);
1435                         if (UNLIKELY(ps->is_flip_object)) {
1436                                 negate_v3(viewDirPersp);
1437                         }
1438
1439                         angle_cos = dot_v3v3(viewDirPersp, no);
1440                 }
1441
1442                 if (angle_cos <= ps->normal_angle__cos) {
1443                         return 0.0f; /* outsize the normal limit*/
1444                 }
1445                 else if (angle_cos < ps->normal_angle_inner__cos) {
1446                         mask *= (ps->normal_angle - acosf(angle_cos)) / ps->normal_angle_range;
1447                 } /* otherwise no mask normal is needed, were within the limit */
1448         }
1449
1450         /* This only works when the opacity dosnt change while painting, stylus pressure messes with this
1451          * so don't use it. */
1452         // if (ps->is_airbrush == 0) mask *= BKE_brush_alpha_get(ps->brush);
1453
1454         return mask;
1455 }
1456
1457 static int project_paint_pixel_sizeof(const short tool)
1458 {
1459         if ((tool == PAINT_TOOL_CLONE) || (tool == PAINT_TOOL_SMEAR)) {
1460                 return sizeof(ProjPixelClone);
1461         }
1462         else {
1463                 return sizeof(ProjPixel);
1464         }
1465 }
1466
1467 static int project_paint_undo_subtiles(const TileInfo *tinf, int tx, int ty)
1468 {
1469         ProjPaintImage *pjIma = tinf->pjima;
1470         int tile_index = tx + ty * tinf->tile_width;
1471         bool generate_tile = false;
1472
1473         /* double check lock to avoid locking */
1474         if (UNLIKELY(!pjIma->undoRect[tile_index])) {
1475                 if (tinf->lock)
1476                         BLI_spin_lock(tinf->lock);
1477                 if (LIKELY(!pjIma->undoRect[tile_index])) {
1478                         pjIma->undoRect[tile_index] = TILE_PENDING;
1479                         generate_tile = true;
1480                 }
1481                 if (tinf->lock)
1482                         BLI_spin_unlock(tinf->lock);
1483         }
1484
1485
1486         if (generate_tile) {
1487                 volatile void *undorect;
1488                 if (tinf->masked) {
1489                         undorect = image_undo_push_tile(
1490                                 pjIma->ima, pjIma->ibuf, tinf->tmpibuf,
1491                                 tx, ty, &pjIma->maskRect[tile_index], &pjIma->valid[tile_index], true, false);
1492                 }
1493                 else {
1494                         undorect = image_undo_push_tile(
1495                                 pjIma->ima, pjIma->ibuf, tinf->tmpibuf,
1496                                 tx, ty, NULL, &pjIma->valid[tile_index], true, false);
1497                 }
1498
1499                 pjIma->ibuf->userflags |= IB_BITMAPDIRTY;
1500                 /* tile ready, publish */
1501                 if (tinf->lock)
1502                         BLI_spin_lock(tinf->lock);
1503                 pjIma->undoRect[tile_index] = undorect;
1504                 if (tinf->lock)
1505                         BLI_spin_unlock(tinf->lock);
1506
1507         }
1508
1509         return tile_index;
1510 }
1511
1512 /* run this function when we know a bucket's, face's pixel can be initialized,
1513  * return the ProjPixel which is added to 'ps->bucketRect[bucket_index]' */
1514 static ProjPixel *project_paint_uvpixel_init(
1515         const ProjPaintState *ps,
1516         MemArena *arena,
1517         const TileInfo *tinf,
1518         int x_px, int y_px,
1519         const float mask,
1520         const int tri_index,
1521         const float pixelScreenCo[4],
1522         const float world_spaceCo[3],
1523         const float w[3])
1524 {
1525         ProjPixel *projPixel;
1526         int x_tile, y_tile;
1527         int x_round, y_round;
1528         int tile_offset;
1529         /* volatile is important here to ensure pending check is not optimized away by compiler*/
1530         volatile int tile_index;
1531
1532         ProjPaintImage *projima = tinf->pjima;
1533         ImBuf *ibuf = projima->ibuf;
1534         /* wrap pixel location */
1535
1536         x_px = mod_i(x_px, ibuf->x);
1537         y_px = mod_i(y_px, ibuf->y);
1538
1539         BLI_assert(ps->pixel_sizeof == project_paint_pixel_sizeof(ps->tool));
1540         projPixel = BLI_memarena_alloc(arena, ps->pixel_sizeof);
1541
1542         /* calculate the undo tile offset of the pixel, used to store the original
1543          * pixel color and accumulated mask if any */
1544         x_tile =  x_px >> IMAPAINT_TILE_BITS;
1545         y_tile =  y_px >> IMAPAINT_TILE_BITS;
1546
1547         x_round = x_tile * IMAPAINT_TILE_SIZE;
1548         y_round = y_tile * IMAPAINT_TILE_SIZE;
1549         //memset(projPixel, 0, size);
1550
1551         tile_offset = (x_px - x_round) + (y_px - y_round) * IMAPAINT_TILE_SIZE;
1552         tile_index = project_paint_undo_subtiles(tinf, x_tile, y_tile);
1553
1554         /* other thread may be initializing the tile so wait here */
1555         while (projima->undoRect[tile_index] == TILE_PENDING)
1556                 ;
1557
1558         BLI_assert(tile_index < (IMAPAINT_TILE_NUMBER(ibuf->x) * IMAPAINT_TILE_NUMBER(ibuf->y)));
1559         BLI_assert(tile_offset < (IMAPAINT_TILE_SIZE * IMAPAINT_TILE_SIZE));
1560
1561         projPixel->valid = projima->valid[tile_index];
1562
1563         if (ibuf->rect_float) {
1564                 projPixel->pixel.f_pt = ibuf->rect_float + ((x_px + y_px * ibuf->x) * 4);
1565                 projPixel->origColor.f_pt = (float *)projima->undoRect[tile_index] + 4 * tile_offset;
1566                 zero_v4(projPixel->newColor.f);
1567         }
1568         else {
1569                 projPixel->pixel.ch_pt = (unsigned char *)(ibuf->rect + (x_px + y_px * ibuf->x));
1570                 projPixel->origColor.uint_pt = (unsigned int *)projima->undoRect[tile_index] + tile_offset;
1571                 projPixel->newColor.uint = 0;
1572         }
1573
1574         /* screenspace unclamped, we could keep its z and w values but don't need them at the moment */
1575         if (ps->brush->mtex.brush_map_mode == MTEX_MAP_MODE_3D) {
1576                 copy_v3_v3(projPixel->worldCoSS, world_spaceCo);
1577         }
1578
1579         copy_v2_v2(projPixel->projCoSS, pixelScreenCo);
1580
1581         projPixel->x_px = x_px;
1582         projPixel->y_px = y_px;
1583
1584         projPixel->mask = (unsigned short)(mask * 65535);
1585         if (ps->do_masking)
1586                 projPixel->mask_accum = projima->maskRect[tile_index] + tile_offset;
1587         else
1588                 projPixel->mask_accum = NULL;
1589
1590         /* which bounding box cell are we in?, needed for undo */
1591         projPixel->bb_cell_index = ((int)(((float)x_px / (float)ibuf->x) * PROJ_BOUNDBOX_DIV)) +
1592                                    ((int)(((float)y_px / (float)ibuf->y) * PROJ_BOUNDBOX_DIV)) * PROJ_BOUNDBOX_DIV;
1593
1594         /* done with view3d_project_float inline */
1595         if (ps->tool == PAINT_TOOL_CLONE) {
1596                 if (ps->dm_mloopuv_clone) {
1597                         ImBuf *ibuf_other;
1598                         Image *other_tpage = project_paint_face_clone_image(ps, tri_index);
1599
1600                         if (other_tpage && (ibuf_other = BKE_image_acquire_ibuf(other_tpage, NULL, NULL))) {
1601                                 const MLoopTri *lt_other = &ps->dm_mlooptri[tri_index];
1602                                 const float *lt_other_tri_uv[3] = { PS_LOOPTRI_AS_UV_3(ps->dm_mloopuv_clone, lt_other) };
1603
1604                                 /* BKE_image_acquire_ibuf - TODO - this may be slow */
1605
1606                                 if (ibuf->rect_float) {
1607                                         if (ibuf_other->rect_float) { /* from float to float */
1608                                                 project_face_pixel(lt_other_tri_uv, ibuf_other, w, NULL, ((ProjPixelClone *)projPixel)->clonepx.f);
1609                                         }
1610                                         else { /* from char to float */
1611                                                 unsigned char rgba_ub[4];
1612                                                 float rgba[4];
1613                                                 project_face_pixel(lt_other_tri_uv, ibuf_other, w, rgba_ub, NULL);
1614                                                 srgb_to_linearrgb_uchar4(rgba, rgba_ub);
1615                                                 straight_to_premul_v4_v4(((ProjPixelClone *)projPixel)->clonepx.f, rgba);
1616                                         }
1617                                 }
1618                                 else {
1619                                         if (ibuf_other->rect_float) { /* float to char */
1620                                                 float rgba[4];
1621                                                 project_face_pixel(lt_other_tri_uv, ibuf_other, w, NULL, rgba);
1622                                                 premul_to_straight_v4(rgba);
1623                                                 linearrgb_to_srgb_uchar3(((ProjPixelClone *)projPixel)->clonepx.ch, rgba);
1624                                                 ((ProjPixelClone *)projPixel)->clonepx.ch[3] =  rgba[3] * 255;
1625                                         }
1626                                         else { /* char to char */
1627                                                 project_face_pixel(lt_other_tri_uv, ibuf_other, w, ((ProjPixelClone *)projPixel)->clonepx.ch, NULL);
1628                                         }
1629                                 }
1630
1631                                 BKE_image_release_ibuf(other_tpage, ibuf_other, NULL);
1632                         }
1633                         else {
1634                                 if (ibuf->rect_float) {
1635                                         ((ProjPixelClone *)projPixel)->clonepx.f[3] = 0;
1636                                 }
1637                                 else {
1638                                         ((ProjPixelClone *)projPixel)->clonepx.ch[3] = 0;
1639                                 }
1640                         }
1641
1642                 }
1643                 else {
1644                         float co[2];
1645                         sub_v2_v2v2(co, projPixel->projCoSS, ps->cloneOffset);
1646
1647                         /* no need to initialize the bucket, we're only checking buckets faces and for this
1648                          * the faces are already initialized in project_paint_delayed_face_init(...) */
1649                         if (ibuf->rect_float) {
1650                                 if (!project_paint_PickColor(ps, co, ((ProjPixelClone *)projPixel)->clonepx.f, NULL, 1)) {
1651                                         ((ProjPixelClone *)projPixel)->clonepx.f[3] = 0; /* zero alpha - ignore */
1652                                 }
1653                         }
1654                         else {
1655                                 if (!project_paint_PickColor(ps, co, NULL, ((ProjPixelClone *)projPixel)->clonepx.ch, 1)) {
1656                                         ((ProjPixelClone *)projPixel)->clonepx.ch[3] = 0; /* zero alpha - ignore */
1657                                 }
1658                         }
1659                 }
1660         }
1661
1662 #ifdef PROJ_DEBUG_PAINT
1663         if (ibuf->rect_float) projPixel->pixel.f_pt[0] = 0;
1664         else                  projPixel->pixel.ch_pt[0] = 0;
1665 #endif
1666         /* pointer arithmetics */
1667         projPixel->image_index = projima - ps->projImages;
1668
1669         return projPixel;
1670 }
1671
1672 static bool line_clip_rect2f(
1673         const rctf *cliprect,
1674         const rctf *rect,
1675         const float l1[2], const float l2[2],
1676         float l1_clip[2], float l2_clip[2])
1677 {
1678         /* first account for horizontal, then vertical lines */
1679         /* horiz */
1680         if (fabsf(l1[1] - l2[1]) < PROJ_PIXEL_TOLERANCE) {
1681                 /* is the line out of range on its Y axis? */
1682                 if (l1[1] < rect->ymin || l1[1] > rect->ymax) {
1683                         return 0;
1684                 }
1685                 /* line is out of range on its X axis */
1686                 if ((l1[0] < rect->xmin && l2[0] < rect->xmin) || (l1[0] > rect->xmax && l2[0] > rect->xmax)) {
1687                         return 0;
1688                 }
1689
1690
1691                 if (fabsf(l1[0] - l2[0]) < PROJ_PIXEL_TOLERANCE) { /* this is a single point  (or close to)*/
1692                         if (BLI_rctf_isect_pt_v(rect, l1)) {
1693                                 copy_v2_v2(l1_clip, l1);
1694                                 copy_v2_v2(l2_clip, l2);
1695                                 return 1;
1696                         }
1697                         else {
1698                                 return 0;
1699                         }
1700                 }
1701
1702                 copy_v2_v2(l1_clip, l1);
1703                 copy_v2_v2(l2_clip, l2);
1704                 CLAMP(l1_clip[0], rect->xmin, rect->xmax);
1705                 CLAMP(l2_clip[0], rect->xmin, rect->xmax);
1706                 return 1;
1707         }
1708         else if (fabsf(l1[0] - l2[0]) < PROJ_PIXEL_TOLERANCE) {
1709                 /* is the line out of range on its X axis? */
1710                 if (l1[0] < rect->xmin || l1[0] > rect->xmax) {
1711                         return 0;
1712                 }
1713
1714                 /* line is out of range on its Y axis */
1715                 if ((l1[1] < rect->ymin && l2[1] < rect->ymin) || (l1[1] > rect->ymax && l2[1] > rect->ymax)) {
1716                         return 0;
1717                 }
1718
1719                 if (fabsf(l1[1] - l2[1]) < PROJ_PIXEL_TOLERANCE) { /* this is a single point  (or close to)*/
1720                         if (BLI_rctf_isect_pt_v(rect, l1)) {
1721                                 copy_v2_v2(l1_clip, l1);
1722                                 copy_v2_v2(l2_clip, l2);
1723                                 return 1;
1724                         }
1725                         else {
1726                                 return 0;
1727                         }
1728                 }
1729
1730                 copy_v2_v2(l1_clip, l1);
1731                 copy_v2_v2(l2_clip, l2);
1732                 CLAMP(l1_clip[1], rect->ymin, rect->ymax);
1733                 CLAMP(l2_clip[1], rect->ymin, rect->ymax);
1734                 return 1;
1735         }
1736         else {
1737                 float isect;
1738                 short ok1 = 0;
1739                 short ok2 = 0;
1740
1741                 /* Done with vertical lines */
1742
1743                 /* are either of the points inside the rectangle ? */
1744                 if (BLI_rctf_isect_pt_v(rect, l1)) {
1745                         copy_v2_v2(l1_clip, l1);
1746                         ok1 = 1;
1747                 }
1748
1749                 if (BLI_rctf_isect_pt_v(rect, l2)) {
1750                         copy_v2_v2(l2_clip, l2);
1751                         ok2 = 1;
1752                 }
1753
1754                 /* line inside rect */
1755                 if (ok1 && ok2) return 1;
1756
1757                 /* top/bottom */
1758                 if (line_isect_y(l1, l2, rect->ymin, &isect) && (isect >= cliprect->xmin) && (isect <= cliprect->xmax)) {
1759                         if (l1[1] < l2[1]) { /* line 1 is outside */
1760                                 l1_clip[0] = isect;
1761                                 l1_clip[1] = rect->ymin;
1762                                 ok1 = 1;
1763                         }
1764                         else {
1765                                 l2_clip[0] = isect;
1766                                 l2_clip[1] = rect->ymin;
1767                                 ok2 = 2;
1768                         }
1769                 }
1770
1771                 if (ok1 && ok2) return 1;
1772
1773                 if (line_isect_y(l1, l2, rect->ymax, &isect) && (isect >= cliprect->xmin) && (isect <= cliprect->xmax)) {
1774                         if (l1[1] > l2[1]) { /* line 1 is outside */
1775                                 l1_clip[0] = isect;
1776                                 l1_clip[1] = rect->ymax;
1777                                 ok1 = 1;
1778                         }
1779                         else {
1780                                 l2_clip[0] = isect;
1781                                 l2_clip[1] = rect->ymax;
1782                                 ok2 = 2;
1783                         }
1784                 }
1785
1786                 if (ok1 && ok2) return 1;
1787
1788                 /* left/right */
1789                 if (line_isect_x(l1, l2, rect->xmin, &isect) && (isect >= cliprect->ymin) && (isect <= cliprect->ymax)) {
1790                         if (l1[0] < l2[0]) { /* line 1 is outside */
1791                                 l1_clip[0] = rect->xmin;
1792                                 l1_clip[1] = isect;
1793                                 ok1 = 1;
1794                         }
1795                         else {
1796                                 l2_clip[0] = rect->xmin;
1797                                 l2_clip[1] = isect;
1798                                 ok2 = 2;
1799                         }
1800                 }
1801
1802                 if (ok1 && ok2) return 1;
1803
1804                 if (line_isect_x(l1, l2, rect->xmax, &isect) && (isect >= cliprect->ymin) && (isect <= cliprect->ymax)) {
1805                         if (l1[0] > l2[0]) { /* line 1 is outside */
1806                                 l1_clip[0] = rect->xmax;
1807                                 l1_clip[1] = isect;
1808                                 ok1 = 1;
1809                         }
1810                         else {
1811                                 l2_clip[0] = rect->xmax;
1812                                 l2_clip[1] = isect;
1813                                 ok2 = 2;
1814                         }
1815                 }
1816
1817                 if (ok1 && ok2) {
1818                         return 1;
1819                 }
1820                 else {
1821                         return 0;
1822                 }
1823         }
1824 }
1825
1826
1827
1828 /**
1829  * Scale the tri about its center
1830  * scaling by #PROJ_FACE_SCALE_SEAM (0.99x) is used for getting fake UV pixel coords that are on the
1831  * edge of the face but slightly inside it occlusion tests don't return hits on adjacent faces
1832  */
1833 #ifndef PROJ_DEBUG_NOSEAMBLEED
1834
1835 static void scale_tri(float insetCos[3][3], const float *origCos[4], const float inset)
1836 {
1837         float cent[3];
1838         cent[0] = (origCos[0][0] + origCos[1][0] + origCos[2][0]) * (1.0f / 3.0f);
1839         cent[1] = (origCos[0][1] + origCos[1][1] + origCos[2][1]) * (1.0f / 3.0f);
1840         cent[2] = (origCos[0][2] + origCos[1][2] + origCos[2][2]) * (1.0f / 3.0f);
1841
1842         sub_v3_v3v3(insetCos[0], origCos[0], cent);
1843         sub_v3_v3v3(insetCos[1], origCos[1], cent);
1844         sub_v3_v3v3(insetCos[2], origCos[2], cent);
1845
1846         mul_v3_fl(insetCos[0], inset);
1847         mul_v3_fl(insetCos[1], inset);
1848         mul_v3_fl(insetCos[2], inset);
1849
1850         add_v3_v3(insetCos[0], cent);
1851         add_v3_v3(insetCos[1], cent);
1852         add_v3_v3(insetCos[2], cent);
1853 }
1854 #endif //PROJ_DEBUG_NOSEAMBLEED
1855
1856 static float len_squared_v2v2_alt(const float v1[2], const float v2_1, const float v2_2)
1857 {
1858         float x, y;
1859
1860         x = v1[0] - v2_1;
1861         y = v1[1] - v2_2;
1862         return x * x + y * y;
1863 }
1864
1865 /* note, use a squared value so we can use len_squared_v2v2
1866  * be sure that you have done a bounds check first or this may fail */
1867 /* only give bucket_bounds as an arg because we need it elsewhere */
1868 static bool project_bucket_isect_circle(const float cent[2], const float radius_squared, const rctf *bucket_bounds)
1869 {
1870
1871         /* Would normally to a simple intersection test, however we know the bounds of these 2 already intersect
1872          * so we only need to test if the center is inside the vertical or horizontal bounds on either axis,
1873          * this is even less work then an intersection test
1874          */
1875 #if 0
1876         if (BLI_rctf_isect_pt_v(bucket_bounds, cent))
1877                 return 1;
1878 #endif
1879
1880         if ((bucket_bounds->xmin <= cent[0] && bucket_bounds->xmax >= cent[0]) ||
1881             (bucket_bounds->ymin <= cent[1] && bucket_bounds->ymax >= cent[1]))
1882         {
1883                 return 1;
1884         }
1885
1886         /* out of bounds left */
1887         if (cent[0] < bucket_bounds->xmin) {
1888                 /* lower left out of radius test */
1889                 if (cent[1] < bucket_bounds->ymin) {
1890                         return (len_squared_v2v2_alt(cent, bucket_bounds->xmin, bucket_bounds->ymin) < radius_squared) ? 1 : 0;
1891                 }
1892                 /* top left test */
1893                 else if (cent[1] > bucket_bounds->ymax) {
1894                         return (len_squared_v2v2_alt(cent, bucket_bounds->xmin, bucket_bounds->ymax) < radius_squared) ? 1 : 0;
1895                 }
1896         }
1897         else if (cent[0] > bucket_bounds->xmax) {
1898                 /* lower right out of radius test */
1899                 if (cent[1] < bucket_bounds->ymin) {
1900                         return (len_squared_v2v2_alt(cent, bucket_bounds->xmax, bucket_bounds->ymin) < radius_squared) ? 1 : 0;
1901                 }
1902                 /* top right test */
1903                 else if (cent[1] > bucket_bounds->ymax) {
1904                         return (len_squared_v2v2_alt(cent, bucket_bounds->xmax, bucket_bounds->ymax) < radius_squared) ? 1 : 0;
1905                 }
1906         }
1907
1908         return 0;
1909 }
1910
1911
1912
1913 /* Note for rect_to_uvspace_ortho() and rect_to_uvspace_persp()
1914  * in ortho view this function gives good results when bucket_bounds are outside the triangle
1915  * however in some cases, perspective view will mess up with faces that have minimal screenspace area
1916  * (viewed from the side)
1917  *
1918  * for this reason its not reliable in this case so we'll use the Simple Barycentric'
1919  * funcs that only account for points inside the triangle.
1920  * however switching back to this for ortho is always an option */
1921
1922 static void rect_to_uvspace_ortho(
1923         const rctf *bucket_bounds,
1924         const float *v1coSS, const float *v2coSS, const float *v3coSS,
1925         const float *uv1co, const float *uv2co, const float *uv3co,
1926         float bucket_bounds_uv[4][2],
1927         const int flip)
1928 {
1929         float uv[2];
1930         float w[3];
1931
1932         /* get the UV space bounding box */
1933         uv[0] = bucket_bounds->xmax;
1934         uv[1] = bucket_bounds->ymin;
1935         barycentric_weights_v2(v1coSS, v2coSS, v3coSS, uv, w);
1936         interp_v2_v2v2v2(bucket_bounds_uv[flip ? 3 : 0], uv1co, uv2co, uv3co, w);
1937
1938         //uv[0] = bucket_bounds->xmax; // set above
1939         uv[1] = bucket_bounds->ymax;
1940         barycentric_weights_v2(v1coSS, v2coSS, v3coSS, uv, w);
1941         interp_v2_v2v2v2(bucket_bounds_uv[flip ? 2 : 1], uv1co, uv2co, uv3co, w);
1942
1943         uv[0] = bucket_bounds->xmin;
1944         //uv[1] = bucket_bounds->ymax; // set above
1945         barycentric_weights_v2(v1coSS, v2coSS, v3coSS, uv, w);
1946         interp_v2_v2v2v2(bucket_bounds_uv[flip ? 1 : 2], uv1co, uv2co, uv3co, w);
1947
1948         //uv[0] = bucket_bounds->xmin; // set above
1949         uv[1] = bucket_bounds->ymin;
1950         barycentric_weights_v2(v1coSS, v2coSS, v3coSS, uv, w);
1951         interp_v2_v2v2v2(bucket_bounds_uv[flip ? 0 : 3], uv1co, uv2co, uv3co, w);
1952 }
1953
1954 /* same as above but use barycentric_weights_v2_persp */
1955 static void rect_to_uvspace_persp(
1956         const rctf *bucket_bounds,
1957         const float *v1coSS, const float *v2coSS, const float *v3coSS,
1958         const float *uv1co, const float *uv2co, const float *uv3co,
1959         float bucket_bounds_uv[4][2],
1960         const int flip
1961         )
1962 {
1963         float uv[2];
1964         float w[3];
1965
1966         /* get the UV space bounding box */
1967         uv[0] = bucket_bounds->xmax;
1968         uv[1] = bucket_bounds->ymin;
1969         barycentric_weights_v2_persp(v1coSS, v2coSS, v3coSS, uv, w);
1970         interp_v2_v2v2v2(bucket_bounds_uv[flip ? 3 : 0], uv1co, uv2co, uv3co, w);
1971
1972         //uv[0] = bucket_bounds->xmax; // set above
1973         uv[1] = bucket_bounds->ymax;
1974         barycentric_weights_v2_persp(v1coSS, v2coSS, v3coSS, uv, w);
1975         interp_v2_v2v2v2(bucket_bounds_uv[flip ? 2 : 1], uv1co, uv2co, uv3co, w);
1976
1977         uv[0] = bucket_bounds->xmin;
1978         //uv[1] = bucket_bounds->ymax; // set above
1979         barycentric_weights_v2_persp(v1coSS, v2coSS, v3coSS, uv, w);
1980         interp_v2_v2v2v2(bucket_bounds_uv[flip ? 1 : 2], uv1co, uv2co, uv3co, w);
1981
1982         //uv[0] = bucket_bounds->xmin; // set above
1983         uv[1] = bucket_bounds->ymin;
1984         barycentric_weights_v2_persp(v1coSS, v2coSS, v3coSS, uv, w);
1985         interp_v2_v2v2v2(bucket_bounds_uv[flip ? 0 : 3], uv1co, uv2co, uv3co, w);
1986 }
1987
1988 /* This works as we need it to but we can save a few steps and not use it */
1989
1990 #if 0
1991 static float angle_2d_clockwise(const float p1[2], const float p2[2], const float p3[2])
1992 {
1993         float v1[2], v2[2];
1994
1995         v1[0] = p1[0] - p2[0];    v1[1] = p1[1] - p2[1];
1996         v2[0] = p3[0] - p2[0];    v2[1] = p3[1] - p2[1];
1997
1998         return -atan2f(v1[0] * v2[1] - v1[1] * v2[0], v1[0] * v2[0] + v1[1] * v2[1]);
1999 }
2000 #endif
2001
2002 #define ISECT_1 (1)
2003 #define ISECT_2 (1 << 1)
2004 #define ISECT_3 (1 << 2)
2005 #define ISECT_4 (1 << 3)
2006 #define ISECT_ALL3 ((1 << 3) - 1)
2007 #define ISECT_ALL4 ((1 << 4) - 1)
2008
2009 /* limit must be a fraction over 1.0f */
2010 static bool IsectPT2Df_limit(
2011         const float pt[2],
2012         const float v1[2], const float v2[2], const float v3[2],
2013         const float limit)
2014 {
2015         return ((area_tri_v2(pt, v1, v2) +
2016                  area_tri_v2(pt, v2, v3) +
2017                  area_tri_v2(pt, v3, v1)) / (area_tri_v2(v1, v2, v3))) < limit;
2018 }
2019
2020 /* Clip the face by a bucket and set the uv-space bucket_bounds_uv
2021  * so we have the clipped UV's to do pixel intersection tests with
2022  * */
2023 static int float_z_sort_flip(const void *p1, const void *p2)
2024 {
2025         return (((float *)p1)[2] < ((float *)p2)[2] ? 1 : -1);
2026 }
2027
2028 static int float_z_sort(const void *p1, const void *p2)
2029 {
2030         return (((float *)p1)[2] < ((float *)p2)[2] ? -1 : 1);
2031 }
2032
2033 /* assumes one point is within the rectangle */
2034 static bool line_rect_clip(
2035         const rctf *rect,
2036         const float l1[4], const float l2[4],
2037         const float uv1[2], const float uv2[2],
2038         float uv[2], bool is_ortho)
2039 {
2040         float min = FLT_MAX, tmp;
2041         float xlen = l2[0] - l1[0];
2042         float ylen = l2[1] - l1[1];
2043
2044         /* 0.1 might seem too much, but remember, this is pixels! */
2045         if (xlen > 0.1f) {
2046                 if ((l1[0] - rect->xmin) * (l2[0] - rect->xmin) <= 0) {
2047                         tmp = rect->xmin;
2048                         min = min_ff((tmp - l1[0]) / xlen, min);
2049                 }
2050                 else if ((l1[0] - rect->xmax) * (l2[0] - rect->xmax) < 0) {
2051                         tmp = rect->xmax;
2052                         min = min_ff((tmp - l1[0]) / xlen, min);
2053                 }
2054         }
2055
2056         if (ylen > 0.1f) {
2057                 if ((l1[1] - rect->ymin) * (l2[1] - rect->ymin) <= 0) {
2058                         tmp = rect->ymin;
2059                         min = min_ff((tmp - l1[1]) / ylen, min);
2060                 }
2061                 else if ((l1[1] - rect->ymax) * (l2[1] - rect->ymax) < 0) {
2062                         tmp = rect->ymax;
2063                         min = min_ff((tmp - l1[1]) / ylen, min);
2064                 }
2065         }
2066
2067         if (min == FLT_MAX)
2068                 return false;
2069
2070         tmp = (is_ortho) ? 1.0f : (l1[3] + min * (l2[3] - l1[3]));
2071
2072         uv[0] = (uv1[0] + min / tmp * (uv2[0] - uv1[0]));
2073         uv[1] = (uv1[1] + min / tmp * (uv2[1] - uv1[1]));
2074
2075         return true;
2076 }
2077
2078
2079 static void project_bucket_clip_face(
2080         const bool is_ortho, const bool is_flip_object,
2081         const rctf *cliprect,
2082         const rctf *bucket_bounds,
2083         const float *v1coSS, const float *v2coSS, const float *v3coSS,
2084         const float *uv1co, const float *uv2co, const float *uv3co,
2085         float bucket_bounds_uv[8][2],
2086         int *tot, bool cull)
2087 {
2088         int inside_bucket_flag = 0;
2089         int inside_face_flag = 0;
2090         int flip;
2091         bool collinear = false;
2092         
2093         float bucket_bounds_ss[4][2];
2094
2095         /* detect pathological case where face the three vertices are almost collinear in screen space.
2096          * mostly those will be culled but when flood filling or with smooth shading it's a possibility */
2097         if (dist_squared_to_line_v2(v1coSS, v2coSS, v3coSS) < 0.5f ||
2098             dist_squared_to_line_v2(v2coSS, v3coSS, v1coSS) < 0.5f)
2099         {
2100                 collinear = true;
2101         }
2102         
2103         /* get the UV space bounding box */
2104         inside_bucket_flag |= BLI_rctf_isect_pt_v(bucket_bounds, v1coSS);
2105         inside_bucket_flag |= BLI_rctf_isect_pt_v(bucket_bounds, v2coSS) << 1;
2106         inside_bucket_flag |= BLI_rctf_isect_pt_v(bucket_bounds, v3coSS) << 2;
2107         
2108         if (inside_bucket_flag == ISECT_ALL3) {
2109                 /* is_flip_object is used here because we use the face winding */
2110                 flip = (((line_point_side_v2(v1coSS, v2coSS, v3coSS) > 0.0f) != is_flip_object) !=
2111                         (line_point_side_v2(uv1co, uv2co, uv3co) > 0.0f));
2112
2113                 /* all screenspace points are inside the bucket bounding box,
2114                  * this means we don't need to clip and can simply return the UVs */
2115                 if (flip) { /* facing the back? */
2116                         copy_v2_v2(bucket_bounds_uv[0], uv3co);
2117                         copy_v2_v2(bucket_bounds_uv[1], uv2co);
2118                         copy_v2_v2(bucket_bounds_uv[2], uv1co);
2119                 }
2120                 else {
2121                         copy_v2_v2(bucket_bounds_uv[0], uv1co);
2122                         copy_v2_v2(bucket_bounds_uv[1], uv2co);
2123                         copy_v2_v2(bucket_bounds_uv[2], uv3co);
2124                 }               
2125                 
2126                 *tot = 3;
2127                 return;
2128         }
2129         /* handle pathological case here, no need for further intersections below since tringle area is almost zero */
2130         if (collinear) {
2131                 int flag;
2132                 
2133                 (*tot) = 0;
2134
2135                 if (cull)
2136                         return;
2137                 
2138                 if (inside_bucket_flag & ISECT_1) { copy_v2_v2(bucket_bounds_uv[*tot], uv1co); (*tot)++; }
2139
2140                 flag = inside_bucket_flag & (ISECT_1 | ISECT_2);
2141                 if (flag && flag != (ISECT_1 | ISECT_2)) {
2142                         if (line_rect_clip(bucket_bounds, v1coSS, v2coSS, uv1co, uv2co, bucket_bounds_uv[*tot], is_ortho))
2143                                 (*tot)++;
2144                 }
2145                 
2146                 if (inside_bucket_flag & ISECT_2) { copy_v2_v2(bucket_bounds_uv[*tot], uv2co); (*tot)++; }
2147                 
2148                 flag = inside_bucket_flag & (ISECT_2 | ISECT_3);
2149                 if (flag && flag != (ISECT_2 | ISECT_3)) {
2150                         if (line_rect_clip(bucket_bounds, v2coSS, v3coSS, uv2co, uv3co, bucket_bounds_uv[*tot], is_ortho))
2151                                 (*tot)++;
2152                 }
2153
2154                 if (inside_bucket_flag & ISECT_3) { copy_v2_v2(bucket_bounds_uv[*tot], uv3co); (*tot)++; }
2155
2156                 flag = inside_bucket_flag & (ISECT_3 | ISECT_1);
2157                 if (flag && flag != (ISECT_3 | ISECT_1)) {
2158                         if (line_rect_clip(bucket_bounds, v3coSS, v1coSS, uv3co, uv1co, bucket_bounds_uv[*tot], is_ortho))
2159                                 (*tot)++;
2160                 }
2161                 
2162                 if ((*tot) < 3) {
2163                         /* no intersections to speak of, but more probable is that all face is just outside the
2164                          * rectangle and culled due to float precision issues. Since above teste have failed,
2165                          * just dump triangle as is for painting */
2166                         *tot = 0;
2167                         copy_v2_v2(bucket_bounds_uv[*tot], uv1co); (*tot)++;
2168                         copy_v2_v2(bucket_bounds_uv[*tot], uv2co); (*tot)++;
2169                         copy_v2_v2(bucket_bounds_uv[*tot], uv3co); (*tot)++;
2170                         return;
2171                 }
2172
2173                 return;
2174         }
2175
2176         /* get the UV space bounding box */
2177         /* use IsectPT2Df_limit here so we catch points are are touching the tri edge (or a small fraction over) */
2178         bucket_bounds_ss[0][0] = bucket_bounds->xmax;
2179         bucket_bounds_ss[0][1] = bucket_bounds->ymin;
2180         inside_face_flag |= (IsectPT2Df_limit(bucket_bounds_ss[0], v1coSS, v2coSS, v3coSS, 1 + PROJ_GEOM_TOLERANCE) ? ISECT_1 : 0);
2181
2182         bucket_bounds_ss[1][0] = bucket_bounds->xmax;
2183         bucket_bounds_ss[1][1] = bucket_bounds->ymax;
2184         inside_face_flag |= (IsectPT2Df_limit(bucket_bounds_ss[1], v1coSS, v2coSS, v3coSS, 1 + PROJ_GEOM_TOLERANCE) ? ISECT_2 : 0);
2185
2186         bucket_bounds_ss[2][0] = bucket_bounds->xmin;
2187         bucket_bounds_ss[2][1] = bucket_bounds->ymax;
2188         inside_face_flag |= (IsectPT2Df_limit(bucket_bounds_ss[2], v1coSS, v2coSS, v3coSS, 1 + PROJ_GEOM_TOLERANCE) ? ISECT_3 : 0);
2189
2190         bucket_bounds_ss[3][0] = bucket_bounds->xmin;
2191         bucket_bounds_ss[3][1] = bucket_bounds->ymin;
2192         inside_face_flag |= (IsectPT2Df_limit(bucket_bounds_ss[3], v1coSS, v2coSS, v3coSS, 1 + PROJ_GEOM_TOLERANCE) ? ISECT_4 : 0);
2193
2194         flip = ((line_point_side_v2(v1coSS, v2coSS, v3coSS) > 0.0f) !=
2195                 (line_point_side_v2(uv1co, uv2co, uv3co) > 0.0f));
2196
2197         if (inside_face_flag == ISECT_ALL4) {
2198                 /* bucket is totally inside the screenspace face, we can safely use weights */
2199
2200                 if (is_ortho) {
2201                         rect_to_uvspace_ortho(bucket_bounds, v1coSS, v2coSS, v3coSS, uv1co, uv2co, uv3co, bucket_bounds_uv, flip);
2202                 }
2203                 else {
2204                         rect_to_uvspace_persp(bucket_bounds, v1coSS, v2coSS, v3coSS, uv1co, uv2co, uv3co, bucket_bounds_uv, flip);
2205                 }
2206
2207                 *tot = 4;
2208                 return;
2209         }
2210         else {
2211                 /* The Complicated Case!
2212                  *
2213                  * The 2 cases above are where the face is inside the bucket or the bucket is inside the face.
2214                  *
2215                  * we need to make a convex polyline from the intersection between the screenspace face
2216                  * and the bucket bounds.
2217                  *
2218                  * There are a number of ways this could be done, currently it just collects all intersecting verts,
2219                  * and line intersections,  then sorts them clockwise, this is a lot easier then evaluating the geometry to
2220                  * do a correct clipping on both shapes. */
2221
2222
2223                 /* add a bunch of points, we know must make up the convex hull which is the clipped rect and triangle */
2224
2225
2226
2227                 /* Maximum possible 6 intersections when using a rectangle and triangle */
2228                 float isectVCosSS[8][3]; /* The 3rd float is used to store angle for qsort(), NOT as a Z location */
2229                 float v1_clipSS[2], v2_clipSS[2];
2230                 float w[3];
2231
2232                 /* calc center */
2233                 float cent[2] = {0.0f, 0.0f};
2234                 /*float up[2] = {0.0f, 1.0f};*/
2235                 int i;
2236                 bool doubles;
2237
2238                 (*tot) = 0;
2239
2240                 if (inside_face_flag & ISECT_1) { copy_v2_v2(isectVCosSS[*tot], bucket_bounds_ss[0]); (*tot)++; }
2241                 if (inside_face_flag & ISECT_2) { copy_v2_v2(isectVCosSS[*tot], bucket_bounds_ss[1]); (*tot)++; }
2242                 if (inside_face_flag & ISECT_3) { copy_v2_v2(isectVCosSS[*tot], bucket_bounds_ss[2]); (*tot)++; }
2243                 if (inside_face_flag & ISECT_4) { copy_v2_v2(isectVCosSS[*tot], bucket_bounds_ss[3]); (*tot)++; }
2244
2245                 if (inside_bucket_flag & ISECT_1) { copy_v2_v2(isectVCosSS[*tot], v1coSS); (*tot)++; }
2246                 if (inside_bucket_flag & ISECT_2) { copy_v2_v2(isectVCosSS[*tot], v2coSS); (*tot)++; }
2247                 if (inside_bucket_flag & ISECT_3) { copy_v2_v2(isectVCosSS[*tot], v3coSS); (*tot)++; }
2248
2249                 if ((inside_bucket_flag & (ISECT_1 | ISECT_2)) != (ISECT_1 | ISECT_2)) {
2250                         if (line_clip_rect2f(cliprect, bucket_bounds, v1coSS, v2coSS, v1_clipSS, v2_clipSS)) {
2251                                 if ((inside_bucket_flag & ISECT_1) == 0) { copy_v2_v2(isectVCosSS[*tot], v1_clipSS); (*tot)++; }
2252                                 if ((inside_bucket_flag & ISECT_2) == 0) { copy_v2_v2(isectVCosSS[*tot], v2_clipSS); (*tot)++; }
2253                         }
2254                 }
2255
2256                 if ((inside_bucket_flag & (ISECT_2 | ISECT_3)) != (ISECT_2 | ISECT_3)) {
2257                         if (line_clip_rect2f(cliprect, bucket_bounds, v2coSS, v3coSS, v1_clipSS, v2_clipSS)) {
2258                                 if ((inside_bucket_flag & ISECT_2) == 0) { copy_v2_v2(isectVCosSS[*tot], v1_clipSS); (*tot)++; }
2259                                 if ((inside_bucket_flag & ISECT_3) == 0) { copy_v2_v2(isectVCosSS[*tot], v2_clipSS); (*tot)++; }
2260                         }
2261                 }
2262
2263                 if ((inside_bucket_flag & (ISECT_3 | ISECT_1)) != (ISECT_3 | ISECT_1)) {
2264                         if (line_clip_rect2f(cliprect, bucket_bounds, v3coSS, v1coSS, v1_clipSS, v2_clipSS)) {
2265                                 if ((inside_bucket_flag & ISECT_3) == 0) { copy_v2_v2(isectVCosSS[*tot], v1_clipSS); (*tot)++; }
2266                                 if ((inside_bucket_flag & ISECT_1) == 0) { copy_v2_v2(isectVCosSS[*tot], v2_clipSS); (*tot)++; }
2267                         }
2268                 }
2269
2270
2271                 if ((*tot) < 3) { /* no intersections to speak of */
2272                         *tot = 0;
2273                         return;
2274                 }
2275
2276                 /* now we have all points we need, collect their angles and sort them clockwise */
2277
2278                 for (i = 0; i < (*tot); i++) {
2279                         cent[0] += isectVCosSS[i][0];
2280                         cent[1] += isectVCosSS[i][1];
2281                 }
2282                 cent[0] = cent[0] / (float)(*tot);
2283                 cent[1] = cent[1] / (float)(*tot);
2284
2285
2286
2287                 /* Collect angles for every point around the center point */
2288
2289
2290 #if 0   /* uses a few more cycles then the above loop */
2291                 for (i = 0; i < (*tot); i++) {
2292                         isectVCosSS[i][2] = angle_2d_clockwise(up, cent, isectVCosSS[i]);
2293                 }
2294 #endif
2295
2296                 v1_clipSS[0] = cent[0]; /* Abuse this var for the loop below */
2297                 v1_clipSS[1] = cent[1] + 1.0f;
2298
2299                 for (i = 0; i < (*tot); i++) {
2300                         v2_clipSS[0] = isectVCosSS[i][0] - cent[0];
2301                         v2_clipSS[1] = isectVCosSS[i][1] - cent[1];
2302                         isectVCosSS[i][2] = atan2f(v1_clipSS[0] * v2_clipSS[1] - v1_clipSS[1] * v2_clipSS[0],
2303                                                    v1_clipSS[0] * v2_clipSS[0] + v1_clipSS[1] * v2_clipSS[1]);
2304                 }
2305
2306                 if (flip) qsort(isectVCosSS, *tot, sizeof(float) * 3, float_z_sort_flip);
2307                 else      qsort(isectVCosSS, *tot, sizeof(float) * 3, float_z_sort);
2308
2309                 doubles = true;
2310                 while (doubles == true) {
2311                         doubles = false;
2312
2313                         for (i = 0; i < (*tot); i++) {
2314                                 if (fabsf(isectVCosSS[(i + 1) % *tot][0] - isectVCosSS[i][0]) < PROJ_PIXEL_TOLERANCE &&
2315                                     fabsf(isectVCosSS[(i + 1) % *tot][1] - isectVCosSS[i][1]) < PROJ_PIXEL_TOLERANCE)
2316                                 {
2317                                         int j;
2318                                         for (j = i; j < (*tot) - 1; j++) {
2319                                                 isectVCosSS[j][0] = isectVCosSS[j + 1][0];
2320                                                 isectVCosSS[j][1] = isectVCosSS[j + 1][1];
2321                                         }
2322                                         doubles = true; /* keep looking for more doubles */
2323                                         (*tot)--;
2324                                 }
2325                         }
2326                         
2327                         /* its possible there is only a few left after remove doubles */
2328                         if ((*tot) < 3) {
2329                                 // printf("removed too many doubles B\n");
2330                                 *tot = 0;
2331                                 return;
2332                         }
2333                 }
2334
2335                 if (is_ortho) {
2336                         for (i = 0; i < (*tot); i++) {
2337                                 barycentric_weights_v2(v1coSS, v2coSS, v3coSS, isectVCosSS[i], w);
2338                                 interp_v2_v2v2v2(bucket_bounds_uv[i], uv1co, uv2co, uv3co, w);
2339                         }
2340                 }
2341                 else {
2342                         for (i = 0; i < (*tot); i++) {
2343                                 barycentric_weights_v2_persp(v1coSS, v2coSS, v3coSS, isectVCosSS[i], w);
2344                                 interp_v2_v2v2v2(bucket_bounds_uv[i], uv1co, uv2co, uv3co, w);
2345                         }
2346                 }
2347         }
2348
2349 #ifdef PROJ_DEBUG_PRINT_CLIP
2350         /* include this at the bottom of the above function to debug the output */
2351
2352         {
2353                 /* If there are ever any problems, */
2354                 float test_uv[4][2];
2355                 int i;
2356                 if (is_ortho) rect_to_uvspace_ortho(bucket_bounds, v1coSS, v2coSS, v3coSS, uv1co, uv2co, uv3co, test_uv, flip);
2357                 else          rect_to_uvspace_persp(bucket_bounds, v1coSS, v2coSS, v3coSS, uv1co, uv2co, uv3co, test_uv, flip);
2358                 printf("(  [(%f,%f), (%f,%f), (%f,%f), (%f,%f)], ",
2359                        test_uv[0][0], test_uv[0][1],   test_uv[1][0], test_uv[1][1],
2360                        test_uv[2][0], test_uv[2][1],    test_uv[3][0], test_uv[3][1]);
2361
2362                 printf("  [(%f,%f), (%f,%f), (%f,%f)], ", uv1co[0], uv1co[1],   uv2co[0], uv2co[1],    uv3co[0], uv3co[1]);
2363
2364                 printf("[");
2365                 for (i = 0; i < (*tot); i++) {
2366                         printf("(%f, %f),", bucket_bounds_uv[i][0], bucket_bounds_uv[i][1]);
2367                 }
2368                 printf("]),\\\n");
2369         }
2370 #endif
2371 }
2372
2373 /*
2374  * # This script creates faces in a blender scene from printed data above.
2375  *
2376  * project_ls = [
2377  * ...(output from above block)...
2378  * ]
2379  *
2380  * from Blender import Scene, Mesh, Window, sys, Mathutils
2381  *
2382  * import bpy
2383  *
2384  * V = Mathutils.Vector
2385  *
2386  * def main():
2387  *     sce = bpy.data.scenes.active
2388  *
2389  *     for item in project_ls:
2390  *         bb = item[0]
2391  *         uv = item[1]
2392  *         poly = item[2]
2393  *
2394  *         me = bpy.data.meshes.new()
2395  *         ob = sce.objects.new(me)
2396  *
2397  *         me.verts.extend([V(bb[0]).xyz, V(bb[1]).xyz, V(bb[2]).xyz, V(bb[3]).xyz])
2398  *         me.faces.extend([(0,1,2,3),])
2399  *         me.verts.extend([V(uv[0]).xyz, V(uv[1]).xyz, V(uv[2]).xyz])
2400  *         me.faces.extend([(4,5,6),])
2401  *
2402  *         vs = [V(p).xyz for p in poly]
2403  *         print len(vs)
2404  *         l = len(me.verts)
2405  *         me.verts.extend(vs)
2406  *
2407  *         i = l
2408  *         while i < len(me.verts):
2409  *             ii = i + 1
2410  *             if ii == len(me.verts):
2411  *                 ii = l
2412  *             me.edges.extend([i, ii])
2413  *             i += 1
2414  *
2415  * if __name__ == '__main__':
2416  *     main()
2417  */
2418
2419
2420 #undef ISECT_1
2421 #undef ISECT_2
2422 #undef ISECT_3
2423 #undef ISECT_4
2424 #undef ISECT_ALL3
2425 #undef ISECT_ALL4
2426
2427
2428 /* checks if pt is inside a convex 2D polyline, the polyline must be ordered rotating clockwise
2429  * otherwise it would have to test for mixed (line_point_side_v2 > 0.0f) cases */
2430 static bool IsectPoly2Df(const float pt[2], float uv[][2], const int tot)
2431 {
2432         int i;
2433         if (line_point_side_v2(uv[tot - 1], uv[0], pt) < 0.0f)
2434                 return 0;
2435
2436         for (i = 1; i < tot; i++) {
2437                 if (line_point_side_v2(uv[i - 1], uv[i], pt) < 0.0f)
2438                         return 0;
2439
2440         }
2441
2442         return 1;
2443 }
2444 static bool IsectPoly2Df_twoside(const float pt[2], float uv[][2], const int tot)
2445 {
2446         int i;
2447         bool side = (line_point_side_v2(uv[tot - 1], uv[0], pt) > 0.0f);
2448
2449         for (i = 1; i < tot; i++) {
2450                 if ((line_point_side_v2(uv[i - 1], uv[i], pt) > 0.0f) != side)
2451                         return 0;
2452
2453         }
2454
2455         return 1;
2456 }
2457
2458 /* One of the most important function for projection painting,
2459  * since it selects the pixels to be added into each bucket.
2460  *
2461  * initialize pixels from this face where it intersects with the bucket_index,
2462  * optionally initialize pixels for removing seams */
2463 static void project_paint_face_init(
2464         const ProjPaintState *ps,
2465         const int thread_index, const int bucket_index, const int tri_index, const int image_index,
2466         const rctf *clip_rect, const rctf *bucket_bounds, ImBuf *ibuf, ImBuf **tmpibuf,
2467         const bool clamp_u, const bool clamp_v)
2468 {
2469         /* Projection vars, to get the 3D locations into screen space  */
2470         MemArena *arena = ps->arena_mt[thread_index];
2471         LinkNode **bucketPixelNodes = ps->bucketRect + bucket_index;
2472         LinkNode *bucketFaceNodes = ps->bucketFaces[bucket_index];
2473         bool threaded = (ps->thread_tot > 1);
2474
2475         TileInfo tinf = {
2476                 ps->tile_lock,
2477                 ps->do_masking,
2478                 IMAPAINT_TILE_NUMBER(ibuf->x),
2479                 tmpibuf,
2480                 ps->projImages + image_index
2481         };
2482
2483         const MLoopTri *lt = &ps->dm_mlooptri[tri_index];
2484         const int lt_vtri[3] = { PS_LOOPTRI_AS_VERT_INDEX_3(ps, lt) };
2485         const float *lt_tri_uv[3] = { PS_LOOPTRI_AS_UV_3(ps->dm_mloopuv, lt) };
2486
2487         /* UV/pixel seeking data */
2488         int x; /* Image X-Pixel */
2489         int y; /* Image Y-Pixel */
2490         float mask;
2491         float uv[2]; /* Image floating point UV - same as x, y but from 0.0-1.0 */
2492
2493         const float *v1coSS, *v2coSS, *v3coSS; /* vert co screen-space, these will be assigned to lt_vtri[0-2] */
2494
2495         const float *vCo[3]; /* vertex screenspace coords */
2496
2497         float w[3], wco[3];
2498
2499         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 */
2500         float pixelScreenCo[4];
2501         bool do_3d_mapping = ps->brush->mtex.brush_map_mode == MTEX_MAP_MODE_3D;
2502
2503         rcti bounds_px; /* ispace bounds */
2504         /* vars for getting uvspace bounds */
2505
2506         float lt_uv_pxoffset[3][2]; /* bucket bounds in UV space so we can init pixels only for this face,  */
2507         float xhalfpx, yhalfpx;
2508         const float ibuf_xf = (float)ibuf->x, ibuf_yf = (float)ibuf->y;
2509
2510         int has_x_isect = 0, has_isect = 0; /* for early loop exit */
2511
2512         float uv_clip[8][2];
2513         int uv_clip_tot;
2514         const bool is_ortho = ps->is_ortho;
2515         const bool is_flip_object = ps->is_flip_object;
2516         const bool do_backfacecull = ps->do_backfacecull;
2517         const bool do_clip = ps->rv3d ? ps->rv3d->rflag & RV3D_CLIPPING : 0;
2518
2519         vCo[0] = ps->dm_mvert[lt_vtri[0]].co;
2520         vCo[1] = ps->dm_mvert[lt_vtri[1]].co;
2521         vCo[2] = ps->dm_mvert[lt_vtri[2]].co;
2522
2523
2524         /* Use lt_uv_pxoffset instead of lt_tri_uv so we can offset the UV half a pixel
2525          * this is done so we can avoid offsetting all the pixels by 0.5 which causes
2526          * problems when wrapping negative coords */
2527         xhalfpx = (0.5f + (PROJ_PIXEL_TOLERANCE * (1.0f / 3.0f))) / ibuf_xf;
2528         yhalfpx = (0.5f + (PROJ_PIXEL_TOLERANCE * (1.0f / 4.0f))) / ibuf_yf;
2529
2530         /* Note about (PROJ_GEOM_TOLERANCE/x) above...
2531          * Needed to add this offset since UV coords are often quads aligned to pixels.
2532          * In this case pixels can be exactly between 2 triangles causing nasty
2533          * artifacts.
2534          *
2535          * This workaround can be removed and painting will still work on most cases
2536          * but since the first thing most people try is painting onto a quad- better make it work.
2537          */
2538
2539         lt_uv_pxoffset[0][0] = lt_tri_uv[0][0] - xhalfpx;
2540         lt_uv_pxoffset[0][1] = lt_tri_uv[0][1] - yhalfpx;
2541
2542         lt_uv_pxoffset[1][0] = lt_tri_uv[1][0] - xhalfpx;
2543         lt_uv_pxoffset[1][1] = lt_tri_uv[1][1] - yhalfpx;
2544
2545         lt_uv_pxoffset[2][0] = lt_tri_uv[2][0] - xhalfpx;
2546         lt_uv_pxoffset[2][1] = lt_tri_uv[2][1] - yhalfpx;
2547
2548         {
2549                 uv1co = lt_uv_pxoffset[0]; // was lt_tri_uv[i1];
2550                 uv2co = lt_uv_pxoffset[1]; // was lt_tri_uv[i2];
2551                 uv3co = lt_uv_pxoffset[2]; // was lt_tri_uv[i3];
2552
2553                 v1coSS = ps->screenCoords[lt_vtri[0]];
2554                 v2coSS = ps->screenCoords[lt_vtri[1]];
2555                 v3coSS = ps->screenCoords[lt_vtri[2]];
2556
2557                 /* This funtion gives is a concave polyline in UV space from the clipped tri*/
2558                 project_bucket_clip_face(
2559                         is_ortho, is_flip_object,
2560                         clip_rect, bucket_bounds,
2561                         v1coSS, v2coSS, v3coSS,
2562                         uv1co, uv2co, uv3co,
2563                         uv_clip, &uv_clip_tot,
2564                         do_backfacecull || ps->do_occlude);
2565
2566                 /* sometimes this happens, better just allow for 8 intersectiosn even though there should be max 6 */
2567 #if 0
2568                 if (uv_clip_tot > 6) {
2569                         printf("this should never happen! %d\n", uv_clip_tot);
2570                 }
2571 #endif
2572
2573                 if (pixel_bounds_array(uv_clip, &bounds_px, ibuf->x, ibuf->y, uv_clip_tot)) {
2574
2575                         if (clamp_u) {
2576                                 CLAMP(bounds_px.xmin, 0, ibuf->x);
2577                                 CLAMP(bounds_px.xmax, 0, ibuf->x);
2578                         }
2579
2580                         if (clamp_v) {
2581                                 CLAMP(bounds_px.ymin, 0, ibuf->y);
2582                                 CLAMP(bounds_px.ymax, 0, ibuf->y);
2583                         }
2584
2585 #if 0
2586                         project_paint_undo_tiles_init(&bounds_px, ps->projImages + image_index, tmpibuf,
2587                                                       tile_width, threaded, ps->do_masking);
2588 #endif
2589                         /* clip face and */
2590
2591                         has_isect = 0;
2592                         for (y = bounds_px.ymin; y < bounds_px.ymax; y++) {
2593                                 //uv[1] = (((float)y) + 0.5f) / (float)ibuf->y;
2594                                 uv[1] = (float)y / ibuf_yf; /* use pixel offset UV coords instead */
2595
2596                                 has_x_isect = 0;
2597                                 for (x = bounds_px.xmin; x < bounds_px.xmax; x++) {
2598                                         //uv[0] = (((float)x) + 0.5f) / ibuf->x;
2599                                         uv[0] = (float)x / ibuf_xf; /* use pixel offset UV coords instead */
2600
2601                                         /* Note about IsectPoly2Df_twoside, checking the face or uv flipping doesnt work,
2602                                          * could check the poly direction but better to do this */
2603                                         if ((do_backfacecull == true  && IsectPoly2Df(uv, uv_clip, uv_clip_tot)) ||
2604                                             (do_backfacecull == false && IsectPoly2Df_twoside(uv, uv_clip, uv_clip_tot)))
2605                                         {
2606
2607                                                 has_x_isect = has_isect = 1;
2608
2609                                                 if (is_ortho) screen_px_from_ortho(uv, v1coSS, v2coSS, v3coSS, uv1co, uv2co, uv3co, pixelScreenCo, w);
2610                                                 else screen_px_from_persp(uv, v1coSS, v2coSS, v3coSS, uv1co, uv2co, uv3co, pixelScreenCo, w);
2611
2612                                                 /* a pity we need to get the worldspace pixel location here */
2613                                                 if (do_clip || do_3d_mapping) {
2614                                                         interp_v3_v3v3v3(
2615                                                                 wco,
2616                                                                 ps->dm_mvert[lt_vtri[0]].co,
2617                                                                 ps->dm_mvert[lt_vtri[1]].co,
2618                                                                 ps->dm_mvert[lt_vtri[2]].co,
2619                                                                 w);
2620                                                         if (do_clip && ED_view3d_clipping_test(ps->rv3d, wco, true)) {
2621                                                                 continue; /* Watch out that no code below this needs to run */
2622                                                         }
2623                                                 }
2624
2625                                                 /* Is this UV visible from the view? - raytrace */
2626                                                 /* project_paint_PickFace is less complex, use for testing */
2627                                                 //if (project_paint_PickFace(ps, pixelScreenCo, w, &side) == tri_index) {
2628                                                 if ((ps->do_occlude == false) ||
2629                                                     !project_bucket_point_occluded(ps, bucketFaceNodes, tri_index, pixelScreenCo))
2630                                                 {
2631                                                         mask = project_paint_uvpixel_mask(ps, tri_index, w);
2632
2633                                                         if (mask > 0.0f) {
2634                                                                 BLI_linklist_prepend_arena(
2635                                                                         bucketPixelNodes,
2636                                                                         project_paint_uvpixel_init(ps, arena, &tinf, x, y, mask, tri_index,
2637                                                                                                    pixelScreenCo, wco, w),
2638                                                                         arena
2639                                                                         );
2640                                                         }
2641                                                 }
2642
2643                                         }
2644 //#if 0
2645                                         else if (has_x_isect) {
2646                                                 /* assuming the face is not a bow-tie - we know we cant intersect again on the X */
2647                                                 break;
2648                                         }
2649 //#endif
2650                                 }
2651
2652
2653 #if 0           /* TODO - investigate why this dosnt work sometimes! it should! */
2654                                 /* no intersection for this entire row, after some intersection above means we can quit now */
2655                                 if (has_x_isect == 0 && has_isect) {
2656                                         break;
2657                                 }
2658 #endif
2659                         }
2660                 }
2661         }
2662
2663
2664 #ifndef PROJ_DEBUG_NOSEAMBLEED
2665         if (ps->seam_bleed_px > 0.0f) {
2666                 int face_seam_flag;
2667
2668                 if (threaded)
2669                         BLI_lock_thread(LOCK_CUSTOM1);  /* Other threads could be modifying these vars */
2670
2671                 face_seam_flag = ps->faceSeamFlags[tri_index];
2672
2673                 /* are any of our edges un-initialized? */
2674                 if ((face_seam_flag & (PROJ_FACE_SEAM1 | PROJ_FACE_NOSEAM1)) == 0 ||
2675                     (face_seam_flag & (PROJ_FACE_SEAM2 | PROJ_FACE_NOSEAM2)) == 0 ||
2676                     (face_seam_flag & (PROJ_FACE_SEAM3 | PROJ_FACE_NOSEAM3)) == 0)
2677                 {
2678                         project_face_seams_init(ps, tri_index);
2679                         face_seam_flag = ps->faceSeamFlags[tri_index];
2680                         //printf("seams - %d %d %d %d\n", flag&PROJ_FACE_SEAM1, flag&PROJ_FACE_SEAM2, flag&PROJ_FACE_SEAM3);
2681                 }
2682
2683                 if ((face_seam_flag & (PROJ_FACE_SEAM1 | PROJ_FACE_SEAM2 | PROJ_FACE_SEAM3)) == 0) {
2684
2685                         if (threaded)
2686                                 BLI_unlock_thread(LOCK_CUSTOM1);  /* Other threads could be modifying these vars */
2687
2688                 }
2689                 else {
2690                         /* we have a seam - deal with it! */
2691
2692                         /* Now create new UV's for the seam face */
2693                         float (*outset_uv)[2] = ps->faceSeamUVs[tri_index];
2694                         float insetCos[3][3]; /* inset face coords.  NOTE!!! ScreenSace for ortho, Worldspace in prespective view */
2695
2696                         const float *vCoSS[3]; /* vertex screenspace coords */
2697
2698                         float bucket_clip_edges[2][2]; /* store the screenspace coords of the face, clipped by the bucket's screen aligned rectangle */
2699                         float edge_verts_inset_clip[2][3];
2700                         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 */
2701
2702                         float seam_subsection[4][2];
2703                         float fac1, fac2;
2704
2705                         if (outset_uv[0][0] == FLT_MAX) /* first time initialize */
2706                                 uv_image_outset(
2707                                         lt_uv_pxoffset, outset_uv, ps->seam_bleed_px,
2708                                         ibuf->x, ibuf->y, (ps->faceWindingFlags[tri_index] & PROJ_FACE_WINDING_CW) == 0);
2709
2710                         /* ps->faceSeamUVs cant be modified when threading, now this is done we can unlock */
2711                         if (threaded)
2712                                 BLI_unlock_thread(LOCK_CUSTOM1);  /* Other threads could be modifying these vars */
2713
2714                         vCoSS[0] = ps->screenCoords[lt_vtri[0]];
2715                         vCoSS[1] = ps->screenCoords[lt_vtri[1]];
2716                         vCoSS[2] = ps->screenCoords[lt_vtri[2]];
2717
2718                         /* PROJ_FACE_SCALE_SEAM must be slightly less then 1.0f */
2719                         if (is_ortho) {
2720                                 scale_tri(insetCos, vCoSS, PROJ_FACE_SCALE_SEAM);
2721                         }
2722                         else {
2723                                 scale_tri(insetCos, vCo, PROJ_FACE_SCALE_SEAM);
2724                         }
2725
2726                         for (fidx1 = 0; fidx1 < 3; fidx1++) {
2727                                 fidx2 = (fidx1 == 2) ? 0 : fidx1 + 1;  /* next fidx in the face (0,1,2) -> (1,2,0) */
2728
2729                                 if ((face_seam_flag & (1 << fidx1)) && /* 1<<fidx1 -> PROJ_FACE_SEAM# */
2730                                     line_clip_rect2f(clip_rect, bucket_bounds, vCoSS[fidx1], vCoSS[fidx2], bucket_clip_edges[0], bucket_clip_edges[1]))
2731                                 {
2732                                         if (len_squared_v2v2(vCoSS[fidx1], vCoSS[fidx2]) > FLT_EPSILON) { /* avoid div by zero */
2733
2734                                                 if (is_ortho) {
2735                                                         fac1 = line_point_factor_v2(bucket_clip_edges[0], vCoSS[fidx1], vCoSS[fidx2]);
2736                                                         fac2 = line_point_factor_v2(bucket_clip_edges[1], vCoSS[fidx1], vCoSS[fidx2]);
2737                                                 }
2738                                                 else {
2739                                                         fac1 = screen_px_line_point_factor_v2_persp(ps, bucket_clip_edges[0], vCo[fidx1], vCo[fidx2]);
2740                                                         fac2 = screen_px_line_point_factor_v2_persp(ps, bucket_clip_edges[1], vCo[fidx1], vCo[fidx2]);
2741                                                 }
2742
2743                                                 interp_v2_v2v2(seam_subsection[0], lt_uv_pxoffset[fidx1], lt_uv_pxoffset[fidx2], fac1);
2744                                                 interp_v2_v2v2(seam_subsection[1], lt_uv_pxoffset[fidx1], lt_uv_pxoffset[fidx2], fac2);
2745
2746                                                 interp_v2_v2v2(seam_subsection[2], outset_uv[fidx1], outset_uv[fidx2], fac2);
2747                                                 interp_v2_v2v2(seam_subsection[3], outset_uv[fidx1], outset_uv[fidx2], fac1);
2748
2749                                                 /* if the bucket_clip_edges values Z values was kept we could avoid this
2750                                                  * Inset needs to be added so occlusion tests wont hit adjacent faces */
2751                                                 interp_v3_v3v3(edge_verts_inset_clip[0], insetCos[fidx1], insetCos[fidx2], fac1);
2752                                                 interp_v3_v3v3(edge_verts_inset_clip[1], insetCos[fidx1], insetCos[fidx2], fac2);
2753
2754
2755                                                 if (pixel_bounds_uv((const float (*)[2])seam_subsection, &bounds_px, ibuf->x, ibuf->y)) {
2756                                                         /* bounds between the seam rect and the uvspace bucket pixels */
2757
2758                                                         has_isect = 0;
2759                                                         for (y = bounds_px.ymin; y < bounds_px.ymax; y++) {
2760                                                                 // uv[1] = (((float)y) + 0.5f) / (float)ibuf->y;
2761                                                                 uv[1] = (float)y / ibuf_yf; /* use offset uvs instead */
2762
2763                                                                 has_x_isect = 0;
2764                                                                 for (x = bounds_px.xmin; x < bounds_px.xmax; x++) {
2765                                                                         //uv[0] = (((float)x) + 0.5f) / (float)ibuf->x;
2766                                                                         uv[0] = (float)x / ibuf_xf; /* use offset uvs instead */
2767
2768                                                                         /* test we're inside uvspace bucket and triangle bounds */
2769                                                                         if (isect_point_quad_v2(uv, UNPACK4(seam_subsection))) {
2770                                                                                 float fac;
2771
2772                                                                                 /* We need to find the closest point along the face edge,
2773                                                                                  * getting the screen_px_from_*** wont work because our actual location
2774                                                                                  * is not relevant, since we are outside the face, Use VecLerpf to find
2775                                                                                  * our location on the side of the face's UV */
2776 #if 0
2777                                                                                 if (is_ortho) screen_px_from_ortho(ps, uv, v1co, v2co, v3co, uv1co, uv2co, uv3co, pixelScreenCo);
2778                                                                                 else          screen_px_from_persp(ps, uv, v1co, v2co, v3co, uv1co, uv2co, uv3co, pixelScreenCo);
2779 #endif
2780
2781                                                                                 /* Since this is a seam we need to work out where on the line this pixel is */
2782                                                                                 //fac = line_point_factor_v2(uv, uv_seam_quad[0], uv_seam_quad[1]);
2783                                                                                 fac = resolve_quad_u_v2(uv, UNPACK4(seam_subsection));
2784                                                                                 interp_v3_v3v3(pixelScreenCo, edge_verts_inset_clip[0], edge_verts_inset_clip[1], fac);
2785
2786                                                                                 if (!is_ortho) {
2787                                                                                         pixelScreenCo[3] = 1.0f;
2788                                                                                         mul_m4_v4((float(*)[4])ps->projectMat, pixelScreenCo); /* cast because of const */
2789                                                                                         pixelScreenCo[0] = (float)(ps->winx * 0.5f) + (ps->winx * 0.5f) * pixelScreenCo[0] / pixelScreenCo[3];
2790                                                                                         pixelScreenCo[1] = (float)(ps->winy * 0.5f) + (ps->winy * 0.5f) * pixelScreenCo[1] / pixelScreenCo[3];
2791                                                                                         pixelScreenCo[2] = pixelScreenCo[2] / pixelScreenCo[3]; /* Use the depth for bucket point occlusion */
2792                                                                                 }
2793
2794                                                                                 if ((ps->do_occlude == false) ||
2795                                                                                     !project_bucket_point_occluded(ps, bucketFaceNodes, tri_index, pixelScreenCo))
2796                                                                                 {
2797                                                                                         /* Only bother calculating the weights if we intersect */
2798                                                                                         if (ps->do_mask_normal || ps->dm_mloopuv_clone) {
2799                                                                                                 const float uv_fac = fac1 + (fac * (fac2 - fac1));
2800 #if 0
2801                                                                                                 /* get the UV on the line since we want to copy the pixels from there for bleeding */
2802                                                                                                 float uv_close[2];
2803                                                                                                 interp_v2_v2v2(uv_close, lt_uv_pxoffset[fidx1], lt_uv_pxoffset[fidx2], uv_fac);
2804                                                                                                 barycentric_weights_v2(lt_uv_pxoffset[0], lt_uv_pxoffset[1], lt_uv_pxoffset[2], uv_close, w);
2805 #else
2806
2807                                                                                                 /* Cheat, we know where we are along the edge so work out the weights from that */
2808                                                                                                 w[0] = w[1] = w[2] = 0.0;
2809                                                                                                 w[fidx1] = 1.0f - uv_fac;
2810                                                                                                 w[fidx2] = uv_fac;
2811 #endif
2812                                                                                         }
2813
2814                                                                                         /* a pity we need to get the worldspace pixel location here */
2815                                                                                         if (do_clip || do_3d_mapping) {
2816                                                                                                 interp_v3_v3v3v3(wco, vCo[0], vCo[1], vCo[2], w);
2817
2818                                                                                                 if (do_clip && ED_view3d_clipping_test(ps->rv3d, wco, true)) {
2819                                                                                                         continue; /* Watch out that no code below this needs to run */
2820                                                                                                 }
2821                                                                                         }
2822
2823                                                                                         mask = project_paint_uvpixel_mask(ps, tri_index, w);
2824
2825                                                                                         if (mask > 0.0f) {
2826                                                                                                 BLI_linklist_prepend_arena(
2827                                                                                                         bucketPixelNodes,
2828                                                                                                         project_paint_uvpixel_init(ps, arena, &tinf, x, y, mask, tri_index,
2829                                                                                                         pixelScreenCo, wco, w),
2830                                                                                                         arena
2831                                                                                                         );
2832                                                                                         }
2833
2834                                                                                 }
2835                                                                         }
2836                                                                         else if (has_x_isect) {
2837                                                                                 /* assuming the face is not a bow-tie - we know we cant intersect again on the X */
2838                                                                                 break;
2839                                                                         }
2840                                                                 }
2841
2842 #if 0                           /* TODO - investigate why this dosnt work sometimes! it should! */
2843                                                                 /* no intersection for this entire row, after some intersection above means we can quit now */
2844                                                                 if (has_x_isect == 0 && has_isect) {
2845                                                                         break;
2846                                                                 }
2847 #endif
2848                                                         }
2849                                                 }
2850                                         }
2851                                 }
2852                         }
2853                 }
2854         }
2855 #else
2856         UNUSED_VARS(vCo, threaded);
2857 #endif // PROJ_DEBUG_NOSEAMBLEED
2858 }
2859
2860
2861 /* takes floating point screenspace min/max and returns int min/max to be used as indices for ps->bucketRect, ps->bucketFlags */
2862 static void project_paint_bucket_bounds(const ProjPaintState *ps, const float min[2], const float max[2], int bucketMin[2], int bucketMax[2])
2863 {
2864         /* divide by bucketWidth & bucketHeight so the bounds are offset in bucket grid units */
2865         /* 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 */
2866         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 */
2867         bucketMin[1] = (int)((int)(((float)(min[1] - ps->screenMin[1]) / ps->screen_height) * ps->buckets_y) + 0.5f);
2868
2869         bucketMax[0] = (int)((int)(((float)(max[0] - ps->screenMin[0]) / ps->screen_width) * ps->buckets_x) + 1.5f);
2870         bucketMax[1] = (int)((int)(((float)(max[1] - ps->screenMin[1]) / ps->screen_height) * ps->buckets_y) + 1.5f);