be9a614a6fe5f361fc59e7c906a7255fe1da6053
[blender.git] / source / blender / editors / sculpt_paint / paint_image_proj.c
1 /*
2  * ***** BEGIN GPL LICENSE BLOCK *****
3  *
4  * This program is free software; you can redistribute it and/or
5  * modify it under the terms of the GNU General Public License
6  * as published by the Free Software Foundation; either version 2
7  * of the License, or (at your option) any later version.
8  *
9  * This program is distributed in the hope that it will be useful,
10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
12  * GNU General Public License for more details.
13  *
14  * along with this program; if not, write to the Free Software Foundation,
15  * Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
16  *
17  * The Original Code is Copyright (C) 2001-2002 by NaN Holding BV.
18  * All rights reserved.
19  *
20  * The Original Code is: some of this file.
21  *
22  * Contributor(s): Jens Ole Wund (bjornmose), Campbell Barton (ideasman42)
23  *
24  * ***** END GPL LICENSE BLOCK *****
25  */
26
27 /** \file blender/editors/sculpt_paint/paint_image_proj.c
28  *  \ingroup edsculpt
29  *  \brief Functions to paint images in 2D and 3D.
30  */
31
32 #include <float.h>
33 #include <string.h>
34 #include <stdio.h>
35 #include <math.h>
36
37 #include "MEM_guardedalloc.h"
38
39 #ifdef WIN32
40 #  include "BLI_winstuff.h"
41 #endif
42
43 #include "BLI_blenlib.h"
44 #include "BLI_linklist.h"
45 #include "BLI_math.h"
46 #include "BLI_math_color_blend.h"
47 #include "BLI_memarena.h"
48 #include "BLI_threads.h"
49 #include "BLI_utildefines.h"
50
51 #include "BLF_translation.h"
52
53 #include "PIL_time.h"
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_colortools.h"
66 #include "BKE_context.h"
67 #include "BKE_depsgraph.h"
68 #include "BKE_DerivedMesh.h"
69 #include "BKE_idprop.h"
70 #include "BKE_brush.h"
71 #include "BKE_image.h"
72 #include "BKE_library.h"
73 #include "BKE_main.h"
74 #include "BKE_material.h"
75 #include "BKE_mesh.h"
76 #include "BKE_mesh_mapping.h"
77 #include "BKE_paint.h"
78 #include "BKE_report.h"
79 #include "BKE_scene.h"
80 #include "BKE_texture.h"
81
82 #include "UI_view2d.h"
83 #include "UI_interface.h"
84
85 #include "ED_image.h"
86 #include "ED_mesh.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 #include "GPU_buffers.h"
103
104 #include "IMB_colormanagement.h"
105
106 #include "paint_intern.h"
107
108 /* Defines and Structs */
109 /* FTOCHAR as inline function */
110 BLI_INLINE unsigned char f_to_char(const float val)
111 {
112         return FTOCHAR(val);
113 }
114
115 /* ProjectionPaint defines */
116
117 /* approx the number of buckets to have under the brush,
118  * used with the brush size to set the ps->buckets_x and ps->buckets_y value.
119  *
120  * When 3 - a brush should have ~9 buckets under it at once
121  * ...this helps for threading while painting as well as
122  * avoiding initializing pixels that wont touch the brush */
123 #define PROJ_BUCKET_BRUSH_DIV 4
124
125 #define PROJ_BUCKET_RECT_MIN 4
126 #define PROJ_BUCKET_RECT_MAX 256
127
128 #define PROJ_BOUNDBOX_DIV 8
129 #define PROJ_BOUNDBOX_SQUARED  (PROJ_BOUNDBOX_DIV * PROJ_BOUNDBOX_DIV)
130
131 //#define PROJ_DEBUG_PAINT 1
132 //#define PROJ_DEBUG_NOSEAMBLEED 1
133 //#define PROJ_DEBUG_PRINT_CLIP 1
134 #define PROJ_DEBUG_WINCLIP 1
135
136 /* projectFaceSeamFlags options */
137 //#define PROJ_FACE_IGNORE      (1<<0)  /* When the face is hidden, backfacing or occluded */
138 //#define PROJ_FACE_INIT        (1<<1)  /* When we have initialized the faces data */
139 #define PROJ_FACE_SEAM1 (1 << 0)  /* If this face has a seam on any of its edges */
140 #define PROJ_FACE_SEAM2 (1 << 1)
141 #define PROJ_FACE_SEAM3 (1 << 2)
142 #define PROJ_FACE_SEAM4 (1 << 3)
143
144 #define PROJ_FACE_NOSEAM1   (1 << 4)
145 #define PROJ_FACE_NOSEAM2   (1 << 5)
146 #define PROJ_FACE_NOSEAM3   (1 << 6)
147 #define PROJ_FACE_NOSEAM4   (1 << 7)
148
149 /* face winding */
150 #define PROJ_FACE_WINDING_INIT 1
151 #define PROJ_FACE_WINDING_CW 2
152
153 #define PROJ_SRC_VIEW       1
154 #define PROJ_SRC_IMAGE_CAM  2
155 #define PROJ_SRC_IMAGE_VIEW 3
156 #define PROJ_SRC_VIEW_FILL  4
157
158 #define PROJ_VIEW_DATA_ID "view_data"
159 #define PROJ_VIEW_DATA_SIZE (4 * 4 + 4 * 4 + 3) /* viewmat + winmat + clipsta + clipend + is_ortho */
160
161
162 /* a slightly scaled down face is used to get fake 3D location for edge pixels in the seams
163  * as this number approaches  1.0f the likelihood increases of float precision errors where
164  * it is occluded by an adjacent face */
165 #define PROJ_FACE_SCALE_SEAM    0.99f
166
167 #define PROJ_BUCKET_NULL        0
168 #define PROJ_BUCKET_INIT        (1 << 0)
169 // #define PROJ_BUCKET_CLONE_INIT       (1<<1)
170
171 /* used for testing doubles, if a point is on a line etc */
172 #define PROJ_GEOM_TOLERANCE 0.00075f
173 #define PROJ_PIXEL_TOLERANCE 0.01f
174
175 /* vert flags */
176 #define PROJ_VERT_CULL 1
177
178 /* to avoid locking in tile initialization */
179 #define TILE_PENDING SET_INT_IN_POINTER(-1)
180
181 /* This is mainly a convenience struct used so we can keep an array of images we use
182  * Thir imbufs, etc, in 1 array, When using threads this array is copied for each thread
183  * because 'partRedrawRect' and 'touch' values would not be thread safe */
184 typedef struct ProjPaintImage {
185         Image *ima;
186         ImBuf *ibuf;
187         ImagePaintPartialRedraw *partRedrawRect;
188         volatile void **undoRect; /* only used to build undo tiles during painting */
189         unsigned short **maskRect; /* the mask accumulation must happen on canvas, not on space screen bucket.
190                           * Here we store the mask rectangle */
191         bool **valid; /* store flag to enforce validation of undo rectangle */
192         int touch;
193 } ProjPaintImage;
194
195 /* Main projection painting struct passed to all projection painting functions */
196 typedef struct ProjPaintState {
197         View3D *v3d;
198         RegionView3D *rv3d;
199         ARegion *ar;
200         Scene *scene;
201         int source; /* PROJ_SRC_**** */
202
203         /* the paint color. It can change depending of inverted mode or not */
204         float paint_color[3];
205         float paint_color_linear[3];
206
207         Brush *brush;
208         short tool, blend, mode;
209         int orig_brush_size;
210         float brush_size;
211         Object *ob;
212         /* end similarities with ImagePaintState */
213
214         DerivedMesh    *dm;
215         int dm_totface;
216         int dm_totvert;
217         int dm_release;
218
219         MVert          *dm_mvert;
220         MFace          *dm_mface;
221         MTFace         **dm_mtface;
222         MTFace         **dm_mtface_clone;    /* other UV map, use for cloning between layers */
223         MTFace         *dm_mtface_stencil;
224
225         Image *stencil_ima;
226         Image *canvas_ima;
227         Image *clone_ima;
228         float stencil_value;
229
230         /* projection painting only */
231         MemArena *arena_mt[BLENDER_MAX_THREADS]; /* for multithreading, the first item is sometimes used for non threaded cases too */
232         LinkNode **bucketRect;              /* screen sized 2D array, each pixel has a linked list of ProjPixel's */
233         LinkNode **bucketFaces;             /* bucketRect aligned array linkList of faces overlapping each bucket */
234         unsigned char *bucketFlags;         /* store if the bucks have been initialized  */
235 #ifndef PROJ_DEBUG_NOSEAMBLEED
236         char *faceSeamFlags;                /* store info about faces, if they are initialized etc*/
237         char *faceWindingFlags;             /* save the winding of the face in uv space, helps as an extra validation step for seam detection */
238         float (*faceSeamUVs)[4][2];         /* expanded UVs for faces to use as seams */
239         LinkNode **vertFaces;               /* Only needed for when seam_bleed_px is enabled, use to find UV seams */
240 #endif
241         char *vertFlags;                    /* store options per vert, now only store if the vert is pointing away from the view */
242         int buckets_x;                      /* The size of the bucket grid, the grid span's screenMin/screenMax so you can paint outsize the screen or with 2 brushes at once */
243         int buckets_y;
244
245         ProjPaintImage *projImages;
246
247         int pixel_sizeof;           /* result of project_paint_pixel_sizeof(), constant per stroke */
248
249         int image_tot;              /* size of projectImages array */
250
251         float (*screenCoords)[4];   /* verts projected into floating point screen space */
252
253         float screenMin[2];         /* 2D bounds for mesh verts on the screen's plane (screenspace) */
254         float screenMax[2];
255         float screen_width;         /* Calculated from screenMin & screenMax */
256         float screen_height;
257         int winx, winy;             /* from the carea or from the projection render */
258
259         /* options for projection painting */
260         bool  do_layer_clone;
261         bool  do_layer_stencil;
262         bool  do_layer_stencil_inv;
263         bool  do_stencil_brush;
264         bool  do_material_slots;
265
266         bool  do_occlude;               /* Use raytraced occlusion? - ortherwise will paint right through to the back*/
267         bool  do_backfacecull;          /* ignore faces with normals pointing away, skips a lot of raycasts if your normals are correctly flipped */
268         bool  do_mask_normal;           /* mask out pixels based on their normals */
269         bool  do_new_shading_nodes;     /* cache BKE_scene_use_new_shading_nodes value */
270         float normal_angle;             /* what angle to mask at*/
271         float normal_angle_inner;
272         float normal_angle_range;       /* difference between normal_angle and normal_angle_inner, for easy access */
273
274         bool do_face_sel;               /* quick access to (me->editflag & ME_EDIT_PAINT_FACE_SEL) */
275         bool is_ortho;
276         bool do_masking;              /* use masking during painting. Some operations such as airbrush may disable */
277         bool is_texbrush;              /* only to avoid running  */
278         bool is_maskbrush;            /* mask brush is applied before masking */
279 #ifndef PROJ_DEBUG_NOSEAMBLEED
280         float seam_bleed_px;
281 #endif
282         /* clone vars */
283         float cloneOffset[2];
284
285         float projectMat[4][4];     /* Projection matrix, use for getting screen coords */
286         float viewDir[3];           /* View vector, use for do_backfacecull and for ray casting with an ortho viewport  */
287         float viewPos[3];           /* View location in object relative 3D space, so can compare to verts  */
288         float clipsta, clipend;
289
290         /* reproject vars */
291         Image *reproject_image;
292         ImBuf *reproject_ibuf;
293
294         /* threads */
295         int thread_tot;
296         int bucketMin[2];
297         int bucketMax[2];
298         int context_bucket_x, context_bucket_y; /* must lock threads while accessing these */
299
300         /* redraw */
301         bool need_redraw;
302
303         BlurKernel *blurkernel;
304
305         SpinLock *tile_lock;
306 } ProjPaintState;
307
308 typedef union pixelPointer {
309         float *f_pt;            /* float buffer */
310         unsigned int *uint_pt; /* 2 ways to access a char buffer */
311         unsigned char *ch_pt;
312 } PixelPointer;
313
314 typedef union pixelStore {
315         unsigned char ch[4];
316         unsigned int uint;
317         float f[4];
318 } PixelStore;
319
320 typedef struct ProjPixel {
321         float projCoSS[2]; /* the floating point screen projection of this pixel */
322         float worldCoSS[3];
323         /* Only used when the airbrush is disabled.
324          * Store the max mask value to avoid painting over an area with a lower opacity
325          * with an advantage that we can avoid touching the pixel at all, if the
326          * new mask value is lower then mask_accum */
327         unsigned short *mask_accum;
328
329         /* for various reasons we may want to mask out painting onto this pixel */
330         unsigned short mask;
331
332         short x_px, y_px;
333         /* horrible hack, store tile valid flag pointer here to re-validate tiles used for anchored and drag-dot strokes */
334         bool *valid;
335
336         PixelPointer origColor;
337         PixelStore newColor;
338         PixelPointer pixel;
339
340         short image_index; /* if anyone wants to paint onto more than 32768 images they can bite me */
341         unsigned char bb_cell_index;
342 } ProjPixel;
343
344 typedef struct ProjPixelClone {
345         struct ProjPixel __pp;
346         PixelStore clonepx;
347 } ProjPixelClone;
348
349 /* undo tile pushing */
350 typedef struct {
351         SpinLock *lock;
352         bool masked;
353         unsigned short tile_width;
354         ImBuf **tmpibuf;
355         ProjPaintImage *pjima;
356 } TileInfo;
357
358
359 /* Finish projection painting structs */
360
361 static TexPaintSlot *project_paint_face_paint_slot(const ProjPaintState *ps, int face_index)
362 {
363         MFace *mf = ps->dm_mface + face_index;
364         Material *ma = ps->dm->mat[mf->mat_nr];
365         return ma->texpaintslot + ma->paint_active_slot;
366 }
367
368 static Image *project_paint_face_paint_image(const ProjPaintState *ps, int face_index)
369 {
370         if (ps->do_stencil_brush) {
371                 return ps->stencil_ima;
372         }
373         else {
374                 MFace *mf = ps->dm_mface + face_index;
375                 Material *ma = ps->dm->mat[mf->mat_nr];
376                 TexPaintSlot *slot = ma->texpaintslot + ma->paint_active_slot;
377                 return slot ? slot->ima : ps->canvas_ima;
378         }
379 }
380
381 static TexPaintSlot *project_paint_face_clone_slot(const ProjPaintState *ps, int face_index)
382 {
383         MFace *mf = ps->dm_mface + face_index;
384         Material *ma = ps->dm->mat[mf->mat_nr];
385         return ma->texpaintslot + ma->paint_clone_slot;
386 }
387
388 static Image *project_paint_face_clone_image(const ProjPaintState *ps, int face_index)
389 {
390         MFace *mf = ps->dm_mface + face_index;
391         Material *ma = ps->dm->mat[mf->mat_nr];
392         TexPaintSlot *slot = ma->texpaintslot + ma->paint_clone_slot;
393         return slot ? slot->ima : ps->clone_ima;
394 }
395
396 /* fast projection bucket array lookup, use the safe version for bound checking  */
397 static int project_bucket_offset(const ProjPaintState *ps, const float projCoSS[2])
398 {
399         /* If we were not dealing with screenspace 2D coords we could simple do...
400          * ps->bucketRect[x + (y*ps->buckets_y)] */
401
402         /* please explain?
403          * projCoSS[0] - ps->screenMin[0]   : zero origin
404          * ... / ps->screen_width           : range from 0.0 to 1.0
405          * ... * ps->buckets_x              : use as a bucket index
406          *
407          * Second multiplication does similar but for vertical offset
408          */
409         return ( (int)(((projCoSS[0] - ps->screenMin[0]) / ps->screen_width)  * ps->buckets_x)) +
410                (((int)(((projCoSS[1] - ps->screenMin[1]) / ps->screen_height) * ps->buckets_y)) * ps->buckets_x);
411 }
412
413 static int project_bucket_offset_safe(const ProjPaintState *ps, const float projCoSS[2])
414 {
415         int bucket_index = project_bucket_offset(ps, projCoSS);
416
417         if (bucket_index < 0 || bucket_index >= ps->buckets_x * ps->buckets_y) {
418                 return -1;
419         }
420         else {
421                 return bucket_index;
422         }
423 }
424
425 static float VecZDepthOrtho(const float pt[2],
426                             const float v1[3], const float v2[3], const float v3[3],
427                             float w[3])
428 {
429         barycentric_weights_v2(v1, v2, v3, pt, w);
430         return (v1[2] * w[0]) + (v2[2] * w[1]) + (v3[2] * w[2]);
431 }
432
433 static float VecZDepthPersp(const float pt[2],
434                             const float v1[4], const float v2[4], const float v3[4],
435                             float w[3])
436 {
437         float wtot_inv, wtot;
438         float w_tmp[3];
439
440         barycentric_weights_v2_persp(v1, v2, v3, pt, w);
441         /* for the depth we need the weights to match what
442          * barycentric_weights_v2 would return, in this case its easiest just to
443          * undo the 4th axis division and make it unit-sum
444          *
445          * don't call barycentric_weights_v2() because our callers expect 'w'
446          * to be weighted from the perspective */
447         w_tmp[0] = w[0] * v1[3];
448         w_tmp[1] = w[1] * v2[3];
449         w_tmp[2] = w[2] * v3[3];
450
451         wtot = w_tmp[0] + w_tmp[1] + w_tmp[2];
452
453         if (wtot != 0.0f) {
454                 wtot_inv = 1.0f / wtot;
455
456                 w_tmp[0] = w_tmp[0] * wtot_inv;
457                 w_tmp[1] = w_tmp[1] * wtot_inv;
458                 w_tmp[2] = w_tmp[2] * wtot_inv;
459         }
460         else /* dummy values for zero area face */
461                 w_tmp[0] = w_tmp[1] = w_tmp[2] = 1.0f / 3.0f;
462         /* done mimicing barycentric_weights_v2() */
463
464         return (v1[2] * w_tmp[0]) + (v2[2] * w_tmp[1]) + (v3[2] * w_tmp[2]);
465 }
466
467
468 /* Return the top-most face index that the screen space coord 'pt' touches (or -1) */
469 static int project_paint_PickFace(const ProjPaintState *ps, const float pt[2], float w[3], int *side)
470 {
471         LinkNode *node;
472         float w_tmp[3];
473         const float *v1, *v2, *v3, *v4;
474         int bucket_index;
475         int face_index;
476         int best_side = -1;
477         int best_face_index = -1;
478         float z_depth_best = FLT_MAX, z_depth;
479         MFace *mf;
480
481         bucket_index = project_bucket_offset_safe(ps, pt);
482         if (bucket_index == -1)
483                 return -1;
484
485
486
487         /* we could return 0 for 1 face buckets, as long as this function assumes
488          * that the point its testing is only every originated from an existing face */
489
490         for (node = ps->bucketFaces[bucket_index]; node; node = node->next) {
491                 face_index = GET_INT_FROM_POINTER(node->link);
492                 mf = ps->dm_mface + face_index;
493
494                 v1 = ps->screenCoords[mf->v1];
495                 v2 = ps->screenCoords[mf->v2];
496                 v3 = ps->screenCoords[mf->v3];
497
498                 if (isect_point_tri_v2(pt, v1, v2, v3)) {
499                         if (ps->is_ortho) z_depth = VecZDepthOrtho(pt, v1, v2, v3, w_tmp);
500                         else z_depth = VecZDepthPersp(pt, v1, v2, v3, w_tmp);
501
502                         if (z_depth < z_depth_best) {
503                                 best_face_index = face_index;
504                                 best_side = 0;
505                                 z_depth_best = z_depth;
506                                 copy_v3_v3(w, w_tmp);
507                         }
508                 }
509                 else if (mf->v4) {
510                         v4 = ps->screenCoords[mf->v4];
511
512                         if (isect_point_tri_v2(pt, v1, v3, v4)) {
513                                 if (ps->is_ortho) z_depth = VecZDepthOrtho(pt, v1, v3, v4, w_tmp);
514                                 else z_depth = VecZDepthPersp(pt, v1, v3, v4, w_tmp);
515
516                                 if (z_depth < z_depth_best) {
517                                         best_face_index = face_index;
518                                         best_side = 1;
519                                         z_depth_best = z_depth;
520                                         copy_v3_v3(w, w_tmp);
521                                 }
522                         }
523                 }
524         }
525
526         *side = best_side;
527         return best_face_index; /* will be -1 or a valid face */
528 }
529
530 /* Converts a uv coord into a pixel location wrapping if the uv is outside 0-1 range */
531 static void uvco_to_wrapped_pxco(const float uv[2], int ibuf_x, int ibuf_y, float *x, float *y)
532 {
533         /* use */
534         *x = fmodf(uv[0], 1.0f);
535         *y = fmodf(uv[1], 1.0f);
536
537         if (*x < 0.0f) *x += 1.0f;
538         if (*y < 0.0f) *y += 1.0f;
539
540         *x = *x * ibuf_x - 0.5f;
541         *y = *y * ibuf_y - 0.5f;
542 }
543
544 /* Set the top-most face color that the screen space coord 'pt' touches (or return 0 if none touch) */
545 static bool project_paint_PickColor(const ProjPaintState *ps, const float pt[2],
546                                     float *rgba_fp, unsigned char *rgba, const bool interp)
547 {
548         float w[3], uv[2];
549         int side;
550         int face_index;
551         MTFace *tf;
552         Image *ima;
553         ImBuf *ibuf;
554         int xi, yi;
555
556
557         face_index = project_paint_PickFace(ps, pt, w, &side);
558
559         if (face_index == -1)
560                 return 0;
561
562         tf = *(ps->dm_mtface + face_index);
563
564         if (side == 0) {
565                 interp_v2_v2v2v2(uv, tf->uv[0], tf->uv[1], tf->uv[2], w);
566         }
567         else { /* QUAD */
568                 interp_v2_v2v2v2(uv, tf->uv[0], tf->uv[2], tf->uv[3], w);
569         }
570
571         ima = project_paint_face_paint_image(ps, face_index);
572         ibuf = BKE_image_get_first_ibuf(ima); /* we must have got the imbuf before getting here */
573         if (!ibuf) return 0;
574
575         if (interp) {
576                 float x, y;
577                 uvco_to_wrapped_pxco(uv, ibuf->x, ibuf->y, &x, &y);
578
579                 if (ibuf->rect_float) {
580                         if (rgba_fp) {
581                                 bilinear_interpolation_color_wrap(ibuf, NULL, rgba_fp, x, y);
582                         }
583                         else {
584                                 float rgba_tmp_f[4];
585                                 bilinear_interpolation_color_wrap(ibuf, NULL, rgba_tmp_f, x, y);
586                                 premul_float_to_straight_uchar(rgba, rgba_tmp_f);
587                         }
588                 }
589                 else {
590                         if (rgba) {
591                                 bilinear_interpolation_color_wrap(ibuf, rgba, NULL, x, y);
592                         }
593                         else {
594                                 unsigned char rgba_tmp[4];
595                                 bilinear_interpolation_color_wrap(ibuf, rgba_tmp, NULL, x, y);
596                                 straight_uchar_to_premul_float(rgba_fp, rgba_tmp);
597                         }
598                 }
599         }
600         else {
601                 //xi = (int)((uv[0]*ibuf->x) + 0.5f);
602                 //yi = (int)((uv[1]*ibuf->y) + 0.5f);
603                 //if (xi < 0 || xi >= ibuf->x  ||  yi < 0 || yi >= ibuf->y) return 0;
604
605                 /* wrap */
606                 xi = mod_i((int)(uv[0] * ibuf->x), ibuf->x);
607                 yi = mod_i((int)(uv[1] * ibuf->y), ibuf->y);
608
609                 if (rgba) {
610                         if (ibuf->rect_float) {
611                                 const float *rgba_tmp_fp = ibuf->rect_float + (xi + yi * ibuf->x * 4);
612                                 premul_float_to_straight_uchar(rgba, rgba_tmp_fp);
613                         }
614                         else {
615                                 *((unsigned int *)rgba) = *(unsigned int *)(((char *)ibuf->rect) + ((xi + yi * ibuf->x) * 4));
616                         }
617                 }
618
619                 if (rgba_fp) {
620                         if (ibuf->rect_float) {
621                                 copy_v4_v4(rgba_fp, (ibuf->rect_float + ((xi + yi * ibuf->x) * 4)));
622                         }
623                         else {
624                                 unsigned char *tmp_ch = ((unsigned char *)ibuf->rect) + ((xi + yi * ibuf->x) * 4);
625                                 straight_uchar_to_premul_float(rgba_fp, tmp_ch);
626                         }
627                 }
628         }
629         BKE_image_release_ibuf(ima, ibuf, NULL);
630         return 1;
631 }
632
633 /* Check if 'pt' is infront of the 3 verts on the Z axis (used for screenspace occlusuion test)
634  * return...
635  *  0   : no occlusion
636  * -1   : no occlusion but 2D intersection is true (avoid testing the other half of a quad)
637  *  1   : occluded
638  *  2   : occluded with w[3] weights set (need to know in some cases) */
639
640 static int project_paint_occlude_ptv(const float pt[3],
641                                      const float v1[4], const float v2[4], const float v3[4],
642                                      float w[3], const bool is_ortho)
643 {
644         /* if all are behind us, return false */
645         if (v1[2] > pt[2] && v2[2] > pt[2] && v3[2] > pt[2])
646                 return 0;
647
648         /* do a 2D point in try intersection */
649         if (!isect_point_tri_v2(pt, v1, v2, v3))
650                 return 0;  /* we know there is  */
651
652
653         /* From here on we know there IS an intersection */
654         /* if ALL of the verts are infront of us then we know it intersects ? */
655         if (v1[2] < pt[2] && v2[2] < pt[2] && v3[2] < pt[2]) {
656                 return 1;
657         }
658         else {
659                 /* we intersect? - find the exact depth at the point of intersection */
660                 /* Is this point is occluded by another face? */
661                 if (is_ortho) {
662                         if (VecZDepthOrtho(pt, v1, v2, v3, w) < pt[2]) return 2;
663                 }
664                 else {
665                         if (VecZDepthPersp(pt, v1, v2, v3, w) < pt[2]) return 2;
666                 }
667         }
668         return -1;
669 }
670
671
672 static int project_paint_occlude_ptv_clip(const ProjPaintState *ps, const MFace *mf,
673                                           const float pt[3], const float v1[4], const float v2[4], const float v3[4],
674                                           const int side)
675 {
676         float w[3], wco[3];
677         int ret = project_paint_occlude_ptv(pt, v1, v2, v3, w, ps->is_ortho);
678
679         if (ret <= 0)
680                 return ret;
681
682         if (ret == 1) { /* weights not calculated */
683                 if (ps->is_ortho) barycentric_weights_v2(v1, v2, v3, pt, w);
684                 else barycentric_weights_v2_persp(v1, v2, v3, pt, w);
685         }
686
687         /* Test if we're in the clipped area, */
688         if (side) interp_v3_v3v3v3(wco, ps->dm_mvert[mf->v1].co, ps->dm_mvert[mf->v3].co, ps->dm_mvert[mf->v4].co, w);
689         else interp_v3_v3v3v3(wco, ps->dm_mvert[mf->v1].co, ps->dm_mvert[mf->v2].co, ps->dm_mvert[mf->v3].co, w);
690
691         if (!ED_view3d_clipping_test(ps->rv3d, wco, true)) {
692                 return 1;
693         }
694
695         return -1;
696 }
697
698
699 /* Check if a screenspace location is occluded by any other faces
700  * check, pixelScreenCo must be in screenspace, its Z-Depth only needs to be used for comparison
701  * and doesn't need to be correct in relation to X and Y coords (this is the case in perspective view) */
702 static bool project_bucket_point_occluded(const ProjPaintState *ps, LinkNode *bucketFace,
703                                           const int orig_face, const float pixelScreenCo[4])
704 {
705         MFace *mf;
706         int face_index;
707         int isect_ret;
708         float w[3]; /* not needed when clipping */
709         const short do_clip = ps->rv3d ? ps->rv3d->rflag & RV3D_CLIPPING : 0;
710
711         /* we could return 0 for 1 face buckets, as long as this function assumes
712          * that the point its testing is only every originated from an existing face */
713
714         for (; bucketFace; bucketFace = bucketFace->next) {
715                 face_index = GET_INT_FROM_POINTER(bucketFace->link);
716
717                 if (orig_face != face_index) {
718                         mf = ps->dm_mface + face_index;
719                         if (do_clip)
720                                 isect_ret = project_paint_occlude_ptv_clip(ps, mf, pixelScreenCo, ps->screenCoords[mf->v1], ps->screenCoords[mf->v2], ps->screenCoords[mf->v3], 0);
721                         else
722                                 isect_ret = project_paint_occlude_ptv(pixelScreenCo, ps->screenCoords[mf->v1], ps->screenCoords[mf->v2], ps->screenCoords[mf->v3], w, ps->is_ortho);
723
724                         /* Note, if (isect_ret == -1) then we don't want to test the other side of the quad */
725                         if (isect_ret == 0 && mf->v4) {
726                                 if (do_clip)
727                                         isect_ret = project_paint_occlude_ptv_clip(ps, mf, pixelScreenCo, ps->screenCoords[mf->v1], ps->screenCoords[mf->v3], ps->screenCoords[mf->v4], 1);
728                                 else
729                                         isect_ret = project_paint_occlude_ptv(pixelScreenCo, ps->screenCoords[mf->v1], ps->screenCoords[mf->v3], ps->screenCoords[mf->v4], w, ps->is_ortho);
730                         }
731                         if (isect_ret >= 1) {
732                                 /* TODO - we may want to cache the first hit,
733                                  * it is not possible to swap the face order in the list anymore */
734                                 return true;
735                         }
736                 }
737         }
738         return false;
739 }
740
741 /* basic line intersection, could move to math_geom.c, 2 points with a horiz line
742  * 1 for an intersection, 2 if the first point is aligned, 3 if the second point is aligned */
743 #define ISECT_TRUE 1
744 #define ISECT_TRUE_P1 2
745 #define ISECT_TRUE_P2 3
746 static int line_isect_y(const float p1[2], const float p2[2], const float y_level, float *x_isect)
747 {
748         float y_diff;
749
750         if (y_level == p1[1]) { /* are we touching the first point? - no interpolation needed */
751                 *x_isect = p1[0];
752                 return ISECT_TRUE_P1;
753         }
754         if (y_level == p2[1]) { /* are we touching the second point? - no interpolation needed */
755                 *x_isect = p2[0];
756                 return ISECT_TRUE_P2;
757         }
758
759         y_diff = fabsf(p1[1] - p2[1]); /* yuck, horizontal line, we cant do much here */
760
761         if (y_diff < 0.000001f) {
762                 *x_isect = (p1[0] + p2[0]) * 0.5f;
763                 return ISECT_TRUE;
764         }
765
766         if (p1[1] > y_level && p2[1] < y_level) {
767                 *x_isect = (p2[0] * (p1[1] - y_level) + p1[0] * (y_level - p2[1])) / y_diff;  /*(p1[1]-p2[1]);*/
768                 return ISECT_TRUE;
769         }
770         else if (p1[1] < y_level && p2[1] > y_level) {
771                 *x_isect = (p2[0] * (y_level - p1[1]) + p1[0] * (p2[1] - y_level)) / y_diff;  /*(p2[1]-p1[1]);*/
772                 return ISECT_TRUE;
773         }
774         else {
775                 return 0;
776         }
777 }
778
779 static int line_isect_x(const float p1[2], const float p2[2], const float x_level, float *y_isect)
780 {
781         float x_diff;
782
783         if (x_level == p1[0]) { /* are we touching the first point? - no interpolation needed */
784                 *y_isect = p1[1];
785                 return ISECT_TRUE_P1;
786         }
787         if (x_level == p2[0]) { /* are we touching the second point? - no interpolation needed */
788                 *y_isect = p2[1];
789                 return ISECT_TRUE_P2;
790         }
791
792         x_diff = fabsf(p1[0] - p2[0]); /* yuck, horizontal line, we cant do much here */
793
794         if (x_diff < 0.000001f) { /* yuck, vertical line, we cant do much here */
795                 *y_isect = (p1[0] + p2[0]) * 0.5f;
796                 return ISECT_TRUE;
797         }
798
799         if (p1[0] > x_level && p2[0] < x_level) {
800                 *y_isect = (p2[1] * (p1[0] - x_level) + p1[1] * (x_level - p2[0])) / x_diff; /*(p1[0]-p2[0]);*/
801                 return ISECT_TRUE;
802         }
803         else if (p1[0] < x_level && p2[0] > x_level) {
804                 *y_isect = (p2[1] * (x_level - p1[0]) + p1[1] * (p2[0] - x_level)) / x_diff; /*(p2[0]-p1[0]);*/
805                 return ISECT_TRUE;
806         }
807         else {
808                 return 0;
809         }
810 }
811
812 /* simple func use for comparing UV locations to check if there are seams.
813  * Its possible this gives incorrect results, when the UVs for 1 face go into the next
814  * tile, but do not do this for the adjacent face, it could return a false positive.
815  * This is so unlikely that Id not worry about it. */
816 #ifndef PROJ_DEBUG_NOSEAMBLEED
817 static bool cmp_uv(const float vec2a[2], const float vec2b[2])
818 {
819         /* if the UV's are not between 0.0 and 1.0 */
820         float xa = fmodf(vec2a[0], 1.0f);
821         float ya = fmodf(vec2a[1], 1.0f);
822
823         float xb = fmodf(vec2b[0], 1.0f);
824         float yb = fmodf(vec2b[1], 1.0f);
825
826         if (xa < 0.0f) xa += 1.0f;
827         if (ya < 0.0f) ya += 1.0f;
828
829         if (xb < 0.0f) xb += 1.0f;
830         if (yb < 0.0f) yb += 1.0f;
831
832         return ((fabsf(xa - xb) < PROJ_GEOM_TOLERANCE) && (fabsf(ya - yb) < PROJ_GEOM_TOLERANCE)) ? 1 : 0;
833 }
834 #endif
835
836 /* set min_px and max_px to the image space bounds of the UV coords
837  * return zero if there is no area in the returned rectangle */
838 #ifndef PROJ_DEBUG_NOSEAMBLEED
839 static bool pixel_bounds_uv(
840         const float uv1[2], const float uv2[2], const float uv3[2], const float uv4[2],
841         rcti *bounds_px,
842         const int ibuf_x, const int ibuf_y,
843         const bool is_quad
844         )
845 {
846         float min_uv[2], max_uv[2]; /* UV bounds */
847
848         INIT_MINMAX2(min_uv, max_uv);
849
850         minmax_v2v2_v2(min_uv, max_uv, uv1);
851         minmax_v2v2_v2(min_uv, max_uv, uv2);
852         minmax_v2v2_v2(min_uv, max_uv, uv3);
853         if (is_quad)
854                 minmax_v2v2_v2(min_uv, max_uv, uv4);
855
856         bounds_px->xmin = (int)(ibuf_x * min_uv[0]);
857         bounds_px->ymin = (int)(ibuf_y * min_uv[1]);
858
859         bounds_px->xmax = (int)(ibuf_x * max_uv[0]) + 1;
860         bounds_px->ymax = (int)(ibuf_y * max_uv[1]) + 1;
861
862         /*printf("%d %d %d %d\n", min_px[0], min_px[1], max_px[0], max_px[1]);*/
863
864         /* face uses no UV area when quantized to pixels? */
865         return (bounds_px->xmin == bounds_px->xmax || bounds_px->ymin == bounds_px->ymax) ? 0 : 1;
866 }
867 #endif
868
869 static bool pixel_bounds_array(float (*uv)[2], rcti *bounds_px, const int ibuf_x, const int ibuf_y, int tot)
870 {
871         float min_uv[2], max_uv[2]; /* UV bounds */
872
873         if (tot == 0) {
874                 return 0;
875         }
876
877         INIT_MINMAX2(min_uv, max_uv);
878
879         while (tot--) {
880                 minmax_v2v2_v2(min_uv, max_uv, (*uv));
881                 uv++;
882         }
883
884         bounds_px->xmin = (int)(ibuf_x * min_uv[0]);
885         bounds_px->ymin = (int)(ibuf_y * min_uv[1]);
886
887         bounds_px->xmax = (int)(ibuf_x * max_uv[0]) + 1;
888         bounds_px->ymax = (int)(ibuf_y * max_uv[1]) + 1;
889
890         /*printf("%d %d %d %d\n", min_px[0], min_px[1], max_px[0], max_px[1]);*/
891
892         /* face uses no UV area when quantized to pixels? */
893         return (bounds_px->xmin == bounds_px->xmax || bounds_px->ymin == bounds_px->ymax) ? 0 : 1;
894 }
895
896 #ifndef PROJ_DEBUG_NOSEAMBLEED
897
898 static void project_face_winding_init(const ProjPaintState *ps, const int face_index)
899 {
900         /* detect the winding of faces in uv space */
901         MTFace *tf = ps->dm_mtface[face_index];
902         float winding = cross_tri_v2(tf->uv[0], tf->uv[1], tf->uv[2]);
903
904         if (ps->dm_mface[face_index].v4)
905                 winding += cross_tri_v2(tf->uv[2], tf->uv[3], tf->uv[0]);
906
907         if (winding > 0)
908                 ps->faceWindingFlags[face_index] |= PROJ_FACE_WINDING_CW;
909
910         ps->faceWindingFlags[face_index] |= PROJ_FACE_WINDING_INIT;
911 }
912
913 /* This function returns 1 if this face has a seam along the 2 face-vert indices
914  * 'orig_i1_fidx' and 'orig_i2_fidx' */
915 static bool check_seam(const ProjPaintState *ps,
916                        const int orig_face, const int orig_i1_fidx, const int orig_i2_fidx,
917                        int *other_face, int *orig_fidx)
918 {
919         LinkNode *node;
920         int face_index;
921         unsigned int i1, i2;
922         int i1_fidx = -1, i2_fidx = -1; /* index in face */
923         MFace *mf;
924         MTFace *tf;
925         const MFace *orig_mf = ps->dm_mface + orig_face;
926         const MTFace *orig_tf = ps->dm_mtface[orig_face];
927
928         /* vert indices from face vert order indices */
929         i1 = (*(&orig_mf->v1 + orig_i1_fidx));
930         i2 = (*(&orig_mf->v1 + orig_i2_fidx));
931
932         for (node = ps->vertFaces[i1]; node; node = node->next) {
933                 face_index = GET_INT_FROM_POINTER(node->link);
934
935                 if (face_index != orig_face) {
936                         mf = ps->dm_mface + face_index;
937                         /* could check if the 2 faces images match here,
938                          * but then there wouldn't be a way to return the opposite face's info */
939
940
941                         /* We need to know the order of the verts in the adjacent face
942                          * set the i1_fidx and i2_fidx to (0,1,2,3) */
943                         i1_fidx = BKE_MESH_TESSFACE_VINDEX_ORDER(mf, i1);
944                         i2_fidx = BKE_MESH_TESSFACE_VINDEX_ORDER(mf, i2);
945
946                         /* Only need to check if 'i2_fidx' is valid because we know i1_fidx is the same vert on both faces */
947                         if (i2_fidx != -1) {
948                                 Image *tpage = project_paint_face_paint_image(ps, face_index);
949                                 Image *orig_tpage = project_paint_face_paint_image(ps, orig_face);
950
951                                 BLI_assert(i1_fidx != -1);
952
953                                 /* This IS an adjacent face!, now lets check if the UVs are ok */
954                                 tf = ps->dm_mtface[face_index];
955
956                                 /* set up the other face */
957                                 *other_face = face_index;
958                                 
959                                 /* we check if difference is 1 here, else we might have a case of edge 2-0 or 3-0 for quads */
960                                 *orig_fidx = (i1_fidx < i2_fidx && (i2_fidx - i1_fidx == 1)) ? i1_fidx : i2_fidx;
961
962                                 /* initialize face winding if needed */
963                                 if ((ps->faceWindingFlags[face_index] & PROJ_FACE_WINDING_INIT) == 0)
964                                         project_face_winding_init(ps, face_index);
965
966                                 /* first test if they have the same image */
967                                 if ((orig_tpage == tpage) &&
968                                     cmp_uv(orig_tf->uv[orig_i1_fidx], tf->uv[i1_fidx]) &&
969                                     cmp_uv(orig_tf->uv[orig_i2_fidx], tf->uv[i2_fidx]))
970                                 {
971                                         /* if faces don't have the same winding in uv space,
972                                          * they are on the same side so edge is boundary */
973                                         if ((ps->faceWindingFlags[face_index] & PROJ_FACE_WINDING_CW) !=
974                                             (ps->faceWindingFlags[orig_face] & PROJ_FACE_WINDING_CW))
975                                         {
976                                                 return 1;
977                                         }
978
979                                         // printf("SEAM (NONE)\n");
980                                         return 0;
981
982                                 }
983                                 else {
984                                         // printf("SEAM (UV GAP)\n");
985                                         return 1;
986                                 }
987                         }
988                 }
989         }
990         // printf("SEAM (NO FACE)\n");
991         *other_face = -1;
992         return 1;
993 }
994
995 /* Calculate outset UV's, this is not the same as simply scaling the UVs,
996  * since the outset coords are a margin that keep an even distance from the original UV's,
997  * note that the image aspect is taken into account */
998 static void uv_image_outset(float (*orig_uv)[2], float (*outset_uv)[2], const float scaler,
999                             const int ibuf_x, const int ibuf_y, const bool is_quad)
1000 {
1001         float a1, a2, a3, a4 = 0.0f;
1002         float puv[4][2]; /* pixelspace uv's */
1003         float no1[2], no2[2], no3[2], no4[2]; /* normals */
1004         float dir1[2], dir2[2], dir3[2], dir4[2];
1005         float ibuf_inv[2];
1006
1007         ibuf_inv[0] = 1.0f / (float)ibuf_x;
1008         ibuf_inv[1] = 1.0f / (float)ibuf_y;
1009
1010         /* make UV's in pixel space so we can */
1011         puv[0][0] = orig_uv[0][0] * ibuf_x;
1012         puv[0][1] = orig_uv[0][1] * ibuf_y;
1013
1014         puv[1][0] = orig_uv[1][0] * ibuf_x;
1015         puv[1][1] = orig_uv[1][1] * ibuf_y;
1016
1017         puv[2][0] = orig_uv[2][0] * ibuf_x;
1018         puv[2][1] = orig_uv[2][1] * ibuf_y;
1019
1020         if (is_quad) {
1021                 puv[3][0] = orig_uv[3][0] * ibuf_x;
1022                 puv[3][1] = orig_uv[3][1] * ibuf_y;
1023         }
1024
1025         /* face edge directions */
1026         sub_v2_v2v2(dir1, puv[1], puv[0]);
1027         sub_v2_v2v2(dir2, puv[2], puv[1]);
1028         normalize_v2(dir1);
1029         normalize_v2(dir2);
1030
1031         if (is_quad) {
1032                 sub_v2_v2v2(dir3, puv[3], puv[2]);
1033                 sub_v2_v2v2(dir4, puv[0], puv[3]);
1034                 normalize_v2(dir3);
1035                 normalize_v2(dir4);
1036         }
1037         else {
1038                 sub_v2_v2v2(dir3, puv[0], puv[2]);
1039                 normalize_v2(dir3);
1040         }
1041
1042         if (is_quad) {
1043                 a1 = shell_v2v2_mid_normalized_to_dist(dir4, dir1);
1044                 a2 = shell_v2v2_mid_normalized_to_dist(dir1, dir2);
1045                 a3 = shell_v2v2_mid_normalized_to_dist(dir2, dir3);
1046                 a4 = shell_v2v2_mid_normalized_to_dist(dir3, dir4);
1047         }
1048         else {
1049                 a1 = shell_v2v2_mid_normalized_to_dist(dir3, dir1);
1050                 a2 = shell_v2v2_mid_normalized_to_dist(dir1, dir2);
1051                 a3 = shell_v2v2_mid_normalized_to_dist(dir2, dir3);
1052         }
1053
1054         if (is_quad) {
1055                 sub_v2_v2v2(no1, dir4, dir1);
1056                 sub_v2_v2v2(no2, dir1, dir2);
1057                 sub_v2_v2v2(no3, dir2, dir3);
1058                 sub_v2_v2v2(no4, dir3, dir4);
1059                 normalize_v2(no1);
1060                 normalize_v2(no2);
1061                 normalize_v2(no3);
1062                 normalize_v2(no4);
1063                 mul_v2_fl(no1, a1 * scaler);
1064                 mul_v2_fl(no2, a2 * scaler);
1065                 mul_v2_fl(no3, a3 * scaler);
1066                 mul_v2_fl(no4, a4 * scaler);
1067                 add_v2_v2v2(outset_uv[0], puv[0], no1);
1068                 add_v2_v2v2(outset_uv[1], puv[1], no2);
1069                 add_v2_v2v2(outset_uv[2], puv[2], no3);
1070                 add_v2_v2v2(outset_uv[3], puv[3], no4);
1071                 mul_v2_v2(outset_uv[0], ibuf_inv);
1072                 mul_v2_v2(outset_uv[1], ibuf_inv);
1073                 mul_v2_v2(outset_uv[2], ibuf_inv);
1074                 mul_v2_v2(outset_uv[3], ibuf_inv);
1075         }
1076         else {
1077                 sub_v2_v2v2(no1, dir3, dir1);
1078                 sub_v2_v2v2(no2, dir1, dir2);
1079                 sub_v2_v2v2(no3, dir2, dir3);
1080                 normalize_v2(no1);
1081                 normalize_v2(no2);
1082                 normalize_v2(no3);
1083                 mul_v2_fl(no1, a1 * scaler);
1084                 mul_v2_fl(no2, a2 * scaler);
1085                 mul_v2_fl(no3, a3 * scaler);
1086                 add_v2_v2v2(outset_uv[0], puv[0], no1);
1087                 add_v2_v2v2(outset_uv[1], puv[1], no2);
1088                 add_v2_v2v2(outset_uv[2], puv[2], no3);
1089
1090                 mul_v2_v2(outset_uv[0], ibuf_inv);
1091                 mul_v2_v2(outset_uv[1], ibuf_inv);
1092                 mul_v2_v2(outset_uv[2], ibuf_inv);
1093         }
1094 }
1095
1096 /*
1097  * Be tricky with flags, first 4 bits are PROJ_FACE_SEAM1 to 4, last 4 bits are PROJ_FACE_NOSEAM1 to 4
1098  * 1<<i - where i is (0-3)
1099  *
1100  * If we're multithreadng, make sure threads are locked when this is called
1101  */
1102 static void project_face_seams_init(const ProjPaintState *ps, const int face_index, const int is_quad)
1103 {
1104         int other_face, other_fidx; /* vars for the other face, we also set its flag */
1105         int fidx1 = is_quad ? 3 : 2;
1106         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 */
1107
1108         /* initialize face winding if needed */
1109         if ((ps->faceWindingFlags[face_index] & PROJ_FACE_WINDING_INIT) == 0)
1110                 project_face_winding_init(ps, face_index);
1111
1112         do {
1113                 if ((ps->faceSeamFlags[face_index] & (1 << fidx1 | 16 << fidx1)) == 0) {
1114                         if (check_seam(ps, face_index, fidx1, fidx2, &other_face, &other_fidx)) {
1115                                 ps->faceSeamFlags[face_index] |= 1 << fidx1;
1116                                 if (other_face != -1)
1117                                         ps->faceSeamFlags[other_face] |= 1 << other_fidx;
1118                         }
1119                         else {
1120                                 ps->faceSeamFlags[face_index] |= 16 << fidx1;
1121                                 if (other_face != -1)
1122                                         ps->faceSeamFlags[other_face] |= 16 << other_fidx;  /* second 4 bits for disabled */
1123                         }
1124                 }
1125
1126                 fidx2 = fidx1;
1127         } while (fidx1--);
1128 }
1129 #endif // PROJ_DEBUG_NOSEAMBLEED
1130
1131
1132 /* Converts a UV location to a 3D screenspace location
1133  * Takes a 'uv' and 3 UV coords, and sets the values of pixelScreenCo
1134  *
1135  * This is used for finding a pixels location in screenspace for painting */
1136 static void screen_px_from_ortho(
1137         const float uv[2],
1138         const float v1co[3], const float v2co[3], const float v3co[3],  /* Screenspace coords */
1139         const float uv1co[2], const float uv2co[2], const float uv3co[2],
1140         float pixelScreenCo[4],
1141         float w[3])
1142 {
1143         barycentric_weights_v2(uv1co, uv2co, uv3co, uv, w);
1144         interp_v3_v3v3v3(pixelScreenCo, v1co, v2co, v3co, w);
1145 }
1146
1147 /* same as screen_px_from_ortho except we
1148  * do perspective correction on the pixel coordinate */
1149 static void screen_px_from_persp(
1150         const float uv[2],
1151         const float v1co[4], const float v2co[4], const float v3co[4],  /* screenspace coords */
1152         const float uv1co[2], const float uv2co[2], const float uv3co[2],
1153         float pixelScreenCo[4],
1154         float w[3])
1155 {
1156         float w_int[3];
1157         float wtot_inv, wtot;
1158         barycentric_weights_v2(uv1co, uv2co, uv3co, uv, w);
1159
1160         /* re-weight from the 4th coord of each screen vert */
1161         w_int[0] = w[0] * v1co[3];
1162         w_int[1] = w[1] * v2co[3];
1163         w_int[2] = w[2] * v3co[3];
1164
1165         wtot = w_int[0] + w_int[1] + w_int[2];
1166
1167         if (wtot > 0.0f) {
1168                 wtot_inv = 1.0f / wtot;
1169                 w_int[0] *= wtot_inv;
1170                 w_int[1] *= wtot_inv;
1171                 w_int[2] *= wtot_inv;
1172         }
1173         else {
1174                 w[0] = w[1] = w[2] =
1175                 w_int[0] = w_int[1] = w_int[2] = 1.0f / 3.0f;  /* dummy values for zero area face */
1176         }
1177         /* done re-weighting */
1178
1179         /* do interpolation based on projected weight */
1180         interp_v3_v3v3v3(pixelScreenCo, v1co, v2co, v3co, w_int);
1181 }
1182
1183
1184 static void project_face_pixel(const MTFace *tf_other, ImBuf *ibuf_other, const float w[3],
1185                                int side, unsigned char rgba_ub[4], float rgba_f[4])
1186 {
1187         const float *uvCo1, *uvCo2, *uvCo3;
1188         float uv_other[2], x, y;
1189
1190         uvCo1 =  (float *)tf_other->uv[0];
1191         if (side == 1) {
1192                 uvCo2 =  (float *)tf_other->uv[2];
1193                 uvCo3 =  (float *)tf_other->uv[3];
1194         }
1195         else {
1196                 uvCo2 =  (float *)tf_other->uv[1];
1197                 uvCo3 =  (float *)tf_other->uv[2];
1198         }
1199
1200         interp_v2_v2v2v2(uv_other, uvCo1, uvCo2, uvCo3, (float *)w);
1201
1202         /* use */
1203         uvco_to_wrapped_pxco(uv_other, ibuf_other->x, ibuf_other->y, &x, &y);
1204
1205
1206         if (ibuf_other->rect_float) { /* from float to float */
1207                 bilinear_interpolation_color_wrap(ibuf_other, NULL, rgba_f, x, y);
1208         }
1209         else { /* from char to float */
1210                 bilinear_interpolation_color_wrap(ibuf_other, rgba_ub, NULL, x, y);
1211         }
1212
1213 }
1214
1215 /* run this outside project_paint_uvpixel_init since pixels with mask 0 don't need init */
1216 static float project_paint_uvpixel_mask(
1217         const ProjPaintState *ps,
1218         const int face_index,
1219         const int side,
1220         const float w[3])
1221 {
1222         float mask;
1223
1224         /* Image Mask */
1225         if (ps->do_layer_stencil) {
1226                 /* another UV maps image is masking this one's */
1227                 ImBuf *ibuf_other;
1228                 Image *other_tpage = ps->stencil_ima;
1229                 const MTFace *tf_other = ps->dm_mtface_stencil + face_index;
1230
1231                 if (other_tpage && (ibuf_other = BKE_image_acquire_ibuf(other_tpage, NULL, NULL))) {
1232                         /* BKE_image_acquire_ibuf - TODO - this may be slow */
1233                         unsigned char rgba_ub[4];
1234                         float rgba_f[4];
1235
1236                         project_face_pixel(tf_other, ibuf_other, w, side, rgba_ub, rgba_f);
1237
1238                         if (ibuf_other->rect_float) { /* from float to float */
1239                                 mask = ((rgba_f[0] + rgba_f[1] + rgba_f[2]) * (1.0f / 3.0f)) * rgba_f[3];
1240                         }
1241                         else { /* from char to float */
1242                                 mask = ((rgba_ub[0] + rgba_ub[1] + rgba_ub[2]) * (1.0f / (255.0f * 3.0f))) * (rgba_ub[3] * (1.0f / 255.0f));
1243                         }
1244
1245                         BKE_image_release_ibuf(other_tpage, ibuf_other, NULL);
1246
1247                         if (!ps->do_layer_stencil_inv) /* matching the gimps layer mask black/white rules, white==full opacity */
1248                                 mask = (1.0f - mask);
1249
1250                         if (mask == 0.0f) {
1251                                 return 0.0f;
1252                         }
1253                 }
1254                 else {
1255                         return 0.0f;
1256                 }
1257         }
1258         else {
1259                 mask = 1.0f;
1260         }
1261
1262         /* calculate mask */
1263         if (ps->do_mask_normal) {
1264                 MFace *mf = &ps->dm_mface[face_index];
1265                 float no[3], angle;
1266                 if (mf->flag & ME_SMOOTH) {
1267                         const short *no1, *no2, *no3;
1268                         no1 = ps->dm_mvert[mf->v1].no;
1269                         if (side == 1) {
1270                                 no2 = ps->dm_mvert[mf->v3].no;
1271                                 no3 = ps->dm_mvert[mf->v4].no;
1272                         }
1273                         else {
1274                                 no2 = ps->dm_mvert[mf->v2].no;
1275                                 no3 = ps->dm_mvert[mf->v3].no;
1276                         }
1277
1278                         no[0] = w[0] * no1[0] + w[1] * no2[0] + w[2] * no3[0];
1279                         no[1] = w[0] * no1[1] + w[1] * no2[1] + w[2] * no3[1];
1280                         no[2] = w[0] * no1[2] + w[1] * no2[2] + w[2] * no3[2];
1281                         normalize_v3(no);
1282                 }
1283                 else {
1284                         /* incase the */
1285 #if 1
1286                         /* normalizing per pixel isn't optimal, we could cache or check ps->*/
1287                         if (mf->v4)
1288                                 normal_quad_v3(no,
1289                                                ps->dm_mvert[mf->v1].co,
1290                                                ps->dm_mvert[mf->v2].co,
1291                                                ps->dm_mvert[mf->v3].co,
1292                                                ps->dm_mvert[mf->v4].co);
1293                         else
1294                                 normal_tri_v3(no,
1295                                               ps->dm_mvert[mf->v1].co,
1296                                               ps->dm_mvert[mf->v2].co,
1297                                               ps->dm_mvert[mf->v3].co);
1298 #else
1299                         /* don't use because some modifiers dont have normal data (subsurf for eg) */
1300                         copy_v3_v3(no, (float *)ps->dm->getTessFaceData(ps->dm, face_index, CD_NORMAL));
1301 #endif
1302                 }
1303
1304                 /* now we can use the normal as a mask */
1305                 if (ps->is_ortho) {
1306                         angle = angle_normalized_v3v3((float *)ps->viewDir, no);
1307                 }
1308                 else {
1309                         /* Annoying but for the perspective view we need to get the pixels location in 3D space :/ */
1310                         float viewDirPersp[3];
1311                         const float *co1, *co2, *co3;
1312                         co1 = ps->dm_mvert[mf->v1].co;
1313                         if (side == 1) {
1314                                 co2 = ps->dm_mvert[mf->v3].co;
1315                                 co3 = ps->dm_mvert[mf->v4].co;
1316                         }
1317                         else {
1318                                 co2 = ps->dm_mvert[mf->v2].co;
1319                                 co3 = ps->dm_mvert[mf->v3].co;
1320                         }
1321
1322                         /* Get the direction from the viewPoint to the pixel and normalize */
1323                         viewDirPersp[0] = (ps->viewPos[0] - (w[0] * co1[0] + w[1] * co2[0] + w[2] * co3[0]));
1324                         viewDirPersp[1] = (ps->viewPos[1] - (w[0] * co1[1] + w[1] * co2[1] + w[2] * co3[1]));
1325                         viewDirPersp[2] = (ps->viewPos[2] - (w[0] * co1[2] + w[1] * co2[2] + w[2] * co3[2]));
1326                         normalize_v3(viewDirPersp);
1327
1328                         angle = angle_normalized_v3v3(viewDirPersp, no);
1329                 }
1330
1331                 if (angle >= ps->normal_angle) {
1332                         return 0.0f; /* outsize the normal limit*/
1333                 }
1334                 else if (angle > ps->normal_angle_inner) {
1335                         mask *= (ps->normal_angle - angle) / ps->normal_angle_range;
1336                 } /* otherwise no mask normal is needed, were within the limit */
1337         }
1338
1339         /* This only works when the opacity dosnt change while painting, stylus pressure messes with this
1340          * so don't use it. */
1341         // if (ps->is_airbrush == 0) mask *= BKE_brush_alpha_get(ps->brush);
1342
1343         return mask;
1344 }
1345
1346 static int project_paint_pixel_sizeof(const short tool)
1347 {
1348         if ((tool == PAINT_TOOL_CLONE) || (tool == PAINT_TOOL_SMEAR)) {
1349                 return sizeof(ProjPixelClone);
1350         }
1351         else {
1352                 return sizeof(ProjPixel);
1353         }
1354 }
1355
1356 static int project_paint_undo_subtiles(const TileInfo *tinf, int tx, int ty)
1357 {
1358         ProjPaintImage *pjIma = tinf->pjima;
1359         int tile_index = tx + ty * tinf->tile_width;
1360         bool generate_tile = false;
1361
1362         /* double check lock to avoid locking */
1363         if (UNLIKELY(!pjIma->undoRect[tile_index])) {
1364                 if (tinf->lock)
1365                         BLI_spin_lock(tinf->lock);
1366                 if (LIKELY(!pjIma->undoRect[tile_index])) {
1367                         pjIma->undoRect[tile_index] = TILE_PENDING;
1368                         generate_tile = true;
1369                 }
1370                 if (tinf->lock)
1371                         BLI_spin_unlock(tinf->lock);
1372         }
1373
1374
1375         if (generate_tile) {
1376                 volatile void *undorect;
1377                 if (tinf->masked) {
1378                         undorect = image_undo_push_tile(pjIma->ima, pjIma->ibuf, tinf->tmpibuf, tx, ty, &pjIma->maskRect[tile_index], &pjIma->valid[tile_index], true);
1379                 }
1380                 else {
1381                         undorect = image_undo_push_tile(pjIma->ima, pjIma->ibuf, tinf->tmpibuf, tx, ty, NULL, &pjIma->valid[tile_index], true);
1382                 }
1383
1384                 pjIma->ibuf->userflags |= IB_BITMAPDIRTY;
1385                 /* tile ready, publish */
1386                 if (tinf->lock)
1387                         BLI_spin_lock(tinf->lock);
1388                 pjIma->undoRect[tile_index] = undorect;
1389                 if (tinf->lock)
1390                         BLI_spin_unlock(tinf->lock);
1391
1392         }
1393
1394         return tile_index;
1395 }
1396
1397 /* run this function when we know a bucket's, face's pixel can be initialized,
1398  * return the ProjPixel which is added to 'ps->bucketRect[bucket_index]' */
1399 static ProjPixel *project_paint_uvpixel_init(
1400         const ProjPaintState *ps,
1401         MemArena *arena,
1402         const TileInfo *tinf,
1403         int x_px, int y_px,
1404         const float mask,
1405         const int face_index,
1406         const float pixelScreenCo[4],
1407         const float world_spaceCo[3],
1408         const int side,
1409         const float w[3])
1410 {
1411         ProjPixel *projPixel;
1412         int x_tile, y_tile;
1413         int x_round, y_round;
1414         int tile_offset;
1415         /* volatile is important here to ensure pending check is not optimized away by compiler*/
1416         volatile int tile_index;
1417
1418         ProjPaintImage *projima = tinf->pjima;
1419         ImBuf *ibuf = projima->ibuf;
1420         /* wrap pixel location */
1421
1422         x_px = mod_i(x_px, ibuf->x);
1423         y_px = mod_i(y_px, ibuf->y);
1424
1425         BLI_assert(ps->pixel_sizeof == project_paint_pixel_sizeof(ps->tool));
1426         projPixel = (ProjPixel *)BLI_memarena_alloc(arena, ps->pixel_sizeof);
1427
1428         /* calculate the undo tile offset of the pixel, used to store the original
1429          * pixel color and accumulated mask if any */
1430         x_tile =  x_px >> IMAPAINT_TILE_BITS;
1431         y_tile =  y_px >> IMAPAINT_TILE_BITS;
1432
1433         x_round = x_tile * IMAPAINT_TILE_SIZE;
1434         y_round = y_tile * IMAPAINT_TILE_SIZE;
1435         //memset(projPixel, 0, size);
1436
1437         tile_offset = (x_px - x_round) + (y_px - y_round) * IMAPAINT_TILE_SIZE;
1438         tile_index = project_paint_undo_subtiles(tinf, x_tile, y_tile);
1439
1440         /* other thread may be initializing the tile so wait here */
1441         while (projima->undoRect[tile_index] == TILE_PENDING)
1442                 ;
1443
1444         BLI_assert(tile_index < (IMAPAINT_TILE_NUMBER(ibuf->x) * IMAPAINT_TILE_NUMBER(ibuf->y)));
1445         BLI_assert(tile_offset < (IMAPAINT_TILE_SIZE * IMAPAINT_TILE_SIZE));
1446
1447         projPixel->valid = projima->valid[tile_index];
1448
1449         if (ibuf->rect_float) {
1450                 projPixel->pixel.f_pt = ibuf->rect_float + ((x_px + y_px * ibuf->x) * 4);
1451                 projPixel->origColor.f_pt = (float *)projima->undoRect[tile_index] + 4 * tile_offset;
1452                 zero_v4(projPixel->newColor.f);
1453         }
1454         else {
1455                 projPixel->pixel.ch_pt = (unsigned char *)(ibuf->rect + (x_px + y_px * ibuf->x));
1456                 projPixel->origColor.uint_pt = (unsigned int *)projima->undoRect[tile_index] + tile_offset;
1457                 projPixel->newColor.uint = 0;
1458         }
1459
1460         /* screenspace unclamped, we could keep its z and w values but don't need them at the moment */
1461         if (ps->brush->mtex.brush_map_mode == MTEX_MAP_MODE_3D) {
1462                 copy_v3_v3(projPixel->worldCoSS, world_spaceCo);
1463         }
1464
1465         copy_v2_v2(projPixel->projCoSS, pixelScreenCo);
1466
1467         projPixel->x_px = x_px;
1468         projPixel->y_px = y_px;
1469
1470         projPixel->mask = (unsigned short)(mask * 65535);
1471         if (ps->do_masking)
1472                 projPixel->mask_accum = projima->maskRect[tile_index] + tile_offset;
1473         else
1474                 projPixel->mask_accum = NULL;
1475
1476         /* which bounding box cell are we in?, needed for undo */
1477         projPixel->bb_cell_index = ((int)(((float)x_px / (float)ibuf->x) * PROJ_BOUNDBOX_DIV)) +
1478                                    ((int)(((float)y_px / (float)ibuf->y) * PROJ_BOUNDBOX_DIV)) * PROJ_BOUNDBOX_DIV;
1479
1480         /* done with view3d_project_float inline */
1481         if (ps->tool == PAINT_TOOL_CLONE) {
1482                 if (ps->dm_mtface_clone) {
1483                         ImBuf *ibuf_other;
1484                         Image *other_tpage = project_paint_face_clone_image(ps, face_index);
1485                         const MTFace *tf_other = ps->dm_mtface_clone[face_index];
1486
1487                         if (other_tpage && (ibuf_other = BKE_image_acquire_ibuf(other_tpage, NULL, NULL))) {
1488                                 /* BKE_image_acquire_ibuf - TODO - this may be slow */
1489
1490                                 if (ibuf->rect_float) {
1491                                         if (ibuf_other->rect_float) { /* from float to float */
1492                                                 project_face_pixel(tf_other, ibuf_other, w, side, NULL, ((ProjPixelClone *)projPixel)->clonepx.f);
1493                                         }
1494                                         else { /* from char to float */
1495                                                 unsigned char rgba_ub[4];
1496                                                 float rgba[4];
1497                                                 project_face_pixel(tf_other, ibuf_other, w, side, rgba_ub, NULL);
1498                                                 srgb_to_linearrgb_uchar4(rgba, rgba_ub);
1499                                                 straight_to_premul_v4_v4(((ProjPixelClone *)projPixel)->clonepx.f, rgba);
1500                                         }
1501                                 }
1502                                 else {
1503                                         if (ibuf_other->rect_float) { /* float to char */
1504                                                 float rgba[4];
1505                                                 project_face_pixel(tf_other, ibuf_other, w, side, NULL, rgba);
1506                                                 premul_to_straight_v4(rgba);
1507                                                 linearrgb_to_srgb_uchar3(((ProjPixelClone *)projPixel)->clonepx.ch, rgba);
1508                                         }
1509                                         else { /* char to char */
1510                                                 project_face_pixel(tf_other, ibuf_other, w, side, ((ProjPixelClone *)projPixel)->clonepx.ch, NULL);
1511                                         }
1512                                 }
1513
1514                                 BKE_image_release_ibuf(other_tpage, ibuf_other, NULL);
1515                         }
1516                         else {
1517                                 if (ibuf->rect_float) {
1518                                         ((ProjPixelClone *)projPixel)->clonepx.f[3] = 0;
1519                                 }
1520                                 else {
1521                                         ((ProjPixelClone *)projPixel)->clonepx.ch[3] = 0;
1522                                 }
1523                         }
1524
1525                 }
1526                 else {
1527                         float co[2];
1528                         sub_v2_v2v2(co, projPixel->projCoSS, (float *)ps->cloneOffset);
1529
1530                         /* no need to initialize the bucket, we're only checking buckets faces and for this
1531                          * the faces are already initialized in project_paint_delayed_face_init(...) */
1532                         if (ibuf->rect_float) {
1533                                 if (!project_paint_PickColor(ps, co, ((ProjPixelClone *)projPixel)->clonepx.f, NULL, 1)) {
1534                                         ((ProjPixelClone *)projPixel)->clonepx.f[3] = 0; /* zero alpha - ignore */
1535                                 }
1536                         }
1537                         else {
1538                                 if (!project_paint_PickColor(ps, co, NULL, ((ProjPixelClone *)projPixel)->clonepx.ch, 1)) {
1539                                         ((ProjPixelClone *)projPixel)->clonepx.ch[3] = 0; /* zero alpha - ignore */
1540                                 }
1541                         }
1542                 }
1543         }
1544
1545 #ifdef PROJ_DEBUG_PAINT
1546         if (ibuf->rect_float) projPixel->pixel.f_pt[0] = 0;
1547         else                  projPixel->pixel.ch_pt[0] = 0;
1548 #endif
1549         /* pointer arithmetics */
1550         projPixel->image_index = projima - ps->projImages;
1551
1552         return projPixel;
1553 }
1554
1555 static bool line_clip_rect2f(
1556         rctf *rect,
1557         const float l1[2], const float l2[2],
1558         float l1_clip[2], float l2_clip[2])
1559 {
1560         /* first account for horizontal, then vertical lines */
1561         /* horiz */
1562         if (fabsf(l1[1] - l2[1]) < PROJ_GEOM_TOLERANCE) {
1563                 /* is the line out of range on its Y axis? */
1564                 if (l1[1] < rect->ymin || l1[1] > rect->ymax) {
1565                         return 0;
1566                 }
1567                 /* line is out of range on its X axis */
1568                 if ((l1[0] < rect->xmin && l2[0] < rect->xmin) || (l1[0] > rect->xmax && l2[0] > rect->xmax)) {
1569                         return 0;
1570                 }
1571
1572
1573                 if (fabsf(l1[0] - l2[0]) < PROJ_GEOM_TOLERANCE) { /* this is a single point  (or close to)*/
1574                         if (BLI_rctf_isect_pt_v(rect, l1)) {
1575                                 copy_v2_v2(l1_clip, l1);
1576                                 copy_v2_v2(l2_clip, l2);
1577                                 return 1;
1578                         }
1579                         else {
1580                                 return 0;
1581                         }
1582                 }
1583
1584                 copy_v2_v2(l1_clip, l1);
1585                 copy_v2_v2(l2_clip, l2);
1586                 CLAMP(l1_clip[0], rect->xmin, rect->xmax);
1587                 CLAMP(l2_clip[0], rect->xmin, rect->xmax);
1588                 return 1;
1589         }
1590         else if (fabsf(l1[0] - l2[0]) < PROJ_GEOM_TOLERANCE) {
1591                 /* is the line out of range on its X axis? */
1592                 if (l1[0] < rect->xmin || l1[0] > rect->xmax) {
1593                         return 0;
1594                 }
1595
1596                 /* line is out of range on its Y axis */
1597                 if ((l1[1] < rect->ymin && l2[1] < rect->ymin) || (l1[1] > rect->ymax && l2[1] > rect->ymax)) {
1598                         return 0;
1599                 }
1600
1601                 if (fabsf(l1[1] - l2[1]) < PROJ_GEOM_TOLERANCE) { /* this is a single point  (or close to)*/
1602                         if (BLI_rctf_isect_pt_v(rect, l1)) {
1603                                 copy_v2_v2(l1_clip, l1);
1604                                 copy_v2_v2(l2_clip, l2);
1605                                 return 1;
1606                         }
1607                         else {
1608                                 return 0;
1609                         }
1610                 }
1611
1612                 copy_v2_v2(l1_clip, l1);
1613                 copy_v2_v2(l2_clip, l2);
1614                 CLAMP(l1_clip[1], rect->ymin, rect->ymax);
1615                 CLAMP(l2_clip[1], rect->ymin, rect->ymax);
1616                 return 1;
1617         }
1618         else {
1619                 float isect;
1620                 short ok1 = 0;
1621                 short ok2 = 0;
1622
1623                 /* Done with vertical lines */
1624
1625                 /* are either of the points inside the rectangle ? */
1626                 if (BLI_rctf_isect_pt_v(rect, l1)) {
1627                         copy_v2_v2(l1_clip, l1);
1628                         ok1 = 1;
1629                 }
1630
1631                 if (BLI_rctf_isect_pt_v(rect, l2)) {
1632                         copy_v2_v2(l2_clip, l2);
1633                         ok2 = 1;
1634                 }
1635
1636                 /* line inside rect */
1637                 if (ok1 && ok2) return 1;
1638
1639                 /* top/bottom */
1640                 if (line_isect_y(l1, l2, rect->ymin, &isect) && (isect >= rect->xmin) && (isect <= rect->xmax)) {
1641                         if (l1[1] < l2[1]) { /* line 1 is outside */
1642                                 l1_clip[0] = isect;
1643                                 l1_clip[1] = rect->ymin;
1644                                 ok1 = 1;
1645                         }
1646                         else {
1647                                 l2_clip[0] = isect;
1648                                 l2_clip[1] = rect->ymin;
1649                                 ok2 = 2;
1650                         }
1651                 }
1652
1653                 if (ok1 && ok2) return 1;
1654
1655                 if (line_isect_y(l1, l2, rect->ymax, &isect) && (isect >= rect->xmin) && (isect <= rect->xmax)) {
1656                         if (l1[1] > l2[1]) { /* line 1 is outside */
1657                                 l1_clip[0] = isect;
1658                                 l1_clip[1] = rect->ymax;
1659                                 ok1 = 1;
1660                         }
1661                         else {
1662                                 l2_clip[0] = isect;
1663                                 l2_clip[1] = rect->ymax;
1664                                 ok2 = 2;
1665                         }
1666                 }
1667
1668                 if (ok1 && ok2) return 1;
1669
1670                 /* left/right */
1671                 if (line_isect_x(l1, l2, rect->xmin, &isect) && (isect >= rect->ymin) && (isect <= rect->ymax)) {
1672                         if (l1[0] < l2[0]) { /* line 1 is outside */
1673                                 l1_clip[0] = rect->xmin;
1674                                 l1_clip[1] = isect;
1675                                 ok1 = 1;
1676                         }
1677                         else {
1678                                 l2_clip[0] = rect->xmin;
1679                                 l2_clip[1] = isect;
1680                                 ok2 = 2;
1681                         }
1682                 }
1683
1684                 if (ok1 && ok2) return 1;
1685
1686                 if (line_isect_x(l1, l2, rect->xmax, &isect) && (isect >= rect->ymin) && (isect <= rect->ymax)) {
1687                         if (l1[0] > l2[0]) { /* line 1 is outside */
1688                                 l1_clip[0] = rect->xmax;
1689                                 l1_clip[1] = isect;
1690                                 ok1 = 1;
1691                         }
1692                         else {
1693                                 l2_clip[0] = rect->xmax;
1694                                 l2_clip[1] = isect;
1695                                 ok2 = 2;
1696                         }
1697                 }
1698
1699                 if (ok1 && ok2) {
1700                         return 1;
1701                 }
1702                 else {
1703                         return 0;
1704                 }
1705         }
1706 }
1707
1708
1709
1710 /* scale the quad & tri about its center
1711  * scaling by PROJ_FACE_SCALE_SEAM (0.99x) is used for getting fake UV pixel coords that are on the
1712  * edge of the face but slightly inside it occlusion tests don't return hits on adjacent faces */
1713 #ifndef PROJ_DEBUG_NOSEAMBLEED
1714 static void scale_quad(float insetCos[4][3], float *origCos[4], const float inset)
1715 {
1716         float cent[3];
1717         cent[0] = (origCos[0][0] + origCos[1][0] + origCos[2][0] + origCos[3][0]) * (1.0f / 4.0f);
1718         cent[1] = (origCos[0][1] + origCos[1][1] + origCos[2][1] + origCos[3][1]) * (1.0f / 4.0f);
1719         cent[2] = (origCos[0][2] + origCos[1][2] + origCos[2][2] + origCos[3][2]) * (1.0f / 4.0f);
1720
1721         sub_v3_v3v3(insetCos[0], origCos[0], cent);
1722         sub_v3_v3v3(insetCos[1], origCos[1], cent);
1723         sub_v3_v3v3(insetCos[2], origCos[2], cent);
1724         sub_v3_v3v3(insetCos[3], origCos[3], cent);
1725
1726         mul_v3_fl(insetCos[0], inset);
1727         mul_v3_fl(insetCos[1], inset);
1728         mul_v3_fl(insetCos[2], inset);
1729         mul_v3_fl(insetCos[3], inset);
1730
1731         add_v3_v3(insetCos[0], cent);
1732         add_v3_v3(insetCos[1], cent);
1733         add_v3_v3(insetCos[2], cent);
1734         add_v3_v3(insetCos[3], cent);
1735 }
1736
1737
1738 static void scale_tri(float insetCos[4][3], float *origCos[4], const float inset)
1739 {
1740         float cent[3];
1741         cent[0] = (origCos[0][0] + origCos[1][0] + origCos[2][0]) * (1.0f / 3.0f);
1742         cent[1] = (origCos[0][1] + origCos[1][1] + origCos[2][1]) * (1.0f / 3.0f);
1743         cent[2] = (origCos[0][2] + origCos[1][2] + origCos[2][2]) * (1.0f / 3.0f);
1744
1745         sub_v3_v3v3(insetCos[0], origCos[0], cent);
1746         sub_v3_v3v3(insetCos[1], origCos[1], cent);
1747         sub_v3_v3v3(insetCos[2], origCos[2], cent);
1748
1749         mul_v3_fl(insetCos[0], inset);
1750         mul_v3_fl(insetCos[1], inset);
1751         mul_v3_fl(insetCos[2], inset);
1752
1753         add_v3_v3(insetCos[0], cent);
1754         add_v3_v3(insetCos[1], cent);
1755         add_v3_v3(insetCos[2], cent);
1756 }
1757 #endif //PROJ_DEBUG_NOSEAMBLEED
1758
1759 static float len_squared_v2v2_alt(const float v1[2], const float v2_1, const float v2_2)
1760 {
1761         float x, y;
1762
1763         x = v1[0] - v2_1;
1764         y = v1[1] - v2_2;
1765         return x * x + y * y;
1766 }
1767
1768 /* note, use a squared value so we can use len_squared_v2v2
1769  * be sure that you have done a bounds check first or this may fail */
1770 /* only give bucket_bounds as an arg because we need it elsewhere */
1771 static bool project_bucket_isect_circle(const float cent[2], const float radius_squared, rctf *bucket_bounds)
1772 {
1773
1774         /* Would normally to a simple intersection test, however we know the bounds of these 2 already intersect
1775          * so we only need to test if the center is inside the vertical or horizontal bounds on either axis,
1776          * this is even less work then an intersection test
1777          */
1778 #if 0
1779         if (BLI_rctf_isect_pt_v(bucket_bounds, cent))
1780                 return 1;
1781 #endif
1782
1783         if ((bucket_bounds->xmin <= cent[0] && bucket_bounds->xmax >= cent[0]) ||
1784             (bucket_bounds->ymin <= cent[1] && bucket_bounds->ymax >= cent[1]))
1785         {
1786                 return 1;
1787         }
1788
1789         /* out of bounds left */
1790         if (cent[0] < bucket_bounds->xmin) {
1791                 /* lower left out of radius test */
1792                 if (cent[1] < bucket_bounds->ymin) {
1793                         return (len_squared_v2v2_alt(cent, bucket_bounds->xmin, bucket_bounds->ymin) < radius_squared) ? 1 : 0;
1794                 }
1795                 /* top left test */
1796                 else if (cent[1] > bucket_bounds->ymax) {
1797                         return (len_squared_v2v2_alt(cent, bucket_bounds->xmin, bucket_bounds->ymax) < radius_squared) ? 1 : 0;
1798                 }
1799         }
1800         else if (cent[0] > bucket_bounds->xmax) {
1801                 /* lower right out of radius test */
1802                 if (cent[1] < bucket_bounds->ymin) {
1803                         return (len_squared_v2v2_alt(cent, bucket_bounds->xmax, bucket_bounds->ymin) < radius_squared) ? 1 : 0;
1804                 }
1805                 /* top right test */
1806                 else if (cent[1] > bucket_bounds->ymax) {
1807                         return (len_squared_v2v2_alt(cent, bucket_bounds->xmax, bucket_bounds->ymax) < radius_squared) ? 1 : 0;
1808                 }
1809         }
1810
1811         return 0;
1812 }
1813
1814
1815
1816 /* Note for rect_to_uvspace_ortho() and rect_to_uvspace_persp()
1817  * in ortho view this function gives good results when bucket_bounds are outside the triangle
1818  * however in some cases, perspective view will mess up with faces that have minimal screenspace area
1819  * (viewed from the side)
1820  *
1821  * for this reason its not reliable in this case so we'll use the Simple Barycentric'
1822  * funcs that only account for points inside the triangle.
1823  * however switching back to this for ortho is always an option */
1824
1825 static void rect_to_uvspace_ortho(
1826         rctf *bucket_bounds,
1827         const float *v1coSS, const float *v2coSS, const float *v3coSS,
1828         const float *uv1co, const float *uv2co, const float *uv3co,
1829         float bucket_bounds_uv[4][2],
1830         const int flip)
1831 {
1832         float uv[2];
1833         float w[3];
1834
1835         /* get the UV space bounding box */
1836         uv[0] = bucket_bounds->xmax;
1837         uv[1] = bucket_bounds->ymin;
1838         barycentric_weights_v2(v1coSS, v2coSS, v3coSS, uv, w);
1839         interp_v2_v2v2v2(bucket_bounds_uv[flip ? 3 : 0], uv1co, uv2co, uv3co, w);
1840
1841         //uv[0] = bucket_bounds->xmax; // set above
1842         uv[1] = bucket_bounds->ymax;
1843         barycentric_weights_v2(v1coSS, v2coSS, v3coSS, uv, w);
1844         interp_v2_v2v2v2(bucket_bounds_uv[flip ? 2 : 1], uv1co, uv2co, uv3co, w);
1845
1846         uv[0] = bucket_bounds->xmin;
1847         //uv[1] = bucket_bounds->ymax; // set above
1848         barycentric_weights_v2(v1coSS, v2coSS, v3coSS, uv, w);
1849         interp_v2_v2v2v2(bucket_bounds_uv[flip ? 1 : 2], uv1co, uv2co, uv3co, w);
1850
1851         //uv[0] = bucket_bounds->xmin; // set above
1852         uv[1] = bucket_bounds->ymin;
1853         barycentric_weights_v2(v1coSS, v2coSS, v3coSS, uv, w);
1854         interp_v2_v2v2v2(bucket_bounds_uv[flip ? 0 : 3], uv1co, uv2co, uv3co, w);
1855 }
1856
1857 /* same as above but use barycentric_weights_v2_persp */
1858 static void rect_to_uvspace_persp(
1859         rctf *bucket_bounds,
1860         const float *v1coSS, const float *v2coSS, const float *v3coSS,
1861         const float *uv1co, const float *uv2co, const float *uv3co,
1862         float bucket_bounds_uv[4][2],
1863         const int flip
1864         )
1865 {
1866         float uv[2];
1867         float w[3];
1868
1869         /* get the UV space bounding box */
1870         uv[0] = bucket_bounds->xmax;
1871         uv[1] = bucket_bounds->ymin;
1872         barycentric_weights_v2_persp(v1coSS, v2coSS, v3coSS, uv, w);
1873         interp_v2_v2v2v2(bucket_bounds_uv[flip ? 3 : 0], uv1co, uv2co, uv3co, w);
1874
1875         //uv[0] = bucket_bounds->xmax; // set above
1876         uv[1] = bucket_bounds->ymax;
1877         barycentric_weights_v2_persp(v1coSS, v2coSS, v3coSS, uv, w);
1878         interp_v2_v2v2v2(bucket_bounds_uv[flip ? 2 : 1], uv1co, uv2co, uv3co, w);
1879
1880         uv[0] = bucket_bounds->xmin;
1881         //uv[1] = bucket_bounds->ymax; // set above
1882         barycentric_weights_v2_persp(v1coSS, v2coSS, v3coSS, uv, w);
1883         interp_v2_v2v2v2(bucket_bounds_uv[flip ? 1 : 2], uv1co, uv2co, uv3co, w);
1884
1885         //uv[0] = bucket_bounds->xmin; // set above
1886         uv[1] = bucket_bounds->ymin;
1887         barycentric_weights_v2_persp(v1coSS, v2coSS, v3coSS, uv, w);
1888         interp_v2_v2v2v2(bucket_bounds_uv[flip ? 0 : 3], uv1co, uv2co, uv3co, w);
1889 }
1890
1891 /* This works as we need it to but we can save a few steps and not use it */
1892
1893 #if 0
1894 static float angle_2d_clockwise(const float p1[2], const float p2[2], const float p3[2])
1895 {
1896         float v1[2], v2[2];
1897
1898         v1[0] = p1[0] - p2[0];    v1[1] = p1[1] - p2[1];
1899         v2[0] = p3[0] - p2[0];    v2[1] = p3[1] - p2[1];
1900
1901         return -atan2(v1[0] * v2[1] - v1[1] * v2[0], v1[0] * v2[0] + v1[1] * v2[1]);
1902 }
1903 #endif
1904
1905 #define ISECT_1 (1)
1906 #define ISECT_2 (1 << 1)
1907 #define ISECT_3 (1 << 2)
1908 #define ISECT_4 (1 << 3)
1909 #define ISECT_ALL3 ((1 << 3) - 1)
1910 #define ISECT_ALL4 ((1 << 4) - 1)
1911
1912 /* limit must be a fraction over 1.0f */
1913 static bool IsectPT2Df_limit(float pt[2], float v1[2], float v2[2], float v3[2], float limit)
1914 {
1915         return ((area_tri_v2(pt, v1, v2) +
1916                  area_tri_v2(pt, v2, v3) +
1917                  area_tri_v2(pt, v3, v1)) / (area_tri_v2(v1, v2, v3))) < limit;
1918 }
1919
1920 /* Clip the face by a bucket and set the uv-space bucket_bounds_uv
1921  * so we have the clipped UV's to do pixel intersection tests with
1922  * */
1923 static int float_z_sort_flip(const void *p1, const void *p2)
1924 {
1925         return (((float *)p1)[2] < ((float *)p2)[2] ? 1 : -1);
1926 }
1927
1928 static int float_z_sort(const void *p1, const void *p2)
1929 {
1930         return (((float *)p1)[2] < ((float *)p2)[2] ? -1 : 1);
1931 }
1932
1933 static void project_bucket_clip_face(
1934         const bool is_ortho,
1935         rctf *bucket_bounds,
1936         float *v1coSS, float *v2coSS, float *v3coSS,
1937         const float *uv1co, const float *uv2co, const float *uv3co,
1938         float bucket_bounds_uv[8][2],
1939         int *tot)
1940 {
1941         int inside_bucket_flag = 0;
1942         int inside_face_flag = 0;
1943         const int flip = ((line_point_side_v2(v1coSS, v2coSS, v3coSS) > 0.0f) != (line_point_side_v2(uv1co, uv2co, uv3co) > 0.0f));
1944
1945         float bucket_bounds_ss[4][2];
1946
1947         /* get the UV space bounding box */
1948         inside_bucket_flag |= BLI_rctf_isect_pt_v(bucket_bounds, v1coSS);
1949         inside_bucket_flag |= BLI_rctf_isect_pt_v(bucket_bounds, v2coSS) << 1;
1950         inside_bucket_flag |= BLI_rctf_isect_pt_v(bucket_bounds, v3coSS) << 2;
1951
1952         if (inside_bucket_flag == ISECT_ALL3) {
1953                 /* all screenspace points are inside the bucket bounding box, this means we don't need to clip and can simply return the UVs */
1954                 if (flip) { /* facing the back? */
1955                         copy_v2_v2(bucket_bounds_uv[0], uv3co);
1956                         copy_v2_v2(bucket_bounds_uv[1], uv2co);
1957                         copy_v2_v2(bucket_bounds_uv[2], uv1co);
1958                 }
1959                 else {
1960                         copy_v2_v2(bucket_bounds_uv[0], uv1co);
1961                         copy_v2_v2(bucket_bounds_uv[1], uv2co);
1962                         copy_v2_v2(bucket_bounds_uv[2], uv3co);
1963                 }
1964
1965                 *tot = 3;
1966                 return;
1967         }
1968
1969         /* get the UV space bounding box */
1970         /* use IsectPT2Df_limit here so we catch points are are touching the tri edge (or a small fraction over) */
1971         bucket_bounds_ss[0][0] = bucket_bounds->xmax;
1972         bucket_bounds_ss[0][1] = bucket_bounds->ymin;
1973         inside_face_flag |= (IsectPT2Df_limit(bucket_bounds_ss[0], v1coSS, v2coSS, v3coSS, 1 + PROJ_GEOM_TOLERANCE) ? ISECT_1 : 0);
1974
1975         bucket_bounds_ss[1][0] = bucket_bounds->xmax;
1976         bucket_bounds_ss[1][1] = bucket_bounds->ymax;
1977         inside_face_flag |= (IsectPT2Df_limit(bucket_bounds_ss[1], v1coSS, v2coSS, v3coSS, 1 + PROJ_GEOM_TOLERANCE) ? ISECT_2 : 0);
1978
1979         bucket_bounds_ss[2][0] = bucket_bounds->xmin;
1980         bucket_bounds_ss[2][1] = bucket_bounds->ymax;
1981         inside_face_flag |= (IsectPT2Df_limit(bucket_bounds_ss[2], v1coSS, v2coSS, v3coSS, 1 + PROJ_GEOM_TOLERANCE) ? ISECT_3 : 0);
1982
1983         bucket_bounds_ss[3][0] = bucket_bounds->xmin;
1984         bucket_bounds_ss[3][1] = bucket_bounds->ymin;
1985         inside_face_flag |= (IsectPT2Df_limit(bucket_bounds_ss[3], v1coSS, v2coSS, v3coSS, 1 + PROJ_GEOM_TOLERANCE) ? ISECT_4 : 0);
1986
1987         if (inside_face_flag == ISECT_ALL4) {
1988                 /* bucket is totally inside the screenspace face, we can safely use weights */
1989
1990                 if (is_ortho) rect_to_uvspace_ortho(bucket_bounds, v1coSS, v2coSS, v3coSS, uv1co, uv2co, uv3co, bucket_bounds_uv, flip);
1991                 else rect_to_uvspace_persp(bucket_bounds, v1coSS, v2coSS, v3coSS, uv1co, uv2co, uv3co, bucket_bounds_uv, flip);
1992
1993                 *tot = 4;
1994                 return;
1995         }
1996         else {
1997                 /* The Complicated Case!
1998                  *
1999                  * The 2 cases above are where the face is inside the bucket or the bucket is inside the face.
2000                  *
2001                  * we need to make a convex polyline from the intersection between the screenspace face
2002                  * and the bucket bounds.
2003                  *
2004                  * There are a number of ways this could be done, currently it just collects all intersecting verts,
2005                  * and line intersections,  then sorts them clockwise, this is a lot easier then evaluating the geometry to
2006                  * do a correct clipping on both shapes. */
2007
2008
2009                 /* add a bunch of points, we know must make up the convex hull which is the clipped rect and triangle */
2010
2011
2012
2013                 /* Maximum possible 6 intersections when using a rectangle and triangle */
2014                 float isectVCosSS[8][3]; /* The 3rd float is used to store angle for qsort(), NOT as a Z location */
2015                 float v1_clipSS[2], v2_clipSS[2];
2016                 float w[3];
2017
2018                 /* calc center */
2019                 float cent[2] = {0.0f, 0.0f};
2020                 /*float up[2] = {0.0f, 1.0f};*/
2021                 int i;
2022                 short doubles;
2023
2024                 (*tot) = 0;
2025
2026                 if (inside_face_flag & ISECT_1) { copy_v2_v2(isectVCosSS[*tot], bucket_bounds_ss[0]); (*tot)++; }
2027                 if (inside_face_flag & ISECT_2) { copy_v2_v2(isectVCosSS[*tot], bucket_bounds_ss[1]); (*tot)++; }
2028                 if (inside_face_flag & ISECT_3) { copy_v2_v2(isectVCosSS[*tot], bucket_bounds_ss[2]); (*tot)++; }
2029                 if (inside_face_flag & ISECT_4) { copy_v2_v2(isectVCosSS[*tot], bucket_bounds_ss[3]); (*tot)++; }
2030
2031                 if (inside_bucket_flag & ISECT_1) { copy_v2_v2(isectVCosSS[*tot], v1coSS); (*tot)++; }
2032                 if (inside_bucket_flag & ISECT_2) { copy_v2_v2(isectVCosSS[*tot], v2coSS); (*tot)++; }
2033                 if (inside_bucket_flag & ISECT_3) { copy_v2_v2(isectVCosSS[*tot], v3coSS); (*tot)++; }
2034
2035                 if ((inside_bucket_flag & (ISECT_1 | ISECT_2)) != (ISECT_1 | ISECT_2)) {
2036                         if (line_clip_rect2f(bucket_bounds, v1coSS, v2coSS, v1_clipSS, v2_clipSS)) {
2037                                 if ((inside_bucket_flag & ISECT_1) == 0) { copy_v2_v2(isectVCosSS[*tot], v1_clipSS); (*tot)++; }
2038                                 if ((inside_bucket_flag & ISECT_2) == 0) { copy_v2_v2(isectVCosSS[*tot], v2_clipSS); (*tot)++; }
2039                         }
2040                 }
2041
2042                 if ((inside_bucket_flag & (ISECT_2 | ISECT_3)) != (ISECT_2 | ISECT_3)) {
2043                         if (line_clip_rect2f(bucket_bounds, v2coSS, v3coSS, v1_clipSS, v2_clipSS)) {
2044                                 if ((inside_bucket_flag & ISECT_2) == 0) { copy_v2_v2(isectVCosSS[*tot], v1_clipSS); (*tot)++; }
2045                                 if ((inside_bucket_flag & ISECT_3) == 0) { copy_v2_v2(isectVCosSS[*tot], v2_clipSS); (*tot)++; }
2046                         }
2047                 }
2048
2049                 if ((inside_bucket_flag & (ISECT_3 | ISECT_1)) != (ISECT_3 | ISECT_1)) {
2050                         if (line_clip_rect2f(bucket_bounds, v3coSS, v1coSS, v1_clipSS, v2_clipSS)) {
2051                                 if ((inside_bucket_flag & ISECT_3) == 0) { copy_v2_v2(isectVCosSS[*tot], v1_clipSS); (*tot)++; }
2052                                 if ((inside_bucket_flag & ISECT_1) == 0) { copy_v2_v2(isectVCosSS[*tot], v2_clipSS); (*tot)++; }
2053                         }
2054                 }
2055
2056
2057                 if ((*tot) < 3) { /* no intersections to speak of */
2058                         *tot = 0;
2059                         return;
2060                 }
2061
2062                 /* now we have all points we need, collect their angles and sort them clockwise */
2063
2064                 for (i = 0; i < (*tot); i++) {
2065                         cent[0] += isectVCosSS[i][0];
2066                         cent[1] += isectVCosSS[i][1];
2067                 }
2068                 cent[0] = cent[0] / (float)(*tot);
2069                 cent[1] = cent[1] / (float)(*tot);
2070
2071
2072
2073                 /* Collect angles for every point around the center point */
2074
2075
2076 #if 0   /* uses a few more cycles then the above loop */
2077                 for (i = 0; i < (*tot); i++) {
2078                         isectVCosSS[i][2] = angle_2d_clockwise(up, cent, isectVCosSS[i]);
2079                 }
2080 #endif
2081
2082                 v1_clipSS[0] = cent[0]; /* Abuse this var for the loop below */
2083                 v1_clipSS[1] = cent[1] + 1.0f;
2084
2085                 for (i = 0; i < (*tot); i++) {
2086                         v2_clipSS[0] = isectVCosSS[i][0] - cent[0];
2087                         v2_clipSS[1] = isectVCosSS[i][1] - cent[1];
2088                         isectVCosSS[i][2] = atan2f(v1_clipSS[0] * v2_clipSS[1] - v1_clipSS[1] * v2_clipSS[0], v1_clipSS[0] * v2_clipSS[0] + v1_clipSS[1] * v2_clipSS[1]);
2089                 }
2090
2091                 if (flip) qsort(isectVCosSS, *tot, sizeof(float) * 3, float_z_sort_flip);
2092                 else      qsort(isectVCosSS, *tot, sizeof(float) * 3, float_z_sort);
2093
2094                 /* remove doubles */
2095                 /* first/last check */
2096                 if (fabsf(isectVCosSS[0][0] - isectVCosSS[(*tot) - 1][0]) < PROJ_PIXEL_TOLERANCE &&
2097                     fabsf(isectVCosSS[0][1] - isectVCosSS[(*tot) - 1][1]) < PROJ_PIXEL_TOLERANCE)
2098                 {
2099                         (*tot)--;
2100                 }
2101
2102                 /* its possible there is only a few left after remove doubles */
2103                 if ((*tot) < 3) {
2104                         // printf("removed too many doubles A\n");
2105                         *tot = 0;
2106                         return;
2107                 }
2108
2109                 doubles = true;
2110                 while (doubles == true) {
2111                         doubles = false;
2112                         for (i = 1; i < (*tot); i++) {
2113                                 if (fabsf(isectVCosSS[i - 1][0] - isectVCosSS[i][0]) < PROJ_PIXEL_TOLERANCE &&
2114                                     fabsf(isectVCosSS[i - 1][1] - isectVCosSS[i][1]) < PROJ_PIXEL_TOLERANCE)
2115                                 {
2116                                         int j;
2117                                         for (j = i + 1; j < (*tot); j++) {
2118                                                 isectVCosSS[j - 1][0] = isectVCosSS[j][0];
2119                                                 isectVCosSS[j - 1][1] = isectVCosSS[j][1];
2120                                         }
2121                                         doubles = true; /* keep looking for more doubles */
2122                                         (*tot)--;
2123                                 }
2124                         }
2125                 }
2126
2127                 /* its possible there is only a few left after remove doubles */
2128                 if ((*tot) < 3) {
2129                         // printf("removed too many doubles B\n");
2130                         *tot = 0;
2131                         return;
2132                 }
2133
2134
2135                 if (is_ortho) {
2136                         for (i = 0; i < (*tot); i++) {
2137                                 barycentric_weights_v2(v1coSS, v2coSS, v3coSS, isectVCosSS[i], w);
2138                                 interp_v2_v2v2v2(bucket_bounds_uv[i], uv1co, uv2co, uv3co, w);
2139                         }
2140                 }
2141                 else {
2142                         for (i = 0; i < (*tot); i++) {
2143                                 barycentric_weights_v2_persp(v1coSS, v2coSS, v3coSS, isectVCosSS[i], w);
2144                                 interp_v2_v2v2v2(bucket_bounds_uv[i], uv1co, uv2co, uv3co, w);
2145                         }
2146                 }
2147         }
2148
2149 #ifdef PROJ_DEBUG_PRINT_CLIP
2150         /* include this at the bottom of the above function to debug the output */
2151
2152         {
2153                 /* If there are ever any problems, */
2154                 float test_uv[4][2];
2155                 int i;
2156                 if (is_ortho) rect_to_uvspace_ortho(bucket_bounds, v1coSS, v2coSS, v3coSS, uv1co, uv2co, uv3co, test_uv, flip);
2157                 else          rect_to_uvspace_persp(bucket_bounds, v1coSS, v2coSS, v3coSS, uv1co, uv2co, uv3co, test_uv, flip);
2158                 printf("(  [(%f,%f), (%f,%f), (%f,%f), (%f,%f)], ", test_uv[0][0], test_uv[0][1],   test_uv[1][0], test_uv[1][1],    test_uv[2][0], test_uv[2][1],    test_uv[3][0], test_uv[3][1]);
2159
2160                 printf("  [(%f,%f), (%f,%f), (%f,%f)], ", uv1co[0], uv1co[1],   uv2co[0], uv2co[1],    uv3co[0], uv3co[1]);
2161
2162                 printf("[");
2163                 for (i = 0; i < (*tot); i++) {
2164                         printf("(%f, %f),", bucket_bounds_uv[i][0], bucket_bounds_uv[i][1]);
2165                 }
2166                 printf("]),\\\n");
2167         }
2168 #endif
2169 }
2170
2171 /*
2172  * # This script creates faces in a blender scene from printed data above.
2173  *
2174  * project_ls = [
2175  * ...(output from above block)...
2176  * ]
2177  *
2178  * from Blender import Scene, Mesh, Window, sys, Mathutils
2179  *
2180  * import bpy
2181  *
2182  * V = Mathutils.Vector
2183  *
2184  * def main():
2185  *     sce = bpy.data.scenes.active
2186  *
2187  *     for item in project_ls:
2188  *         bb = item[0]
2189  *         uv = item[1]
2190  *         poly = item[2]
2191  *
2192  *         me = bpy.data.meshes.new()
2193  *         ob = sce.objects.new(me)
2194  *
2195  *         me.verts.extend([V(bb[0]).xyz, V(bb[1]).xyz, V(bb[2]).xyz, V(bb[3]).xyz])
2196  *         me.faces.extend([(0,1,2,3),])
2197  *         me.verts.extend([V(uv[0]).xyz, V(uv[1]).xyz, V(uv[2]).xyz])
2198  *         me.faces.extend([(4,5,6),])
2199  *
2200  *         vs = [V(p).xyz for p in poly]
2201  *         print len(vs)
2202  *         l = len(me.verts)
2203  *         me.verts.extend(vs)
2204  *
2205  *         i = l
2206  *         while i < len(me.verts):
2207  *             ii = i + 1
2208  *             if ii == len(me.verts):
2209  *                 ii = l
2210  *             me.edges.extend([i, ii])
2211  *             i += 1
2212  *
2213  * if __name__ == '__main__':
2214  *     main()
2215  */
2216
2217
2218 #undef ISECT_1
2219 #undef ISECT_2
2220 #undef ISECT_3
2221 #undef ISECT_4
2222 #undef ISECT_ALL3
2223 #undef ISECT_ALL4
2224
2225
2226 /* checks if pt is inside a convex 2D polyline, the polyline must be ordered rotating clockwise
2227  * otherwise it would have to test for mixed (line_point_side_v2 > 0.0f) cases */
2228 static bool IsectPoly2Df(const float pt[2], float uv[][2], const int tot)
2229 {
2230         int i;
2231         if (line_point_side_v2(uv[tot - 1], uv[0], pt) < 0.0f)
2232                 return 0;
2233
2234         for (i = 1; i < tot; i++) {
2235                 if (line_point_side_v2(uv[i - 1], uv[i], pt) < 0.0f)
2236                         return 0;
2237
2238         }
2239
2240         return 1;
2241 }
2242 static bool IsectPoly2Df_twoside(const float pt[2], float uv[][2], const int tot)
2243 {
2244         int i;
2245         int side = (line_point_side_v2(uv[tot - 1], uv[0], pt) > 0.0f);
2246
2247         for (i = 1; i < tot; i++) {
2248                 if ((line_point_side_v2(uv[i - 1], uv[i], pt) > 0.0f) != side)
2249                         return 0;
2250
2251         }
2252
2253         return 1;
2254 }
2255
2256 /* One of the most important function for projection painting, since it selects the pixels to be added into each bucket.
2257  * initialize pixels from this face where it intersects with the bucket_index, optionally initialize pixels for removing seams */
2258 static void project_paint_face_init(const ProjPaintState *ps, const int thread_index, const int bucket_index, const int face_index, const int image_index, rctf *bucket_bounds, ImBuf *ibuf, ImBuf **tmpibuf, const short clamp_u, const short clamp_v)
2259 {
2260         /* Projection vars, to get the 3D locations into screen space  */
2261         MemArena *arena = ps->arena_mt[thread_index];
2262         LinkNode **bucketPixelNodes = ps->bucketRect + bucket_index;
2263         LinkNode *bucketFaceNodes = ps->bucketFaces[bucket_index];
2264         bool threaded = (ps->thread_tot > 1);
2265
2266         TileInfo tinf = {
2267                 ps->tile_lock,
2268                 ps->do_masking,
2269                 IMAPAINT_TILE_NUMBER(ibuf->x),
2270                 tmpibuf,
2271                 ps->projImages + image_index
2272         };
2273
2274         const MFace *mf = ps->dm_mface + face_index;
2275         const MTFace *tf = ps->dm_mtface[face_index];
2276
2277         /* UV/pixel seeking data */
2278         int x; /* Image X-Pixel */
2279         int y; /* Image Y-Pixel */
2280         float mask;
2281         float uv[2]; /* Image floating point UV - same as x, y but from 0.0-1.0 */
2282
2283         int side;
2284         float *v1coSS, *v2coSS, *v3coSS; /* vert co screen-space, these will be assigned to mf->v1,2,3 or mf->v1,3,4 */
2285
2286         float *vCo[4]; /* vertex screenspace coords */
2287
2288         float w[3], wco[3];
2289
2290         float *uv1co, *uv2co, *uv3co; /* for convenience only, these will be assigned to tf->uv[0],1,2 or tf->uv[0],2,3 */
2291         float pixelScreenCo[4];
2292         bool do_3d_mapping = ps->brush->mtex.brush_map_mode == MTEX_MAP_MODE_3D;
2293
2294         rcti bounds_px; /* ispace bounds */
2295         /* vars for getting uvspace bounds */
2296
2297         float tf_uv_pxoffset[4][2]; /* bucket bounds in UV space so we can init pixels only for this face,  */
2298         float xhalfpx, yhalfpx;
2299         const float ibuf_xf = (float)ibuf->x, ibuf_yf = (float)ibuf->y;
2300
2301         int has_x_isect = 0, has_isect = 0; /* for early loop exit */
2302
2303         int i1, i2, i3;
2304
2305         float uv_clip[8][2];
2306         int uv_clip_tot;
2307         const bool is_ortho = ps->is_ortho;
2308         const bool do_backfacecull = ps->do_backfacecull;
2309         const bool do_clip = ps->rv3d ? ps->rv3d->rflag & RV3D_CLIPPING : 0;
2310
2311         vCo[0] = ps->dm_mvert[mf->v1].co;
2312         vCo[1] = ps->dm_mvert[mf->v2].co;
2313         vCo[2] = ps->dm_mvert[mf->v3].co;
2314
2315
2316         /* Use tf_uv_pxoffset instead of tf->uv so we can offset the UV half a pixel
2317          * this is done so we can avoid offsetting all the pixels by 0.5 which causes
2318          * problems when wrapping negative coords */
2319         xhalfpx = (0.5f + (PROJ_PIXEL_TOLERANCE * (1.0f / 3.0f))) / ibuf_xf;
2320         yhalfpx = (0.5f + (PROJ_PIXEL_TOLERANCE * (1.0f / 4.0f))) / ibuf_yf;
2321
2322         /* Note about (PROJ_GEOM_TOLERANCE/x) above...
2323          * Needed to add this offset since UV coords are often quads aligned to pixels.
2324          * In this case pixels can be exactly between 2 triangles causing nasty
2325          * artifacts.
2326          *
2327          * This workaround can be removed and painting will still work on most cases
2328          * but since the first thing most people try is painting onto a quad- better make it work.
2329          */
2330
2331         tf_uv_pxoffset[0][0] = tf->uv[0][0] - xhalfpx;
2332         tf_uv_pxoffset[0][1] = tf->uv[0][1] - yhalfpx;
2333
2334         tf_uv_pxoffset[1][0] = tf->uv[1][0] - xhalfpx;
2335         tf_uv_pxoffset[1][1] = tf->uv[1][1] - yhalfpx;
2336
2337         tf_uv_pxoffset[2][0] = tf->uv[2][0] - xhalfpx;
2338         tf_uv_pxoffset[2][1] = tf->uv[2][1] - yhalfpx;
2339
2340         if (mf->v4) {
2341                 vCo[3] = ps->dm_mvert[mf->v4].co;
2342
2343                 tf_uv_pxoffset[3][0] = tf->uv[3][0] - xhalfpx;
2344                 tf_uv_pxoffset[3][1] = tf->uv[3][1] - yhalfpx;
2345                 side = 1;
2346         }
2347         else {
2348                 side = 0;
2349         }
2350
2351         do {
2352                 if (side == 1) {
2353                         i1 = 0; i2 = 2; i3 = 3;
2354                 }
2355                 else {
2356                         i1 = 0; i2 = 1; i3 = 2;
2357                 }
2358
2359                 uv1co = tf_uv_pxoffset[i1]; // was tf->uv[i1];
2360                 uv2co = tf_uv_pxoffset[i2]; // was tf->uv[i2];
2361                 uv3co = tf_uv_pxoffset[i3]; // was tf->uv[i3];
2362
2363                 v1coSS = ps->screenCoords[(*(&mf->v1 + i1))];
2364                 v2coSS = ps->screenCoords[(*(&mf->v1 + i2))];
2365                 v3coSS = ps->screenCoords[(*(&mf->v1 + i3))];
2366
2367                 /* This funtion gives is a concave polyline in UV space from the clipped quad and tri*/
2368                 project_bucket_clip_face(
2369                         is_ortho, bucket_bounds,
2370                         v1coSS, v2coSS, v3coSS,
2371                         uv1co, uv2co, uv3co,
2372                         uv_clip, &uv_clip_tot
2373                         );
2374
2375                 /* sometimes this happens, better just allow for 8 intersectiosn even though there should be max 6 */
2376 #if 0
2377                 if (uv_clip_tot > 6) {
2378                         printf("this should never happen! %d\n", uv_clip_tot);
2379                 }
2380 #endif
2381
2382                 if (pixel_bounds_array(uv_clip, &bounds_px, ibuf->x, ibuf->y, uv_clip_tot)) {
2383
2384                         if (clamp_u) {
2385                                 CLAMP(bounds_px.xmin, 0, ibuf->x);
2386                                 CLAMP(bounds_px.xmax, 0, ibuf->x);
2387                         }
2388
2389                         if (clamp_v) {
2390                                 CLAMP(bounds_px.ymin, 0, ibuf->y);
2391                                 CLAMP(bounds_px.ymax, 0, ibuf->y);
2392                         }
2393
2394                         /*
2395                         project_paint_undo_tiles_init(&bounds_px, ps->projImages + image_index, tmpibuf,
2396                                                       tile_width, threaded, ps->do_masking);
2397                         */
2398                         /* clip face and */
2399
2400                         has_isect = 0;
2401                         for (y = bounds_px.ymin; y < bounds_px.ymax; y++) {
2402                                 //uv[1] = (((float)y) + 0.5f) / (float)ibuf->y;
2403                                 uv[1] = (float)y / ibuf_yf; /* use pixel offset UV coords instead */
2404
2405                                 has_x_isect = 0;
2406                                 for (x = bounds_px.xmin; x < bounds_px.xmax; x++) {
2407                                         //uv[0] = (((float)x) + 0.5f) / ibuf->x;
2408                                         uv[0] = (float)x / ibuf_xf; /* use pixel offset UV coords instead */
2409
2410                                         /* Note about IsectPoly2Df_twoside, checking the face or uv flipping doesnt work,
2411                                          * could check the poly direction but better to do this */
2412                                         if ((do_backfacecull == true  && IsectPoly2Df(uv, uv_clip, uv_clip_tot)) ||
2413                                             (do_backfacecull == false && IsectPoly2Df_twoside(uv, uv_clip, uv_clip_tot)))
2414                                         {
2415
2416                                                 has_x_isect = has_isect = 1;
2417
2418                                                 if (is_ortho) screen_px_from_ortho(uv, v1coSS, v2coSS, v3coSS, uv1co, uv2co, uv3co, pixelScreenCo, w);
2419                                                 else screen_px_from_persp(uv, v1coSS, v2coSS, v3coSS, uv1co, uv2co, uv3co, pixelScreenCo, w);
2420
2421                                                 /* a pity we need to get the worldspace pixel location here */
2422                                                 if (do_clip || do_3d_mapping) {
2423                                                         interp_v3_v3v3v3(wco, ps->dm_mvert[(*(&mf->v1 + i1))].co, ps->dm_mvert[(*(&mf->v1 + i2))].co, ps->dm_mvert[(*(&mf->v1 + i3))].co, w);
2424                                                         if (do_clip && ED_view3d_clipping_test(ps->rv3d, wco, true)) {
2425                                                                 continue; /* Watch out that no code below this needs to run */
2426                                                         }
2427                                                 }
2428
2429                                                 /* Is this UV visible from the view? - raytrace */
2430                                                 /* project_paint_PickFace is less complex, use for testing */
2431                                                 //if (project_paint_PickFace(ps, pixelScreenCo, w, &side) == face_index) {
2432                                                 if ((ps->do_occlude == false) ||
2433                                                     !project_bucket_point_occluded(ps, bucketFaceNodes, face_index, pixelScreenCo))
2434                                                 {
2435                                                         mask = project_paint_uvpixel_mask(ps, face_index, side, w);
2436
2437                                                         if (mask > 0.0f) {
2438                                                                 BLI_linklist_prepend_arena(
2439                                                                         bucketPixelNodes,
2440                                                                         project_paint_uvpixel_init(ps, arena, &tinf, x, y, mask, face_index,
2441                                                                                                    pixelScreenCo, wco, side, w),
2442                                                                         arena
2443                                                                         );
2444                                                         }
2445                                                 }
2446
2447                                         }
2448 //#if 0
2449                                         else if (has_x_isect) {
2450                                                 /* assuming the face is not a bow-tie - we know we cant intersect again on the X */
2451                                                 break;
2452                                         }
2453 //#endif
2454                                 }
2455
2456
2457 #if 0           /* TODO - investigate why this dosnt work sometimes! it should! */
2458                                 /* no intersection for this entire row, after some intersection above means we can quit now */
2459                                 if (has_x_isect == 0 && has_isect) {
2460                                         break;
2461                                 }
2462 #endif
2463                         }
2464                 }
2465         } while (side--);
2466
2467
2468
2469 #ifndef PROJ_DEBUG_NOSEAMBLEED
2470         if (ps->seam_bleed_px > 0.0f) {
2471                 int face_seam_flag;
2472
2473                 if (threaded)
2474                         BLI_lock_thread(LOCK_CUSTOM1);  /* Other threads could be modifying these vars */
2475
2476                 face_seam_flag = ps->faceSeamFlags[face_index];
2477
2478                 /* are any of our edges un-initialized? */
2479                 if ((face_seam_flag & (PROJ_FACE_SEAM1 | PROJ_FACE_NOSEAM1)) == 0 ||
2480                     (face_seam_flag & (PROJ_FACE_SEAM2 | PROJ_FACE_NOSEAM2)) == 0 ||
2481                     (face_seam_flag & (PROJ_FACE_SEAM3 | PROJ_FACE_NOSEAM3)) == 0 ||
2482                     (face_seam_flag & (PROJ_FACE_SEAM4 | PROJ_FACE_NOSEAM4)) == 0)
2483                 {
2484                         project_face_seams_init(ps, face_index, mf->v4);
2485                         face_seam_flag = ps->faceSeamFlags[face_index];
2486                         //printf("seams - %d %d %d %d\n", flag&PROJ_FACE_SEAM1, flag&PROJ_FACE_SEAM2, flag&PROJ_FACE_SEAM3, flag&PROJ_FACE_SEAM4);
2487                 }
2488
2489                 if ((face_seam_flag & (PROJ_FACE_SEAM1 | PROJ_FACE_SEAM2 | PROJ_FACE_SEAM3 | PROJ_FACE_SEAM4)) == 0) {
2490
2491                         if (threaded)
2492                                 BLI_unlock_thread(LOCK_CUSTOM1);  /* Other threads could be modifying these vars */
2493
2494                 }
2495                 else {
2496                         /* we have a seam - deal with it! */
2497
2498                         /* Now create new UV's for the seam face */
2499                         float (*outset_uv)[2] = ps->faceSeamUVs[face_index];
2500                         float insetCos[4][3]; /* inset face coords.  NOTE!!! ScreenSace for ortho, Worldspace in prespective view */
2501
2502                         float *vCoSS[4]; /* vertex screenspace coords */
2503
2504                         float bucket_clip_edges[2][2]; /* store the screenspace coords of the face, clipped by the bucket's screen aligned rectangle */
2505                         float edge_verts_inset_clip[2][3];
2506                         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 */
2507
2508                         float seam_subsection[4][2];
2509                         float fac1, fac2, ftot;
2510
2511
2512                         if (outset_uv[0][0] == FLT_MAX) /* first time initialize */
2513                                 uv_image_outset(tf_uv_pxoffset, outset_uv, ps->seam_bleed_px, ibuf->x, ibuf->y, mf->v4 != 0);
2514
2515                         /* ps->faceSeamUVs cant be modified when threading, now this is done we can unlock */
2516                         if (threaded)
2517                                 BLI_unlock_thread(LOCK_CUSTOM1);  /* Other threads could be modifying these vars */
2518
2519                         vCoSS[0] = ps->screenCoords[mf->v1];
2520                         vCoSS[1] = ps->screenCoords[mf->v2];
2521                         vCoSS[2] = ps->screenCoords[mf->v3];
2522                         if (mf->v4)
2523                                 vCoSS[3] = ps->screenCoords[mf->v4];
2524
2525                         /* PROJ_FACE_SCALE_SEAM must be slightly less then 1.0f */
2526                         if (is_ortho) {
2527                                 if (mf->v4) scale_quad(insetCos, vCoSS, PROJ_FACE_SCALE_SEAM);
2528                                 else        scale_tri(insetCos, vCoSS, PROJ_FACE_SCALE_SEAM);
2529                         }
2530                         else {
2531                                 if (mf->v4) scale_quad(insetCos, vCo, PROJ_FACE_SCALE_SEAM);
2532                                 else        scale_tri(insetCos, vCo, PROJ_FACE_SCALE_SEAM);
2533                         }
2534
2535                         side = 0; /* for triangles this wont need to change */
2536
2537                         for (fidx1 = 0; fidx1 < (mf->v4 ? 4 : 3); fidx1++) {
2538                                 if (mf->v4) fidx2 = (fidx1 == 3) ? 0 : fidx1 + 1;  /* next fidx in the face (0,1,2,3) -> (1,2,3,0) */
2539                                 else        fidx2 = (fidx1 == 2) ? 0 : fidx1 + 1;  /* next fidx in the face (0,1,2) -> (1,2,0) */
2540
2541                                 if ((face_seam_flag & (1 << fidx1)) && /* 1<<fidx1 -> PROJ_FACE_SEAM# */
2542                                     line_clip_rect2f(bucket_bounds, vCoSS[fidx1], vCoSS[fidx2], bucket_clip_edges[0], bucket_clip_edges[1]))
2543                                 {
2544
2545                                         ftot = len_v2v2(vCoSS[fidx1], vCoSS[fidx2]); /* screenspace edge length */
2546
2547                                         if (ftot > 0.0f) { /* avoid div by zero */
2548                                                 if (mf->v4) {
2549                                                         if (fidx1 == 2 || fidx2 == 2) side = 1;
2550                                                         else side = 0;
2551                                                 }
2552
2553                                                 fac1 = len_v2v2(vCoSS[fidx1], bucket_clip_edges[0]) / ftot;
2554                                                 fac2 = len_v2v2(vCoSS[fidx1], bucket_clip_edges[1]) / ftot;
2555
2556                                                 interp_v2_v2v2(seam_subsection[0], tf_uv_pxoffset[fidx1], tf_uv_pxoffset[fidx2], fac1);
2557                                                 interp_v2_v2v2(seam_subsection[1], tf_uv_pxoffset[fidx1], tf_uv_pxoffset[fidx2], fac2);
2558
2559                                                 interp_v2_v2v2(seam_subsection[2], outset_uv[fidx1], outset_uv[fidx2], fac2);
2560                                                 interp_v2_v2v2(seam_subsection[3], outset_uv[fidx1], outset_uv[fidx2], fac1);
2561
2562                                                 /* if the bucket_clip_edges values Z values was kept we could avoid this
2563                                                  * Inset needs to be added so occlusion tests wont hit adjacent faces */
2564                                                 interp_v3_v3v3(edge_verts_inset_clip[0], insetCos[fidx1], insetCos[fidx2], fac1);
2565                                                 interp_v3_v3v3(edge_verts_inset_clip[1], insetCos[fidx1], insetCos[fidx2], fac2);
2566
2567
2568                                                 if (pixel_bounds_uv(seam_subsection[0], seam_subsection[1], seam_subsection[2], seam_subsection[3], &bounds_px, ibuf->x, ibuf->y, true)) {
2569                                                         /* bounds between the seam rect and the uvspace bucket pixels */
2570
2571                                                         has_isect = 0;
2572                                                         for (y = bounds_px.ymin; y < bounds_px.ymax; y++) {
2573                                                                 // uv[1] = (((float)y) + 0.5f) / (float)ibuf->y;
2574                                                                 uv[1] = (float)y / ibuf_yf; /* use offset uvs instead */
2575
2576                                                                 has_x_isect = 0;
2577                                                                 for (x = bounds_px.xmin; x < bounds_px.xmax; x++) {
2578                                                                         //uv[0] = (((float)x) + 0.5f) / (float)ibuf->x;
2579                                                                         uv[0] = (float)x / ibuf_xf; /* use offset uvs instead */
2580
2581                                                                         /* test we're inside uvspace bucket and triangle bounds */
2582                                                                         if (isect_point_quad_v2(uv, seam_subsection[0], seam_subsection[1], seam_subsection[2], seam_subsection[3])) {
2583                                                                                 float fac;
2584
2585                                                                                 /* We need to find the closest point along the face edge,
2586                                                                                  * getting the screen_px_from_*** wont work because our actual location
2587                                                                                  * is not relevant, since we are outside the face, Use VecLerpf to find
2588                                                                                  * our location on the side of the face's UV */
2589 #if 0
2590                                                                                 if (is_ortho) screen_px_from_ortho(ps, uv, v1co, v2co, v3co, uv1co, uv2co, uv3co, pixelScreenCo);
2591                                                                                 else          screen_px_from_persp(ps, uv, v1co, v2co, v3co, uv1co, uv2co, uv3co, pixelScreenCo);
2592 #endif
2593
2594                                                                                 /* Since this is a seam we need to work out where on the line this pixel is */
2595                                                                                 //fac = line_point_factor_v2(uv, uv_seam_quad[0], uv_seam_quad[1]);
2596
2597                                                                                 fac = line_point_factor_v2(uv, seam_subsection[0], seam_subsection[1]);
2598                                                                                 if      (fac < 0.0f) { copy_v3_v3(pixelScreenCo, edge_verts_inset_clip[0]); }
2599                                                                                 else if (fac > 1.0f) { copy_v3_v3(pixelScreenCo, edge_verts_inset_clip[1]); }
2600                                                                                 else                 { interp_v3_v3v3(pixelScreenCo, edge_verts_inset_clip[0], edge_verts_inset_clip[1], fac); }
2601
2602                                                                                 if (!is_ortho) {
2603                                                                                         pixelScreenCo[3] = 1.0f;
2604                                                                                         mul_m4_v4((float(*)[4])ps->projectMat, pixelScreenCo); /* cast because of const */
2605                                                                                         pixelScreenCo[0] = (float)(ps->winx * 0.5f) + (ps->winx * 0.5f) * pixelScreenCo[0] / pixelScreenCo[3];
2606                                                                                         pixelScreenCo[1] = (float)(ps->winy * 0.5f) + (ps->winy * 0.5f) * pixelScreenCo[1] / pixelScreenCo[3];
2607                                                                                         pixelScreenCo[2] = pixelScreenCo[2] / pixelScreenCo[3]; /* Use the depth for bucket point occlusion */
2608                                                                                 }
2609
2610                                                                                 if ((ps->do_occlude == false) ||
2611                                                                                     !project_bucket_point_occluded(ps, bucketFaceNodes, face_index, pixelScreenCo))
2612                                                                                 {
2613                                                                                         /* Only bother calculating the weights if we intersect */
2614                                                                                         if (ps->do_mask_normal || ps->dm_mtface_clone) {
2615 #if 1
2616                                                                                                 /* get the UV on the line since we want to copy the pixels from there for bleeding */
2617                                                                                                 float uv_close[2];
2618                                                                                                 float uv_fac = closest_to_line_v2(uv_close, uv, tf_uv_pxoffset[fidx1], tf_uv_pxoffset[fidx2]);
2619                                                                                                 if      (uv_fac < 0.0f) copy_v2_v2(uv_close, tf_uv_pxoffset[fidx1]);
2620                                                                                                 else if (uv_fac > 1.0f) copy_v2_v2(uv_close, tf_uv_pxoffset[fidx2]);
2621
2622                                                                                                 if (side) {
2623                                                                                                         barycentric_weights_v2(tf_uv_pxoffset[0], tf_uv_pxoffset[2], tf_uv_pxoffset[3], uv_close, w);
2624                                                                                                 }
2625                                                                                                 else {
2626                                                                                                         barycentric_weights_v2(tf_uv_pxoffset[0], tf_uv_pxoffset[1], tf_uv_pxoffset[2], uv_close, w);
2627                                                                                                 }
2628 #else                                                                                   /* this is buggy with quads, don't use for now */
2629
2630                                                                                                 /* Cheat, we know where we are along the edge so work out the weights from that */
2631                                                                                                 uv_fac = fac1 + (uv_fac * (fac2 - fac1));
2632
2633                                                                                                 w[0] = w[1] = w[2] = 0.0;
2634                                                                                                 if (side) {
2635                                                                                                         w[fidx1 ? fidx1 - 1 : 0] = 1.0f - uv_fac;
2636                                                                                                         w[fidx2 ? fidx2 - 1 : 0] = uv_fac;
2637                                                                                                 }
2638                                                                                                 else {
2639                                                                                                         w[fidx1] = 1.0f - uv_fac;
2640                                                                                                         w[fidx2] = uv_fac;
2641                                                                                                 }
2642 #endif
2643                                                                                         }
2644
2645                                                                                         /* a pity we need to get the worldspace pixel location here */
2646                                                                                         if (do_clip || do_3d_mapping) {
2647                                                                                                 if (side) interp_v3_v3v3v3(wco, ps->dm_mvert[mf->v1].co, ps->dm_mvert[mf->v3].co, ps->dm_mvert[mf->v4].co, w);
2648                                                                                                 else      interp_v3_v3v3v3(wco, ps->dm_mvert[mf->v1].co, ps->dm_mvert[mf->v2].co, ps->dm_mvert[mf->v3].co, w);
2649
2650                                                                                                 if (do_clip && ED_view3d_clipping_test(ps->rv3d, wco, true)) {
2651                                                                                                         continue; /* Watch out that no code below this needs to run */
2652                                                                                                 }
2653                                                                                         }
2654
2655                                                                                         mask = project_paint_uvpixel_mask(ps, face_index, side, w);
2656
2657                                                                                         if (mask > 0.0f) {
2658                                                                                                 BLI_linklist_prepend_arena(
2659                                                                                                         bucketPixelNodes,
2660                                                                                                         project_paint_uvpixel_init(ps, arena, &tinf, x, y, mask, face_index,
2661                                                                                                         pixelScreenCo, wco, side, w),
2662                                                                                                         arena
2663                                                                                                         );
2664                                                                                         }
2665
2666                                                                                 }
2667                                                                         }
2668                                                                         else if (has_x_isect) {
2669                                                                                 /* assuming the face is not a bow-tie - we know we cant intersect again on the X */
2670                                                                                 break;
2671                                                                         }
2672                                                                 }
2673
2674 #if 0                           /* TODO - investigate why this dosnt work sometimes! it should! */
2675                                                                 /* no intersection for this entire row, after some intersection above means we can quit now */
2676                                                                 if (has_x_isect == 0 && has_isect) {
2677                                                                         break;
2678                                                                 }
2679 #endif
2680                                                         }
2681                                                 }
2682                                         }
2683                                 }
2684                         }
2685                 }
2686         }
2687 #endif // PROJ_DEBUG_NOSEAMBLEED
2688 }
2689
2690
2691 /* takes floating point screenspace min/max and returns int min/max to be used as indices for ps->bucketRect, ps->bucketFlags */
2692 static void project_paint_bucket_bounds(const ProjPaintState *ps, const float min[2], const float max[2], int bucketMin[2], int bucketMax[2])
2693 {
2694         /* divide by bucketWidth & bucketHeight so the bounds are offset in bucket grid units */
2695         /* 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 */
2696         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 */
2697         bucketMin[1] = (int)((int)(((float)(min[1] - ps->screenMin[1]) / ps->screen_height) * ps->buckets_y) + 0.5f);
2698
2699         bucketMax[0] = (int)((int)(((float)(max[0] - ps->screenMin[0]) / ps->screen_width) * ps->buckets_x) + 1.5f);
2700         bucketMax[1] = (int)((int)(((float)(max[1] - ps->screenMin[1]) / ps->screen_height) * ps->buckets_y) + 1.5f);
2701
2702         /* in case the rect is outside the mesh 2d bounds */
2703         CLAMP(bucketMin[0], 0, ps->buckets_x);
2704         CLAMP(bucketMin[1], 0, ps->buckets_y);
2705
2706         CLAMP(bucketMax[0], 0, ps->buckets_x);
2707         CLAMP(bucketMax[1], 0, ps->buckets_y);
2708 }
2709
2710 /* set bucket_bounds to a screen space-aligned floating point bound-box */
2711 static void project_bucket_bounds(const ProjPaintState *ps, const int bucket_x, const int bucket_y, rctf *bucket_bounds)
2712 {
2713         bucket_bounds->xmin = ps->screenMin[0] + ((bucket_x) * (ps->screen_width / ps->buckets_x));     /* left */
2714         bucket_bounds->xmax = ps->screenMin[0] + ((bucket_x + 1) * (ps->screen_width / ps->buckets_x)); /* right */
2715
2716         bucket_bounds->ymin = ps->screenMin[1] + ((bucket_y) * (ps->screen_height / ps->buckets_y));      /* bottom */
2717         bucket_bounds->ymax = ps->screenMin[1] + ((bucket_y + 1) * (ps->screen_height  / ps->buckets_y)); /* top */
2718 }
2719
2720 /* Fill this bucket with pixels from the faces that intersect it.
2721  *
2722  * have bucket_bounds as an argument so we don't need to give bucket_x/y the rect function needs */
2723 static void project_bucket_init(const ProjPaintState *ps, const int thread_index, const int bucket_index, rctf *bucket_bounds)
2724 {
2725         LinkNode *node;
2726         int face_index, image_index = 0;
2727         ImBuf *ibuf = NULL;
2728         Image *tpage_last = NULL, *tpage;
2729         Image *ima = NULL;
2730         ImBuf *tmpibuf = NULL;
2731
2732         if (ps->image_tot == 1) {
2733                 /* Simple loop, no context switching */
2734                 ibuf = ps->projImages[0].ibuf;
2735                 ima = ps->projImages[0].ima;
2736
2737                 for (node = ps->bucketFaces[bucket_index]; node; node = node->next) {
2738                         project_paint_face_init(ps, thread_index, bucket_index, GET_INT_FROM_POINTER(node->link), 0, bucket_bounds, ibuf, &tmpibuf, ima->tpageflag & IMA_CLAMP_U, ima->tpageflag & IMA_CLAMP_V);
2739                 }
2740         }
2741         else {
2742
2743                 /* More complicated loop, switch between images */
2744                 for (node = ps->bucketFaces[bucket_index]; node; node = node->next) {
2745                         face_index = GET_INT_FROM_POINTER(node->link);
2746
2747                         /* Image context switching */
2748                         tpage = project_paint_face_paint_image(ps, face_index);
2749                         if (tpage_last != tpage) {
2750                                 tpage_last = tpage;
2751
2752                                 for (image_index = 0; image_index < ps->image_tot; image_index++) {
2753                                         if (ps->projImages[image_index].ima == tpage_last) {
2754                                                 ibuf = ps->projImages[image_index].ibuf;
2755                                                 ima = ps->projImages[image_index].ima;
2756                                                 break;
2757                                         }
2758                                 }
2759                         }
2760                         /* context switching done */
2761
2762                         project_paint_face_init(ps, thread_index, bucket_index, face_index, image_index, bucket_bounds, ibuf, &tmpibuf, ima->tpageflag & IMA_CLAMP_U, ima->tpageflag & IMA_CLAMP_V);
2763                 }
2764         }
2765
2766         if (tmpibuf)
2767                 IMB_freeImBuf(tmpibuf);
2768
2769         ps->bucketFlags[bucket_index] |= PROJ_BUCKET_INIT;
2770 }
2771
2772
2773 /* We want to know if a bucket and a face overlap in screen-space
2774  *
2775  * Note, if this ever returns false positives its not that bad, since a face in the bounding area will have its pixels
2776  * calculated when it might not be needed later, (at the moment at least)
2777  * obviously it shouldn't have bugs though */
2778
2779 static bool project_bucket_face_isect(ProjPaintState *ps, int bucket_x, int bucket_y, const MFace *mf)
2780 {
2781         /* TODO - replace this with a tricker method that uses sideofline for all screenCoords's edges against the closest bucket corner */
2782         rctf bucket_bounds;
2783         float p1[2], p2[2], p3[2], p4[2];
2784         const float *v, *v1, *v2, *v3, *v4 = NULL;
2785         int fidx;
2786
2787         project_bucket_bounds(ps, bucket_x, bucket_y, &bucket_bounds);
2788
2789         /* Is one of the faces verts in the bucket bounds? */
2790
2791         fidx = mf->v4 ? 3 : 2;
2792         do {
2793                 v = ps->screenCoords[(*(&mf->v1 + fidx))];
2794                 if (BLI_rctf_isect_pt_v(&bucket_bounds, v)) {
2795                         return 1;
2796                 }
2797         } while (fidx--);
2798
2799         v1 = ps->screenCoords[mf->v1];
2800         v2 = ps->screenCoords[mf->v2];
2801         v3 = ps->screenCoords[mf->v3];
2802         if (mf->v4) {
2803                 v4 = ps->screenCoords[mf->v4];
2804         }
2805
2806         p1[0] = bucket_bounds.xmin; p1[1] = bucket_bounds.ymin;
2807         p2[0] = bucket_bounds.xmin; p2[1] = bucket_bounds.ymax;
2808         p3[0] = bucket_bounds.xmax; p3[1] = bucket_bounds.ymax;
2809         p4[0] = bucket_bounds.xmax; p4[1] = bucket_bounds.ymin;
2810
2811         if (mf->v4) {
2812                 if (isect_point_quad_v2(p1, v1, v2, v3, v4) ||
2813                     isect_point_quad_v2(p2, v1, v2, v3, v4) ||
2814                     isect_point_quad_v2(p3, v1, v2, v3, v4) ||
2815                     isect_point_quad_v2(p4, v1, v2, v3, v4) ||
2816
2817                     /* we can avoid testing v3,v1 because another intersection MUST exist if this intersects */
2818                     (isect_line_line_v2(p1, p2, v1, v2) || isect_line_line_v2(p1, p2, v2, v3) || isect_line_line_v2(p1, p2, v3, v4)) ||
2819                     (isect_line_line_v2(p2, p3, v1, v2) || isect_line_line_v2(p2, p3, v2, v3) || isect_line_line_v2(p2, p3, v3, v4)) ||
2820                     (isect_line_line_v2(p3, p4, v1, v2) || isect_line_line_v2(p3, p4, v2, v3) || isect_line_line_v2(p3, p4, v3, v4)) ||
2821                     (isect_line_line_v2(p4, p1, v1, v2) || isect_line_line_v2(p4, p1, v2, v3) || isect_line_line_v2(p4, p1, v3, v4)))
2822                 {
2823                         return 1;
2824                 }
2825         }
2826         else {
2827                 if (isect_point_tri_v2(p1, v1, v2, v3) ||
2828                     isect_point_tri_v2(p2, v1, v2, v3) ||
2829                     isect_point_tri_v2(p3, v1, v2, v3) ||
2830                     isect_point_tri_v2(p4, v1, v2, v3) ||
2831                     /* we can avoid testing v3,v1 because another intersection MUST exist if this intersects */
2832                     (isect_line_line_v2(p1, p2, v1, v2) || isect_line_line_v2(p1, p2, v2, v3)) ||
2833                     (isect_line_line_v2(p2, p3, v1, v2) || isect_line_line_v2(p2, p3, v2, v3)) ||
2834                     (isect_line_line_v2(p3, p4, v1, v2) || isect_line_line_v2(p3, p4, v2, v3)) ||
2835                     (isect_line_line_v2(p4, p1, v1, v2) || isect_line_line_v2(p4, p1, v2, v3)))
2836                 {
2837                         return 1;
2838                 }
2839         }
2840
2841         return 0;
2842 }
2843
2844 /* Add faces to the bucket but don't initialize its pixels
2845  * TODO - when painting occluded, sort the faces on their min-Z and only add faces that faces that are not occluded */
2846 static void project_paint_delayed_face_init(ProjPaintState *ps, const MFace *mf, const int face_index)
2847 {
2848         float min[2], max[2], *vCoSS;
2849         int bucketMin[2], bucketMax[2]; /* for  ps->bucketRect indexing */
2850         int fidx, bucket_x, bucket_y;
2851         int has_x_isect = -1, has_isect = 0; /* for early loop exit */
2852         MemArena *arena = ps->arena_mt[0]; /* just use the first thread arena since threading has not started yet */
2853
2854         INIT_MINMAX2(min, max);
2855
2856         fidx = mf->v4 ? 3 : 2;
2857         do {
2858                 vCoSS = ps->screenCoords[*(&mf->v1 + fidx)];
2859                 minmax_v2v2_v2(min, max, vCoSS);
2860         } while (fidx--);
2861
2862         project_paint_bucket_bounds(ps, min, max, bucketMin, bucketMax);
2863
2864         for (bucket_y = bucketMin[1]; bucket_y < bucketMax[1]; bucket_y++) {
2865                 has_x_isect = 0;
2866                 for (bucket_x = bucketMin[0]; bucket_x < bucketMax[0]; bucket_x++) {
2867                         if (project_bucket_face_isect(ps, bucket_x, bucket_y, mf)) {
2868                                 int bucket_index = bucket_x + (bucket_y * ps->buckets_x);
2869                                 BLI_linklist_prepend_arena(
2870                                         &ps->bucketFaces[bucket_index],
2871                                         SET_INT_IN_POINTER(face_index), /* cast to a pointer to shut up the compiler */
2872                                         arena
2873                                         );
2874
2875                                 has_x_isect = has_isect = 1;
2876                         }
2877                         else if (has_x_isect) {