Attempt to fix #35057 and #35372: slow texture painting performance.
[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 "PIL_time.h"
52
53 #include "IMB_imbuf.h"
54 #include "IMB_imbuf_types.h"
55
56 #include "DNA_brush_types.h"
57 #include "DNA_mesh_types.h"
58 #include "DNA_node_types.h"
59 #include "DNA_object_types.h"
60
61 #include "BKE_camera.h"
62 #include "BKE_context.h"
63 #include "BKE_depsgraph.h"
64 #include "BKE_DerivedMesh.h"
65 #include "BKE_idprop.h"
66 #include "BKE_brush.h"
67 #include "BKE_image.h"
68 #include "BKE_library.h"
69 #include "BKE_main.h"
70 #include "BKE_mesh.h"
71 #include "BKE_node.h"
72 #include "BKE_object.h"
73 #include "BKE_paint.h"
74 #include "BKE_report.h"
75 #include "BKE_scene.h"
76 #include "BKE_colortools.h"
77
78 #include "BKE_editmesh.h"
79
80 #include "BIF_gl.h"
81 #include "BIF_glutil.h"
82
83 #include "UI_view2d.h"
84
85 #include "ED_image.h"
86 #include "ED_screen.h"
87 #include "ED_sculpt.h"
88 #include "ED_uvedit.h"
89 #include "ED_view3d.h"
90 #include "ED_mesh.h"
91
92 #include "GPU_extensions.h"
93
94 #include "WM_api.h"
95 #include "WM_types.h"
96
97 #include "RNA_access.h"
98 #include "RNA_define.h"
99 #include "RNA_enum_types.h"
100
101 #include "GPU_draw.h"
102
103 #include "IMB_colormanagement.h"
104
105 #include "paint_intern.h"
106
107 /* Defines and Structs */
108 /* FTOCHAR as inline function */
109 BLI_INLINE unsigned char f_to_char(const float val)
110 {
111         return FTOCHAR(val);
112 }
113
114 /* ProjectionPaint defines */
115
116 /* approx the number of buckets to have under the brush,
117  * used with the brush size to set the ps->buckets_x and ps->buckets_y value.
118  *
119  * When 3 - a brush should have ~9 buckets under it at once
120  * ...this helps for threading while painting as well as
121  * avoiding initializing pixels that wont touch the brush */
122 #define PROJ_BUCKET_BRUSH_DIV 4
123
124 #define PROJ_BUCKET_RECT_MIN 4
125 #define PROJ_BUCKET_RECT_MAX 256
126
127 #define PROJ_BOUNDBOX_DIV 8
128 #define PROJ_BOUNDBOX_SQUARED  (PROJ_BOUNDBOX_DIV * PROJ_BOUNDBOX_DIV)
129
130 //#define PROJ_DEBUG_PAINT 1
131 //#define PROJ_DEBUG_NOSEAMBLEED 1
132 //#define PROJ_DEBUG_PRINT_CLIP 1
133 #define PROJ_DEBUG_WINCLIP 1
134
135 /* projectFaceSeamFlags options */
136 //#define PROJ_FACE_IGNORE      (1<<0)  /* When the face is hidden, backfacing or occluded */
137 //#define PROJ_FACE_INIT        (1<<1)  /* When we have initialized the faces data */
138 #define PROJ_FACE_SEAM1 (1 << 0)  /* If this face has a seam on any of its edges */
139 #define PROJ_FACE_SEAM2 (1 << 1)
140 #define PROJ_FACE_SEAM3 (1 << 2)
141 #define PROJ_FACE_SEAM4 (1 << 3)
142
143 #define PROJ_FACE_NOSEAM1   (1 << 4)
144 #define PROJ_FACE_NOSEAM2   (1 << 5)
145 #define PROJ_FACE_NOSEAM3   (1 << 6)
146 #define PROJ_FACE_NOSEAM4   (1 << 7)
147
148 #define PROJ_SRC_VIEW       1
149 #define PROJ_SRC_IMAGE_CAM  2
150 #define PROJ_SRC_IMAGE_VIEW 3
151
152 #define PROJ_VIEW_DATA_ID "view_data"
153 #define PROJ_VIEW_DATA_SIZE (4 * 4 + 4 * 4 + 3) /* viewmat + winmat + clipsta + clipend + is_ortho */
154
155
156 /* a slightly scaled down face is used to get fake 3D location for edge pixels in the seams
157  * as this number approaches  1.0f the likelihood increases of float precision errors where
158  * it is occluded by an adjacent face */
159 #define PROJ_FACE_SCALE_SEAM    0.99f
160
161 #define PROJ_BUCKET_NULL        0
162 #define PROJ_BUCKET_INIT        (1 << 0)
163 // #define PROJ_BUCKET_CLONE_INIT       (1<<1)
164
165 /* used for testing doubles, if a point is on a line etc */
166 #define PROJ_GEOM_TOLERANCE 0.00075f
167
168 /* vert flags */
169 #define PROJ_VERT_CULL 1
170
171 /* This is mainly a convenience struct used so we can keep an array of images we use
172  * Thir imbufs, etc, in 1 array, When using threads this array is copied for each thread
173  * because 'partRedrawRect' and 'touch' values would not be thread safe */
174 typedef struct ProjPaintImage {
175         Image *ima;
176         ImBuf *ibuf;
177         ImagePaintPartialRedraw *partRedrawRect;
178         void **undoRect; /* only used to build undo tiles after painting */
179         int touch;
180 } ProjPaintImage;
181
182 /* Main projection painting struct passed to all projection painting functions */
183 typedef struct ProjPaintState {
184         View3D *v3d;
185         RegionView3D *rv3d;
186         ARegion *ar;
187         Scene *scene;
188         int source; /* PROJ_SRC_**** */
189
190         Brush *brush;
191         short tool, blend, mode;
192         int orig_brush_size;
193         Object *ob;
194         /* end similarities with ImagePaintState */
195
196         DerivedMesh    *dm;
197         int dm_totface;
198         int dm_totvert;
199         int dm_release;
200
201         MVert          *dm_mvert;
202         MFace          *dm_mface;
203         MTFace         *dm_mtface;
204         MTFace         *dm_mtface_clone;    /* other UV map, use for cloning between layers */
205         MTFace         *dm_mtface_stencil;
206
207         /* projection painting only */
208         MemArena *arena_mt[BLENDER_MAX_THREADS]; /* for multithreading, the first item is sometimes used for non threaded cases too */
209         LinkNode **bucketRect;              /* screen sized 2D array, each pixel has a linked list of ProjPixel's */
210         LinkNode **bucketFaces;             /* bucketRect aligned array linkList of faces overlapping each bucket */
211         unsigned char *bucketFlags;         /* store if the bucks have been initialized  */
212 #ifndef PROJ_DEBUG_NOSEAMBLEED
213         char *faceSeamFlags;                /* store info about faces, if they are initialized etc*/
214         float (*faceSeamUVs)[4][2];         /* expanded UVs for faces to use as seams */
215         LinkNode **vertFaces;               /* Only needed for when seam_bleed_px is enabled, use to find UV seams */
216 #endif
217         char *vertFlags;                    /* store options per vert, now only store if the vert is pointing away from the view */
218         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 */
219         int buckets_y;
220
221         ProjPaintImage *projImages;
222
223         int pixel_sizeof;           /* result of project_paint_pixel_sizeof(), constant per stroke */
224
225         int image_tot;              /* size of projectImages array */
226
227         float (*screenCoords)[4];   /* verts projected into floating point screen space */
228
229         float screenMin[2];         /* 2D bounds for mesh verts on the screen's plane (screenspace) */
230         float screenMax[2];
231         float screen_width;         /* Calculated from screenMin & screenMax */
232         float screen_height;
233         int winx, winy;             /* from the carea or from the projection render */
234
235         /* options for projection painting */
236         int do_layer_clone;
237         int do_layer_stencil;
238         int do_layer_stencil_inv;
239
240         short do_occlude;               /* Use raytraced occlusion? - ortherwise will paint right through to the back*/
241         short do_backfacecull;          /* ignore faces with normals pointing away, skips a lot of raycasts if your normals are correctly flipped */
242         short do_mask_normal;           /* mask out pixels based on their normals */
243         short do_new_shading_nodes;     /* cache BKE_scene_use_new_shading_nodes value */
244         float normal_angle;             /* what angle to mask at*/
245         float normal_angle_inner;
246         float normal_angle_range;       /* difference between normal_angle and normal_angle_inner, for easy access */
247
248         short is_ortho;
249         bool do_masking;              /* use masking during painting. Some operations such as airbrush may disable */
250         bool is_texbrush;              /* only to avoid running  */
251         bool is_maskbrush;
252 #ifndef PROJ_DEBUG_NOSEAMBLEED
253         float seam_bleed_px;
254 #endif
255         /* clone vars */
256         float cloneOffset[2];
257
258         float projectMat[4][4];     /* Projection matrix, use for getting screen coords */
259         float viewDir[3];           /* View vector, use for do_backfacecull and for ray casting with an ortho viewport  */
260         float viewPos[3];           /* View location in object relative 3D space, so can compare to verts  */
261         float clipsta, clipend;
262
263         /* reproject vars */
264         Image *reproject_image;
265         ImBuf *reproject_ibuf;
266
267         /* threads */
268         int thread_tot;
269         int bucketMin[2];
270         int bucketMax[2];
271         int context_bucket_x, context_bucket_y; /* must lock threads while accessing these */
272
273         /* redraw */
274         bool need_redraw;
275 } ProjPaintState;
276
277 typedef union pixelPointer {
278         float *f_pt;            /* float buffer */
279         unsigned int *uint_pt; /* 2 ways to access a char buffer */
280         unsigned char *ch_pt;
281 } PixelPointer;
282
283 typedef union pixelStore {
284         unsigned char ch[4];
285         unsigned int uint;
286         float f[4];
287 } PixelStore;
288
289 typedef struct ProjPixel {
290         float projCoSS[2]; /* the floating point screen projection of this pixel */
291         float worldCoSS[3];
292         /* Only used when the airbrush is disabled.
293          * Store the max mask value to avoid painting over an area with a lower opacity
294          * with an advantage that we can avoid touching the pixel at all, if the
295          * new mask value is lower then mask_accum */
296         unsigned short mask_accum;
297
298         /* for various reasons we may want to mask out painting onto this pixel */
299         unsigned short mask;
300
301         short x_px, y_px;
302
303         PixelStore origColor;
304         PixelStore newColor;
305         PixelPointer pixel;
306
307         short image_index; /* if anyone wants to paint onto more than 32768 images they can bite me */
308         unsigned char bb_cell_index;
309 } ProjPixel;
310
311 typedef struct ProjPixelClone {
312         struct ProjPixel __pp;
313         PixelStore clonepx;
314 } ProjPixelClone;
315
316 /* blur, store surrounding colors */
317 #define PROJ_PIXEL_SOFTEN_TOT 4
318 /* blur picking offset (in screenspace) */
319 #define PROJ_PIXEL_SOFTEN_OFS_PX 1.0f
320
321 static const float proj_pixel_soften_v2[PROJ_PIXEL_SOFTEN_TOT][2] = {
322         {-PROJ_PIXEL_SOFTEN_OFS_PX,                         0.0f},
323         { 0.0f,                        -PROJ_PIXEL_SOFTEN_OFS_PX},
324         { 0.0f,                         PROJ_PIXEL_SOFTEN_OFS_PX},
325         { PROJ_PIXEL_SOFTEN_OFS_PX,                         0.0f},
326 };
327
328 /* Finish projection painting structs */
329
330 static Image *project_paint_face_image(const ProjPaintState *ps, MTFace *dm_mtface, int face_index)
331 {
332         Image *ima;
333
334         if (ps->do_new_shading_nodes) { /* cached BKE_scene_use_new_shading_nodes result */
335                 MFace *mf = ps->dm_mface + face_index;
336                 ED_object_get_active_image(ps->ob, mf->mat_nr + 1, &ima, NULL, NULL);
337         }
338         else {
339                 ima = dm_mtface[face_index].tpage;
340         }
341
342         return ima;
343 }
344
345 /* fast projection bucket array lookup, use the safe version for bound checking  */
346 static int project_bucket_offset(const ProjPaintState *ps, const float projCoSS[2])
347 {
348         /* If we were not dealing with screenspace 2D coords we could simple do...
349          * ps->bucketRect[x + (y*ps->buckets_y)] */
350
351         /* please explain?
352          * projCoSS[0] - ps->screenMin[0]   : zero origin
353          * ... / ps->screen_width           : range from 0.0 to 1.0
354          * ... * ps->buckets_x              : use as a bucket index
355          *
356          * Second multiplication does similar but for vertical offset
357          */
358         return ( (int)(((projCoSS[0] - ps->screenMin[0]) / ps->screen_width)  * ps->buckets_x)) +
359                (((int)(((projCoSS[1] - ps->screenMin[1]) / ps->screen_height) * ps->buckets_y)) * ps->buckets_x);
360 }
361
362 static int project_bucket_offset_safe(const ProjPaintState *ps, const float projCoSS[2])
363 {
364         int bucket_index = project_bucket_offset(ps, projCoSS);
365
366         if (bucket_index < 0 || bucket_index >= ps->buckets_x * ps->buckets_y) {
367                 return -1;
368         }
369         else {
370                 return bucket_index;
371         }
372 }
373
374 /* still use 2D X,Y space but this works for verts transformed by a perspective matrix, using their 4th component as a weight */
375 static void barycentric_weights_v2_persp(const float v1[4], const float v2[4], const float v3[4], const float co[2], float w[3])
376 {
377         float wtot_inv, wtot;
378
379         w[0] = area_tri_signed_v2(v2, v3, co) / v1[3];
380         w[1] = area_tri_signed_v2(v3, v1, co) / v2[3];
381         w[2] = area_tri_signed_v2(v1, v2, co) / v3[3];
382         wtot = w[0] + w[1] + w[2];
383
384         if (wtot != 0.0f) {
385                 wtot_inv = 1.0f / wtot;
386
387                 w[0] = w[0] * wtot_inv;
388                 w[1] = w[1] * wtot_inv;
389                 w[2] = w[2] * wtot_inv;
390         }
391         else /* dummy values for zero area face */
392                 w[0] = w[1] = w[2] = 1.0f / 3.0f;
393 }
394
395 static float VecZDepthOrtho(const float pt[2],
396                             const float v1[3], const float v2[3], const float v3[3],
397                             float w[3])
398 {
399         barycentric_weights_v2(v1, v2, v3, pt, w);
400         return (v1[2] * w[0]) + (v2[2] * w[1]) + (v3[2] * w[2]);
401 }
402
403 static float VecZDepthPersp(const float pt[2],
404                             const float v1[4], const float v2[4], const float v3[4],
405                             float w[3])
406 {
407         float wtot_inv, wtot;
408         float w_tmp[3];
409
410         barycentric_weights_v2_persp(v1, v2, v3, pt, w);
411         /* for the depth we need the weights to match what
412          * barycentric_weights_v2 would return, in this case its easiest just to
413          * undo the 4th axis division and make it unit-sum
414          *
415          * don't call barycentric_weights_v2() because our callers expect 'w'
416          * to be weighted from the perspective */
417         w_tmp[0] = w[0] * v1[3];
418         w_tmp[1] = w[1] * v2[3];
419         w_tmp[2] = w[2] * v3[3];
420
421         wtot = w_tmp[0] + w_tmp[1] + w_tmp[2];
422
423         if (wtot != 0.0f) {
424                 wtot_inv = 1.0f / wtot;
425
426                 w_tmp[0] = w_tmp[0] * wtot_inv;
427                 w_tmp[1] = w_tmp[1] * wtot_inv;
428                 w_tmp[2] = w_tmp[2] * wtot_inv;
429         }
430         else /* dummy values for zero area face */
431                 w_tmp[0] = w_tmp[1] = w_tmp[2] = 1.0f / 3.0f;
432         /* done mimicing barycentric_weights_v2() */
433
434         return (v1[2] * w_tmp[0]) + (v2[2] * w_tmp[1]) + (v3[2] * w_tmp[2]);
435 }
436
437
438 /* Return the top-most face index that the screen space coord 'pt' touches (or -1) */
439 static int project_paint_PickFace(const ProjPaintState *ps, const float pt[2], float w[3], int *side)
440 {
441         LinkNode *node;
442         float w_tmp[3];
443         float *v1, *v2, *v3, *v4;
444         int bucket_index;
445         int face_index;
446         int best_side = -1;
447         int best_face_index = -1;
448         float z_depth_best = FLT_MAX, z_depth;
449         MFace *mf;
450
451         bucket_index = project_bucket_offset_safe(ps, pt);
452         if (bucket_index == -1)
453                 return -1;
454
455
456
457         /* we could return 0 for 1 face buckets, as long as this function assumes
458          * that the point its testing is only every originated from an existing face */
459
460         for (node = ps->bucketFaces[bucket_index]; node; node = node->next) {
461                 face_index = GET_INT_FROM_POINTER(node->link);
462                 mf = ps->dm_mface + face_index;
463
464                 v1 = ps->screenCoords[mf->v1];
465                 v2 = ps->screenCoords[mf->v2];
466                 v3 = ps->screenCoords[mf->v3];
467
468                 if (isect_point_tri_v2(pt, v1, v2, v3)) {
469                         if (ps->is_ortho) z_depth = VecZDepthOrtho(pt, v1, v2, v3, w_tmp);
470                         else z_depth = VecZDepthPersp(pt, v1, v2, v3, w_tmp);
471
472                         if (z_depth < z_depth_best) {
473                                 best_face_index = face_index;
474                                 best_side = 0;
475                                 z_depth_best = z_depth;
476                                 copy_v3_v3(w, w_tmp);
477                         }
478                 }
479                 else if (mf->v4) {
480                         v4 = ps->screenCoords[mf->v4];
481
482                         if (isect_point_tri_v2(pt, v1, v3, v4)) {
483                                 if (ps->is_ortho) z_depth = VecZDepthOrtho(pt, v1, v3, v4, w_tmp);
484                                 else z_depth = VecZDepthPersp(pt, v1, v3, v4, w_tmp);
485
486                                 if (z_depth < z_depth_best) {
487                                         best_face_index = face_index;
488                                         best_side = 1;
489                                         z_depth_best = z_depth;
490                                         copy_v3_v3(w, w_tmp);
491                                 }
492                         }
493                 }
494         }
495
496         *side = best_side;
497         return best_face_index; /* will be -1 or a valid face */
498 }
499
500 /* Converts a uv coord into a pixel location wrapping if the uv is outside 0-1 range */
501 static void uvco_to_wrapped_pxco(const float uv[2], int ibuf_x, int ibuf_y, float *x, float *y)
502 {
503         /* use */
504         *x = (float)fmodf(uv[0], 1.0f);
505         *y = (float)fmodf(uv[1], 1.0f);
506
507         if (*x < 0.0f) *x += 1.0f;
508         if (*y < 0.0f) *y += 1.0f;
509
510         *x = *x * ibuf_x - 0.5f;
511         *y = *y * ibuf_y - 0.5f;
512 }
513
514 /* Set the top-most face color that the screen space coord 'pt' touches (or return 0 if none touch) */
515 static int project_paint_PickColor(const ProjPaintState *ps, const float pt[2],
516                                    float *rgba_fp, unsigned char *rgba, const int interp)
517 {
518         float w[3], uv[2];
519         int side;
520         int face_index;
521         MTFace *tf;
522         Image *ima;
523         ImBuf *ibuf;
524         int xi, yi;
525
526
527         face_index = project_paint_PickFace(ps, pt, w, &side);
528
529         if (face_index == -1)
530                 return 0;
531
532         tf = ps->dm_mtface + face_index;
533
534         if (side == 0) {
535                 interp_v2_v2v2v2(uv, tf->uv[0], tf->uv[1], tf->uv[2], w);
536         }
537         else { /* QUAD */
538                 interp_v2_v2v2v2(uv, tf->uv[0], tf->uv[2], tf->uv[3], w);
539         }
540
541         ima = project_paint_face_image(ps, ps->dm_mtface, face_index);
542         ibuf = ima->ibufs.first; /* we must have got the imbuf before getting here */
543         if (!ibuf) return 0;
544
545         if (interp) {
546                 float x, y;
547                 uvco_to_wrapped_pxco(uv, ibuf->x, ibuf->y, &x, &y);
548
549                 if (ibuf->rect_float) {
550                         if (rgba_fp) {
551                                 bilinear_interpolation_color_wrap(ibuf, NULL, rgba_fp, x, y);
552                         }
553                         else {
554                                 float rgba_tmp_f[4];
555                                 bilinear_interpolation_color_wrap(ibuf, NULL, rgba_tmp_f, x, y);
556                                 premul_float_to_straight_uchar(rgba, rgba_tmp_f);
557                         }
558                 }
559                 else {
560                         if (rgba) {
561                                 bilinear_interpolation_color_wrap(ibuf, rgba, NULL, x, y);
562                         }
563                         else {
564                                 unsigned char rgba_tmp[4];
565                                 bilinear_interpolation_color_wrap(ibuf, rgba_tmp, NULL, x, y);
566                                 straight_uchar_to_premul_float(rgba_fp, rgba_tmp);
567                         }
568                 }
569         }
570         else {
571                 //xi = (int)((uv[0]*ibuf->x) + 0.5f);
572                 //yi = (int)((uv[1]*ibuf->y) + 0.5f);
573                 //if (xi < 0 || xi >= ibuf->x  ||  yi < 0 || yi >= ibuf->y) return 0;
574
575                 /* wrap */
576                 xi = ((int)(uv[0] * ibuf->x)) % ibuf->x;
577                 if (xi < 0) xi += ibuf->x;
578                 yi = ((int)(uv[1] * ibuf->y)) % ibuf->y;
579                 if (yi < 0) yi += ibuf->y;
580
581
582                 if (rgba) {
583                         if (ibuf->rect_float) {
584                                 float *rgba_tmp_fp = ibuf->rect_float + (xi + yi * ibuf->x * 4);
585                                 premul_float_to_straight_uchar(rgba, rgba_tmp_fp);
586                         }
587                         else {
588                                 *((unsigned int *)rgba) = *(unsigned int *)(((char *)ibuf->rect) + ((xi + yi * ibuf->x) * 4));
589                         }
590                 }
591
592                 if (rgba_fp) {
593                         if (ibuf->rect_float) {
594                                 copy_v4_v4(rgba_fp, (ibuf->rect_float + ((xi + yi * ibuf->x) * 4)));
595                         }
596                         else {
597                                 unsigned char *tmp_ch = ((unsigned char *)ibuf->rect) + ((xi + yi * ibuf->x) * 4);
598                                 straight_uchar_to_premul_float(rgba_fp, tmp_ch);
599                         }
600                 }
601         }
602         return 1;
603 }
604
605 /* Check if 'pt' is infront of the 3 verts on the Z axis (used for screenspace occlusuion test)
606  * return...
607  *  0   : no occlusion
608  * -1   : no occlusion but 2D intersection is true (avoid testing the other half of a quad)
609  *  1   : occluded
610  *  2   : occluded with w[3] weights set (need to know in some cases) */
611
612 static int project_paint_occlude_ptv(float pt[3], float v1[4], float v2[4], float v3[4], float w[3], int is_ortho)
613 {
614         /* if all are behind us, return false */
615         if (v1[2] > pt[2] && v2[2] > pt[2] && v3[2] > pt[2])
616                 return 0;
617
618         /* do a 2D point in try intersection */
619         if (!isect_point_tri_v2(pt, v1, v2, v3))
620                 return 0;  /* we know there is  */
621
622
623         /* From here on we know there IS an intersection */
624         /* if ALL of the verts are infront of us then we know it intersects ? */
625         if (v1[2] < pt[2] && v2[2] < pt[2] && v3[2] < pt[2]) {
626                 return 1;
627         }
628         else {
629                 /* we intersect? - find the exact depth at the point of intersection */
630                 /* Is this point is occluded by another face? */
631                 if (is_ortho) {
632                         if (VecZDepthOrtho(pt, v1, v2, v3, w) < pt[2]) return 2;
633                 }
634                 else {
635                         if (VecZDepthPersp(pt, v1, v2, v3, w) < pt[2]) return 2;
636                 }
637         }
638         return -1;
639 }
640
641
642 static int project_paint_occlude_ptv_clip(const ProjPaintState *ps, const MFace *mf,
643                                           float pt[3], float v1[4], float v2[4], float v3[4],
644                                           const int side)
645 {
646         float w[3], wco[3];
647         int ret = project_paint_occlude_ptv(pt, v1, v2, v3, w, ps->is_ortho);
648
649         if (ret <= 0)
650                 return ret;
651
652         if (ret == 1) { /* weights not calculated */
653                 if (ps->is_ortho) barycentric_weights_v2(v1, v2, v3, pt, w);
654                 else barycentric_weights_v2_persp(v1, v2, v3, pt, w);
655         }
656
657         /* Test if we're in the clipped area, */
658         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);
659         else interp_v3_v3v3v3(wco, ps->dm_mvert[mf->v1].co, ps->dm_mvert[mf->v2].co, ps->dm_mvert[mf->v3].co, w);
660
661         if (!ED_view3d_clipping_test(ps->rv3d, wco, TRUE)) {
662                 return 1;
663         }
664
665         return -1;
666 }
667
668
669 /* Check if a screenspace location is occluded by any other faces
670  * check, pixelScreenCo must be in screenspace, its Z-Depth only needs to be used for comparison
671  * and doesn't need to be correct in relation to X and Y coords (this is the case in perspective view) */
672 static int project_bucket_point_occluded(const ProjPaintState *ps, LinkNode *bucketFace, const int orig_face, float pixelScreenCo[4])
673 {
674         MFace *mf;
675         int face_index;
676         int isect_ret;
677         float w[3]; /* not needed when clipping */
678         const short do_clip = ps->rv3d ? ps->rv3d->rflag & RV3D_CLIPPING : 0;
679
680         /* we could return 0 for 1 face buckets, as long as this function assumes
681          * that the point its testing is only every originated from an existing face */
682
683         for (; bucketFace; bucketFace = bucketFace->next) {
684                 face_index = GET_INT_FROM_POINTER(bucketFace->link);
685
686                 if (orig_face != face_index) {
687                         mf = ps->dm_mface + face_index;
688                         if (do_clip)
689                                 isect_ret = project_paint_occlude_ptv_clip(ps, mf, pixelScreenCo, ps->screenCoords[mf->v1], ps->screenCoords[mf->v2], ps->screenCoords[mf->v3], 0);
690                         else
691                                 isect_ret = project_paint_occlude_ptv(pixelScreenCo, ps->screenCoords[mf->v1], ps->screenCoords[mf->v2], ps->screenCoords[mf->v3], w, ps->is_ortho);
692
693                         /* Note, if (isect_ret == -1) then we don't want to test the other side of the quad */
694                         if (isect_ret == 0 && mf->v4) {
695                                 if (do_clip)
696                                         isect_ret = project_paint_occlude_ptv_clip(ps, mf, pixelScreenCo, ps->screenCoords[mf->v1], ps->screenCoords[mf->v3], ps->screenCoords[mf->v4], 1);
697                                 else
698                                         isect_ret = project_paint_occlude_ptv(pixelScreenCo, ps->screenCoords[mf->v1], ps->screenCoords[mf->v3], ps->screenCoords[mf->v4], w, ps->is_ortho);
699                         }
700                         if (isect_ret >= 1) {
701                                 /* TODO - we may want to cache the first hit,
702                                  * it is not possible to swap the face order in the list anymore */
703                                 return 1;
704                         }
705                 }
706         }
707         return 0;
708 }
709
710 /* basic line intersection, could move to math_geom.c, 2 points with a horiz line
711  * 1 for an intersection, 2 if the first point is aligned, 3 if the second point is aligned */
712 #define ISECT_TRUE 1
713 #define ISECT_TRUE_P1 2
714 #define ISECT_TRUE_P2 3
715 static int line_isect_y(const float p1[2], const float p2[2], const float y_level, float *x_isect)
716 {
717         float y_diff;
718
719         if (y_level == p1[1]) { /* are we touching the first point? - no interpolation needed */
720                 *x_isect = p1[0];
721                 return ISECT_TRUE_P1;
722         }
723         if (y_level == p2[1]) { /* are we touching the second point? - no interpolation needed */
724                 *x_isect = p2[0];
725                 return ISECT_TRUE_P2;
726         }
727
728         y_diff = fabsf(p1[1] - p2[1]); /* yuck, horizontal line, we cant do much here */
729
730         if (y_diff < 0.000001f) {
731                 *x_isect = (p1[0] + p2[0]) * 0.5f;
732                 return ISECT_TRUE;
733         }
734
735         if (p1[1] > y_level && p2[1] < y_level) {
736                 *x_isect = (p2[0] * (p1[1] - y_level) + p1[0] * (y_level - p2[1])) / y_diff;  /*(p1[1]-p2[1]);*/
737                 return ISECT_TRUE;
738         }
739         else if (p1[1] < y_level && p2[1] > y_level) {
740                 *x_isect = (p2[0] * (y_level - p1[1]) + p1[0] * (p2[1] - y_level)) / y_diff;  /*(p2[1]-p1[1]);*/
741                 return ISECT_TRUE;
742         }
743         else {
744                 return 0;
745         }
746 }
747
748 static int line_isect_x(const float p1[2], const float p2[2], const float x_level, float *y_isect)
749 {
750         float x_diff;
751
752         if (x_level == p1[0]) { /* are we touching the first point? - no interpolation needed */
753                 *y_isect = p1[1];
754                 return ISECT_TRUE_P1;
755         }
756         if (x_level == p2[0]) { /* are we touching the second point? - no interpolation needed */
757                 *y_isect = p2[1];
758                 return ISECT_TRUE_P2;
759         }
760
761         x_diff = fabsf(p1[0] - p2[0]); /* yuck, horizontal line, we cant do much here */
762
763         if (x_diff < 0.000001f) { /* yuck, vertical line, we cant do much here */
764                 *y_isect = (p1[0] + p2[0]) * 0.5f;
765                 return ISECT_TRUE;
766         }
767
768         if (p1[0] > x_level && p2[0] < x_level) {
769                 *y_isect = (p2[1] * (p1[0] - x_level) + p1[1] * (x_level - p2[0])) / x_diff; /*(p1[0]-p2[0]);*/
770                 return ISECT_TRUE;
771         }
772         else if (p1[0] < x_level && p2[0] > x_level) {
773                 *y_isect = (p2[1] * (x_level - p1[0]) + p1[1] * (p2[0] - x_level)) / x_diff; /*(p2[0]-p1[0]);*/
774                 return ISECT_TRUE;
775         }
776         else {
777                 return 0;
778         }
779 }
780
781 /* simple func use for comparing UV locations to check if there are seams.
782  * Its possible this gives incorrect results, when the UVs for 1 face go into the next
783  * tile, but do not do this for the adjacent face, it could return a false positive.
784  * This is so unlikely that Id not worry about it. */
785 #ifndef PROJ_DEBUG_NOSEAMBLEED
786 static int cmp_uv(const float vec2a[2], const float vec2b[2])
787 {
788         /* if the UV's are not between 0.0 and 1.0 */
789         float xa = (float)fmodf(vec2a[0], 1.0f);
790         float ya = (float)fmodf(vec2a[1], 1.0f);
791
792         float xb = (float)fmodf(vec2b[0], 1.0f);
793         float yb = (float)fmodf(vec2b[1], 1.0f);
794
795         if (xa < 0.0f) xa += 1.0f;
796         if (ya < 0.0f) ya += 1.0f;
797
798         if (xb < 0.0f) xb += 1.0f;
799         if (yb < 0.0f) yb += 1.0f;
800
801         return ((fabsf(xa - xb) < PROJ_GEOM_TOLERANCE) && (fabsf(ya - yb) < PROJ_GEOM_TOLERANCE)) ? 1 : 0;
802 }
803 #endif
804
805 /* set min_px and max_px to the image space bounds of the UV coords
806  * return zero if there is no area in the returned rectangle */
807 #ifndef PROJ_DEBUG_NOSEAMBLEED
808 static int pixel_bounds_uv(
809         const float uv1[2], const float uv2[2], const float uv3[2], const float uv4[2],
810         rcti *bounds_px,
811         const int ibuf_x, const int ibuf_y,
812         int is_quad
813         )
814 {
815         float min_uv[2], max_uv[2]; /* UV bounds */
816
817         INIT_MINMAX2(min_uv, max_uv);
818
819         minmax_v2v2_v2(min_uv, max_uv, uv1);
820         minmax_v2v2_v2(min_uv, max_uv, uv2);
821         minmax_v2v2_v2(min_uv, max_uv, uv3);
822         if (is_quad)
823                 minmax_v2v2_v2(min_uv, max_uv, uv4);
824
825         bounds_px->xmin = (int)(ibuf_x * min_uv[0]);
826         bounds_px->ymin = (int)(ibuf_y * min_uv[1]);
827
828         bounds_px->xmax = (int)(ibuf_x * max_uv[0]) + 1;
829         bounds_px->ymax = (int)(ibuf_y * max_uv[1]) + 1;
830
831         /*printf("%d %d %d %d\n", min_px[0], min_px[1], max_px[0], max_px[1]);*/
832
833         /* face uses no UV area when quantized to pixels? */
834         return (bounds_px->xmin == bounds_px->xmax || bounds_px->ymin == bounds_px->ymax) ? 0 : 1;
835 }
836 #endif
837
838 static int pixel_bounds_array(float (*uv)[2], rcti *bounds_px, const int ibuf_x, const int ibuf_y, int tot)
839 {
840         float min_uv[2], max_uv[2]; /* UV bounds */
841
842         if (tot == 0) {
843                 return 0;
844         }
845
846         INIT_MINMAX2(min_uv, max_uv);
847
848         while (tot--) {
849                 minmax_v2v2_v2(min_uv, max_uv, (*uv));
850                 uv++;
851         }
852
853         bounds_px->xmin = (int)(ibuf_x * min_uv[0]);
854         bounds_px->ymin = (int)(ibuf_y * min_uv[1]);
855
856         bounds_px->xmax = (int)(ibuf_x * max_uv[0]) + 1;
857         bounds_px->ymax = (int)(ibuf_y * max_uv[1]) + 1;
858
859         /*printf("%d %d %d %d\n", min_px[0], min_px[1], max_px[0], max_px[1]);*/
860
861         /* face uses no UV area when quantized to pixels? */
862         return (bounds_px->xmin == bounds_px->xmax || bounds_px->ymin == bounds_px->ymax) ? 0 : 1;
863 }
864
865 #ifndef PROJ_DEBUG_NOSEAMBLEED
866
867 /* This function returns 1 if this face has a seam along the 2 face-vert indices
868  * 'orig_i1_fidx' and 'orig_i2_fidx' */
869 static int check_seam(const ProjPaintState *ps, const int orig_face, const int orig_i1_fidx, const int orig_i2_fidx, int *other_face, int *orig_fidx)
870 {
871         LinkNode *node;
872         int face_index;
873         unsigned int i1, i2;
874         int i1_fidx = -1, i2_fidx = -1; /* index in face */
875         MFace *mf;
876         MTFace *tf;
877         const MFace *orig_mf = ps->dm_mface + orig_face;
878         const MTFace *orig_tf = ps->dm_mtface + orig_face;
879
880         /* vert indices from face vert order indices */
881         i1 = (*(&orig_mf->v1 + orig_i1_fidx));
882         i2 = (*(&orig_mf->v1 + orig_i2_fidx));
883
884         for (node = ps->vertFaces[i1]; node; node = node->next) {
885                 face_index = GET_INT_FROM_POINTER(node->link);
886
887                 if (face_index != orig_face) {
888                         mf = ps->dm_mface + face_index;
889                         /* could check if the 2 faces images match here,
890                          * but then there wouldn't be a way to return the opposite face's info */
891
892
893                         /* We need to know the order of the verts in the adjacent face
894                          * set the i1_fidx and i2_fidx to (0,1,2,3) */
895                         if      (mf->v1 == i1) i1_fidx = 0;
896                         else if (mf->v2 == i1) i1_fidx = 1;
897                         else if (mf->v3 == i1) i1_fidx = 2;
898                         else if (mf->v4 && mf->v4 == i1) i1_fidx = 3;
899
900                         if      (mf->v1 == i2) i2_fidx = 0;
901                         else if (mf->v2 == i2) i2_fidx = 1;
902                         else if (mf->v3 == i2) i2_fidx = 2;
903                         else if (mf->v4 && mf->v4 == i2) i2_fidx = 3;
904
905                         /* Only need to check if 'i2_fidx' is valid because we know i1_fidx is the same vert on both faces */
906                         if (i2_fidx != -1) {
907                                 Image *tpage = project_paint_face_image(ps, ps->dm_mtface, face_index);
908                                 Image *orig_tpage = project_paint_face_image(ps, ps->dm_mtface, orig_face);
909
910                                 /* This IS an adjacent face!, now lets check if the UVs are ok */
911                                 tf = ps->dm_mtface + face_index;
912
913                                 /* set up the other face */
914                                 *other_face = face_index;
915                                 *orig_fidx = (i1_fidx < i2_fidx) ? i1_fidx : i2_fidx;
916
917                                 /* first test if they have the same image */
918                                 if ((orig_tpage == tpage) &&
919                                     cmp_uv(orig_tf->uv[orig_i1_fidx], tf->uv[i1_fidx]) &&
920                                     cmp_uv(orig_tf->uv[orig_i2_fidx], tf->uv[i2_fidx]) )
921                                 {
922                                         // printf("SEAM (NONE)\n");
923                                         return 0;
924
925                                 }
926                                 else {
927                                         // printf("SEAM (UV GAP)\n");
928                                         return 1;
929                                 }
930                         }
931                 }
932         }
933         // printf("SEAM (NO FACE)\n");
934         *other_face = -1;
935         return 1;
936 }
937
938 /* Calculate outset UV's, this is not the same as simply scaling the UVs,
939  * since the outset coords are a margin that keep an even distance from the original UV's,
940  * note that the image aspect is taken into account */
941 static void uv_image_outset(float (*orig_uv)[2], float (*outset_uv)[2], const float scaler,
942                             const int ibuf_x, const int ibuf_y, const int is_quad)
943 {
944         float a1, a2, a3, a4 = 0.0f;
945         float puv[4][2]; /* pixelspace uv's */
946         float no1[2], no2[2], no3[2], no4[2]; /* normals */
947         float dir1[2], dir2[2], dir3[2], dir4[2];
948         float ibuf_inv[2];
949
950         ibuf_inv[0] = 1.0f / (float)ibuf_x;
951         ibuf_inv[1] = 1.0f / (float)ibuf_y;
952
953         /* make UV's in pixel space so we can */
954         puv[0][0] = orig_uv[0][0] * ibuf_x;
955         puv[0][1] = orig_uv[0][1] * ibuf_y;
956
957         puv[1][0] = orig_uv[1][0] * ibuf_x;
958         puv[1][1] = orig_uv[1][1] * ibuf_y;
959
960         puv[2][0] = orig_uv[2][0] * ibuf_x;
961         puv[2][1] = orig_uv[2][1] * ibuf_y;
962
963         if (is_quad) {
964                 puv[3][0] = orig_uv[3][0] * ibuf_x;
965                 puv[3][1] = orig_uv[3][1] * ibuf_y;
966         }
967
968         /* face edge directions */
969         sub_v2_v2v2(dir1, puv[1], puv[0]);
970         sub_v2_v2v2(dir2, puv[2], puv[1]);
971         normalize_v2(dir1);
972         normalize_v2(dir2);
973
974         if (is_quad) {
975                 sub_v2_v2v2(dir3, puv[3], puv[2]);
976                 sub_v2_v2v2(dir4, puv[0], puv[3]);
977                 normalize_v2(dir3);
978                 normalize_v2(dir4);
979         }
980         else {
981                 sub_v2_v2v2(dir3, puv[0], puv[2]);
982                 normalize_v2(dir3);
983         }
984
985         /* TODO - angle_normalized_v2v2(...) * (M_PI/180.0f)
986          * This is incorrect. Its already given radians but without it wont work.
987          * need to look into a fix - campbell */
988         if (is_quad) {
989                 a1 = shell_angle_to_dist(angle_normalized_v2v2(dir4, dir1) * ((float)M_PI / 180.0f));
990                 a2 = shell_angle_to_dist(angle_normalized_v2v2(dir1, dir2) * ((float)M_PI / 180.0f));
991                 a3 = shell_angle_to_dist(angle_normalized_v2v2(dir2, dir3) * ((float)M_PI / 180.0f));
992                 a4 = shell_angle_to_dist(angle_normalized_v2v2(dir3, dir4) * ((float)M_PI / 180.0f));
993         }
994         else {
995                 a1 = shell_angle_to_dist(angle_normalized_v2v2(dir3, dir1) * ((float)M_PI / 180.0f));
996                 a2 = shell_angle_to_dist(angle_normalized_v2v2(dir1, dir2) * ((float)M_PI / 180.0f));
997                 a3 = shell_angle_to_dist(angle_normalized_v2v2(dir2, dir3) * ((float)M_PI / 180.0f));
998         }
999
1000         if (is_quad) {
1001                 sub_v2_v2v2(no1, dir4, dir1);
1002                 sub_v2_v2v2(no2, dir1, dir2);
1003                 sub_v2_v2v2(no3, dir2, dir3);
1004                 sub_v2_v2v2(no4, dir3, dir4);
1005                 normalize_v2(no1);
1006                 normalize_v2(no2);
1007                 normalize_v2(no3);
1008                 normalize_v2(no4);
1009                 mul_v2_fl(no1, a1 * scaler);
1010                 mul_v2_fl(no2, a2 * scaler);
1011                 mul_v2_fl(no3, a3 * scaler);
1012                 mul_v2_fl(no4, a4 * scaler);
1013                 add_v2_v2v2(outset_uv[0], puv[0], no1);
1014                 add_v2_v2v2(outset_uv[1], puv[1], no2);
1015                 add_v2_v2v2(outset_uv[2], puv[2], no3);
1016                 add_v2_v2v2(outset_uv[3], puv[3], no4);
1017                 mul_v2_v2(outset_uv[0], ibuf_inv);
1018                 mul_v2_v2(outset_uv[1], ibuf_inv);
1019                 mul_v2_v2(outset_uv[2], ibuf_inv);
1020                 mul_v2_v2(outset_uv[3], ibuf_inv);
1021         }
1022         else {
1023                 sub_v2_v2v2(no1, dir3, dir1);
1024                 sub_v2_v2v2(no2, dir1, dir2);
1025                 sub_v2_v2v2(no3, dir2, dir3);
1026                 normalize_v2(no1);
1027                 normalize_v2(no2);
1028                 normalize_v2(no3);
1029                 mul_v2_fl(no1, a1 * scaler);
1030                 mul_v2_fl(no2, a2 * scaler);
1031                 mul_v2_fl(no3, a3 * scaler);
1032                 add_v2_v2v2(outset_uv[0], puv[0], no1);
1033                 add_v2_v2v2(outset_uv[1], puv[1], no2);
1034                 add_v2_v2v2(outset_uv[2], puv[2], no3);
1035
1036                 mul_v2_v2(outset_uv[0], ibuf_inv);
1037                 mul_v2_v2(outset_uv[1], ibuf_inv);
1038                 mul_v2_v2(outset_uv[2], ibuf_inv);
1039         }
1040 }
1041
1042 /*
1043  * Be tricky with flags, first 4 bits are PROJ_FACE_SEAM1 to 4, last 4 bits are PROJ_FACE_NOSEAM1 to 4
1044  * 1<<i - where i is (0-3)
1045  *
1046  * If we're multithreadng, make sure threads are locked when this is called
1047  */
1048 static void project_face_seams_init(const ProjPaintState *ps, const int face_index, const int is_quad)
1049 {
1050         int other_face, other_fidx; /* vars for the other face, we also set its flag */
1051         int fidx1 = is_quad ? 3 : 2;
1052         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 */
1053
1054         do {
1055                 if ((ps->faceSeamFlags[face_index] & (1 << fidx1 | 16 << fidx1)) == 0) {
1056                         if (check_seam(ps, face_index, fidx1, fidx2, &other_face, &other_fidx)) {
1057                                 ps->faceSeamFlags[face_index] |= 1 << fidx1;
1058                                 if (other_face != -1)
1059                                         ps->faceSeamFlags[other_face] |= 1 << other_fidx;
1060                         }
1061                         else {
1062                                 ps->faceSeamFlags[face_index] |= 16 << fidx1;
1063                                 if (other_face != -1)
1064                                         ps->faceSeamFlags[other_face] |= 16 << other_fidx;  /* second 4 bits for disabled */
1065                         }
1066                 }
1067
1068                 fidx2 = fidx1;
1069         } while (fidx1--);
1070 }
1071 #endif // PROJ_DEBUG_NOSEAMBLEED
1072
1073
1074 /* Converts a UV location to a 3D screenspace location
1075  * Takes a 'uv' and 3 UV coords, and sets the values of pixelScreenCo
1076  *
1077  * This is used for finding a pixels location in screenspace for painting */
1078 static void screen_px_from_ortho(
1079         float uv[2],
1080         float v1co[3], float v2co[3], float v3co[3],  /* Screenspace coords */
1081         float uv1co[2], float uv2co[2], float uv3co[2],
1082         float pixelScreenCo[4],
1083         float w[3])
1084 {
1085         barycentric_weights_v2(uv1co, uv2co, uv3co, uv, w);
1086         interp_v3_v3v3v3(pixelScreenCo, v1co, v2co, v3co, w);
1087 }
1088
1089 /* same as screen_px_from_ortho except we need to take into account
1090  * the perspective W coord for each vert */
1091 static void screen_px_from_persp(
1092         float uv[2],
1093         float v1co[4], float v2co[4], float v3co[4],  /* screenspace coords */
1094         float uv1co[2], float uv2co[2], float uv3co[2],
1095         float pixelScreenCo[4],
1096         float w[3])
1097 {
1098
1099         float wtot_inv, wtot;
1100         barycentric_weights_v2(uv1co, uv2co, uv3co, uv, w);
1101
1102         /* re-weight from the 4th coord of each screen vert */
1103         w[0] *= v1co[3];
1104         w[1] *= v2co[3];
1105         w[2] *= v3co[3];
1106
1107         wtot = w[0] + w[1] + w[2];
1108
1109         if (wtot > 0.0f) {
1110                 wtot_inv = 1.0f / wtot;
1111                 w[0] *= wtot_inv;
1112                 w[1] *= wtot_inv;
1113                 w[2] *= wtot_inv;
1114         }
1115         else {
1116                 w[0] = w[1] = w[2] = 1.0f / 3.0f;  /* dummy values for zero area face */
1117         }
1118         /* done re-weighting */
1119
1120         interp_v3_v3v3v3(pixelScreenCo, v1co, v2co, v3co, w);
1121 }
1122
1123 static void project_face_pixel(const MTFace *tf_other, ImBuf *ibuf_other, const float w[3],
1124                                int side, unsigned char rgba_ub[4], float rgba_f[4])
1125 {
1126         float *uvCo1, *uvCo2, *uvCo3;
1127         float uv_other[2], x, y;
1128
1129         uvCo1 =  (float *)tf_other->uv[0];
1130         if (side == 1) {
1131                 uvCo2 =  (float *)tf_other->uv[2];
1132                 uvCo3 =  (float *)tf_other->uv[3];
1133         }
1134         else {
1135                 uvCo2 =  (float *)tf_other->uv[1];
1136                 uvCo3 =  (float *)tf_other->uv[2];
1137         }
1138
1139         interp_v2_v2v2v2(uv_other, uvCo1, uvCo2, uvCo3, (float *)w);
1140
1141         /* use */
1142         uvco_to_wrapped_pxco(uv_other, ibuf_other->x, ibuf_other->y, &x, &y);
1143
1144
1145         if (ibuf_other->rect_float) { /* from float to float */
1146                 bilinear_interpolation_color_wrap(ibuf_other, NULL, rgba_f, x, y);
1147         }
1148         else { /* from char to float */
1149                 bilinear_interpolation_color_wrap(ibuf_other, rgba_ub, NULL, x, y);
1150         }
1151
1152 }
1153
1154 /* run this outside project_paint_uvpixel_init since pixels with mask 0 don't need init */
1155 static float project_paint_uvpixel_mask(
1156         const ProjPaintState *ps,
1157         const int face_index,
1158         const int side,
1159         const float w[3])
1160 {
1161         float mask;
1162
1163         /* Image Mask */
1164         if (ps->do_layer_stencil) {
1165                 /* another UV maps image is masking this one's */
1166                 ImBuf *ibuf_other;
1167                 Image *other_tpage = project_paint_face_image(ps, ps->dm_mtface_stencil, face_index);
1168                 const MTFace *tf_other = ps->dm_mtface_stencil + face_index;
1169
1170                 if (other_tpage && (ibuf_other = BKE_image_acquire_ibuf(other_tpage, NULL, NULL))) {
1171                         /* BKE_image_acquire_ibuf - TODO - this may be slow */
1172                         unsigned char rgba_ub[4];
1173                         float rgba_f[4];
1174
1175                         project_face_pixel(tf_other, ibuf_other, w, side, rgba_ub, rgba_f);
1176
1177                         if (ibuf_other->rect_float) { /* from float to float */
1178                                 mask = ((rgba_f[0] + rgba_f[1] + rgba_f[2]) * (1.0f / 3.0f)) * rgba_f[3];
1179                         }
1180                         else { /* from char to float */
1181                                 mask = ((rgba_ub[0] + rgba_ub[1] + rgba_ub[2]) * (1.0f / (255.0f * 3.0f))) * (rgba_ub[3] * (1.0f / 255.0f));
1182                         }
1183
1184                         BKE_image_release_ibuf(other_tpage, ibuf_other, NULL);
1185
1186                         if (!ps->do_layer_stencil_inv) /* matching the gimps layer mask black/white rules, white==full opacity */
1187                                 mask = (1.0f - mask);
1188
1189                         if (mask == 0.0f) {
1190                                 return 0.0f;
1191                         }
1192                 }
1193                 else {
1194                         return 0.0f;
1195                 }
1196         }
1197         else {
1198                 mask = 1.0f;
1199         }
1200
1201         /* calculate mask */
1202         if (ps->do_mask_normal) {
1203                 MFace *mf = &ps->dm_mface[face_index];
1204                 float no[3], angle;
1205                 if (mf->flag & ME_SMOOTH) {
1206                         short *no1, *no2, *no3;
1207                         no1 = ps->dm_mvert[mf->v1].no;
1208                         if (side == 1) {
1209                                 no2 = ps->dm_mvert[mf->v3].no;
1210                                 no3 = ps->dm_mvert[mf->v4].no;
1211                         }
1212                         else {
1213                                 no2 = ps->dm_mvert[mf->v2].no;
1214                                 no3 = ps->dm_mvert[mf->v3].no;
1215                         }
1216
1217                         no[0] = w[0] * no1[0] + w[1] * no2[0] + w[2] * no3[0];
1218                         no[1] = w[0] * no1[1] + w[1] * no2[1] + w[2] * no3[1];
1219                         no[2] = w[0] * no1[2] + w[1] * no2[2] + w[2] * no3[2];
1220                         normalize_v3(no);
1221                 }
1222                 else {
1223                         /* incase the */
1224 #if 1
1225                         /* normalizing per pixel isn't optimal, we could cache or check ps->*/
1226                         if (mf->v4)
1227                                 normal_quad_v3(no,
1228                                                ps->dm_mvert[mf->v1].co,
1229                                                ps->dm_mvert[mf->v2].co,
1230                                                ps->dm_mvert[mf->v3].co,
1231                                                ps->dm_mvert[mf->v4].co);
1232                         else
1233                                 normal_tri_v3(no,
1234                                               ps->dm_mvert[mf->v1].co,
1235                                               ps->dm_mvert[mf->v2].co,
1236                                               ps->dm_mvert[mf->v3].co);
1237 #else
1238                         /* don't use because some modifiers dont have normal data (subsurf for eg) */
1239                         copy_v3_v3(no, (float *)ps->dm->getTessFaceData(ps->dm, face_index, CD_NORMAL));
1240 #endif
1241                 }
1242
1243                 /* now we can use the normal as a mask */
1244                 if (ps->is_ortho) {
1245                         angle = angle_normalized_v3v3((float *)ps->viewDir, no);
1246                 }
1247                 else {
1248                         /* Annoying but for the perspective view we need to get the pixels location in 3D space :/ */
1249                         float viewDirPersp[3];
1250                         float *co1, *co2, *co3;
1251                         co1 = ps->dm_mvert[mf->v1].co;
1252                         if (side == 1) {
1253                                 co2 = ps->dm_mvert[mf->v3].co;
1254                                 co3 = ps->dm_mvert[mf->v4].co;
1255                         }
1256                         else {
1257                                 co2 = ps->dm_mvert[mf->v2].co;
1258                                 co3 = ps->dm_mvert[mf->v3].co;
1259                         }
1260
1261                         /* Get the direction from the viewPoint to the pixel and normalize */
1262                         viewDirPersp[0] = (ps->viewPos[0] - (w[0] * co1[0] + w[1] * co2[0] + w[2] * co3[0]));
1263                         viewDirPersp[1] = (ps->viewPos[1] - (w[0] * co1[1] + w[1] * co2[1] + w[2] * co3[1]));
1264                         viewDirPersp[2] = (ps->viewPos[2] - (w[0] * co1[2] + w[1] * co2[2] + w[2] * co3[2]));
1265                         normalize_v3(viewDirPersp);
1266
1267                         angle = angle_normalized_v3v3(viewDirPersp, no);
1268                 }
1269
1270                 if (angle >= ps->normal_angle) {
1271                         return 0.0f; /* outsize the normal limit*/
1272                 }
1273                 else if (angle > ps->normal_angle_inner) {
1274                         mask *= (ps->normal_angle - angle) / ps->normal_angle_range;
1275                 } /* otherwise no mask normal is needed, were within the limit */
1276         }
1277
1278         /* This only works when the opacity dosnt change while painting, stylus pressure messes with this
1279          * so don't use it. */
1280         // if (ps->is_airbrush == 0) mask *= BKE_brush_alpha_get(ps->brush);
1281
1282         return mask;
1283 }
1284
1285 static int project_paint_pixel_sizeof(const short tool)
1286 {
1287         if ((tool == PAINT_TOOL_CLONE) || (tool == PAINT_TOOL_SMEAR)) {
1288                 return sizeof(ProjPixelClone);
1289         }
1290         else {
1291                 return sizeof(ProjPixel);
1292         }
1293 }
1294
1295
1296 /* run this function when we know a bucket's, face's pixel can be initialized,
1297  * return the ProjPixel which is added to 'ps->bucketRect[bucket_index]' */
1298 static ProjPixel *project_paint_uvpixel_init(
1299         const ProjPaintState *ps,
1300         MemArena *arena,
1301         const ImBuf *ibuf,
1302         short x_px, short y_px,
1303         const float mask,
1304         const int face_index,
1305         const int image_index,
1306         const float pixelScreenCo[4],
1307         const float world_spaceCo[3],
1308         const int side,
1309         const float w[3])
1310 {
1311         ProjPixel *projPixel;
1312
1313         /* wrap pixel location */
1314         x_px = x_px % ibuf->x;
1315         if (x_px < 0) x_px += ibuf->x;
1316         y_px = y_px % ibuf->y;
1317         if (y_px < 0) y_px += ibuf->y;
1318
1319         BLI_assert(ps->pixel_sizeof == project_paint_pixel_sizeof(ps->tool));
1320         projPixel = (ProjPixel *)BLI_memarena_alloc(arena, ps->pixel_sizeof);
1321         //memset(projPixel, 0, size);
1322
1323         if (ibuf->rect_float) {
1324                 projPixel->pixel.f_pt = ibuf->rect_float + ((x_px + y_px * ibuf->x) * 4);
1325                 projPixel->origColor.f[0] = projPixel->pixel.f_pt[0];
1326                 projPixel->origColor.f[1] = projPixel->pixel.f_pt[1];
1327                 projPixel->origColor.f[2] = projPixel->pixel.f_pt[2];
1328                 projPixel->origColor.f[3] = projPixel->pixel.f_pt[3];
1329                 zero_v4(projPixel->newColor.f);
1330         }
1331         else {
1332                 projPixel->pixel.ch_pt = ((unsigned char *)ibuf->rect + ((x_px + y_px * ibuf->x) * 4));
1333                 projPixel->origColor.uint = *projPixel->pixel.uint_pt;
1334                 projPixel->newColor.uint = 0;
1335         }
1336
1337         /* screenspace unclamped, we could keep its z and w values but don't need them at the moment */
1338         if (ps->brush->mtex.brush_map_mode == MTEX_MAP_MODE_3D) {
1339                 copy_v3_v3(projPixel->worldCoSS, world_spaceCo);
1340         }
1341
1342         copy_v2_v2(projPixel->projCoSS, pixelScreenCo);
1343
1344         projPixel->x_px = x_px;
1345         projPixel->y_px = y_px;
1346
1347         projPixel->mask = (unsigned short)(mask * 65535);
1348         projPixel->mask_accum = 0;
1349
1350         /* which bounding box cell are we in?, needed for undo */
1351         projPixel->bb_cell_index = ((int)(((float)x_px / (float)ibuf->x) * PROJ_BOUNDBOX_DIV)) +
1352                                    ((int)(((float)y_px / (float)ibuf->y) * PROJ_BOUNDBOX_DIV)) * PROJ_BOUNDBOX_DIV;
1353
1354         /* done with view3d_project_float inline */
1355         if (ps->tool == PAINT_TOOL_CLONE) {
1356                 if (ps->dm_mtface_clone) {
1357                         ImBuf *ibuf_other;
1358                         Image *other_tpage = project_paint_face_image(ps, ps->dm_mtface_clone, face_index);
1359                         const MTFace *tf_other = ps->dm_mtface_clone + face_index;
1360
1361                         if (other_tpage && (ibuf_other = BKE_image_acquire_ibuf(other_tpage, NULL, NULL))) {
1362                                 /* BKE_image_acquire_ibuf - TODO - this may be slow */
1363
1364                                 if (ibuf->rect_float) {
1365                                         if (ibuf_other->rect_float) { /* from float to float */
1366                                                 project_face_pixel(tf_other, ibuf_other, w, side, NULL, ((ProjPixelClone *)projPixel)->clonepx.f);
1367                                         }
1368                                         else { /* from char to float */
1369                                                 unsigned char rgba_ub[4];
1370                                                 float rgba[4];
1371                                                 project_face_pixel(tf_other, ibuf_other, w, side, rgba_ub, NULL);
1372                                                 srgb_to_linearrgb_uchar4(rgba, rgba_ub);
1373                                                 straight_to_premul_v4_v4(((ProjPixelClone *)projPixel)->clonepx.f, rgba);
1374                                         }
1375                                 }
1376                                 else {
1377                                         if (ibuf_other->rect_float) { /* float to char */
1378                                                 float rgba[4];
1379                                                 project_face_pixel(tf_other, ibuf_other, w, side, NULL, rgba);
1380                                                 premul_to_straight_v4(rgba);
1381                                                 linearrgb_to_srgb_uchar3(((ProjPixelClone *)projPixel)->clonepx.ch, rgba);
1382                                         }
1383                                         else { /* char to char */
1384                                                 project_face_pixel(tf_other, ibuf_other, w, side, ((ProjPixelClone *)projPixel)->clonepx.ch, NULL);
1385                                         }
1386                                 }
1387
1388                                 BKE_image_release_ibuf(other_tpage, ibuf_other, NULL);
1389                         }
1390                         else {
1391                                 if (ibuf->rect_float) {
1392                                         ((ProjPixelClone *)projPixel)->clonepx.f[3] = 0;
1393                                 }
1394                                 else {
1395                                         ((ProjPixelClone *)projPixel)->clonepx.ch[3] = 0;
1396                                 }
1397                         }
1398
1399                 }
1400                 else {
1401                         float co[2];
1402                         sub_v2_v2v2(co, projPixel->projCoSS, (float *)ps->cloneOffset);
1403
1404                         /* no need to initialize the bucket, we're only checking buckets faces and for this
1405                          * the faces are already initialized in project_paint_delayed_face_init(...) */
1406                         if (ibuf->rect_float) {
1407                                 if (!project_paint_PickColor(ps, co, ((ProjPixelClone *)projPixel)->clonepx.f, NULL, 1)) {
1408                                         ((ProjPixelClone *)projPixel)->clonepx.f[3] = 0; /* zero alpha - ignore */
1409                                 }
1410                         }
1411                         else {
1412                                 if (!project_paint_PickColor(ps, co, NULL, ((ProjPixelClone *)projPixel)->clonepx.ch, 1)) {
1413                                         ((ProjPixelClone *)projPixel)->clonepx.ch[3] = 0; /* zero alpha - ignore */
1414                                 }
1415                         }
1416                 }
1417         }
1418
1419 #ifdef PROJ_DEBUG_PAINT
1420         if (ibuf->rect_float) projPixel->pixel.f_pt[0] = 0;
1421         else                  projPixel->pixel.ch_pt[0] = 0;
1422 #endif
1423         projPixel->image_index = image_index;
1424
1425         return projPixel;
1426 }
1427
1428 static int line_clip_rect2f(
1429         rctf *rect,
1430         const float l1[2], const float l2[2],
1431         float l1_clip[2], float l2_clip[2])
1432 {
1433         /* first account for horizontal, then vertical lines */
1434         /* horiz */
1435         if (fabsf(l1[1] - l2[1]) < PROJ_GEOM_TOLERANCE) {
1436                 /* is the line out of range on its Y axis? */
1437                 if (l1[1] < rect->ymin || l1[1] > rect->ymax) {
1438                         return 0;
1439                 }
1440                 /* line is out of range on its X axis */
1441                 if ((l1[0] < rect->xmin && l2[0] < rect->xmin) || (l1[0] > rect->xmax && l2[0] > rect->xmax)) {
1442                         return 0;
1443                 }
1444
1445
1446                 if (fabsf(l1[0] - l2[0]) < PROJ_GEOM_TOLERANCE) { /* this is a single point  (or close to)*/
1447                         if (BLI_rctf_isect_pt_v(rect, l1)) {
1448                                 copy_v2_v2(l1_clip, l1);
1449                                 copy_v2_v2(l2_clip, l2);
1450                                 return 1;
1451                         }
1452                         else {
1453                                 return 0;
1454                         }
1455                 }
1456
1457                 copy_v2_v2(l1_clip, l1);
1458                 copy_v2_v2(l2_clip, l2);
1459                 CLAMP(l1_clip[0], rect->xmin, rect->xmax);
1460                 CLAMP(l2_clip[0], rect->xmin, rect->xmax);
1461                 return 1;
1462         }
1463         else if (fabsf(l1[0] - l2[0]) < PROJ_GEOM_TOLERANCE) {
1464                 /* is the line out of range on its X axis? */
1465                 if (l1[0] < rect->xmin || l1[0] > rect->xmax) {
1466                         return 0;
1467                 }
1468
1469                 /* line is out of range on its Y axis */
1470                 if ((l1[1] < rect->ymin && l2[1] < rect->ymin) || (l1[1] > rect->ymax && l2[1] > rect->ymax)) {
1471                         return 0;
1472                 }
1473
1474                 if (fabsf(l1[1] - l2[1]) < PROJ_GEOM_TOLERANCE) { /* this is a single point  (or close to)*/
1475                         if (BLI_rctf_isect_pt_v(rect, l1)) {
1476                                 copy_v2_v2(l1_clip, l1);
1477                                 copy_v2_v2(l2_clip, l2);
1478                                 return 1;
1479                         }
1480                         else {
1481                                 return 0;
1482                         }
1483                 }
1484
1485                 copy_v2_v2(l1_clip, l1);
1486                 copy_v2_v2(l2_clip, l2);
1487                 CLAMP(l1_clip[1], rect->ymin, rect->ymax);
1488                 CLAMP(l2_clip[1], rect->ymin, rect->ymax);
1489                 return 1;
1490         }
1491         else {
1492                 float isect;
1493                 short ok1 = 0;
1494                 short ok2 = 0;
1495
1496                 /* Done with vertical lines */
1497
1498                 /* are either of the points inside the rectangle ? */
1499                 if (BLI_rctf_isect_pt_v(rect, l1)) {
1500                         copy_v2_v2(l1_clip, l1);
1501                         ok1 = 1;
1502                 }
1503
1504                 if (BLI_rctf_isect_pt_v(rect, l2)) {
1505                         copy_v2_v2(l2_clip, l2);
1506                         ok2 = 1;
1507                 }
1508
1509                 /* line inside rect */
1510                 if (ok1 && ok2) return 1;
1511
1512                 /* top/bottom */
1513                 if (line_isect_y(l1, l2, rect->ymin, &isect) && (isect >= rect->xmin) && (isect <= rect->xmax)) {
1514                         if (l1[1] < l2[1]) { /* line 1 is outside */
1515                                 l1_clip[0] = isect;
1516                                 l1_clip[1] = rect->ymin;
1517                                 ok1 = 1;
1518                         }
1519                         else {
1520                                 l2_clip[0] = isect;
1521                                 l2_clip[1] = rect->ymin;
1522                                 ok2 = 2;
1523                         }
1524                 }
1525
1526                 if (ok1 && ok2) return 1;
1527
1528                 if (line_isect_y(l1, l2, rect->ymax, &isect) && (isect >= rect->xmin) && (isect <= rect->xmax)) {
1529                         if (l1[1] > l2[1]) { /* line 1 is outside */
1530                                 l1_clip[0] = isect;
1531                                 l1_clip[1] = rect->ymax;
1532                                 ok1 = 1;
1533                         }
1534                         else {
1535                                 l2_clip[0] = isect;
1536                                 l2_clip[1] = rect->ymax;
1537                                 ok2 = 2;
1538                         }
1539                 }
1540
1541                 if (ok1 && ok2) return 1;
1542
1543                 /* left/right */
1544                 if (line_isect_x(l1, l2, rect->xmin, &isect) && (isect >= rect->ymin) && (isect <= rect->ymax)) {
1545                         if (l1[0] < l2[0]) { /* line 1 is outside */
1546                                 l1_clip[0] = rect->xmin;
1547                                 l1_clip[1] = isect;
1548                                 ok1 = 1;
1549                         }
1550                         else {
1551                                 l2_clip[0] = rect->xmin;
1552                                 l2_clip[1] = isect;
1553                                 ok2 = 2;
1554                         }
1555                 }
1556
1557                 if (ok1 && ok2) return 1;
1558
1559                 if (line_isect_x(l1, l2, rect->xmax, &isect) && (isect >= rect->ymin) && (isect <= rect->ymax)) {
1560                         if (l1[0] > l2[0]) { /* line 1 is outside */
1561                                 l1_clip[0] = rect->xmax;
1562                                 l1_clip[1] = isect;
1563                                 ok1 = 1;
1564                         }
1565                         else {
1566                                 l2_clip[0] = rect->xmax;
1567                                 l2_clip[1] = isect;
1568                                 ok2 = 2;
1569                         }
1570                 }
1571
1572                 if (ok1 && ok2) {
1573                         return 1;
1574                 }
1575                 else {
1576                         return 0;
1577                 }
1578         }
1579 }
1580
1581
1582
1583 /* scale the quad & tri about its center
1584  * scaling by PROJ_FACE_SCALE_SEAM (0.99x) is used for getting fake UV pixel coords that are on the
1585  * edge of the face but slightly inside it occlusion tests don't return hits on adjacent faces */
1586 #ifndef PROJ_DEBUG_NOSEAMBLEED
1587 static void scale_quad(float insetCos[4][3], float *origCos[4], const float inset)
1588 {
1589         float cent[3];
1590         cent[0] = (origCos[0][0] + origCos[1][0] + origCos[2][0] + origCos[3][0]) * (1.0f / 4.0f);
1591         cent[1] = (origCos[0][1] + origCos[1][1] + origCos[2][1] + origCos[3][1]) * (1.0f / 4.0f);
1592         cent[2] = (origCos[0][2] + origCos[1][2] + origCos[2][2] + origCos[3][2]) * (1.0f / 4.0f);
1593
1594         sub_v3_v3v3(insetCos[0], origCos[0], cent);
1595         sub_v3_v3v3(insetCos[1], origCos[1], cent);
1596         sub_v3_v3v3(insetCos[2], origCos[2], cent);
1597         sub_v3_v3v3(insetCos[3], origCos[3], cent);
1598
1599         mul_v3_fl(insetCos[0], inset);
1600         mul_v3_fl(insetCos[1], inset);
1601         mul_v3_fl(insetCos[2], inset);
1602         mul_v3_fl(insetCos[3], inset);
1603
1604         add_v3_v3(insetCos[0], cent);
1605         add_v3_v3(insetCos[1], cent);
1606         add_v3_v3(insetCos[2], cent);
1607         add_v3_v3(insetCos[3], cent);
1608 }
1609
1610
1611 static void scale_tri(float insetCos[4][3], float *origCos[4], const float inset)
1612 {
1613         float cent[3];
1614         cent[0] = (origCos[0][0] + origCos[1][0] + origCos[2][0]) * (1.0f / 3.0f);
1615         cent[1] = (origCos[0][1] + origCos[1][1] + origCos[2][1]) * (1.0f / 3.0f);
1616         cent[2] = (origCos[0][2] + origCos[1][2] + origCos[2][2]) * (1.0f / 3.0f);
1617
1618         sub_v3_v3v3(insetCos[0], origCos[0], cent);
1619         sub_v3_v3v3(insetCos[1], origCos[1], cent);
1620         sub_v3_v3v3(insetCos[2], origCos[2], cent);
1621
1622         mul_v3_fl(insetCos[0], inset);
1623         mul_v3_fl(insetCos[1], inset);
1624         mul_v3_fl(insetCos[2], inset);
1625
1626         add_v3_v3(insetCos[0], cent);
1627         add_v3_v3(insetCos[1], cent);
1628         add_v3_v3(insetCos[2], cent);
1629 }
1630 #endif //PROJ_DEBUG_NOSEAMBLEED
1631
1632 static float len_squared_v2v2_alt(const float *v1, const float v2_1, const float v2_2)
1633 {
1634         float x, y;
1635
1636         x = v1[0] - v2_1;
1637         y = v1[1] - v2_2;
1638         return x * x + y * y;
1639 }
1640
1641 /* note, use a squared value so we can use len_squared_v2v2
1642  * be sure that you have done a bounds check first or this may fail */
1643 /* only give bucket_bounds as an arg because we need it elsewhere */
1644 static int project_bucket_isect_circle(const float cent[2], const float radius_squared, rctf *bucket_bounds)
1645 {
1646
1647         /* Would normally to a simple intersection test, however we know the bounds of these 2 already intersect
1648          * so we only need to test if the center is inside the vertical or horizontal bounds on either axis,
1649          * this is even less work then an intersection test
1650          */
1651 #if 0
1652         if (BLI_rctf_isect_pt_v(bucket_bounds, cent))
1653                 return 1;
1654 #endif
1655
1656         if ((bucket_bounds->xmin <= cent[0] && bucket_bounds->xmax >= cent[0]) ||
1657             (bucket_bounds->ymin <= cent[1] && bucket_bounds->ymax >= cent[1]))
1658         {
1659                 return 1;
1660         }
1661
1662         /* out of bounds left */
1663         if (cent[0] < bucket_bounds->xmin) {
1664                 /* lower left out of radius test */
1665                 if (cent[1] < bucket_bounds->ymin) {
1666                         return (len_squared_v2v2_alt(cent, bucket_bounds->xmin, bucket_bounds->ymin) < radius_squared) ? 1 : 0;
1667                 }
1668                 /* top left test */
1669                 else if (cent[1] > bucket_bounds->ymax) {
1670                         return (len_squared_v2v2_alt(cent, bucket_bounds->xmin, bucket_bounds->ymax) < radius_squared) ? 1 : 0;
1671                 }
1672         }
1673         else if (cent[0] > bucket_bounds->xmax) {
1674                 /* lower right out of radius test */
1675                 if (cent[1] < bucket_bounds->ymin) {
1676                         return (len_squared_v2v2_alt(cent, bucket_bounds->xmax, bucket_bounds->ymin) < radius_squared) ? 1 : 0;
1677                 }
1678                 /* top right test */
1679                 else if (cent[1] > bucket_bounds->ymax) {
1680                         return (len_squared_v2v2_alt(cent, bucket_bounds->xmax, bucket_bounds->ymax) < radius_squared) ? 1 : 0;
1681                 }
1682         }
1683
1684         return 0;
1685 }
1686
1687
1688
1689 /* Note for rect_to_uvspace_ortho() and rect_to_uvspace_persp()
1690  * in ortho view this function gives good results when bucket_bounds are outside the triangle
1691  * however in some cases, perspective view will mess up with faces that have minimal screenspace area
1692  * (viewed from the side)
1693  *
1694  * for this reason its not reliable in this case so we'll use the Simple Barycentric'
1695  * funcs that only account for points inside the triangle.
1696  * however switching back to this for ortho is always an option */
1697
1698 static void rect_to_uvspace_ortho(
1699         rctf *bucket_bounds,
1700         float *v1coSS, float *v2coSS, float *v3coSS,
1701         float *uv1co, float *uv2co, float *uv3co,
1702         float bucket_bounds_uv[4][2],
1703         const int flip)
1704 {
1705         float uv[2];
1706         float w[3];
1707
1708         /* get the UV space bounding box */
1709         uv[0] = bucket_bounds->xmax;
1710         uv[1] = bucket_bounds->ymin;
1711         barycentric_weights_v2(v1coSS, v2coSS, v3coSS, uv, w);
1712         interp_v2_v2v2v2(bucket_bounds_uv[flip ? 3 : 0], uv1co, uv2co, uv3co, w);
1713
1714         //uv[0] = bucket_bounds->xmax; // set above
1715         uv[1] = bucket_bounds->ymax;
1716         barycentric_weights_v2(v1coSS, v2coSS, v3coSS, uv, w);
1717         interp_v2_v2v2v2(bucket_bounds_uv[flip ? 2 : 1], uv1co, uv2co, uv3co, w);
1718
1719         uv[0] = bucket_bounds->xmin;
1720         //uv[1] = bucket_bounds->ymax; // set above
1721         barycentric_weights_v2(v1coSS, v2coSS, v3coSS, uv, w);
1722         interp_v2_v2v2v2(bucket_bounds_uv[flip ? 1 : 2], uv1co, uv2co, uv3co, w);
1723
1724         //uv[0] = bucket_bounds->xmin; // set above
1725         uv[1] = bucket_bounds->ymin;
1726         barycentric_weights_v2(v1coSS, v2coSS, v3coSS, uv, w);
1727         interp_v2_v2v2v2(bucket_bounds_uv[flip ? 0 : 3], uv1co, uv2co, uv3co, w);
1728 }
1729
1730 /* same as above but use barycentric_weights_v2_persp */
1731 static void rect_to_uvspace_persp(
1732         rctf *bucket_bounds,
1733         float *v1coSS, float *v2coSS, float *v3coSS,
1734         float *uv1co, float *uv2co, float *uv3co,
1735         float bucket_bounds_uv[4][2],
1736         const int flip
1737         )
1738 {
1739         float uv[2];
1740         float w[3];
1741
1742         /* get the UV space bounding box */
1743         uv[0] = bucket_bounds->xmax;
1744         uv[1] = bucket_bounds->ymin;
1745         barycentric_weights_v2_persp(v1coSS, v2coSS, v3coSS, uv, w);
1746         interp_v2_v2v2v2(bucket_bounds_uv[flip ? 3 : 0], uv1co, uv2co, uv3co, w);
1747
1748         //uv[0] = bucket_bounds->xmax; // set above
1749         uv[1] = bucket_bounds->ymax;
1750         barycentric_weights_v2_persp(v1coSS, v2coSS, v3coSS, uv, w);
1751         interp_v2_v2v2v2(bucket_bounds_uv[flip ? 2 : 1], uv1co, uv2co, uv3co, w);
1752
1753         uv[0] = bucket_bounds->xmin;
1754         //uv[1] = bucket_bounds->ymax; // set above
1755         barycentric_weights_v2_persp(v1coSS, v2coSS, v3coSS, uv, w);
1756         interp_v2_v2v2v2(bucket_bounds_uv[flip ? 1 : 2], uv1co, uv2co, uv3co, w);
1757
1758         //uv[0] = bucket_bounds->xmin; // set above
1759         uv[1] = bucket_bounds->ymin;
1760         barycentric_weights_v2_persp(v1coSS, v2coSS, v3coSS, uv, w);
1761         interp_v2_v2v2v2(bucket_bounds_uv[flip ? 0 : 3], uv1co, uv2co, uv3co, w);
1762 }
1763
1764 /* This works as we need it to but we can save a few steps and not use it */
1765
1766 #if 0
1767 static float angle_2d_clockwise(const float p1[2], const float p2[2], const float p3[2])
1768 {
1769         float v1[2], v2[2];
1770
1771         v1[0] = p1[0] - p2[0];    v1[1] = p1[1] - p2[1];
1772         v2[0] = p3[0] - p2[0];    v2[1] = p3[1] - p2[1];
1773
1774         return -atan2(v1[0] * v2[1] - v1[1] * v2[0], v1[0] * v2[0] + v1[1] * v2[1]);
1775 }
1776 #endif
1777
1778 #define ISECT_1 (1)
1779 #define ISECT_2 (1 << 1)
1780 #define ISECT_3 (1 << 2)
1781 #define ISECT_4 (1 << 3)
1782 #define ISECT_ALL3 ((1 << 3) - 1)
1783 #define ISECT_ALL4 ((1 << 4) - 1)
1784
1785 /* limit must be a fraction over 1.0f */
1786 static int IsectPT2Df_limit(float pt[2], float v1[2], float v2[2], float v3[2], float limit)
1787 {
1788         return ((area_tri_v2(pt, v1, v2) + area_tri_v2(pt, v2, v3) + area_tri_v2(pt, v3, v1)) / (area_tri_v2(v1, v2, v3))) < limit;
1789 }
1790
1791 /* Clip the face by a bucket and set the uv-space bucket_bounds_uv
1792  * so we have the clipped UV's to do pixel intersection tests with
1793  * */
1794 static int float_z_sort_flip(const void *p1, const void *p2)
1795 {
1796         return (((float *)p1)[2] < ((float *)p2)[2] ? 1 : -1);
1797 }
1798
1799 static int float_z_sort(const void *p1, const void *p2)
1800 {
1801         return (((float *)p1)[2] < ((float *)p2)[2] ? -1 : 1);
1802 }
1803
1804 static void project_bucket_clip_face(
1805         const int is_ortho,
1806         rctf *bucket_bounds,
1807         float *v1coSS, float *v2coSS, float *v3coSS,
1808         float *uv1co, float *uv2co, float *uv3co,
1809         float bucket_bounds_uv[8][2],
1810         int *tot)
1811 {
1812         int inside_bucket_flag = 0;
1813         int inside_face_flag = 0;
1814         const int flip = ((line_point_side_v2(v1coSS, v2coSS, v3coSS) > 0.0f) != (line_point_side_v2(uv1co, uv2co, uv3co) > 0.0f));
1815
1816         float bucket_bounds_ss[4][2];
1817
1818         /* get the UV space bounding box */
1819         inside_bucket_flag |= BLI_rctf_isect_pt_v(bucket_bounds, v1coSS);
1820         inside_bucket_flag |= BLI_rctf_isect_pt_v(bucket_bounds, v2coSS) << 1;
1821         inside_bucket_flag |= BLI_rctf_isect_pt_v(bucket_bounds, v3coSS) << 2;
1822
1823         if (inside_bucket_flag == ISECT_ALL3) {
1824                 /* all screenspace points are inside the bucket bounding box, this means we don't need to clip and can simply return the UVs */
1825                 if (flip) { /* facing the back? */
1826                         copy_v2_v2(bucket_bounds_uv[0], uv3co);
1827                         copy_v2_v2(bucket_bounds_uv[1], uv2co);
1828                         copy_v2_v2(bucket_bounds_uv[2], uv1co);
1829                 }
1830                 else {
1831                         copy_v2_v2(bucket_bounds_uv[0], uv1co);
1832                         copy_v2_v2(bucket_bounds_uv[1], uv2co);
1833                         copy_v2_v2(bucket_bounds_uv[2], uv3co);
1834                 }
1835
1836                 *tot = 3;
1837                 return;
1838         }
1839
1840         /* get the UV space bounding box */
1841         /* use IsectPT2Df_limit here so we catch points are are touching the tri edge (or a small fraction over) */
1842         bucket_bounds_ss[0][0] = bucket_bounds->xmax;
1843         bucket_bounds_ss[0][1] = bucket_bounds->ymin;
1844         inside_face_flag |= (IsectPT2Df_limit(bucket_bounds_ss[0], v1coSS, v2coSS, v3coSS, 1 + PROJ_GEOM_TOLERANCE) ? ISECT_1 : 0);
1845
1846         bucket_bounds_ss[1][0] = bucket_bounds->xmax;
1847         bucket_bounds_ss[1][1] = bucket_bounds->ymax;
1848         inside_face_flag |= (IsectPT2Df_limit(bucket_bounds_ss[1], v1coSS, v2coSS, v3coSS, 1 + PROJ_GEOM_TOLERANCE) ? ISECT_2 : 0);
1849
1850         bucket_bounds_ss[2][0] = bucket_bounds->xmin;
1851         bucket_bounds_ss[2][1] = bucket_bounds->ymax;
1852         inside_face_flag |= (IsectPT2Df_limit(bucket_bounds_ss[2], v1coSS, v2coSS, v3coSS, 1 + PROJ_GEOM_TOLERANCE) ? ISECT_3 : 0);
1853
1854         bucket_bounds_ss[3][0] = bucket_bounds->xmin;
1855         bucket_bounds_ss[3][1] = bucket_bounds->ymin;
1856         inside_face_flag |= (IsectPT2Df_limit(bucket_bounds_ss[3], v1coSS, v2coSS, v3coSS, 1 + PROJ_GEOM_TOLERANCE) ? ISECT_4 : 0);
1857
1858         if (inside_face_flag == ISECT_ALL4) {
1859                 /* bucket is totally inside the screenspace face, we can safely use weights */
1860
1861                 if (is_ortho) rect_to_uvspace_ortho(bucket_bounds, v1coSS, v2coSS, v3coSS, uv1co, uv2co, uv3co, bucket_bounds_uv, flip);
1862                 else rect_to_uvspace_persp(bucket_bounds, v1coSS, v2coSS, v3coSS, uv1co, uv2co, uv3co, bucket_bounds_uv, flip);
1863
1864                 *tot = 4;
1865                 return;
1866         }
1867         else {
1868                 /* The Complicated Case!
1869                  *
1870                  * The 2 cases above are where the face is inside the bucket or the bucket is inside the face.
1871                  *
1872                  * we need to make a convex polyline from the intersection between the screenspace face
1873                  * and the bucket bounds.
1874                  *
1875                  * There are a number of ways this could be done, currently it just collects all intersecting verts,
1876                  * and line intersections,  then sorts them clockwise, this is a lot easier then evaluating the geometry to
1877                  * do a correct clipping on both shapes. */
1878
1879
1880                 /* add a bunch of points, we know must make up the convex hull which is the clipped rect and triangle */
1881
1882
1883
1884                 /* Maximum possible 6 intersections when using a rectangle and triangle */
1885                 float isectVCosSS[8][3]; /* The 3rd float is used to store angle for qsort(), NOT as a Z location */
1886                 float v1_clipSS[2], v2_clipSS[2];
1887                 float w[3];
1888
1889                 /* calc center */
1890                 float cent[2] = {0.0f, 0.0f};
1891                 /*float up[2] = {0.0f, 1.0f};*/
1892                 int i;
1893                 short doubles;
1894
1895                 (*tot) = 0;
1896
1897                 if (inside_face_flag & ISECT_1) { copy_v2_v2(isectVCosSS[*tot], bucket_bounds_ss[0]); (*tot)++; }
1898                 if (inside_face_flag & ISECT_2) { copy_v2_v2(isectVCosSS[*tot], bucket_bounds_ss[1]); (*tot)++; }
1899                 if (inside_face_flag & ISECT_3) { copy_v2_v2(isectVCosSS[*tot], bucket_bounds_ss[2]); (*tot)++; }
1900                 if (inside_face_flag & ISECT_4) { copy_v2_v2(isectVCosSS[*tot], bucket_bounds_ss[3]); (*tot)++; }
1901
1902                 if (inside_bucket_flag & ISECT_1) { copy_v2_v2(isectVCosSS[*tot], v1coSS); (*tot)++; }
1903                 if (inside_bucket_flag & ISECT_2) { copy_v2_v2(isectVCosSS[*tot], v2coSS); (*tot)++; }
1904                 if (inside_bucket_flag & ISECT_3) { copy_v2_v2(isectVCosSS[*tot], v3coSS); (*tot)++; }
1905
1906                 if ((inside_bucket_flag & (ISECT_1 | ISECT_2)) != (ISECT_1 | ISECT_2)) {
1907                         if (line_clip_rect2f(bucket_bounds, v1coSS, v2coSS, v1_clipSS, v2_clipSS)) {
1908                                 if ((inside_bucket_flag & ISECT_1) == 0) { copy_v2_v2(isectVCosSS[*tot], v1_clipSS); (*tot)++; }
1909                                 if ((inside_bucket_flag & ISECT_2) == 0) { copy_v2_v2(isectVCosSS[*tot], v2_clipSS); (*tot)++; }
1910                         }
1911                 }
1912
1913                 if ((inside_bucket_flag & (ISECT_2 | ISECT_3)) != (ISECT_2 | ISECT_3)) {
1914                         if (line_clip_rect2f(bucket_bounds, v2coSS, v3coSS, v1_clipSS, v2_clipSS)) {
1915                                 if ((inside_bucket_flag & ISECT_2) == 0) { copy_v2_v2(isectVCosSS[*tot], v1_clipSS); (*tot)++; }
1916                                 if ((inside_bucket_flag & ISECT_3) == 0) { copy_v2_v2(isectVCosSS[*tot], v2_clipSS); (*tot)++; }
1917                         }
1918                 }
1919
1920                 if ((inside_bucket_flag & (ISECT_3 | ISECT_1)) != (ISECT_3 | ISECT_1)) {
1921                         if (line_clip_rect2f(bucket_bounds, v3coSS, v1coSS, v1_clipSS, v2_clipSS)) {
1922                                 if ((inside_bucket_flag & ISECT_3) == 0) { copy_v2_v2(isectVCosSS[*tot], v1_clipSS); (*tot)++; }
1923                                 if ((inside_bucket_flag & ISECT_1) == 0) { copy_v2_v2(isectVCosSS[*tot], v2_clipSS); (*tot)++; }
1924                         }
1925                 }
1926
1927
1928                 if ((*tot) < 3) { /* no intersections to speak of */
1929                         *tot = 0;
1930                         return;
1931                 }
1932
1933                 /* now we have all points we need, collect their angles and sort them clockwise */
1934
1935                 for (i = 0; i < (*tot); i++) {
1936                         cent[0] += isectVCosSS[i][0];
1937                         cent[1] += isectVCosSS[i][1];
1938                 }
1939                 cent[0] = cent[0] / (float)(*tot);
1940                 cent[1] = cent[1] / (float)(*tot);
1941
1942
1943
1944                 /* Collect angles for every point around the center point */
1945
1946
1947 #if 0   /* uses a few more cycles then the above loop */
1948                 for (i = 0; i < (*tot); i++) {
1949                         isectVCosSS[i][2] = angle_2d_clockwise(up, cent, isectVCosSS[i]);
1950                 }
1951 #endif
1952
1953                 v1_clipSS[0] = cent[0]; /* Abuse this var for the loop below */
1954                 v1_clipSS[1] = cent[1] + 1.0f;
1955
1956                 for (i = 0; i < (*tot); i++) {
1957                         v2_clipSS[0] = isectVCosSS[i][0] - cent[0];
1958                         v2_clipSS[1] = isectVCosSS[i][1] - cent[1];
1959                         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]);
1960                 }
1961
1962                 if (flip) qsort(isectVCosSS, *tot, sizeof(float) * 3, float_z_sort_flip);
1963                 else      qsort(isectVCosSS, *tot, sizeof(float) * 3, float_z_sort);
1964
1965                 /* remove doubles */
1966                 /* first/last check */
1967                 if (fabsf(isectVCosSS[0][0] - isectVCosSS[(*tot) - 1][0]) < PROJ_GEOM_TOLERANCE &&
1968                     fabsf(isectVCosSS[0][1] - isectVCosSS[(*tot) - 1][1]) < PROJ_GEOM_TOLERANCE)
1969                 {
1970                         (*tot)--;
1971                 }
1972
1973                 /* its possible there is only a few left after remove doubles */
1974                 if ((*tot) < 3) {
1975                         // printf("removed too many doubles A\n");
1976                         *tot = 0;
1977                         return;
1978                 }
1979
1980                 doubles = TRUE;
1981                 while (doubles == TRUE) {
1982                         doubles = FALSE;
1983                         for (i = 1; i < (*tot); i++) {
1984                                 if (fabsf(isectVCosSS[i - 1][0] - isectVCosSS[i][0]) < PROJ_GEOM_TOLERANCE &&
1985                                     fabsf(isectVCosSS[i - 1][1] - isectVCosSS[i][1]) < PROJ_GEOM_TOLERANCE)
1986                                 {
1987                                         int j;
1988                                         for (j = i + 1; j < (*tot); j++) {
1989                                                 isectVCosSS[j - 1][0] = isectVCosSS[j][0];
1990                                                 isectVCosSS[j - 1][1] = isectVCosSS[j][1];
1991                                         }
1992                                         doubles = TRUE; /* keep looking for more doubles */
1993                                         (*tot)--;
1994                                 }
1995                         }
1996                 }
1997
1998                 /* its possible there is only a few left after remove doubles */
1999                 if ((*tot) < 3) {
2000                         // printf("removed too many doubles B\n");
2001                         *tot = 0;
2002                         return;
2003                 }
2004
2005
2006                 if (is_ortho) {
2007                         for (i = 0; i < (*tot); i++) {
2008                                 barycentric_weights_v2(v1coSS, v2coSS, v3coSS, isectVCosSS[i], w);
2009                                 interp_v2_v2v2v2(bucket_bounds_uv[i], uv1co, uv2co, uv3co, w);
2010                         }
2011                 }
2012                 else {
2013                         for (i = 0; i < (*tot); i++) {
2014                                 barycentric_weights_v2_persp(v1coSS, v2coSS, v3coSS, isectVCosSS[i], w);
2015                                 interp_v2_v2v2v2(bucket_bounds_uv[i], uv1co, uv2co, uv3co, w);
2016                         }
2017                 }
2018         }
2019
2020 #ifdef PROJ_DEBUG_PRINT_CLIP
2021         /* include this at the bottom of the above function to debug the output */
2022
2023         {
2024                 /* If there are ever any problems, */
2025                 float test_uv[4][2];
2026                 int i;
2027                 if (is_ortho) rect_to_uvspace_ortho(bucket_bounds, v1coSS, v2coSS, v3coSS, uv1co, uv2co, uv3co, test_uv, flip);
2028                 else          rect_to_uvspace_persp(bucket_bounds, v1coSS, v2coSS, v3coSS, uv1co, uv2co, uv3co, test_uv, flip);
2029                 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]);
2030
2031                 printf("  [(%f,%f), (%f,%f), (%f,%f)], ", uv1co[0], uv1co[1],   uv2co[0], uv2co[1],    uv3co[0], uv3co[1]);
2032
2033                 printf("[");
2034                 for (i = 0; i < (*tot); i++) {
2035                         printf("(%f, %f),", bucket_bounds_uv[i][0], bucket_bounds_uv[i][1]);
2036                 }
2037                 printf("]),\\\n");
2038         }
2039 #endif
2040 }
2041
2042 /*
2043  * # This script creates faces in a blender scene from printed data above.
2044  *
2045  * project_ls = [
2046  * ...(output from above block)...
2047  * ]
2048  *
2049  * from Blender import Scene, Mesh, Window, sys, Mathutils
2050  *
2051  * import bpy
2052  *
2053  * V = Mathutils.Vector
2054  *
2055  * def main():
2056  *     sce = bpy.data.scenes.active
2057  *
2058  *     for item in project_ls:
2059  *         bb = item[0]
2060  *         uv = item[1]
2061  *         poly = item[2]
2062  *
2063  *         me = bpy.data.meshes.new()
2064  *         ob = sce.objects.new(me)
2065  *
2066  *         me.verts.extend([V(bb[0]).xyz, V(bb[1]).xyz, V(bb[2]).xyz, V(bb[3]).xyz])
2067  *         me.faces.extend([(0,1,2,3),])
2068  *         me.verts.extend([V(uv[0]).xyz, V(uv[1]).xyz, V(uv[2]).xyz])
2069  *         me.faces.extend([(4,5,6),])
2070  *
2071  *         vs = [V(p).xyz for p in poly]
2072  *         print len(vs)
2073  *         l = len(me.verts)
2074  *         me.verts.extend(vs)
2075  *
2076  *         i = l
2077  *         while i < len(me.verts):
2078  *             ii = i + 1
2079  *             if ii == len(me.verts):
2080  *                 ii = l
2081  *             me.edges.extend([i, ii])
2082  *             i += 1
2083  *
2084  * if __name__ == '__main__':
2085  *     main()
2086  */
2087
2088
2089 #undef ISECT_1
2090 #undef ISECT_2
2091 #undef ISECT_3
2092 #undef ISECT_4
2093 #undef ISECT_ALL3
2094 #undef ISECT_ALL4
2095
2096
2097 /* checks if pt is inside a convex 2D polyline, the polyline must be ordered rotating clockwise
2098  * otherwise it would have to test for mixed (line_point_side_v2 > 0.0f) cases */
2099 static int IsectPoly2Df(const float pt[2], float uv[][2], const int tot)
2100 {
2101         int i;
2102         if (line_point_side_v2(uv[tot - 1], uv[0], pt) < 0.0f)
2103                 return 0;
2104
2105         for (i = 1; i < tot; i++) {
2106                 if (line_point_side_v2(uv[i - 1], uv[i], pt) < 0.0f)
2107                         return 0;
2108
2109         }
2110
2111         return 1;
2112 }
2113 static int IsectPoly2Df_twoside(const float pt[2], float uv[][2], const int tot)
2114 {
2115         int i;
2116         int side = (line_point_side_v2(uv[tot - 1], uv[0], pt) > 0.0f);
2117
2118         for (i = 1; i < tot; i++) {
2119                 if ((line_point_side_v2(uv[i - 1], uv[i], pt) > 0.0f) != side)
2120                         return 0;
2121
2122         }
2123
2124         return 1;
2125 }
2126
2127 /* One of the most important function for projection painting, since it selects the pixels to be added into each bucket.
2128  * initialize pixels from this face where it intersects with the bucket_index, optionally initialize pixels for removing seams */
2129 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, const ImBuf *ibuf, const short clamp_u, const short clamp_v)
2130 {
2131         /* Projection vars, to get the 3D locations into screen space  */
2132         MemArena *arena = ps->arena_mt[thread_index];
2133         LinkNode **bucketPixelNodes = ps->bucketRect + bucket_index;
2134         LinkNode *bucketFaceNodes = ps->bucketFaces[bucket_index];
2135
2136         const MFace *mf = ps->dm_mface + face_index;
2137         const MTFace *tf = ps->dm_mtface + face_index;
2138
2139         /* UV/pixel seeking data */
2140         int x; /* Image X-Pixel */
2141         int y; /* Image Y-Pixel */
2142         float mask;
2143         float uv[2]; /* Image floating point UV - same as x, y but from 0.0-1.0 */
2144
2145         int side;
2146         float *v1coSS, *v2coSS, *v3coSS; /* vert co screen-space, these will be assigned to mf->v1,2,3 or mf->v1,3,4 */
2147
2148         float *vCo[4]; /* vertex screenspace coords */
2149
2150         float w[3], wco[3];
2151
2152         float *uv1co, *uv2co, *uv3co; /* for convenience only, these will be assigned to tf->uv[0],1,2 or tf->uv[0],2,3 */
2153         float pixelScreenCo[4];
2154         bool do_3d_mapping = ps->brush->mtex.brush_map_mode == MTEX_MAP_MODE_3D;
2155
2156         rcti bounds_px; /* ispace bounds */
2157         /* vars for getting uvspace bounds */
2158
2159         float tf_uv_pxoffset[4][2]; /* bucket bounds in UV space so we can init pixels only for this face,  */
2160         float xhalfpx, yhalfpx;
2161         const float ibuf_xf = (float)ibuf->x, ibuf_yf = (float)ibuf->y;
2162
2163         int has_x_isect = 0, has_isect = 0; /* for early loop exit */
2164
2165         int i1, i2, i3;
2166
2167         float uv_clip[8][2];
2168         int uv_clip_tot;
2169         const short is_ortho = ps->is_ortho;
2170         const short do_backfacecull = ps->do_backfacecull;
2171         const short do_clip = ps->rv3d ? ps->rv3d->rflag & RV3D_CLIPPING : 0;
2172
2173         vCo[0] = ps->dm_mvert[mf->v1].co;
2174         vCo[1] = ps->dm_mvert[mf->v2].co;
2175         vCo[2] = ps->dm_mvert[mf->v3].co;
2176
2177
2178         /* Use tf_uv_pxoffset instead of tf->uv so we can offset the UV half a pixel
2179          * this is done so we can avoid offsetting all the pixels by 0.5 which causes
2180          * problems when wrapping negative coords */
2181         xhalfpx = (0.5f + (PROJ_GEOM_TOLERANCE * (1.0f / 3.0f))) / ibuf_xf;
2182         yhalfpx = (0.5f + (PROJ_GEOM_TOLERANCE * (1.0f / 4.0f))) / ibuf_yf;
2183
2184         /* Note about (PROJ_GEOM_TOLERANCE/x) above...
2185          * Needed to add this offset since UV coords are often quads aligned to pixels.
2186          * In this case pixels can be exactly between 2 triangles causing nasty
2187          * artifacts.
2188          *
2189          * This workaround can be removed and painting will still work on most cases
2190          * but since the first thing most people try is painting onto a quad- better make it work.
2191          */
2192
2193
2194
2195         tf_uv_pxoffset[0][0] = tf->uv[0][0] - xhalfpx;
2196         tf_uv_pxoffset[0][1] = tf->uv[0][1] - yhalfpx;
2197
2198         tf_uv_pxoffset[1][0] = tf->uv[1][0] - xhalfpx;
2199         tf_uv_pxoffset[1][1] = tf->uv[1][1] - yhalfpx;
2200
2201         tf_uv_pxoffset[2][0] = tf->uv[2][0] - xhalfpx;
2202         tf_uv_pxoffset[2][1] = tf->uv[2][1] - yhalfpx;
2203
2204         if (mf->v4) {
2205                 vCo[3] = ps->dm_mvert[mf->v4].co;
2206
2207                 tf_uv_pxoffset[3][0] = tf->uv[3][0] - xhalfpx;
2208                 tf_uv_pxoffset[3][1] = tf->uv[3][1] - yhalfpx;
2209                 side = 1;
2210         }
2211         else {
2212                 side = 0;
2213         }
2214
2215         do {
2216                 if (side == 1) {
2217                         i1 = 0; i2 = 2; i3 = 3;
2218                 }
2219                 else {
2220                         i1 = 0; i2 = 1; i3 = 2;
2221                 }
2222
2223                 uv1co = tf_uv_pxoffset[i1]; // was tf->uv[i1];
2224                 uv2co = tf_uv_pxoffset[i2]; // was tf->uv[i2];
2225                 uv3co = tf_uv_pxoffset[i3]; // was tf->uv[i3];
2226
2227                 v1coSS = ps->screenCoords[(*(&mf->v1 + i1))];
2228                 v2coSS = ps->screenCoords[(*(&mf->v1 + i2))];
2229                 v3coSS = ps->screenCoords[(*(&mf->v1 + i3))];
2230
2231                 /* This funtion gives is a concave polyline in UV space from the clipped quad and tri*/
2232                 project_bucket_clip_face(
2233                         is_ortho, bucket_bounds,
2234                         v1coSS, v2coSS, v3coSS,
2235                         uv1co, uv2co, uv3co,
2236                         uv_clip, &uv_clip_tot
2237                         );
2238
2239                 /* sometimes this happens, better just allow for 8 intersectiosn even though there should be max 6 */
2240 #if 0
2241                 if (uv_clip_tot > 6) {
2242                         printf("this should never happen! %d\n", uv_clip_tot);
2243                 }
2244 #endif
2245
2246                 if (pixel_bounds_array(uv_clip, &bounds_px, ibuf->x, ibuf->y, uv_clip_tot)) {
2247
2248                         if (clamp_u) {
2249                                 CLAMP(bounds_px.xmin, 0, ibuf->x);
2250                                 CLAMP(bounds_px.xmax, 0, ibuf->x);
2251                         }
2252
2253                         if (clamp_v) {
2254                                 CLAMP(bounds_px.ymin, 0, ibuf->y);
2255                                 CLAMP(bounds_px.ymax, 0, ibuf->y);
2256                         }
2257
2258                         /* clip face and */
2259
2260                         has_isect = 0;
2261                         for (y = bounds_px.ymin; y < bounds_px.ymax; y++) {
2262                                 //uv[1] = (((float)y) + 0.5f) / (float)ibuf->y;
2263                                 uv[1] = (float)y / ibuf_yf; /* use pixel offset UV coords instead */
2264
2265                                 has_x_isect = 0;
2266                                 for (x = bounds_px.xmin; x < bounds_px.xmax; x++) {
2267                                         //uv[0] = (((float)x) + 0.5f) / ibuf->x;
2268                                         uv[0] = (float)x / ibuf_xf; /* use pixel offset UV coords instead */
2269
2270                                         /* Note about IsectPoly2Df_twoside, checking the face or uv flipping doesnt work,
2271                                          * could check the poly direction but better to do this */
2272                                         if ((do_backfacecull == TRUE  && IsectPoly2Df(uv, uv_clip, uv_clip_tot)) ||
2273                                             (do_backfacecull == FALSE && IsectPoly2Df_twoside(uv, uv_clip, uv_clip_tot)))
2274                                         {
2275
2276                                                 has_x_isect = has_isect = 1;
2277
2278                                                 if (is_ortho) screen_px_from_ortho(uv, v1coSS, v2coSS, v3coSS, uv1co, uv2co, uv3co, pixelScreenCo, w);
2279                                                 else          screen_px_from_persp(uv, v1coSS, v2coSS, v3coSS, uv1co, uv2co, uv3co, pixelScreenCo, w);
2280
2281                                                 /* a pity we need to get the worldspace pixel location here */
2282                                                 if (do_clip || do_3d_mapping) {
2283                                                         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);
2284                                                         if (do_clip && ED_view3d_clipping_test(ps->rv3d, wco, TRUE)) {
2285                                                                 continue; /* Watch out that no code below this needs to run */
2286                                                         }
2287                                                 }
2288
2289                                                 /* Is this UV visible from the view? - raytrace */
2290                                                 /* project_paint_PickFace is less complex, use for testing */
2291                                                 //if (project_paint_PickFace(ps, pixelScreenCo, w, &side) == face_index) {
2292                                                 if ((ps->do_occlude == FALSE) ||
2293                                                     !project_bucket_point_occluded(ps, bucketFaceNodes, face_index, pixelScreenCo))
2294                                                 {
2295                                                         mask = project_paint_uvpixel_mask(ps, face_index, side, w);
2296
2297                                                         if (mask > 0.0f) {
2298                                                                 BLI_linklist_prepend_arena(
2299                                                                         bucketPixelNodes,
2300                                                                         project_paint_uvpixel_init(ps, arena, ibuf, x, y, mask, face_index,
2301                                                                                                    image_index, pixelScreenCo, wco, side, w),
2302                                                                         arena
2303                                                                         );
2304                                                         }
2305                                                 }
2306
2307                                         }
2308 //#if 0
2309                                         else if (has_x_isect) {
2310                                                 /* assuming the face is not a bow-tie - we know we cant intersect again on the X */
2311                                                 break;
2312                                         }
2313 //#endif
2314                                 }
2315
2316
2317 #if 0           /* TODO - investigate why this dosnt work sometimes! it should! */
2318                                 /* no intersection for this entire row, after some intersection above means we can quit now */
2319                                 if (has_x_isect == 0 && has_isect) {
2320                                         break;
2321                                 }
2322 #endif
2323                         }
2324                 }
2325         } while (side--);
2326
2327
2328
2329 #ifndef PROJ_DEBUG_NOSEAMBLEED
2330         if (ps->seam_bleed_px > 0.0f) {
2331                 int face_seam_flag;
2332
2333                 if (ps->thread_tot > 1)
2334                         BLI_lock_thread(LOCK_CUSTOM1);  /* Other threads could be modifying these vars */
2335
2336                 face_seam_flag = ps->faceSeamFlags[face_index];
2337
2338                 /* are any of our edges un-initialized? */
2339                 if ((face_seam_flag & (PROJ_FACE_SEAM1 | PROJ_FACE_NOSEAM1)) == 0 ||
2340                     (face_seam_flag & (PROJ_FACE_SEAM2 | PROJ_FACE_NOSEAM2)) == 0 ||
2341                     (face_seam_flag & (PROJ_FACE_SEAM3 | PROJ_FACE_NOSEAM3)) == 0 ||
2342                     (face_seam_flag & (PROJ_FACE_SEAM4 | PROJ_FACE_NOSEAM4)) == 0)
2343                 {
2344                         project_face_seams_init(ps, face_index, mf->v4);
2345                         face_seam_flag = ps->faceSeamFlags[face_index];
2346                         //printf("seams - %d %d %d %d\n", flag&PROJ_FACE_SEAM1, flag&PROJ_FACE_SEAM2, flag&PROJ_FACE_SEAM3, flag&PROJ_FACE_SEAM4);
2347                 }
2348
2349                 if ((face_seam_flag & (PROJ_FACE_SEAM1 | PROJ_FACE_SEAM2 | PROJ_FACE_SEAM3 | PROJ_FACE_SEAM4)) == 0) {
2350
2351                         if (ps->thread_tot > 1)
2352                                 BLI_unlock_thread(LOCK_CUSTOM1);  /* Other threads could be modifying these vars */
2353
2354                 }
2355                 else {
2356                         /* we have a seam - deal with it! */
2357
2358                         /* Now create new UV's for the seam face */
2359                         float (*outset_uv)[2] = ps->faceSeamUVs[face_index];
2360                         float insetCos[4][3]; /* inset face coords.  NOTE!!! ScreenSace for ortho, Worldspace in prespective view */
2361
2362                         float *vCoSS[4]; /* vertex screenspace coords */
2363
2364                         float bucket_clip_edges[2][2]; /* store the screenspace coords of the face, clipped by the bucket's screen aligned rectangle */
2365                         float edge_verts_inset_clip[2][3];
2366                         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 */
2367
2368                         float seam_subsection[4][2];
2369                         float fac1, fac2, ftot;
2370
2371
2372                         if (outset_uv[0][0] == FLT_MAX) /* first time initialize */
2373                                 uv_image_outset(tf_uv_pxoffset, outset_uv, ps->seam_bleed_px, ibuf->x, ibuf->y, mf->v4);
2374
2375                         /* ps->faceSeamUVs cant be modified when threading, now this is done we can unlock */
2376                         if (ps->thread_tot > 1)
2377                                 BLI_unlock_thread(LOCK_CUSTOM1);  /* Other threads could be modifying these vars */
2378
2379                         vCoSS[0] = ps->screenCoords[mf->v1];
2380                         vCoSS[1] = ps->screenCoords[mf->v2];
2381                         vCoSS[2] = ps->screenCoords[mf->v3];
2382                         if (mf->v4)
2383                                 vCoSS[3] = ps->screenCoords[mf->v4];
2384
2385                         /* PROJ_FACE_SCALE_SEAM must be slightly less then 1.0f */
2386                         if (is_ortho) {
2387                                 if (mf->v4) scale_quad(insetCos, vCoSS, PROJ_FACE_SCALE_SEAM);
2388                                 else        scale_tri(insetCos, vCoSS, PROJ_FACE_SCALE_SEAM);
2389                         }
2390                         else {
2391                                 if (mf->v4) scale_quad(insetCos, vCo, PROJ_FACE_SCALE_SEAM);
2392                                 else        scale_tri(insetCos, vCo, PROJ_FACE_SCALE_SEAM);
2393                         }
2394
2395                         side = 0; /* for triangles this wont need to change */
2396
2397                         for (fidx1 = 0; fidx1 < (mf->v4 ? 4 : 3); fidx1++) {
2398                                 if (mf->v4) fidx2 = (fidx1 == 3) ? 0 : fidx1 + 1;  /* next fidx in the face (0,1,2,3) -> (1,2,3,0) */
2399                                 else        fidx2 = (fidx1 == 2) ? 0 : fidx1 + 1;  /* next fidx in the face (0,1,2) -> (1,2,0) */
2400
2401                                 if ((face_seam_flag & (1 << fidx1)) && /* 1<<fidx1 -> PROJ_FACE_SEAM# */
2402                                     line_clip_rect2f(bucket_bounds, vCoSS[fidx1], vCoSS[fidx2], bucket_clip_edges[0], bucket_clip_edges[1]))
2403                                 {
2404
2405                                         ftot = len_v2v2(vCoSS[fidx1], vCoSS[fidx2]); /* screenspace edge length */
2406
2407                                         if (ftot > 0.0f) { /* avoid div by zero */
2408                                                 if (mf->v4) {
2409                                                         if (fidx1 == 2 || fidx2 == 2) side = 1;
2410                                                         else side = 0;
2411                                                 }
2412
2413                                                 fac1 = len_v2v2(vCoSS[fidx1], bucket_clip_edges[0]) / ftot;
2414                                                 fac2 = len_v2v2(vCoSS[fidx1], bucket_clip_edges[1]) / ftot;
2415
2416                                                 interp_v2_v2v2(seam_subsection[0], tf_uv_pxoffset[fidx1], tf_uv_pxoffset[fidx2], fac1);
2417                                                 interp_v2_v2v2(seam_subsection[1], tf_uv_pxoffset[fidx1], tf_uv_pxoffset[fidx2], fac2);
2418
2419                                                 interp_v2_v2v2(seam_subsection[2], outset_uv[fidx1], outset_uv[fidx2], fac2);
2420                                                 interp_v2_v2v2(seam_subsection[3], outset_uv[fidx1], outset_uv[fidx2], fac1);
2421
2422                                                 /* if the bucket_clip_edges values Z values was kept we could avoid this
2423                                                  * Inset needs to be added so occlusion tests wont hit adjacent faces */
2424                                                 interp_v3_v3v3(edge_verts_inset_clip[0], insetCos[fidx1], insetCos[fidx2], fac1);
2425                                                 interp_v3_v3v3(edge_verts_inset_clip[1], insetCos[fidx1], insetCos[fidx2], fac2);
2426
2427
2428                                                 if (pixel_bounds_uv(seam_subsection[0], seam_subsection[1], seam_subsection[2], seam_subsection[3], &bounds_px, ibuf->x, ibuf->y, 1)) {
2429                                                         /* bounds between the seam rect and the uvspace bucket pixels */
2430
2431                                                         has_isect = 0;
2432                                                         for (y = bounds_px.ymin; y < bounds_px.ymax; y++) {
2433                                                                 // uv[1] = (((float)y) + 0.5f) / (float)ibuf->y;
2434                                                                 uv[1] = (float)y / ibuf_yf; /* use offset uvs instead */
2435
2436                                                                 has_x_isect = 0;
2437                                                                 for (x = bounds_px.xmin; x < bounds_px.xmax; x++) {
2438                                                                         //uv[0] = (((float)x) + 0.5f) / (float)ibuf->x;
2439                                                                         uv[0] = (float)x / ibuf_xf; /* use offset uvs instead */
2440
2441                                                                         /* test we're inside uvspace bucket and triangle bounds */
2442                                                                         if (isect_point_quad_v2(uv, seam_subsection[0], seam_subsection[1], seam_subsection[2], seam_subsection[3])) {
2443                                                                                 float fac;
2444
2445                                                                                 /* We need to find the closest point along the face edge,
2446                                                                                  * getting the screen_px_from_*** wont work because our actual location
2447                                                                                  * is not relevant, since we are outside the face, Use VecLerpf to find
2448                                                                                  * our location on the side of the face's UV */
2449 #if 0
2450                                                                                 if (is_ortho) screen_px_from_ortho(ps, uv, v1co, v2co, v3co, uv1co, uv2co, uv3co, pixelScreenCo);
2451                                                                                 else          screen_px_from_persp(ps, uv, v1co, v2co, v3co, uv1co, uv2co, uv3co, pixelScreenCo);
2452 #endif
2453
2454                                                                                 /* Since this is a seam we need to work out where on the line this pixel is */
2455                                                                                 //fac = line_point_factor_v2(uv, uv_seam_quad[0], uv_seam_quad[1]);
2456
2457                                                                                 fac = line_point_factor_v2(uv, seam_subsection[0], seam_subsection[1]);
2458                                                                                 if      (fac < 0.0f) { copy_v3_v3(pixelScreenCo, edge_verts_inset_clip[0]); }
2459                                                                                 else if (fac > 1.0f) { copy_v3_v3(pixelScreenCo, edge_verts_inset_clip[1]); }
2460                                                                                 else                 { interp_v3_v3v3(pixelScreenCo, edge_verts_inset_clip[0], edge_verts_inset_clip[1], fac); }
2461
2462                                                                                 if (!is_ortho) {
2463                                                                                         pixelScreenCo[3] = 1.0f;
2464                                                                                         mul_m4_v4((float(*)[4])ps->projectMat, pixelScreenCo); /* cast because of const */
2465                                                                                         pixelScreenCo[0] = (float)(ps->winx * 0.5f) + (ps->winx * 0.5f) * pixelScreenCo[0] / pixelScreenCo[3];
2466                                                                                         pixelScreenCo[1] = (float)(ps->winy * 0.5f) + (ps->winy * 0.5f) * pixelScreenCo[1] / pixelScreenCo[3];
2467                                                                                         pixelScreenCo[2] = pixelScreenCo[2] / pixelScreenCo[3]; /* Use the depth for bucket point occlusion */
2468                                                                                 }
2469
2470                                                                                 if ((ps->do_occlude == FALSE) ||
2471                                                                                     !project_bucket_point_occluded(ps, bucketFaceNodes, face_index, pixelScreenCo))
2472                                                                                 {
2473                                                                                         /* Only bother calculating the weights if we intersect */
2474                                                                                         if (ps->do_mask_normal || ps->dm_mtface_clone) {
2475 #if 1
2476                                                                                                 /* get the UV on the line since we want to copy the pixels from there for bleeding */
2477                                                                                                 float uv_close[2];
2478                                                                                                 float uv_fac = closest_to_line_v2(uv_close, uv, tf_uv_pxoffset[fidx1], tf_uv_pxoffset[fidx2]);
2479                                                                                                 if      (uv_fac < 0.0f) copy_v2_v2(uv_close, tf_uv_pxoffset[fidx1]);
2480                                                                                                 else if (uv_fac > 1.0f) copy_v2_v2(uv_close, tf_uv_pxoffset[fidx2]);
2481
2482                                                                                                 if (side) {
2483                                                                                                         barycentric_weights_v2(tf_uv_pxoffset[0], tf_uv_pxoffset[2], tf_uv_pxoffset[3], uv_close, w);
2484                                                                                                 }
2485                                                                                                 else {
2486                                                                                                         barycentric_weights_v2(tf_uv_pxoffset[0], tf_uv_pxoffset[1], tf_uv_pxoffset[2], uv_close, w);
2487                                                                                                 }
2488 #else                                                                                   /* this is buggy with quads, don't use for now */
2489
2490                                                                                                 /* Cheat, we know where we are along the edge so work out the weights from that */
2491                                                                                                 uv_fac = fac1 + (uv_fac * (fac2 - fac1));
2492
2493                                                                                                 w[0] = w[1] = w[2] = 0.0;
2494                                                                                                 if (side) {
2495                                                                                                         w[fidx1 ? fidx1 - 1 : 0] = 1.0f - uv_fac;
2496                                                                                                         w[fidx2 ? fidx2 - 1 : 0] = uv_fac;
2497                                                                                                 }
2498                                                                                                 else {
2499                                                                                                         w[fidx1] = 1.0f - uv_fac;
2500                                                                                                         w[fidx2] = uv_fac;
2501                                                                                                 }
2502 #endif
2503                                                                                         }
2504
2505                                                                                         /* a pity we need to get the worldspace pixel location here */
2506                                                                                         if (do_clip || do_3d_mapping) {
2507                                                                                                 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);
2508                                                                                                 else      interp_v3_v3v3v3(wco, ps->dm_mvert[mf->v1].co, ps->dm_mvert[mf->v2].co, ps->dm_mvert[mf->v3].co, w);
2509
2510                                                                                                 if (do_clip && ED_view3d_clipping_test(ps->rv3d, wco, TRUE)) {
2511                                                                                                         continue; /* Watch out that no code below this needs to run */
2512                                                                                                 }
2513                                                                                         }
2514
2515                                                                                         mask = project_paint_uvpixel_mask(ps, face_index, side, w);
2516
2517                                                                                         if (mask > 0.0f) {
2518                                                                                                 BLI_linklist_prepend_arena(
2519                                                                                                         bucketPixelNodes,
2520                                                                                                         project_paint_uvpixel_init(ps, arena, ibuf, x, y, mask, face_index, image_index, pixelScreenCo, wco, side, w),
2521                                                                                                         arena
2522                                                                                                         );
2523                                                                                         }
2524
2525                                                                                 }
2526                                                                         }
2527                                                                         else if (has_x_isect) {
2528                                                                                 /* assuming the face is not a bow-tie - we know we cant intersect again on the X */
2529                                                                                 break;
2530                                                                         }
2531                                                                 }
2532
2533 #if 0                           /* TODO - investigate why this dosnt work sometimes! it should! */
2534                                                                 /* no intersection for this entire row, after some intersection above means we can quit now */
2535                                                                 if (has_x_isect == 0 && has_isect) {
2536                                                                         break;
2537                                                                 }
2538 #endif
2539                                                         }
2540                                                 }
2541                                         }
2542                                 }
2543                         }
2544                 }
2545         }
2546 #endif // PROJ_DEBUG_NOSEAMBLEED
2547 }
2548
2549
2550 /* takes floating point screenspace min/max and returns int min/max to be used as indices for ps->bucketRect, ps->bucketFlags */
2551 static void project_paint_bucket_bounds(const ProjPaintState *ps, const float min[2], const float max[2], int bucketMin[2], int bucketMax[2])
2552 {
2553         /* divide by bucketWidth & bucketHeight so the bounds are offset in bucket grid units */
2554         /* 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 */
2555         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 */
2556         bucketMin[1] = (int)((int)(((float)(min[1] - ps->screenMin[1]) / ps->screen_height) * ps->buckets_y) + 0.5f);
2557
2558         bucketMax[0] = (int)((int)(((float)(max[0] - ps->screenMin[0]) / ps->screen_width) * ps->buckets_x) + 1.5f);
2559         bucketMax[1] = (int)((int)(((float)(max[1] - ps->screenMin[1]) / ps->screen_height) * ps->buckets_y) + 1.5f);
2560
2561         /* in case the rect is outside the mesh 2d bounds */
2562         CLAMP(bucketMin[0], 0, ps->buckets_x);
2563         CLAMP(bucketMin[1], 0, ps->buckets_y);
2564
2565         CLAMP(bucketMax[0], 0, ps->buckets_x);
2566         CLAMP(bucketMax[1], 0, ps->buckets_y);
2567 }
2568
2569 /* set bucket_bounds to a screen space-aligned floating point bound-box */
2570 static void project_bucket_bounds(const ProjPaintState *ps, const int bucket_x, const int bucket_y, rctf *bucket_bounds)
2571 {
2572         bucket_bounds->xmin = ps->screenMin[0] + ((bucket_x) * (ps->screen_width / ps->buckets_x));     /* left */
2573         bucket_bounds->xmax = ps->screenMin[0] + ((bucket_x + 1) * (ps->screen_width / ps->buckets_x)); /* right */
2574
2575         bucket_bounds->ymin = ps->screenMin[1] + ((bucket_y) * (ps->screen_height / ps->buckets_y));      /* bottom */
2576         bucket_bounds->ymax = ps->screenMin[1] + ((bucket_y + 1) * (ps->screen_height  / ps->buckets_y)); /* top */
2577 }
2578
2579 /* Fill this bucket with pixels from the faces that intersect it.
2580  *
2581  * have bucket_bounds as an argument so we don't need to give bucket_x/y the rect function needs */
2582 static void project_bucket_init(const ProjPaintState *ps, const int thread_index, const int bucket_index, rctf *bucket_bounds)
2583 {
2584         LinkNode *node;
2585         int face_index, image_index = 0;
2586         ImBuf *ibuf = NULL;
2587         Image *tpage_last = NULL, *tpage;
2588         Image *ima = NULL;
2589
2590         if (ps->image_tot == 1) {
2591                 /* Simple loop, no context switching */
2592                 ibuf = ps->projImages[0].ibuf;
2593                 ima = ps->projImages[0].ima;
2594
2595                 for (node = ps->bucketFaces[bucket_index]; node; node = node->next) {
2596                         project_paint_face_init(ps, thread_index, bucket_index, GET_INT_FROM_POINTER(node->link), 0, bucket_bounds, ibuf, ima->tpageflag & IMA_CLAMP_U, ima->tpageflag & IMA_CLAMP_V);
2597                 }
2598         }
2599         else {
2600
2601                 /* More complicated loop, switch between images */
2602                 for (node = ps->bucketFaces[bucket_index]; node; node = node->next) {
2603                         face_index = GET_INT_FROM_POINTER(node->link);
2604
2605                         /* Image context switching */
2606                         tpage = project_paint_face_image(ps, ps->dm_mtface, face_index);
2607                         if (tpage_last != tpage) {
2608                                 tpage_last = tpage;
2609
2610                                 for (image_index = 0; image_index < ps->image_tot; image_index++) {
2611                                         if (ps->projImages[image_index].ima == tpage_last) {
2612                                                 ibuf = ps->projImages[image_index].ibuf;
2613                                                 ima = ps->projImages[image_index].ima;
2614                                                 break;
2615                                         }
2616                                 }
2617                         }
2618                         /* context switching done */
2619
2620                         project_paint_face_init(ps, thread_index, bucket_index, face_index, image_index, bucket_bounds, ibuf, ima->tpageflag & IMA_CLAMP_U, ima->tpageflag & IMA_CLAMP_V);
2621                 }
2622         }
2623
2624         ps->bucketFlags[bucket_index] |= PROJ_BUCKET_INIT;
2625 }
2626
2627
2628 /* We want to know if a bucket and a face overlap in screen-space
2629  *
2630  * Note, if this ever returns false positives its not that bad, since a face in the bounding area will have its pixels
2631  * calculated when it might not be needed later, (at the moment at least)
2632  * obviously it shouldn't have bugs though */
2633
2634 static int project_bucket_face_isect(ProjPaintState *ps, int bucket_x, int bucket_y, const MFace *mf)
2635 {
2636         /* TODO - replace this with a tricker method that uses sideofline for all screenCoords's edges against the closest bucket corner */
2637         rctf bucket_bounds;
2638         float p1[2], p2[2], p3[2], p4[2];
2639         float *v, *v1, *v2, *v3, *v4 = NULL;
2640         int fidx;
2641
2642         project_bucket_bounds(ps, bucket_x, bucket_y, &bucket_bounds);
2643
2644         /* Is one of the faces verts in the bucket bounds? */
2645
2646         fidx = mf->v4 ? 3 : 2;
2647         do {
2648                 v = ps->screenCoords[(*(&mf->v1 + fidx))];
2649                 if (BLI_rctf_isect_pt_v(&bucket_bounds, v)) {
2650                         return 1;
2651                 }
2652         } while (fidx--);
2653
2654         v1 = ps->screenCoords[mf->v1];
2655         v2 = ps->screenCoords[mf->v2];
2656         v3 = ps->screenCoords[mf->v3];
2657         if (mf->v4) {
2658                 v4 = ps->screenCoords[mf->v4];
2659         }
2660
2661         p1[0] = bucket_bounds.xmin; p1[1] = bucket_bounds.ymin;
2662         p2[0] = bucket_bounds.xmin; p2[1] = bucket_bounds.ymax;
2663         p3[0] = bucket_bounds.xmax; p3[1] = bucket_bounds.ymax;
2664         p4[0] = bucket_bounds.xmax; p4[1] = bucket_bounds.ymin;
2665
2666         if (mf->v4) {
2667                 if (isect_point_quad_v2(p1, v1, v2, v3, v4) ||
2668                     isect_point_quad_v2(p2, v1, v2, v3, v4) ||
2669                     isect_point_quad_v2(p3, v1, v2, v3, v4) ||
2670                     isect_point_quad_v2(p4, v1, v2, v3, v4) ||
2671
2672                     /* we can avoid testing v3,v1 because another intersection MUST exist if this intersects */
2673                     (isect_line_line_v2(p1, p2, v1, v2) || isect_line_line_v2(p1, p2, v2, v3) || isect_line_line_v2(p1, p2, v3, v4)) ||
2674                     (isect_line_line_v2(p2, p3, v1, v2) || isect_line_line_v2(p2, p3, v2, v3) || isect_line_line_v2(p2, p3, v3, v4)) ||
2675                     (isect_line_line_v2(p3, p4, v1, v2) || isect_line_line_v2(p3, p4, v2, v3) || isect_line_line_v2(p3, p4, v3, v4)) ||
2676                     (isect_line_line_v2(p4, p1, v1, v2) || isect_line_line_v2(p4, p1, v2, v3) || isect_line_line_v2(p4, p1, v3, v4)))
2677                 {
2678                         return 1;
2679                 }
2680         }
2681         else {
2682                 if (isect_point_tri_v2(p1, v1, v2, v3) ||
2683                     isect_point_tri_v2(p2, v1, v2, v3) ||
2684                     isect_point_tri_v2(p3, v1, v2, v3) ||
2685                     isect_point_tri_v2(p4, v1, v2, v3) ||
2686                     /* we can avoid testing v3,v1 because another intersection MUST exist if this intersects */
2687                     (isect_line_line_v2(p1, p2, v1, v2) || isect_line_line_v2(p1, p2, v2, v3)) ||
2688                     (isect_line_line_v2(p2, p3, v1, v2) || isect_line_line_v2(p2, p3, v2, v3)) ||
2689                     (isect_line_line_v2(p3, p4, v1, v2) || isect_line_line_v2(p3, p4, v2, v3)) ||
2690                     (isect_line_line_v2(p4, p1, v1, v2) || isect_line_line_v2(p4, p1, v2, v3)))
2691                 {
2692                         return 1;
2693                 }
2694         }
2695
2696         return 0;
2697 }
2698
2699 /* Add faces to the bucket but don't initialize its pixels
2700  * TODO - when painting occluded, sort the faces on their min-Z and only add faces that faces that are not occluded */
2701 static void project_paint_delayed_face_init(ProjPaintState *ps, const MFace *mf, const int face_index)
2702 {
2703         float min[2], max[2], *vCoSS;
2704         int bucketMin[2], bucketMax[2]; /* for  ps->bucketRect indexing */
2705         int fidx, bucket_x, bucket_y;
2706         int has_x_isect = -1, has_isect = 0; /* for early loop exit */
2707         MemArena *arena = ps->arena_mt[0]; /* just use the first thread arena since threading has not started yet */
2708
2709         INIT_MINMAX2(min, max);
2710
2711         fidx = mf->v4 ? 3 : 2;
2712         do {
2713                 vCoSS = ps->screenCoords[*(&mf->v1 + fidx)];
2714                 minmax_v2v2_v2(min, max, vCoSS);
2715         } while (fidx--);
2716
2717         project_paint_bucket_bounds(ps, min, max, bucketMin, bucketMax);
2718
2719         for (bucket_y = bucketMin[1]; bucket_y < bucketMax[1]; bucket_y++) {
2720                 has_x_isect = 0;
2721                 for (bucket_x = bucketMin[0]; bucket_x < bucketMax[0]; bucket_x++) {
2722                         if (project_bucket_face_isect(ps, bucket_x, bucket_y, mf)) {
2723                                 int bucket_index = bucket_x + (bucket_y * ps->buckets_x);
2724                                 BLI_linklist_prepend_arena(
2725                                         &ps->bucketFaces[bucket_index],
2726                                         SET_INT_IN_POINTER(face_index), /* cast to a pointer to shut up the compiler */
2727                                         arena
2728                                         );
2729
2730                                 has_x_isect = has_isect = 1;
2731                         }
2732                         else if (has_x_isect) {
2733                                 /* assuming the face is not a bow-tie - we know we cant intersect again on the X */
2734                                 break;
2735                         }
2736                 }
2737
2738                 /* no intersection for this entire row, after some intersection above means we can quit now */
2739                 if (has_x_isect == 0 && has_isect) {
2740                         break;
2741                 }
2742         }
2743
2744 #ifndef PROJ_DEBUG_NOSEAMBLEED
2745         if (ps->seam_bleed_px > 0.0f) {
2746                 if (!mf->v4) {
2747                         ps->faceSeamFlags[face_index] |= PROJ_FACE_NOSEAM4; /* so this wont show up as an untagged edge */
2748                 }
2749                 **ps->faceSeamUVs[face_index] = FLT_MAX; /* set as uninitialized */
2750         }
2751 #endif
2752 }
2753
2754 /* run once per stroke before projection painting */
2755 static void project_paint_begin(ProjPaintState *ps)
2756 {
2757         /* Viewport vars */
2758         float mat[3][3];
2759
2760         float no[3];
2761
2762         float *projScreenCo; /* Note, we could have 4D vectors are only needed for */
2763         float projMargin;
2764
2765         /* Image Vars - keep track of images we have used */
2766         LinkNode *image_LinkList = NULL;
2767         LinkNode *node;
2768
2769         ProjPaintImage *projIma;
2770         Image *tpage_last = NULL, *tpage;
2771
2772         /* Face vars */
2773         MFace *mf;
2774         MTFace *tf;
2775
2776         int a, i; /* generic looping vars */
2777         int image_index = -1, face_index;
2778         MVert *mv;
2779
2780         MemArena *arena; /* at the moment this is just ps->arena_mt[0], but use this to show were not multithreading */
2781
2782         const int diameter = 2 * BKE_brush_size_get(ps->scene, ps->brush);
2783
2784         /* ---- end defines ---- */
2785
2786         if (ps->source == PROJ_SRC_VIEW)
2787                 ED_view3d_clipping_local(ps->rv3d, ps->ob->obmat);  /* faster clipping lookups */
2788
2789         /* paint onto the derived mesh */
2790
2791         /* Workaround for subsurf selection, try the display mesh first */
2792         if (ps->source == PROJ_SRC_IMAGE_CAM) {
2793                 /* using render mesh, assume only camera was rendered from */
2794                 ps->dm = mesh_create_derived_render(ps->scene, ps->ob, ps->scene->customdata_mask | CD_MASK_MTFACE);
2795                 ps->dm_release = TRUE;
2796         }
2797         else if (ps->ob->derivedFinal && CustomData_has_layer(&ps->ob->derivedFinal->faceData, CD_MTFACE)) {
2798                 ps->dm = ps->ob->derivedFinal;
2799                 ps->dm_release = FALSE;
2800         }
2801         else {
2802                 ps->dm = mesh_get_derived_final(ps->scene, ps->ob, ps->scene->customdata_mask | CD_MASK_MTFACE);
2803                 ps->dm_release = TRUE;
2804         }
2805
2806         if (!CustomData_has_layer(&ps->dm->faceData, CD_MTFACE) ) {
2807
2808                 if (ps->dm_release)
2809                         ps->dm->release(ps->dm);
2810
2811                 ps->dm = NULL;
2812                 return;
2813         }
2814
2815         ps->dm_mvert = ps->dm->getVertArray(ps->dm);
2816         ps->dm_mface = ps->dm->getTessFaceArray(ps->dm);
2817         ps->dm_mtface = ps->dm->getTessFaceDataArray(ps->dm, CD_MTFACE);
2818
2819         ps->dm_totvert = ps->dm->getNumVerts(ps->dm);
2820         ps->dm_totface = ps->dm->getNumTessFaces(ps->dm);
2821
2822         /* use clone mtface? */
2823
2824
2825         /* Note, use the original mesh for getting the clone and mask layer index
2826          * this avoids re-generating the derived mesh just to get the new index */
2827         if (ps->do_layer_clone) {
2828                 //int layer_num = CustomData_get_clone_layer(&ps->dm->faceData, CD_MTFACE);
2829                 int layer_num = CustomData_get_clone_layer(&((Mesh *)ps->ob->data)->fdata, CD_MTFACE);
2830                 if (layer_num != -1)
2831                         ps->dm_mtface_clone = CustomData_get_layer_n(&ps->dm->faceData, CD_MTFACE, layer_num);
2832
2833                 if (ps->dm_mtface_clone == NULL || ps->dm_mtface_clone == ps->dm_mtface) {
2834                         ps->do_layer_clone = FALSE;
2835                         ps->dm_mtface_clone = NULL;
2836                         printf("ACK!\n");
2837                 }
2838         }
2839
2840         if (ps->do_layer_stencil) {
2841                 //int layer_num = CustomData_get_stencil_layer(&ps->dm->faceData, CD_MTFACE);
2842                 int layer_num = CustomData_get_stencil_layer(&((Mesh *)ps->ob->data)->fdata, CD_MTFACE);
2843                 if (layer_num != -1)
2844                         ps->dm_mtface_stencil = CustomData_get_layer_n(&ps->dm->faceData, CD_MTFACE, layer_num);
2845
2846                 if (ps->dm_mtface_stencil == NULL || ps->dm_mtface_stencil == ps->dm_mtface) {
2847                         ps->do_layer_stencil = FALSE;
2848                         ps->dm_mtface_stencil = NULL;
2849                 }
2850         }
2851
2852         /* when using subsurf or multires, mface arrays are thrown away, we need to keep a copy */
2853         if (ps->dm->type != DM_TYPE_CDDM) {
2854                 ps->dm_mvert = MEM_dupallocN(ps->dm_mvert);
2855                 ps->dm_mface = MEM_dupallocN(ps->dm_mface);
2856                 /* looks like these are ok for now.*/
2857 #if 0
2858                 ps->dm_mtface = MEM_dupallocN(ps->dm_mtface);
2859                 ps->dm_mtface_clone = MEM_dupallocN(ps->dm_mtface_clone);
2860                 ps->dm_mtface_stencil = MEM_dupallocN(ps->dm_mtface_stencil);
2861 #endif
2862         }
2863
2864         ps->viewDir[0] = 0.0f;
2865         ps->viewDir[1] = 0.0f;
2866         ps->viewDir[2] = 1.0f;
2867
2868         {
2869                 float viewmat[4][4];
2870                 float viewinv[4][4];
2871
2872                 invert_m4_m4(ps->ob->imat, ps->ob->obmat);
2873
2874                 if (ps->source == PROJ_SRC_VIEW) {
2875                         /* normal drawing */
2876                         ps->winx = ps->ar->winx;
2877                         ps->winy = ps->ar->winy;
2878
2879                         copy_m4_m4(viewmat, ps->rv3d->viewmat);
2880                         copy_m4_m4(viewinv, ps->rv3d->viewinv);
2881
2882                         ED_view3d_ob_project_mat_get(ps->rv3d, ps->ob, ps->projectMat);
2883
2884                         ps->is_ortho = ED_view3d_clip_range_get(ps->v3d, ps->rv3d, &ps->clipsta, &ps->clipend, true);