1 #define IMAGER_NO_CONTEXT
2 #include "imager.h"
3 #include "draw.h"
4 #include "log.h"
5 #include "imrender.h"
6 #include "imageri.h"
7
8 #define IMTRUNC(x) ((int)((x)*16))
9
10 #define coarse(x) ((x)/16)
11 #define fine(x) ((x)%16)
12
13 /*#define DEBUG_POLY*/
14 #ifdef DEBUG_POLY
15 #define POLY_DEB(x) x
16 #else
17 #define POLY_DEB(x)
18 #endif
19
20
21 typedef i_img_dim pcord;
22
23 typedef struct {
24 size_t n;
25 pcord x,y;
26 } p_point;
27
28 typedef struct {
29 size_t n;
30 pcord x1,y1;
31 pcord x2,y2;
32 pcord miny,maxy;
33 pcord minx,maxx;
34 int updown; /* -1 means down, 0 vertical, 1 up */
35 int dir; /* 1 for down, -1 for up */
36 } p_line;
37
38 typedef struct {
39 size_t n;
40 double x;
41 } p_slice;
42
43 typedef struct {
44 int *line; /* temporary buffer for scanline */
45 i_img_dim linelen; /* length of scanline */
46 } ss_scanline;
47
48 static
49 int
p_compy(const p_point * p1,const p_point * p2)50 p_compy(const p_point *p1, const p_point *p2) {
51 if (p1->y > p2->y) return 1;
52 if (p1->y < p2->y) return -1;
53 return 0;
54 }
55
56 static
57 int
p_compx(const p_slice * p1,const p_slice * p2)58 p_compx(const p_slice *p1, const p_slice *p2) {
59 if (p1->x > p2->x) return 1;
60 if (p1->x < p2->x) return -1;
61 return 0;
62 }
63
64 /* Change this to int? and round right goddamn it! */
65
66 static
67 double
p_eval_aty(p_line * l,pcord y)68 p_eval_aty(p_line *l, pcord y) {
69 int t;
70 t=l->y2-l->y1;
71 if (t) return ( (y-l->y1)*l->x2 + (l->y2-y)*l->x1 )/t;
72 return (l->x1+l->x2)/2.0;
73 }
74
75 static
76 double
p_eval_atx(p_line * l,pcord x)77 p_eval_atx(p_line *l, pcord x) {
78 int t;
79 t = l->x2-l->x1;
80 if (t) return ( (x-l->x1)*l->y2 + (l->x2-x)*l->y1 )/t;
81 return (l->y1+l->y2)/2.0;
82 }
83
84 static
85 p_line *
line_set_new(const i_polygon_t * polys,size_t count,size_t * line_count)86 line_set_new(const i_polygon_t *polys, size_t count, size_t *line_count) {
87 size_t i, j, n;
88 p_line *lset, *line;
89 size_t lines = 0;
90
91 for (i = 0; i < count; ++i)
92 lines += polys[i].count;
93
94 line = lset = mymalloc(sizeof(p_line) * lines);
95
96 n = 0;
97 for (i = 0; i < count; ++i) {
98 const i_polygon_t *p = polys + i;
99
100 for(j = 0; j < p->count; j++) {
101 line->x1 = IMTRUNC(p->x[j]);
102 line->y1 = IMTRUNC(p->y[j]);
103 line->x2 = IMTRUNC(p->x[(j + 1) % p->count]);
104 line->y2 = IMTRUNC(p->y[(j + 1) % p->count]);
105
106 /* don't include purely horizontal lines, we don't usefully
107 intersect with them. */
108 if (line->y1 == line->y2)
109 continue;
110
111 line->miny = i_min(line->y1, line->y2);
112 line->maxy = i_max(line->y1, line->y2);
113 line->minx = i_min(line->x1, line->x2);
114 line->maxx = i_max(line->x1, line->x2);
115 line->n = n++;
116 ++line;
117 }
118 }
119 *line_count = n;
120
121 return lset;
122 }
123
124 static
125 p_point *
point_set_new(const i_polygon_t * polys,size_t count,size_t * point_count)126 point_set_new(const i_polygon_t *polys, size_t count, size_t *point_count) {
127 size_t i, j, n;
128 p_point *pset, *pt;
129 size_t points = 0;
130
131 for (i = 0; i < count; ++i)
132 points += polys[i].count;
133
134 *point_count = points;
135
136 pt = pset = mymalloc(sizeof(p_point) * points);
137
138 n = 0;
139 for (i = 0; i < count; ++i) {
140 const i_polygon_t *p = polys + i;
141
142 for(j = 0; j < p->count; j++) {
143 pt->n = n++;
144 pt->x = IMTRUNC(p->x[j]);
145 pt->y = IMTRUNC(p->y[j]);
146 ++pt;
147 }
148 }
149 return pset;
150 }
151
152 static
153 void
ss_scanline_reset(ss_scanline * ss)154 ss_scanline_reset(ss_scanline *ss) {
155 memset(ss->line, 0, sizeof(int) * ss->linelen);
156 }
157
158 static
159 void
ss_scanline_init(ss_scanline * ss,i_img_dim linelen,int linepairs)160 ss_scanline_init(ss_scanline *ss, i_img_dim linelen, int linepairs) {
161 ss->line = mymalloc( sizeof(int) * linelen );
162 ss->linelen = linelen;
163 ss_scanline_reset(ss);
164 }
165
166 static
167 void
ss_scanline_exorcise(ss_scanline * ss)168 ss_scanline_exorcise(ss_scanline *ss) {
169 myfree(ss->line);
170 }
171
172
173
174
175 /* returns the number of matches */
176
177 static
178 int
lines_in_interval(p_line * lset,int l,p_slice * tllist,pcord minc,pcord maxc)179 lines_in_interval(p_line *lset, int l, p_slice *tllist, pcord minc, pcord maxc) {
180 int k;
181 int count = 0;
182 for(k=0; k<l; k++) {
183 if (lset[k].maxy > minc && lset[k].miny < maxc) {
184 if (lset[k].miny == lset[k].maxy) {
185 POLY_DEB( printf(" HORIZONTAL - skipped\n") );
186 } else {
187 tllist[count].x=p_eval_aty(&lset[k],(minc+maxc)/2.0 );
188 tllist[count].n=k;
189 count++;
190 }
191 }
192 }
193 return count;
194 }
195
196 /* marks the up variable for all lines in a slice */
197
198 static
199 void
mark_updown_slices(pIMCTX,p_line * lset,p_slice * tllist,int count)200 mark_updown_slices(pIMCTX, p_line *lset, p_slice *tllist, int count) {
201 p_line *l, *r;
202 int k;
203 for(k=0; k<count; k+=2) {
204 l = lset + tllist[k].n;
205
206 if (l->y1 == l->y2) {
207 im_log((aIMCTX,1, "mark_updown_slices: horizontal line being marked: internal error!\n"));
208 exit(3);
209 }
210
211 l->updown = (l->x1 == l->x2) ?
212 0 :
213 (l->x1 > l->x2)
214 ?
215 (l->y1 > l->y2) ? -1 : 1
216 :
217 (l->y1 > l->y2) ? 1 : -1;
218 l->dir = l->y1 < l->y2 ? 1 : -1;
219
220 POLY_DEB( printf("marking left line %d as %s(%d)\n", l->n,
221 l->updown ? l->updown == 1 ? "up" : "down" : "vert", l->updown, l->updown)
222 );
223
224 if (k+1 >= count) {
225 im_log((aIMCTX, 1, "Invalid polygon spec, odd number of line crossings.\n"));
226 return;
227 }
228
229 r = lset + tllist[k+1].n;
230 if (r->y1 == r->y2) {
231 im_log((aIMCTX, 1, "mark_updown_slices: horizontal line being marked: internal error!\n"));
232 exit(3);
233 }
234
235 r->updown = (r->x1 == r->x2) ?
236 0 :
237 (r->x1 > r->x2)
238 ?
239 (r->y1 > r->y2) ? -1 : 1
240 :
241 (r->y1 > r->y2) ? 1 : -1;
242 r->dir = r->y1 < r->y2 ? 1 : -1;
243
244 POLY_DEB( printf("marking right line %d as %s(%d)\n", r->n,
245 r->updown ? r->updown == 1 ? "up" : "down" : "vert", r->updown, r->updown)
246 );
247 }
248 }
249
250 static
251 unsigned char
saturate(int in)252 saturate(int in) {
253 if (in>255) { return 255; }
254 else if (in>0) return in;
255 return 0;
256 }
257
258 typedef void (*scanline_flusher)(i_img *im, ss_scanline *ss, int y, void *ctx);
259
260 /* This function must be modified later to do proper blending */
261
262 static void
scanline_flush(i_img * im,ss_scanline * ss,int y,void * ctx)263 scanline_flush(i_img *im, ss_scanline *ss, int y, void *ctx) {
264 int x, ch, tv;
265 i_color t;
266 i_color *val = (i_color *)ctx;
267 POLY_DEB( printf("Flushing line %d\n", y) );
268 for(x=0; x<im->xsize; x++) {
269 tv = saturate(ss->line[x]);
270 i_gpix(im, x, y, &t);
271 for(ch=0; ch<im->channels; ch++)
272 t.channel[ch] = tv/255.0 * val->channel[ch] + (1.0-tv/255.0) * t.channel[ch];
273 i_ppix(im, x, y, &t);
274 }
275 }
276
277
278
279 static
280 int
trap_square(pcord xlen,pcord ylen,double xl,double yl)281 trap_square(pcord xlen, pcord ylen, double xl, double yl) {
282 POLY_DEB( printf("trap_square: %d %d %.2f %.2f\n", xlen, ylen, xl, yl) );
283 return xlen*ylen-(xl*yl)/2.0;
284 }
285
286
287 /*
288 pixel_coverage calculates the 'left side' pixel coverage of a pixel that is
289 within the min/max ranges. The shape always corresponds to a square with some
290 sort of a triangle cut from it (which can also yield a triangle).
291 */
292
293
294 static
295 int
pixel_coverage(p_line * line,pcord minx,pcord maxx,pcord miny,pcord maxy)296 pixel_coverage(p_line *line, pcord minx, pcord maxx, pcord miny, pcord maxy) {
297 double lycross, rycross;
298 int l, r;
299
300 POLY_DEB
301 (
302 printf(" pixel_coverage(..., minx %g, maxx%g, miny %g, maxy %g)\n",
303 minx/16.0, maxx/16.0, miny/16.0, maxy/16.0)
304 );
305
306 if (!line->updown) {
307 l = r = 0;
308 } else {
309 lycross = p_eval_atx(line, minx);
310 rycross = p_eval_atx(line, maxx);
311 l = lycross <= maxy && lycross >= miny; /* true if it enters through left side */
312 r = rycross <= maxy && rycross >= miny; /* true if it enters through left side */
313 }
314 POLY_DEB(
315 printf(" %4s(%+d): ", line->updown ? line->updown == 1 ? "up" : "down" : "vert", line->updown);
316 printf(" (%2d,%2d) [%3d-%3d, %3d-%3d] lycross=%.2f rycross=%.2f", coarse(minx), coarse(miny), minx, maxx, miny, maxy, lycross, rycross);
317 printf(" l=%d r=%d\n", l, r)
318 );
319
320 if (l && r)
321 return line->updown == 1 ?
322 (double)(maxx-minx) * (2.0*maxy-lycross-rycross)/2.0 /* up case */
323 :
324 (double)(maxx-minx) * (lycross+rycross-2*miny)/2.0; /* down case */
325
326 if (!l && !r) return (maxy-miny)*(maxx*2-p_eval_aty(line, miny)-p_eval_aty(line, maxy))/2.0;
327
328 if (l && !r)
329 return line->updown == 1 ?
330 trap_square(maxx-minx, maxy-miny, p_eval_aty(line, miny)-minx, p_eval_atx(line, minx)-miny) :
331 trap_square(maxx-minx, maxy-miny, p_eval_aty(line, maxy)-minx, maxy-p_eval_atx(line, minx));
332
333
334 if (!l && r) {
335 int r = line->updown == 1 ?
336 (maxx-p_eval_aty(line, maxy))*(maxy-p_eval_atx(line, maxx))/2.0 :
337 (maxx-p_eval_aty(line, miny))*(p_eval_atx(line, maxx)-miny)/2.0;
338 return r;
339 }
340
341 /* NOTREACHED */
342 return 0; /* silence compiler warning */
343 }
344
345
346
347
348
349 /*
350 handle the scanline slice in three steps
351
352 1. Where only the left edge is inside a pixel
353 2a. Where both left and right edge are inside a pixel
354 2b. Where neither left or right edge are inside a pixel
355 3. Where only the right edge is inside a pixel
356 */
357
358 static
359 void
render_slice_scanline(ss_scanline * ss,int y,p_line * l,p_line * r,pcord miny,pcord maxy)360 render_slice_scanline(ss_scanline *ss, int y, p_line *l, p_line *r, pcord miny, pcord maxy) {
361
362 pcord lminx, lmaxx; /* left line min/max within y bounds in fine coords */
363 pcord rminx, rmaxx; /* right line min/max within y bounds in fine coords */
364 i_img_dim cpix; /* x-coordinate of current pixel */
365 i_img_dim startpix; /* temporary variable for "start of this interval" */
366 i_img_dim stoppix; /* temporary variable for "end of this interval" */
367
368 /* Find the y bounds of scanline_slice */
369
370 POLY_DEB
371 (
372 printf("render_slice_scanline(..., y=%d)\n");
373 printf(" left n=%d p1(%.2g, %.2g) p2(%.2g,%.2g) min(%.2g, %.2g) max(%.2g,%.2g) updown(%d)\n",
374 l->n, l->x1/16.0, l->y1/16.0, l->x2/16.0, l->y2/16.0,
375 l->minx/16.0, l->miny/16.0, l->maxx/16.0, l->maxy/16.0,
376 l->updown);
377 printf(" right n=%d p1(%.2g, %.2g) p2(%.2g,%.2g) min(%.2g, %.2g) max(%.2g,%.2g) updown(%d)\n",
378 r->n, r->x1/16.0, r->y1/16.0, r->x2/16.0, r->y2/16.0,
379 r->minx/16.0, r->miny/16.0, r->maxx/16.0, r->maxy/16.0,
380 r->updown);
381 );
382
383 lminx = i_min( p_eval_aty(l, maxy), p_eval_aty(l, miny) );
384 lmaxx = i_max( p_eval_aty(l, maxy), p_eval_aty(l, miny) );
385
386 rminx = i_min( p_eval_aty(r, maxy), p_eval_aty(r, miny) );
387 rmaxx = i_max( p_eval_aty(r, maxy), p_eval_aty(r, miny) );
388
389 startpix = i_max( coarse(lminx), 0 );
390 stoppix = i_min( coarse(rmaxx-1), ss->linelen-1 );
391
392 POLY_DEB( printf(" miny=%g maxy=%g\n", miny/16.0, maxy/16.0) );
393
394 for(cpix=startpix; cpix<=stoppix; cpix++) {
395 int lt = coarse(lmaxx-1) >= cpix;
396 int rt = coarse(rminx) <= cpix;
397
398 int A, B, C;
399
400 POLY_DEB( printf(" (%d,%d) lt=%d rt=%d\n", cpix, y, lt, rt) );
401
402 A = lt ? pixel_coverage(l, cpix*16, cpix*16+16, miny, maxy) : 0;
403 B = lt ? 0 : 16*(maxy-miny);
404 C = rt ? pixel_coverage(r, cpix*16, cpix*16+16, miny, maxy) : 0;
405
406 POLY_DEB( printf(" A=%d B=%d C=%d\n", A, B, C) );
407
408 ss->line[cpix] += A+B-C;
409
410 }
411 POLY_DEB( printf("end render_slice_scanline()\n") );
412 }
413
414 /* Antialiasing polygon algorithm
415 specs:
416 1. only nice polygons - no crossovers
417 2. 1/16 pixel resolution
418 3. full antialiasing ( complete spectrum of blends )
419 4. uses hardly any memory
420 5. no subsampling phase
421
422
423 Algorithm outline:
424 1. Split into vertical intervals.
425 2. handle each interval
426
427 For each interval we must:
428 1. find which lines are in it
429 2. order the lines from in increasing x order.
430 since we are assuming no crossovers it is sufficent
431 to check a single point on each line.
432 */
433
434 /*
435 Definitions:
436
437 1. Interval: A vertical segment in which no lines cross nor end.
438 2. Scanline: A physical line, contains 16 subpixels in the horizontal direction
439 3. Slice: A start stop line pair.
440
441 */
442
443
444 static int
i_poly_poly_aa_low(i_img * im,int count,const i_polygon_t * polys,i_poly_fill_mode_t mode,void * ctx,scanline_flusher flusher)445 i_poly_poly_aa_low(i_img *im, int count, const i_polygon_t *polys,
446 i_poly_fill_mode_t mode, void *ctx,
447 scanline_flusher flusher) {
448 int i ,k; /* Index variables */
449 i_img_dim clc; /* Lines inside current interval */
450 /* initialize to avoid compiler warnings */
451 pcord tempy = 0;
452 i_img_dim cscl = 0; /* Current scanline */
453
454 ss_scanline templine; /* scanline accumulator */
455 p_point *pset; /* List of points in polygon */
456 p_line *lset; /* List of lines in polygon */
457 p_slice *tllist; /* List of slices */
458 size_t pcount, lcount;
459 dIMCTX;
460
461 im_log((aIMCTX, 1, "i_poly_poly_aa_low(im %p, count %d, polys %p, ctx %p, flusher %p)\n", im, count, polys, ctx, flusher));
462
463 i_clear_error();
464
465 if (count < 1) {
466 i_push_error(0, "no polygons to draw");
467 return 0;
468 }
469
470 for (k = 0; k < count; ++k) {
471 if (polys[k].count < 3) {
472 i_push_error(0, "polygons must have at least 3 points");
473 return 0;
474 }
475 }
476
477 for (k = 0; k < count; ++k) {
478 const i_polygon_t *p = polys + k;
479 im_log((aIMCTX, 2, "poly %d\n", k));
480 for(i = 0; i < p->count; i++) {
481 im_log((aIMCTX, 2, " (%.2f, %.2f)\n", p->x[i], p->y[i]));
482 }
483 }
484
485
486 POLY_DEB(
487 fflush(stdout);
488 setbuf(stdout, NULL);
489 );
490
491 pset = point_set_new(polys, count, &pcount);
492 lset = line_set_new(polys, count, &lcount);
493
494 ss_scanline_init(&templine, im->xsize, lcount);
495
496 tllist = mymalloc(sizeof(p_slice) * lcount);
497
498 qsort(pset, pcount, sizeof(p_point), (int(*)(const void *,const void *))p_compy);
499
500 POLY_DEB(
501 for(i=0;i<lcount;i++) {
502 printf("%d [ %d ] (%d , %d) -> (%d , %d) yspan ( %d , %d )\n",
503 i, lset[i].n, lset[i].x1, lset[i].y1, lset[i].x2, lset[i].y2, lset[i].miny, lset[i].maxy);
504 }
505 printf("MAIN LOOP\n\n");
506 );
507
508
509 /* loop on intervals */
510 for(i=0; i<pcount-1; i++) {
511 i_img_dim startscan = i_max( coarse(pset[i].y), 0);
512 i_img_dim stopscan = i_min( coarse(pset[i+1].y+15), im->ysize);
513 pcord miny, maxy; /* y bounds in fine coordinates */
514
515 POLY_DEB( pcord cc = (pset[i].y + pset[i+1].y)/2 );
516
517 POLY_DEB(
518 printf("current slice is %d: %d to %d ( cpoint %d ) scanlines %d to %d\n",
519 i, pset[i].y, pset[i+1].y, cc, startscan, stopscan)
520 );
521
522 if (pset[i].y == pset[i+1].y) {
523 POLY_DEB( printf("current slice thickness = 0 => skipping\n") );
524 continue;
525 }
526
527 clc = lines_in_interval(lset, lcount, tllist, pset[i].y, pset[i+1].y);
528 qsort(tllist, clc, sizeof(p_slice), (int(*)(const void *,const void *))p_compx);
529
530 mark_updown_slices(aIMCTX, lset, tllist, clc);
531
532 POLY_DEB
533 (
534 printf("Interval contains %d lines\n", clc);
535 for(k=0; k<clc; k++) {
536 int lno = tllist[k].n;
537 p_line *ln = lset+lno;
538 printf("%d: line #%2d: (%2d, %2d)->(%2d, %2d) (%2d/%2d, %2d/%2d) -> (%2d/%2d, %2d/%2d) alignment=%s\n",
539 k, lno, ln->x1, ln->y1, ln->x2, ln->y2,
540 coarse(ln->x1), fine(ln->x1),
541 coarse(ln->y1), fine(ln->y1),
542 coarse(ln->x2), fine(ln->x2),
543 coarse(ln->y2), fine(ln->y2),
544 ln->updown == 0 ? "vert" : ln->updown == 1 ? "up" : "down");
545
546 }
547 );
548 maxy = im->ysize * 16;
549 miny = 0;
550 for (k = 0; k < clc; ++k) {
551 p_line const * line = lset + tllist[k].n;
552 if (line->miny > miny)
553 miny = line->miny;
554 if (line->maxy < maxy)
555 maxy = line->maxy;
556 POLY_DEB( printf(" line miny %g maxy %g\n", line->miny/16.0, line->maxy/16.0) );
557 }
558 POLY_DEB( printf("miny %g maxy %g\n", miny/16.0, maxy/16.0) );
559
560 for(cscl=startscan; cscl<stopscan; cscl++) {
561 pcord scan_miny = i_max(miny, cscl * 16);
562 pcord scan_maxy = i_min(maxy, (cscl + 1 ) * 16);
563
564 tempy = i_min(cscl*16+16, pset[i+1].y);
565 POLY_DEB( printf("evaluating scan line %d \n", cscl) );
566 if (mode == i_pfm_evenodd) {
567 for(k=0; k<clc-1; k+=2) {
568 POLY_DEB( printf("evaluating slice %d\n", k) );
569 render_slice_scanline(&templine, cscl, lset+tllist[k].n, lset+tllist[k+1].n, scan_miny, scan_maxy);
570 }
571 }
572 else {
573 k = 0;
574 while (k < clc) {
575 p_line *left = lset + tllist[k++].n;
576 p_line *current = NULL;
577 int acc = left->dir;
578
579 while (k < clc && acc) {
580 current = lset + tllist[k++].n;
581 acc += current->dir;
582 }
583 if (acc == 0) {
584 render_slice_scanline(&templine, cscl, left, current,
585 scan_miny, scan_maxy);
586 }
587 }
588 }
589 if (16*coarse(tempy) == tempy) {
590 POLY_DEB( printf("flushing scan line %d\n", cscl) );
591 flusher(im, &templine, cscl, ctx);
592 ss_scanline_reset(&templine);
593 }
594 /*
595 else {
596 scanline_flush(im, &templine, cscl, val);
597 ss_scanline_reset(&templine);
598 return 0;
599 }
600 */
601 }
602 } /* Intervals */
603 if (16*coarse(tempy) != tempy)
604 flusher(im, &templine, cscl-1, ctx);
605
606 ss_scanline_exorcise(&templine);
607 myfree(pset);
608 myfree(lset);
609 myfree(tllist);
610
611 return 1;
612 }
613
614 /*
615 =item i_poly_poly_aa(im, count, polys, mode, color)
616 =synopsis i_poly_poly_aa(im, 1, &poly, mode, color);
617 =category Drawing
618
619 Fill the C<count> polygons defined by C<polys> the color specified by
620 C<color>.
621
622 At least one polygon must be supplied.
623
624 All polygons must have at least 3 points.
625
626 =cut
627 */
628
629 int
i_poly_poly_aa(i_img * im,int count,const i_polygon_t * polys,i_poly_fill_mode_t mode,const i_color * val)630 i_poly_poly_aa(i_img *im, int count, const i_polygon_t *polys,
631 i_poly_fill_mode_t mode, const i_color *val) {
632 i_color c = *val;
633 return i_poly_poly_aa_low(im, count, polys, mode, &c, scanline_flush);
634 }
635
636 /*
637 =item i_poly_aa_m(im, count, x, y, mode, color)
638 =synopsis i_poly_aa_m(im, count, x, y, mode, color);
639 =category Drawing
640
641 Fill a polygon defined by the points specified by the x and y arrays with
642 the color specified by C<color>.
643
644 =cut
645 */
646
647 int
i_poly_aa_m(i_img * im,int l,const double * x,const double * y,i_poly_fill_mode_t mode,const i_color * val)648 i_poly_aa_m(i_img *im, int l, const double *x, const double *y,
649 i_poly_fill_mode_t mode, const i_color *val) {
650 i_polygon_t poly;
651
652 poly.count = l;
653 poly.x = x;
654 poly.y = y;
655 return i_poly_poly_aa(im, 1, &poly, mode, val);
656 }
657
658 int
i_poly_aa(i_img * im,int l,const double * x,const double * y,const i_color * val)659 i_poly_aa(i_img *im, int l, const double *x, const double *y, const i_color *val) {
660 i_polygon_t poly;
661
662 poly.count = l;
663 poly.x = x;
664 poly.y = y;
665 return i_poly_poly_aa(im, 1, &poly, i_pfm_evenodd, val);
666 }
667
668 struct poly_render_state {
669 i_render render;
670 i_fill_t *fill;
671 unsigned char *cover;
672 };
673
674 static void
scanline_flush_render(i_img * im,ss_scanline * ss,int y,void * ctx)675 scanline_flush_render(i_img *im, ss_scanline *ss, int y, void *ctx) {
676 i_img_dim x;
677 i_img_dim left, right;
678 struct poly_render_state *state = (struct poly_render_state *)ctx;
679
680 left = 0;
681 while (left < im->xsize && ss->line[left] <= 0)
682 ++left;
683 if (left < im->xsize) {
684 right = im->xsize;
685 /* since going from the left found something, moving from the
686 right should */
687 while (/* right > left && */ ss->line[right-1] <= 0)
688 --right;
689
690 /* convert to the format the render interface wants */
691 for (x = left; x < right; ++x) {
692 state->cover[x-left] = saturate(ss->line[x]);
693 }
694 i_render_fill(&state->render, left, y, right-left, state->cover,
695 state->fill);
696 }
697 }
698
699 /*
700 =item i_poly_poly_aa_cfill(im, count, polys, mode, fill)
701 =synopsis i_poly_poly_aa_cfill(im, 1, &poly, mode, fill);
702 =category Drawing
703
704 Fill the C<count> polygons defined by C<polys> the fill specified by
705 C<fill>.
706
707 At least one polygon must be supplied.
708
709 All polygons must have at least 3 points.
710
711 =cut
712 */
713
714 int
i_poly_poly_aa_cfill(i_img * im,int count,const i_polygon_t * polys,i_poly_fill_mode_t mode,i_fill_t * fill)715 i_poly_poly_aa_cfill(i_img *im, int count, const i_polygon_t *polys,
716 i_poly_fill_mode_t mode, i_fill_t *fill) {
717 struct poly_render_state ctx;
718 int result;
719
720 i_render_init(&ctx.render, im, im->xsize);
721 ctx.fill = fill;
722 ctx.cover = mymalloc(im->xsize);
723
724 result = i_poly_poly_aa_low(im, count, polys, mode, &ctx,
725 scanline_flush_render);
726
727 myfree(ctx.cover);
728 i_render_done(&ctx.render);
729
730 return result;
731 }
732
733 /*
734 =item i_poly_aa_cfill_m(im, count, x, y, mode, fill)
735 =synopsis i_poly_aa_cfill(im, count, x, y, mode, fill);
736 =category Drawing
737
738 Fill a polygon defined by the points specified by the x and y arrays with
739 the fill specified by C<fill>.
740
741 =cut
742 */
743
744 int
i_poly_aa_cfill_m(i_img * im,int l,const double * x,const double * y,i_poly_fill_mode_t mode,i_fill_t * fill)745 i_poly_aa_cfill_m(i_img *im, int l, const double *x, const double *y,
746 i_poly_fill_mode_t mode, i_fill_t *fill) {
747 i_polygon_t poly;
748
749 poly.count = l;
750 poly.x = x;
751 poly.y = y;
752
753 return i_poly_poly_aa_cfill(im, 1, &poly, mode, fill);
754 }
755
756 int
i_poly_aa_cfill(i_img * im,int l,const double * x,const double * y,i_fill_t * fill)757 i_poly_aa_cfill(i_img *im, int l, const double *x, const double *y,
758 i_fill_t *fill) {
759 i_polygon_t poly;
760
761 poly.count = l;
762 poly.x = x;
763 poly.y = y;
764
765 return i_poly_poly_aa_cfill(im, 1, &poly, i_pfm_evenodd, fill);
766 }
767