From d403c5b5058c049a435bbc439d78f0a5aa35f3aa Mon Sep 17 00:00:00 2001
From: kramm <kramm>
Date: Thu, 22 May 2008 13:58:21 +0000
Subject: [PATCH] added bleeding detection. polygon operations may now return
NULL on error
---
lib/gfxpoly.c | 227 ++++++++++++++++++++++++++++++++++++++++++++++++++-------
1 file changed, 200 insertions(+), 27 deletions(-)
diff --git a/lib/gfxpoly.c b/lib/gfxpoly.c
index c3bb637..8b914a8 100644
--- a/lib/gfxpoly.c
+++ b/lib/gfxpoly.c
@@ -238,25 +238,180 @@ void show_path(ArtSVP*path)
printf("\n");
}
-void check_svp(ArtSVP*svp)
+
+typedef struct svp_segment_part
+{
+ double y1;
+ double y2;
+ char active;
+} svp_segment_part_t;
+
+int compare_double(const void*_y1, const void*_y2)
+{
+ const double*y1 = _y1;
+ const double*y2 = _y2;
+ if(*y1<*y2) return -1;
+ if(*y1>*y2) return 1;
+ else return 0;
+}
+
+int compare_seg_start(const void*_s1, const void*_s2)
+{
+ svp_segment_part_t*s1 = *(svp_segment_part_t**)_s1;
+ svp_segment_part_t*s2 = *(svp_segment_part_t**)_s2;
+ if(s1->y1 < s2->y1) return -1;
+ if(s1->y1 > s2->y1) return 1;
+ else return 0;
+}
+
+int compare_seg_end(const void*_s1, const void*_s2)
+{
+ svp_segment_part_t*s1 = *(svp_segment_part_t**)_s1;
+ svp_segment_part_t*s2 = *(svp_segment_part_t**)_s2;
+ if(s1->y2 < s2->y2) return -1;
+ if(s1->y2 > s2->y2) return 1;
+ else return 0;
+}
+
+void clean_svp(ArtSVP*svp)
{
int t;
+ int oldpoints = 0;
+ int newpoints = 0;
+ int oldsegs = 0;
+ int newsegs = 0;
for(t=0;t<svp->n_segs;t++) {
ArtSVPSeg* seg = &svp->segs[t];
int p;
+ int pos=0;
+ double lasty = 0;
+ oldpoints += seg->n_points;
+ for(p=0;p<seg->n_points;p++) {
+ ArtPoint* p1 = &seg->points[p];
+ if(!p || lasty!=p1->y) {
+ seg->points[pos] = seg->points[p];
+ pos++;
+ lasty = p1->y;
+ }
+ }
+ seg->n_points = pos;
+ newpoints += seg->n_points;
+ }
+ int pos = 0;
+ oldsegs = svp->n_segs;
+ for(t=0;t<svp->n_segs;t++) {
+ if(svp->segs[t].n_points > 1) {
+ svp->segs[pos++] = svp->segs[t];
+ }
+ }
+ svp->n_segs = pos;
+ newsegs = svp->n_segs;
+ if(newsegs < oldsegs || newpoints < oldpoints) {
+ msg("<verbose> Simplified polygon from %d points to %d points, %d to %d segs",
+ oldpoints, newpoints, oldsegs, newsegs);
+ }
+}
+
+int check_svp(ArtSVP*svp)
+{
+ /* count number of y coordinates and segs */
+ int t;
+ int num_points = 0;
+ int num_segs = 0;
+ for(t=0;t<svp->n_segs;t++) {
+ if(!svp->segs[t].n_points) {
+ msg("<error> svp contains segment with zero points\n");
+ return 0;
+ }
+ num_points += svp->segs[t].n_points;
+ num_segs += svp->segs[t].n_points - 1;
+ }
+
+ /* create segs and ys */
+ double*y = malloc(sizeof(double)*num_points);
+ svp_segment_part_t*segs = malloc(sizeof(svp_segment_part_t)*num_segs);
+ svp_segment_part_t**seg_start = malloc(sizeof(svp_segment_part_t*)*num_segs);
+ svp_segment_part_t**seg_end = malloc(sizeof(svp_segment_part_t*)*num_segs);
+
+ int c1=0;
+ num_segs = 0;
+ for(t=0;t<svp->n_segs;t++) {
+ ArtSVPSeg* seg = &svp->segs[t];
+ int p;
+ for(p=0;p<seg->n_points;p++) {
+ y[c1++] = seg->points[p].y;
+ assert(c1 <= num_points);
+ }
for(p=0;p<seg->n_points-1;p++) {
ArtPoint* p1 = &seg->points[p];
ArtPoint* p2 = &seg->points[p+1];
- if(p1->y > p2->y) {
- fprintf(stderr, "bad svp, y in seg %08x is non-increasing\n");
- exit(0);
- }
+
+ if(p1->y >= p2->y) {
+ msg("<error> bad svp, y in seg is non-increasing %.16f -> %.16f\n", p1->y, p2->y);
+ } else {
+ segs[num_segs].y1 = p1->y;
+ segs[num_segs].y2 = p2->y;
+ segs[num_segs].active = 0;
+ seg_start[num_segs] = &segs[num_segs];
+ seg_end[num_segs] = &segs[num_segs];
+ num_segs++;
+ }
}
}
+
+ qsort(y, num_points, sizeof(double), compare_double);
+ qsort(seg_start, num_segs, sizeof(svp_segment_part_t*), compare_seg_start);
+ qsort(seg_end, num_segs, sizeof(svp_segment_part_t*), compare_seg_end);
+
+ double lasty = y[0]+1;
+ int num_active = 0;
+ int bleed = 0;
+ double bleedy1=0,bleedy2 = 0;
+ for(t=0;t<num_points;t++) {
+ if(lasty == y[t])
+ continue;
+ int s;
+ for(s=0;s<num_segs;s++) {
+ if(segs[s].y1==y[t]) {
+ /* segment is starting */
+ segs[s].active = 1;
+ num_active++;
+ } else if(segs[s].y2==y[t]) {
+ segs[s].active = 0;
+ num_active--;
+ }
+ }
+ if(num_active&1) {
+ bleed = num_active;
+ bleedy1 = y[t];
+ } else {
+ if(bleed) {
+ bleedy2 = y[t];
+ break;
+ }
+ }
+ lasty = y[t];
+ }
+ if(bleed) {
+ msg("<warning> svp bleeds from y=%.16f to y=%.16f (%d/%d active segments)\n",
+ bleedy1, bleedy2,
+ bleed, num_segs);
+ free(y);free(segs);free(seg_start);free(seg_end);
+ return 0;
+ }
+
+ free(y);
+ free(segs);
+ free(seg_start);
+ free(seg_end);
+
+ return 1;
}
void write_svp_postscript(const char*filename, ArtSVP*svp)
{
+ if(!svp)
+ return;
printf("writing %s\n", filename);
FILE*fi = fopen(filename, "wb");
int i, j;
@@ -438,36 +593,50 @@ static ArtSVP* gfxfillToSVP(gfxline_t*line, int perturb)
return svp;
}
+//#ifdef SHEAR
+// double shear = find_shear_value(svp);
+// gfxline_t*line = gfxpoly_to_gfxline((gfxpoly_t*)svp);
+// gfxline_t*l = line;
+// while(l) {
+// l->y += l->x*shear;
+// l->sy += l->sx*shear;
+// l= l->next;
+// }
+// svp = (ArtSVP*)gfxpoly_fillToPoly(line);
+// printf("shearing svp by %.16f\n", shear);
+//#endif
+// ....
+//#ifdef SHEAR
+// art_svp_free(svp);
+// shear_svp(result, -shear);
+//#endif
+
+
+
+extern const ArtSVP* current_svp;
+extern void art_report_error();
+extern int art_error_in_intersector;
+
ArtSVP* run_intersector(ArtSVP*svp, ArtWindRule rule)
{
ArtSvpWriter * swr = art_svp_writer_rewind_new(rule);
-#ifdef SHEAR
- double shear = find_shear_value(svp);
- gfxline_t*line = gfxpoly_to_gfxline((gfxpoly_t*)svp);
- gfxline_t*l = line;
- while(l) {
- l->y += l->x*shear;
- l->sy += l->sx*shear;
- l= l->next;
- }
- svp = (ArtSVP*)gfxpoly_fillToPoly(line);
- printf("shearing svp by %.16f\n", shear);
-#endif
-
art_svp_intersector(svp, swr);
ArtSVP*result = art_svp_writer_rewind_reap(swr);
- check_svp(result);
-
-#ifdef SHEAR
- art_svp_free(svp);
- shear_svp(result, -shear);
-#endif
-
+ clean_svp(result);
+ if(!check_svp(result)) {
+ msg("<warning> Error in polygon processing");
+ current_svp = result;
+ art_report_error(); // might set art_error_in_intersector
+ }
+ if(art_error_in_intersector) {
+ art_svp_free(result);
+ art_error_in_intersector=0;
+ return 0;
+ }
return result;
}
-
gfxline_t* gfxpoly_to_gfxline(gfxpoly_t*poly)
{
ArtSVP*svp = (ArtSVP*)poly;
@@ -554,7 +723,7 @@ gfxpoly_t* gfxpoly_fillToPoly(gfxline_t*line)
gfxpoly_t* gfxpoly_intersect(gfxpoly_t*poly1, gfxpoly_t*poly2)
{
ArtSvpWriter *swr;
-
+
static int counter = 0;
ArtSVP* svp1 = (ArtSVP*)poly1;
@@ -640,6 +809,10 @@ gfxline_t* gfxline_circularToEvenOdd(gfxline_t*line)
ArtSVP* svp_rewinded;
svp_rewinded = run_intersector(svp, ART_WIND_RULE_POSITIVE);
+ if(!svp_rewinded) {
+ art_svp_free(svp);
+ return 0;
+ }
gfxline_t* result = gfxpoly_to_gfxline((gfxpoly_t*)svp_rewinded);
art_svp_free(svp);
--
1.7.10.4