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Upgrade Clipper to 07b828b1 to fix self-intersecting polygons

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Eric Fischer
2016-03-18 16:35:29 -07:00
parent 7140a3dd91
commit 707036fe79
10 changed files with 548 additions and 106 deletions
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geometry.cc
+26
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@@ -328,6 +328,32 @@ drawvec clean_or_clip_poly(drawvec &geom, int z, int detail, int buffer, bool cl
return out;
}
void check_polygon(drawvec &geom) {
for (unsigned i = 0; i + 1 < geom.size(); i++) {
for (unsigned j = i + 1; j + 1 < geom.size(); j++) {
if (geom[i + 1].op == VT_LINETO && geom[j + 1].op == VT_LINETO) {
double s1_x = geom[i + 1].x - geom[i + 0].x;
double s1_y = geom[i + 1].y - geom[i + 0].y;
double s2_x = geom[j + 1].x - geom[j + 0].x;
double s2_y = geom[j + 1].y - geom[j + 0].y;
double s, t;
s = (-s1_y * (geom[i + 0].x - geom[j + 0].x) + s1_x * (geom[i + 0].y - geom[j + 0].y)) / (-s2_x * s1_y + s1_x * s2_y);
t = (s2_x * (geom[i + 0].y - geom[j + 0].y) - s2_y * (geom[i + 0].x - geom[j + 0].x)) / (-s2_x * s1_y + s1_x * s2_y);
if (t > 0 && t < 1 && s > 0 && s < 1) {
fprintf(stderr, "Internal error: self-intersecting polygon. %lld,%lld to %lld,%lld intersects %lld,%lld to %lld,%lld\n",
geom[i + 0].x, geom[i + 0].y,
geom[i + 1].x, geom[i + 1].y,
geom[j + 0].x, geom[j + 0].y,
geom[j + 1].x, geom[j + 1].y);
exit(EXIT_FAILURE);
}
}
}
}
}
drawvec close_poly(drawvec &geom) {
drawvec out;