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Upgrade Wagyu to cfc895 and use its Sutherland-Hodgman implementation

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This commit is contained in:
Eric Fischer
2017-01-11 15:43:07 -08:00
parent 2fdec7d2e4
commit 72086b7e92
6 changed files with 146 additions and 99 deletions
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geometry.cpp
-94
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@@ -424,100 +424,6 @@ drawvec close_poly(drawvec &geom) {
return out;
}
static bool inside(draw d, int edge, long long minx, long long miny, long long maxx, long long maxy) {
switch (edge) {
case 0: // top
return d.y > miny;
case 1: // right
return d.x < maxx;
case 2: // bottom
return d.y < maxy;
case 3: // left
return d.x > minx;
}
fprintf(stderr, "internal error inside\n");
exit(EXIT_FAILURE);
}
static draw intersect(draw a, draw b, int edge, long long minx, long long miny, long long maxx, long long maxy) {
// The casts to double are because the product of coordinates
// can overflow a long long if the tile buffer is large.
switch (edge) {
case 0: // top
return draw(VT_LINETO, a.x + (double) (b.x - a.x) * (miny - a.y) / (b.y - a.y), miny);
case 1: // right
return draw(VT_LINETO, maxx, a.y + (double) (b.y - a.y) * (maxx - a.x) / (b.x - a.x));
case 2: // bottom
return draw(VT_LINETO, a.x + (double) (b.x - a.x) * (maxy - a.y) / (b.y - a.y), maxy);
case 3: // left
return draw(VT_LINETO, minx, a.y + (double) (b.y - a.y) * (minx - a.x) / (b.x - a.x));
}
fprintf(stderr, "internal error intersecting\n");
exit(EXIT_FAILURE);
}
// http://en.wikipedia.org/wiki/Sutherland%E2%80%93Hodgman_algorithm
static drawvec clip_poly1(drawvec &geom, long long minx, long long miny, long long maxx, long long maxy) {
drawvec out = geom;
for (int edge = 0; edge < 4; edge++) {
if (out.size() > 0) {
drawvec in = out;
out.resize(0);
draw S = in[in.size() - 1];
for (size_t e = 0; e < in.size(); e++) {
draw E = in[e];
if (inside(E, edge, minx, miny, maxx, maxy)) {
if (!inside(S, edge, minx, miny, maxx, maxy)) {
out.push_back(intersect(S, E, edge, minx, miny, maxx, maxy));
}
out.push_back(E);
} else if (inside(S, edge, minx, miny, maxx, maxy)) {
out.push_back(intersect(S, E, edge, minx, miny, maxx, maxy));
}
S = E;
}
}
}
if (out.size() > 0) {
// If the polygon begins and ends outside the edge,
// the starting and ending points will be left as the
// places where it intersects the edge. Need to add
// another point to close the loop.
if (out[0].x != out[out.size() - 1].x || out[0].y != out[out.size() - 1].y) {
out.push_back(out[0]);
}
if (out.size() < 3) {
// fprintf(stderr, "Polygon degenerated to a line segment\n");
out.clear();
return out;
}
out[0].op = VT_MOVETO;
for (size_t i = 1; i < out.size(); i++) {
out[i].op = VT_LINETO;
}
}
return out;
}
drawvec simple_clip_poly(drawvec &geom, long long minx, long long miny, long long maxx, long long maxy) {
drawvec out;