@xtor/cga.js
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Xtor Compute Geometry Algorithm Libary 计算几何算法库
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JavaScript
;
Object.defineProperty(exports, "__esModule", { value: true });
exports.DelaunaySlow = void 0;
var Vec3_1 = require("../math/Vec3");
var Circle_1 = require("../struct/3d/Circle");
/**
* 只考虑2d的散点，如果是3d的以后会新建一个Delaunay3
*/
var EPSILON = 1.0 / 1048576.0;
var DelaunaySlow = /** @class */ (function () {
function DelaunaySlow(vs) {
this.vs = vs;
}
DelaunaySlow.prototype.supertriangle = function (vertices) {
var xmin = +Infinity, ymin = +Infinity, xmax = -Infinity, ymax = -Infinity, i, dx, dy, dmax, xmid, ymid;
for (i = vertices.length; i--;) {
if (vertices[i].x < xmin)
xmin = vertices[i].x;
if (vertices[i].x > xmax)
xmax = vertices[i].x;
if (vertices[i].y < ymin)
ymin = vertices[i].y;
if (vertices[i].y > ymax)
ymax = vertices[i].y;
}
dx = xmax - xmin;
dy = ymax - ymin;
dmax = Math.max(dx, dy);
xmid = xmin + dx * 0.5;
ymid = ymin + dy * 0.5;
return [
new Vec3_1.Vec3(xmid - 20 * dmax, ymid - dmax),
new Vec3_1.Vec3(xmid, ymid + 20 * dmax),
new Vec3_1.Vec3(xmid + 20 * dmax, ymid - dmax)
];
};
DelaunaySlow.prototype.triangulation = function (vs) {
var vslen = vs.length;
if (vslen < 3)
return [];
var indices = new Array(vslen);
for (var i = vslen; i--;)
indices[i] = i;
indices.sort(function (i, j) {
var diff = vs[j].x - vs[i].x;
return diff !== 0 ? diff : i - j;
});
var superTriangle = this.supertriangle(vs);
vs.push.apply(vs, superTriangle); //新加大三角形点
var open = [this.circumcircle(vs, vslen + 0, vslen + 1, vslen + 2)];
var closed = [];
for (var i_1 = indices.length; i_1--;) {
var edges = [];
var c = indices[i_1];
var point = vs[c];
for (var j = open.length; j--;) {
var openj = open[j];
var dx = point.x - open[j].center.x;
if (dx > 0.0 && dx * dx > open[j].radiusSqr) {
closed.push(open[j]);
open.splice(j, 1);
continue;
}
/* If we're outside the circumcircle, skip this triangle. */
var dy = vs[c].y - open[j].center.y;
if (dx * dx + dy * dy - open[j].radiusSqr > EPSILON)
continue;
/* Remove the triangle and add it's edges to the edge list. */
edges.push(openj.i, openj.j, openj.j, openj.k, openj.k, openj.i);
open.splice(j, 1);
}
this.dedup(edges);
for (var j = edges.length; j;) {
var b = edges[--j];
var a = edges[--j];
open.push(this.circumcircle(vs, a, b, c));
}
}
for (i = open.length; i--;)
closed.push(open[i]);
open.length = 0;
var result = [];
for (i = closed.length; i--;) {
var close = closed[i];
if (close.i < vslen && close.j < vslen && close.k < vslen)
result.push(close.i, close.j, close.k);
}
/* Yay, we're done! */
return result;
};
/**
* 外接圆
* @param vertices 点击
* @param i
* @param j
* @param k
*/
DelaunaySlow.prototype.circumcircle = function (vertices, i, j, k) {
var circle = new Circle_1.Circle().setFrom3Points(vertices[i], vertices[j], vertices[k]);
circle.i = i;
circle.j = j;
circle.k = k;
return circle;
};
DelaunaySlow.prototype.dedup = function (edges) {
var i, j, a, b, m, n;
for (j = edges.length; j;) {
b = edges[--j];
a = edges[--j];
for (i = j; i;) {
n = edges[--i];
m = edges[--i];
if ((a === m && b === n) || (a === n && b === m)) {
edges.splice(j, 2);
edges.splice(i, 2);
break;
}
}
}
};
DelaunaySlow.prototype.contains = function (tri, p) {
/* Bounding box test first, for quick rejections. */
if ((p.x < tri[0].x && p.x < tri[1].x && p.x < tri[2].x) ||
(p.x > tri[0].x && p.x > tri[1].x && p.x > tri[2].x) ||
(p.y < tri[0].y && p.y < tri[1].y && p.y < tri[2].y) ||
(p.y > tri[0].y && p.y > tri[1].y && p.y > tri[2].y))
return null;
var a = tri[1].x - tri[0].x, b = tri[2].x - tri[0].x, c = tri[1].y - tri[0].y, d = tri[2].y - tri[0].y, i = a * d - b * c;
/* Degenerate tri. */
if (i === 0.0)
return null;
var u = (d * (p.x - tri[0].x) - b * (p.y - tri[0].y)) / i, v = (a * (p.y - tri[0].y) - c * (p.x - tri[0].x)) / i;
/* If we're outside the tri, fail. */
if (u < 0.0 || v < 0.0 || (u + v) > 1.0)
return null;
return [u, v];
};
return DelaunaySlow;
}());
exports.DelaunaySlow = DelaunaySlow;