71 lines
1.7 KiB
JavaScript
71 lines
1.7 KiB
JavaScript
var shape = {};
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shape.box = {};
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shape.box.points = function (ll, ur) {
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return [ll, ll.add([ur.x - ll.x, 0]), ur, ll.add([0, ur.y - ll.y])];
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};
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shape.sphere = {};
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shape.circle = {};
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shape.sphere.volume = function (r) {
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return (Math.pi * r * r * r * 4) / 3;
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};
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shape.sphere.random = function (r, theta = [0, 1], phi = [-0.5, 0.5]) {
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if (typeof r === "number") r = [r, r];
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if (typeof theta === "number") theta = [theta, theta];
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if (typeof phi === "number") phi = [phi, phi];
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var ra = Math.random_range(r[0], r[1]);
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var ta = Math.turn2rad(Math.random_range(theta[0], theta[1]));
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var pa = Math.turn2rad(Math.random_range(phi[0], phi[1]));
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return [ra * Math.sin(ta) * Math.cos(pa), ra * Math.sin(ta) * Math.sin(pa), ra * Math.cos(ta)];
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};
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shape.circle.area = function (r) {
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return Math.pi * r * r;
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};
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shape.circle.random = function (r, theta) {
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return shape.sphere.random(r, theta).xz;
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};
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shape.box = function (w, h) {
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w /= 2;
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h /= 2;
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var points = [
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[w, h],
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[-w, h],
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[-w, -h],
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[w, -h],
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];
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return points;
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};
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shape.ngon = function (radius, n) {
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return shape.arc(radius, 360, n);
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};
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shape.arc = function (radius, angle, n, start = 0) {
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start = Math.deg2rad(start);
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if (angle >= 360) angle = 360;
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if (n <= 1) return [];
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var points = [];
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angle = Math.deg2rad(angle);
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var arclen = angle / n;
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for (var i = 0; i < n; i++) points.push(Vector.rotate([radius, 0], start + arclen * i));
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return points;
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};
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shape.circle.points = function (radius, n) {
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if (n <= 1) return [];
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return shape.arc(radius, 360, n);
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};
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shape.corners2points = function (ll, ur) {
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return [ll, ll.add([ur.x, 0]), ur, ll.add([0, ur.y])];
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};
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return { shape };
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