125 lines
3.7 KiB
JavaScript
125 lines
3.7 KiB
JavaScript
import * as vec2 from './vector.js';
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import * as curve from './curve.js';
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var mathMin = Math.min;
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var mathMax = Math.max;
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var mathSin = Math.sin;
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var mathCos = Math.cos;
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var PI2 = Math.PI * 2;
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var start = vec2.create();
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var end = vec2.create();
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var extremity = vec2.create();
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export function fromPoints(points, min, max) {
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if (points.length === 0) {
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return;
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}
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var p = points[0];
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var left = p[0];
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var right = p[0];
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var top = p[1];
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var bottom = p[1];
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for (var i = 1; i < points.length; i++) {
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p = points[i];
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left = mathMin(left, p[0]);
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right = mathMax(right, p[0]);
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top = mathMin(top, p[1]);
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bottom = mathMax(bottom, p[1]);
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}
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min[0] = left;
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min[1] = top;
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max[0] = right;
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max[1] = bottom;
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}
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export function fromLine(x0, y0, x1, y1, min, max) {
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min[0] = mathMin(x0, x1);
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min[1] = mathMin(y0, y1);
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max[0] = mathMax(x0, x1);
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max[1] = mathMax(y0, y1);
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}
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var xDim = [];
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var yDim = [];
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export function fromCubic(x0, y0, x1, y1, x2, y2, x3, y3, min, max) {
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var cubicExtrema = curve.cubicExtrema;
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var cubicAt = curve.cubicAt;
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var n = cubicExtrema(x0, x1, x2, x3, xDim);
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min[0] = Infinity;
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min[1] = Infinity;
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max[0] = -Infinity;
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max[1] = -Infinity;
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for (var i = 0; i < n; i++) {
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var x = cubicAt(x0, x1, x2, x3, xDim[i]);
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min[0] = mathMin(x, min[0]);
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max[0] = mathMax(x, max[0]);
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}
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n = cubicExtrema(y0, y1, y2, y3, yDim);
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for (var i = 0; i < n; i++) {
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var y = cubicAt(y0, y1, y2, y3, yDim[i]);
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min[1] = mathMin(y, min[1]);
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max[1] = mathMax(y, max[1]);
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}
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min[0] = mathMin(x0, min[0]);
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max[0] = mathMax(x0, max[0]);
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min[0] = mathMin(x3, min[0]);
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max[0] = mathMax(x3, max[0]);
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min[1] = mathMin(y0, min[1]);
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max[1] = mathMax(y0, max[1]);
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min[1] = mathMin(y3, min[1]);
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max[1] = mathMax(y3, max[1]);
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}
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export function fromQuadratic(x0, y0, x1, y1, x2, y2, min, max) {
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var quadraticExtremum = curve.quadraticExtremum;
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var quadraticAt = curve.quadraticAt;
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var tx = mathMax(mathMin(quadraticExtremum(x0, x1, x2), 1), 0);
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var ty = mathMax(mathMin(quadraticExtremum(y0, y1, y2), 1), 0);
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var x = quadraticAt(x0, x1, x2, tx);
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var y = quadraticAt(y0, y1, y2, ty);
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min[0] = mathMin(x0, x2, x);
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min[1] = mathMin(y0, y2, y);
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max[0] = mathMax(x0, x2, x);
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max[1] = mathMax(y0, y2, y);
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}
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export function fromArc(x, y, rx, ry, startAngle, endAngle, anticlockwise, min, max) {
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var vec2Min = vec2.min;
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var vec2Max = vec2.max;
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var diff = Math.abs(startAngle - endAngle);
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if (diff % PI2 < 1e-4 && diff > 1e-4) {
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min[0] = x - rx;
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min[1] = y - ry;
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max[0] = x + rx;
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max[1] = y + ry;
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return;
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}
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start[0] = mathCos(startAngle) * rx + x;
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start[1] = mathSin(startAngle) * ry + y;
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end[0] = mathCos(endAngle) * rx + x;
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end[1] = mathSin(endAngle) * ry + y;
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vec2Min(min, start, end);
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vec2Max(max, start, end);
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startAngle = startAngle % (PI2);
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if (startAngle < 0) {
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startAngle = startAngle + PI2;
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}
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endAngle = endAngle % (PI2);
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if (endAngle < 0) {
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endAngle = endAngle + PI2;
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}
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if (startAngle > endAngle && !anticlockwise) {
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endAngle += PI2;
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}
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else if (startAngle < endAngle && anticlockwise) {
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startAngle += PI2;
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}
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if (anticlockwise) {
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var tmp = endAngle;
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endAngle = startAngle;
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startAngle = tmp;
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}
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for (var angle = 0; angle < endAngle; angle += Math.PI / 2) {
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if (angle > startAngle) {
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extremity[0] = mathCos(angle) * rx + x;
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extremity[1] = mathSin(angle) * ry + y;
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vec2Min(min, extremity, min);
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vec2Max(max, extremity, max);
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}
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}
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}
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