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| var Path = require("../Path");
|
| var vec2 = require("../../core/vector");
|
| var _curve = require("../../core/curve");
|
| var quadraticSubdivide = _curve.quadraticSubdivide;
| var cubicSubdivide = _curve.cubicSubdivide;
| var quadraticAt = _curve.quadraticAt;
| var cubicAt = _curve.cubicAt;
| var quadraticDerivativeAt = _curve.quadraticDerivativeAt;
| var cubicDerivativeAt = _curve.cubicDerivativeAt;
|
| /**
| * 贝塞尔曲线
| * @module zrender/shape/BezierCurve
| */
| var out = [];
|
| function someVectorAt(shape, t, isTangent) {
| var cpx2 = shape.cpx2;
| var cpy2 = shape.cpy2;
|
| if (cpx2 === null || cpy2 === null) {
| return [(isTangent ? cubicDerivativeAt : cubicAt)(shape.x1, shape.cpx1, shape.cpx2, shape.x2, t), (isTangent ? cubicDerivativeAt : cubicAt)(shape.y1, shape.cpy1, shape.cpy2, shape.y2, t)];
| } else {
| return [(isTangent ? quadraticDerivativeAt : quadraticAt)(shape.x1, shape.cpx1, shape.x2, t), (isTangent ? quadraticDerivativeAt : quadraticAt)(shape.y1, shape.cpy1, shape.y2, t)];
| }
| }
|
| var _default = Path.extend({
| type: 'bezier-curve',
| shape: {
| x1: 0,
| y1: 0,
| x2: 0,
| y2: 0,
| cpx1: 0,
| cpy1: 0,
| // cpx2: 0,
| // cpy2: 0
| // Curve show percent, for animating
| percent: 1
| },
| style: {
| stroke: '#000',
| fill: null
| },
| buildPath: function (ctx, shape) {
| var x1 = shape.x1;
| var y1 = shape.y1;
| var x2 = shape.x2;
| var y2 = shape.y2;
| var cpx1 = shape.cpx1;
| var cpy1 = shape.cpy1;
| var cpx2 = shape.cpx2;
| var cpy2 = shape.cpy2;
| var percent = shape.percent;
|
| if (percent === 0) {
| return;
| }
|
| ctx.moveTo(x1, y1);
|
| if (cpx2 == null || cpy2 == null) {
| if (percent < 1) {
| quadraticSubdivide(x1, cpx1, x2, percent, out);
| cpx1 = out[1];
| x2 = out[2];
| quadraticSubdivide(y1, cpy1, y2, percent, out);
| cpy1 = out[1];
| y2 = out[2];
| }
|
| ctx.quadraticCurveTo(cpx1, cpy1, x2, y2);
| } else {
| if (percent < 1) {
| cubicSubdivide(x1, cpx1, cpx2, x2, percent, out);
| cpx1 = out[1];
| cpx2 = out[2];
| x2 = out[3];
| cubicSubdivide(y1, cpy1, cpy2, y2, percent, out);
| cpy1 = out[1];
| cpy2 = out[2];
| y2 = out[3];
| }
|
| ctx.bezierCurveTo(cpx1, cpy1, cpx2, cpy2, x2, y2);
| }
| },
|
| /**
| * Get point at percent
| * @param {number} t
| * @return {Array.<number>}
| */
| pointAt: function (t) {
| return someVectorAt(this.shape, t, false);
| },
|
| /**
| * Get tangent at percent
| * @param {number} t
| * @return {Array.<number>}
| */
| tangentAt: function (t) {
| var p = someVectorAt(this.shape, t, true);
| return vec2.normalize(p, p);
| }
| });
|
| module.exports = _default;
|
|
