105 lines
2.5 KiB
JavaScript
105 lines
2.5 KiB
JavaScript
var _vector = require("../../core/vector");
|
|
|
|
var v2Min = _vector.min;
|
|
var v2Max = _vector.max;
|
|
var v2Scale = _vector.scale;
|
|
var v2Distance = _vector.distance;
|
|
var v2Add = _vector.add;
|
|
var v2Clone = _vector.clone;
|
|
var v2Sub = _vector.sub;
|
|
|
|
/**
|
|
* 贝塞尔平滑曲线
|
|
* @module zrender/shape/util/smoothBezier
|
|
* @author pissang (https://www.github.com/pissang)
|
|
* Kener (@Kener-林峰, kener.linfeng@gmail.com)
|
|
* errorrik (errorrik@gmail.com)
|
|
*/
|
|
|
|
/**
|
|
* 贝塞尔平滑曲线
|
|
* @alias module:zrender/shape/util/smoothBezier
|
|
* @param {Array} points 线段顶点数组
|
|
* @param {number} smooth 平滑等级, 0-1
|
|
* @param {boolean} isLoop
|
|
* @param {Array} constraint 将计算出来的控制点约束在一个包围盒内
|
|
* 比如 [[0, 0], [100, 100]], 这个包围盒会与
|
|
* 整个折线的包围盒做一个并集用来约束控制点。
|
|
* @param {Array} 计算出来的控制点数组
|
|
*/
|
|
function _default(points, smooth, isLoop, constraint) {
|
|
var cps = [];
|
|
var v = [];
|
|
var v1 = [];
|
|
var v2 = [];
|
|
var prevPoint;
|
|
var nextPoint;
|
|
var min;
|
|
var max;
|
|
|
|
if (constraint) {
|
|
min = [Infinity, Infinity];
|
|
max = [-Infinity, -Infinity];
|
|
|
|
for (var i = 0, len = points.length; i < len; i++) {
|
|
v2Min(min, min, points[i]);
|
|
v2Max(max, max, points[i]);
|
|
} // 与指定的包围盒做并集
|
|
|
|
|
|
v2Min(min, min, constraint[0]);
|
|
v2Max(max, max, constraint[1]);
|
|
}
|
|
|
|
for (var i = 0, len = points.length; i < len; i++) {
|
|
var point = points[i];
|
|
|
|
if (isLoop) {
|
|
prevPoint = points[i ? i - 1 : len - 1];
|
|
nextPoint = points[(i + 1) % len];
|
|
} else {
|
|
if (i === 0 || i === len - 1) {
|
|
cps.push(v2Clone(points[i]));
|
|
continue;
|
|
} else {
|
|
prevPoint = points[i - 1];
|
|
nextPoint = points[i + 1];
|
|
}
|
|
}
|
|
|
|
v2Sub(v, nextPoint, prevPoint); // use degree to scale the handle length
|
|
|
|
v2Scale(v, v, smooth);
|
|
var d0 = v2Distance(point, prevPoint);
|
|
var d1 = v2Distance(point, nextPoint);
|
|
var sum = d0 + d1;
|
|
|
|
if (sum !== 0) {
|
|
d0 /= sum;
|
|
d1 /= sum;
|
|
}
|
|
|
|
v2Scale(v1, v, -d0);
|
|
v2Scale(v2, v, d1);
|
|
var cp0 = v2Add([], point, v1);
|
|
var cp1 = v2Add([], point, v2);
|
|
|
|
if (constraint) {
|
|
v2Max(cp0, cp0, min);
|
|
v2Min(cp0, cp0, max);
|
|
v2Max(cp1, cp1, min);
|
|
v2Min(cp1, cp1, max);
|
|
}
|
|
|
|
cps.push(cp0);
|
|
cps.push(cp1);
|
|
}
|
|
|
|
if (isLoop) {
|
|
cps.push(cps.shift());
|
|
}
|
|
|
|
return cps;
|
|
}
|
|
|
|
module.exports = _default; |