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| bezier(p0: cc.Vec2, p1: cc.Vec2, p2: cc.Vec2, t: number) {
const p = p0
.mul(Math.pow(1 - t, 2))
.add(p1.mul(2 * t * (1 - t)))
.add(p2.mul(Math.pow(t, 2)));
return p;
},
async bezierUniformMove(pos: cc.Vec2, mid: cc.Vec2, target: cc.Vec2, node: cc.Node, duration: number) {
let samples: { t: number, len: number }[] = [];
let totalLen = 0;
let prev = this.bezier(pos, mid, target, 0);
for (let i = 1; i <= 100; i++) {
let t = i / 100;
let pt = this.bezier(pos, mid, target, t);
let d = prev.sub(pt).mag();
totalLen += d;
samples.push({ t, len: totalLen });
prev = pt;
}
const getTByLen = (curLen: number) => {
for (let i = 0; i < samples.length; i++) {
if (samples[i].len >= curLen) {
// 线性插值
let prev = samples[i - 1] || { t: 0, len: 0 };
let ratio = (curLen - prev.len) / (samples[i].len - prev.len);
return prev.t + (samples[i].t - prev.t) * ratio;
}
}
return 1;
}
await asyncMgr.tween(cc.tween(node).to(duration, { position: target }, {
progress: (start, end, current, ratio) => {
const cl = totalLen * ratio;
const t = getTByLen(cl);
const result = this.bezier(pos, mid, target, t);
return result;
}
}))
}
|