playcanvas
Version:
PlayCanvas WebGL game engine
111 lines (108 loc) • 3.23 kB
JavaScript
import { math } from '../../../core/math/math.js';
import { INTERPOLATION_STEP, INTERPOLATION_CUBIC, INTERPOLATION_LINEAR } from '../constants.js';
class AnimCache {
update(time, input) {
if (time < this._left || time >= this._right) {
var len = input.length;
if (!len) {
this._left = -Infinity;
this._right = Infinity;
this._len = 0;
this._recip = 0;
this._p0 = this._p1 = 0;
} else {
if (time < input[0]) {
this._left = -Infinity;
this._right = input[0];
this._len = 0;
this._recip = 0;
this._p0 = this._p1 = 0;
} else if (time >= input[len - 1]) {
this._left = input[len - 1];
this._right = Infinity;
this._len = 0;
this._recip = 0;
this._p0 = this._p1 = len - 1;
} else {
var index = this._findKey(time, input);
this._left = input[index];
this._right = input[index + 1];
this._len = this._right - this._left;
var diff = 1.0 / this._len;
this._recip = isFinite(diff) ? diff : 0;
this._p0 = index;
this._p1 = index + 1;
}
}
}
this._t = this._recip === 0 ? 0 : (time - this._left) * this._recip;
this._hermite.valid = false;
}
_findKey(time, input) {
var index = 0;
while(time >= input[index + 1]){
index++;
}
return index;
}
eval(result, interpolation, output) {
var data = output._data;
var comp = output._components;
var idx0 = this._p0 * comp;
if (interpolation === INTERPOLATION_STEP) {
for(var i = 0; i < comp; ++i){
result[i] = data[idx0 + i];
}
} else {
var t = this._t;
var idx1 = this._p1 * comp;
switch(interpolation){
case INTERPOLATION_LINEAR:
for(var i1 = 0; i1 < comp; ++i1){
result[i1] = math.lerp(data[idx0 + i1], data[idx1 + i1], t);
}
break;
case INTERPOLATION_CUBIC:
{
var hermite = this._hermite;
if (!hermite.valid) {
var t2 = t * t;
var twot = t + t;
var omt = 1 - t;
var omt2 = omt * omt;
hermite.valid = true;
hermite.p0 = (1 + twot) * omt2;
hermite.m0 = t * omt2;
hermite.p1 = t2 * (3 - twot);
hermite.m1 = t2 * (t - 1);
}
var p0 = (this._p0 * 3 + 1) * comp;
var m0 = (this._p0 * 3 + 2) * comp;
var p1 = (this._p1 * 3 + 1) * comp;
var m1 = (this._p1 * 3 + 0) * comp;
for(var i2 = 0; i2 < comp; ++i2){
result[i2] = hermite.p0 * data[p0 + i2] + hermite.m0 * data[m0 + i2] * this._len + hermite.p1 * data[p1 + i2] + hermite.m1 * data[m1 + i2] * this._len;
}
break;
}
}
}
}
constructor(){
this._left = Infinity;
this._right = -Infinity;
this._len = 0;
this._recip = 0;
this._p0 = 0;
this._p1 = 0;
this._t = 0;
this._hermite = {
valid: false,
p0: 0,
m0: 0,
p1: 0,
m1: 0
};
}
}
export { AnimCache };