bodymovin/player/js/utils/shapes/ShapePath.js

After Effects plugin for exporting animations to SVG + JavaScript or canvas + JavaScript

function ShapePath(){
	this.c = false;
	this._length = 0;
	this._maxLength = 8;
	this.v = Array.apply(null,{length:this._maxLength});
	this.o = Array.apply(null,{length:this._maxLength});
	this.i = Array.apply(null,{length:this._maxLength});
};

ShapePath.prototype.setPathData = function(closed, len) {
	this.c = closed;
	this.setLength(len);
	var i = 0;
	while(i < len){
		this.v[i] = point_pool.newPoint();
		this.o[i] = point_pool.newPoint();
		this.i[i] = point_pool.newPoint();
		i += 1;
	}
};

ShapePath.prototype.setLength = function(len) {
	while(this._maxLength < len) {
		this.doubleArrayLength();
	}
	this._length = len;
}

ShapePath.prototype.doubleArrayLength = function() {
	this.v = this.v.concat(Array.apply(null,{length:this._maxLength}))
	this.i = this.i.concat(Array.apply(null,{length:this._maxLength}))
	this.o = this.o.concat(Array.apply(null,{length:this._maxLength}))
	this._maxLength *= 2;
};

ShapePath.prototype.setXYAt = function(x, y, type, pos, replace) {
	var arr;
	this._length = Math.max(this._length, pos + 1);
	if(this._length >= this._maxLength) {
		this.doubleArrayLength();
	}
	switch(type){
		case 'v':
			arr = this.v;
			break;
		case 'i':
			arr = this.i;
			break;
		case 'o':
			arr = this.o;
			break;
	}
	if(!arr[pos] || (arr[pos] && !replace)){
		arr[pos] = point_pool.newPoint();
	}
	arr[pos][0] = x;
	arr[pos][1] = y;
};

ShapePath.prototype.setTripleAt = function(vX,vY,oX,oY,iX,iY,pos, replace) {
	this.setXYAt(vX,vY,'v',pos, replace);
	this.setXYAt(oX,oY,'o',pos, replace);
	this.setXYAt(iX,iY,'i',pos, replace);
};