delta drawing

gistfile1.js

var y1 = 0, y2 = 0, y3 = 0;
var x1 = 0, x2 = width/2, x3 = width;

_(timestamp.ndeltas()).each(function(delta){
	
	var artist = delta[0];
	var v1 = delta[1];
	var v2 = delta[2];
	var v3 = delta[3];
	
	
	var enter_y = (v1 + v2)/2;
	var exit_y  = (v2 + v3)/2;
	
	ctx.fillStyle = color(artist);
	
	ctx.beginPath();
	ctx.moveTo(x1,y1);
	ctx.lineTo(x1,y1 + enter_y);
	
	ctx.lineTo(x2,y2 + v2);
	
	ctx.lineTo(x3,y3 + exit_y);
	ctx.lineTo(x3,y3);
	
	ctx.lineTo(x2,y2);
	ctx.moveTo(x1,y1);

	ctx.fill();
	
	
	y1 += enter_y;
	y2 += v2;
	y3 += exit_y;
	
});