I have a series of dots with connected lines that I am animating in an easel.js canvas. The dots move around, and the lines stay connected to them as they move. As the dots move, I'm animating their color, so I want the lines to animate color as well.
I tried calling a color tween on the line, but it requires that I cache the line first.
For a circle, that's easy - I get the radius and, since its registration is in the center, its x and y coordinates and width and height are easy to calculate (for a circle with r=100 at 50,50, its cache would be cache(0,0,100,100). But for a line, I'm not sure how to reference the right coordinates for the cache statement, especially since the line start position, end position, and length are always changing.
Anyone have a way to do this?
I'm using greensock's timelinemax / tweenlite with the easeljs plugin to handle all the animations, if that's helpful.
If TweenLite handles color tweens, then you should just be able to update the "style" of your line any time:
var shape = new createjs.Shape();
var colorCommand = shape.graphics.beginStroke("#000000").command;
shape.graphics.moveTo(0,0).lineTo(100,100); // Draw the line
// Any time
colorCommand.style = "#ff0000";
// So in a tween:
TweenLite.to(colorCommand, 20, {style:"#00ffff"});
If you are using EaselJS, you can also use TweenJS, which has a ColorPlugin. Using similar code:
createjs.Tween.get(colorCommand).to({style:"#00fffff"}, 20000);
Here is a fiddle I made tweening the color of a line with TweenJS https://jsfiddle.net/lannymcnie/5zxpb944/
Cheers.