Refactor Mesh#onUpdate/ Color component

[alexanderGugel]

The Color component in utilities/Color.js has an opacity property that is being managed using a Transitionable (just like the RGB values).

• It doesn't make sense for a color component to have an opacity if the Node itself has an opacity (and possibly an Opacity component).
• It is also confusing since the opacity is actually the alpha (which makes a lot more sense, after all that's what the A in RGBA is for).
• On the other hand, it actually is not the alpha value, since the whole point of the alpha would be to enable alpha compositing, which is not the case, nor should it (that's what the node's opacity is for).

Aside from that, the Mesh itself - more or less - has a dependency on the Color component (or at least requires it to expose an isActive method), therefore the two concepts are not really decoupled.

I propose the following changes:

1. Remove Color component
2. Store color simply as a Mesh property
3. Don't requestUpdate in Mesh when a component is active (this violates the current abstraction - the Color component should do that) - see Mesh#onUpdate

Mesh.prototype.onUpdate = function onUpdate() {
    // ...

    if (node) {

        // ...

        // If any invalidations exist, push them into the queue
        if (this.value.color && this.value.color.isActive()) {
            // ...
            this._node.requestUpdateOnNextTick(this._id);
        }
        if (this.value.glossiness && this.value.glossiness[0] && this.value.glossiness[0].isActive()) {
            // ...
            this._node.requestUpdateOnNextTick(this._id);
        }
        else {
            // ...
        }

        // If any invalidations exist, push them into the queue
        // ...
    }
};

[alexanderGugel]

@michaelobriena

[jd-carroll]

So I might be asking dumb questions here...

• Is it possible to have multiple Color components on a single node?
• Can an individual color component be tied to an individual DOMElement?

[alexanderGugel]

@jd-carroll The Color component in a way violates the existing abstractions in the platform. The Color component is not a component. Components define behavior on Nodes, but the color component is only being used for defining the base color of meshes etc.

The color component can only be added to a Mesh, not to a Node.

Can an individual color component be tied to an individual DOMElement?

No. The Color component is only being used for GL.

[michaelobriena]

Color is not a component. I don't think it was ever intended to be. It is just Transitionables for tweening colors.

If we roll the functionality into Mesh I am ok with this. But for solid base colors it is super nice to tween them between values.