Improve Canvas Text Renderer Performance

[frank-weindel]

• Simplify/improve canvas renderer performance by utilizing child nodes and ImageTexture factory.
• All canvas text is now laid out when created, but not actually rasterized until the text becomes renderable (inbounds, positive alpha, etc)
• Canvas textures are now properly able to be cleaned up when they become unrenderable.

TODO

• Run performance tests
• Get multi-page scrolling working again (or this can be deferred) Multi-Page Canvas 2D Text #321

[frank-weindel]

@wouterlucas Could you help me performance test this if you have a chance?

[philippe-wm]

When the text of a node changes, does that require creating a new texture or do you update the text of the texture?

[elsassph]

Seems a waste to clone the resolvedProps just to add shaderProps: null

[frank-weindel]

Agreed. Will fix.

[elsassph]

Why creating a sub node? Is that to decouple the text node size and the texture?

[frank-weindel]

Yeah pretty much. I did do a pass trying to simply update the TextNode's texture but this was the path of least resistance to be able to do this without changing the size characteristics of canvas TextNodes (i.e. without breaking a ton of tests). Open to suggestions for improvement, however I think this in general will be more performant than what we have right now.

[frank-weindel]

When the text of a node changes, does that require creating a new texture or do you update the text of the texture?

In this case I'm creating a new texture. Generally Texture instances have been treated as immutable objects. This doesn't necessarily have to be the case. But it's not an area I have time atm to think about.

[wouterlucas]

@wouterlucas Could you help me performance test this if you have a chance?

See here:

All 3 renderer using Canvas fonts. If you want I can add the same codebase that the PR is from and enable MSDF fonts for comparison. Though it will be fastest.

But still a bit away from L2's performance.