Support for depth testing?

[paulkernfeld]

In certain cases, it might be nice to be able to render text that is behind objects that have already been rendered, i.e. by using depth testing.

I'm not 100% clear on how wgpu_glyph's rendering pipeline should interact with the user's rendering pipeline, but I think it might be possible to have the user pass in a DepthStencilStateDescriptor and a RenderPassDepthStencilAttachmentDescriptor.

[hecrj]

Absolutely. This feature is missing.

The challenge here is to offer a safe API. The issue is that if we create a pipeline with a DepthStencilStateDescriptor, then it should be mandatory for the user to provide a depth attachment to draw_queued.

I think we can easily achieve this with a phantom type D in GlyphBrush. Let me give it a shot.

[hecrj]

I have been able to get a draft implementation with a depth example in #13! I still have to think about some changes a bit, but let me know what you think!

[paulkernfeld]

Overall this does exactly what I was hoping for; thanks so much!