A regression in naga caused a mistranslation of the gradient shader
on the vulkan backend. This caused radial gradients to be rendered
as linear gradients on the vulkan backend. dx12 seems unaffected.
This seems to be cased by a switch statement starting with a default
case Re-order the case statements to avoid this. Looks like it's been
fixed in naga master.
naga is currently lenient about some things which are invalid by
the WGSL spec. The Tint WGSL compiler disagreed, so these shaders
failed to compile in Chrome.
Switch to a single render pass for the whole frame, as opposed to
a render pass per draw call. This should be a large improvement to
performance. This currently requires some unsafe to work around a
self-reference between RenderPass and CommandEncoder in Frame;
this could eventually be cleaned up by changing RenderBackend
to return a Frame object instead of using begin_frame/end_frame
pairs.
Also switch to using push constants for the transform/color
uniforms.
Mike Welsh