Adds a test to visualize the blend modes. Fixes a dumb bug in blend.h and also a more subtle issue where default blending is not the same as clipping, as the former needs to always push a blend group (to cause isolation) and the latter does not. This might be something we need to get back to.
This should fix the rendering, so it fairly closely resembles the Mozilla reference image. There's also a compile-time switch to disable sRGB conversion, which is (sadly) needed for compatible rendering.
This patch adds radial gradients, including both the piet API and some
new methods specifically to support COLRv1, including the ability to
transform the gradient separately from the path.
We always do BeginClip/EndClip if it's a solid tile and the blend mode
is not default.
Also fix missing entry in pipeline layout (affects Vulkan but not Metal).
* Add blend and composition mode enums to API
* Mirror these in the shaders
* Add new public blend function to PietGpuRenderContext that mirrors clip
* Plumb the modes through the pipeline from scene to kernel4
Make the scene dependent on timing.
This commit patches the HAL to reuse command buffers; this works well on
Vulkan and prevents a leak, but breaks the other back-ends. That will
require a solution, possibly including plumbing up the resource lifetime
responsibilities to the client.
Other things might be hacky as well.
