even faster.
* GPU based version started in previous commit, but this fixes errors
and bugs and gets it actually compiling and running.
* Add a way to batch together images to use the same render pass for GPU
premultiplication if they all target the same texture.
* Pending premultiplication uploads are automatically done when calling
`Drawer::third_pass`.
* `fast-srgb8` dep removed, we no longer convert to `f32`s to do the
premultiplication. Two `[u16; 256]` tables are combined to compute the
alpa premultiplied color within the same error bounds used by the
`fast-srgb8` crate. We also no longer use explicit simd.
* Remove explicit lifetimes from `PlayState::render` since `&self` and
`Drawer<'_>` don't need to have the same lifetime.
* Fix existing bug where invalidated cache entries were never set to
valid when reusing them.
* `prepare_graphic` now runs some heuristics to determine whether
premultiplication should be executed CPU side or GPU side and then
returns a bool indicating if GPU premultiplication is needed.
* General progress in setting up code paths to support GPU
premultiplication.
* Created `PremultiplyUpload` type to represent an initiated image
upload where the premultiply pass needs to be ran to complete it.
* Converted from compute pass to render pass since current limitations
make it difficult to write directly to a srgb image from a compute
shader.
* Replace `CachedDetails::Immutable` with keeping track of the
parameters used to create the texture (i.e. the border color).
* Create `TextureRequirements`, `TextureParamters`, and `CacheKey` types
to encode parameters that go into texture creation and image caching
and to determine when the space in texture memory should be reused
when replacing a graphic.
* Add custom texture creation logic for the UI textures since those need
certain usage combinations.
specifically rendering an image at the provided dimensions. Start
working on alpha premultipication which is necessary for being able to
properly sample colors on the GPU with bilinear filtering. Various
tweaks to comments and misc changes.
