core module UBO

[felixpalmer]

For #8997

Change List

• Add UBOs for ScreenPass & tidy types
• Add UBOs for GPU transitions

[coveralls]

coverage: 89.307% (+0.008%) from 89.299%
when pulling 404cc67 on felix/core-ubo
into 6f07ce0 on master.

[ibgreen]

I still think this double type assertion is undesirable. You said you felt it adds clarity. If it is only needed to add clarity in some cases of more "advanced usage" that is one thing. Vut if it always needs to be done I am not so sure I can feel good about it :)

Grist for the mill I suppose...

[felixpalmer]

I wonder if we should review the ShaderModule type, the UniformsT & BindingsT generics don't seem to be that useful IMHO. I think it would be better to have the ShaderModule be generic on PropsT and UniformTypesT, as UniformsT and BindingsT can be obtained by filtering PropsT.

I've had a play and we could remove the nested const satisfies UniformTypes<..> by using the following filtering type helper:

type UniformValue = number | boolean | number[];
type FilterUniformKeys<T> = {[K in keyof T]: T[K] extends UniformValue ? K : never}[keyof T];
type UniformsOnly<T> = {[K in FilterUniformKeys<T>]: T[K]};

We then don't need the ScreenBindingProps & ScreenUniformProps types and can just do:

export const screenUniforms = {
  name: 'screen',
  fs: uniformBlock,
  uniformTypes: {
    texSize: 'vec2<f32>'
  } as const satisfies UniformTypes<UniformsOnly<ScreenProps>>
} as const satisfies ShaderModule<ScreenProps>;

Which could all be encapsulated in luma's ShaderModule definition

[ibgreen]

Now that is some slick typescript.

• You could perhaps test all this in deck by creating a compatible type or wrapper type for ShaderModule in deck.gl and once you have it working we upstream it?
• A possible problem is to find a name that covers both "uniforms and bindings". But I suppose UniformsAndBindings is a possible choice.
• We want to be able to explain that shader modules mapping semantic props to shader uniforms and bindings.

export type ShaderModule<
  PropsT extends Record<string, unknown> = Record<string, unknown>,
  UniformsAndBindingsT extends Record<string, UniformValue | BindingValue> = Record<string, UniformValue | BindingValue>
> = {

[ibgreen]

I really didn't anticipate this type splitting, seems like you have to go through more hoops than I anticipated. Seeing how the system is used in practice is illuminating.