Bind group names and module based on the content

[antonWetzel]

At the moment the bind groups are generated for every shader with the index as name (BindGroup0, BindGroup1, ...)

I would like the reuse bind groups if possible

• Every type must be shared (demangle with module)
• A bind group can be reused if the binding indices and corresponding types match

Idea

• Add setting share_bind_groups: bool or similar
  • Only possible with demangle
  • Place the wrapper in the deepest common module
  • For the shader add method fn bind_bind_group_0(bind_group: &BindGroupShared)
    • The shared bind group has no fixed bind group index
• Add setting bind_group_type_with_names or similar
  • Instead of the index use the binding names for the type name
  • See example below
  • No clue if the member names or types are better suited for the name
  • Always used for shared bind groups, because they have no index

Example for bind_group_type_with_names

@group(0) @binding(0) camera: Camera,

@group(1) @binding(0) settings: Settings,
@group(1) @binding(1) world: World, 

pub struct BindGroupCamera(...);
pub struct BindGroupSettingsWorld(...);

[ScanMountGoat]

This problem has come up a few times in the past. If you sort bind groups by how frequently they update, the per scene or per world bind group is often shared by multiple shaders.

There are some potential issues with sharing bind groups.

• the same bind group could be visible from different shader stages in different shaders
• the bind group names could grow quite large when appending names from bindings
• different bind group names might conflict if they have the same binding names (I'm not sure if this is possible)

[antonWetzel]

the same bind group could be visible from different shader stages in different shaders

This is a problem and I have no good idea to solve this.
Using all stages has problems with enabled features (and maybe performance).
Combining the used stages requires a huge code change and can have the same problem as the first solution.
Maybe a generic marker type could be used for compile time information what stages are required. No clue how usable and clean this is.

the bind group names could grow quite large when appending names from bindings

I think this is true, but still worth it as opt-in. Maybe a type alias from indexed to named or the other way allows the best of both worlds.

different bind group names might conflict if they have the same binding names (I'm not sure if this is possible)

I think this is not possible. For this the global bindings must have identical names, which should be invalid in working shaders.