Swoorup
Rust bindings assume all vertex shaders in a file have the same input, even if they don't
I have a file with multiple vertex shaders, like this:
struct VertexInput {
@location(0) position: vec3f,
};
struct InstanceInput {
@location(1) position: vec3f,
};
@vertex
fn dummy_vertex_shader(vert_in: VertexInput) -> @builtin(position) vec4f {
return vec4f(vert_in.position, 1);
}
@vertex
fn dummy_instanced_vertex_shader(vert_in: VertexInput, instance_in: InstanceInput) -> @builtin(position) vec4f {
return vec4f(vert_in.position + instance_in.position, 1);
}
In the generated rust bindings, there's a generated VERTEX_ATTRIBUTES and vertex_buffer_layout for VertexInput, but not for InstanceInput. Also, their _vertex_shader_entrys are the same, even though dummy_instanced_vertex_shader should have 2 inputs instead of one:
pub fn dummy_vertex_shader_entry(
vertex_input: wgpu::VertexStepMode,
) -> VertexEntry<1> {
VertexEntry {
entry_point: ENTRY_DUMMY_VERTEX_SHADER,
buffers: [VertexInput::vertex_buffer_layout(vertex_input)],
constants: Default::default(),
}
}
pub fn dummy_instanced_vertex_shader_entry(
vertex_input: wgpu::VertexStepMode,
) -> VertexEntry<1> {
VertexEntry {
entry_point: ENTRY_DUMMY_INSTANCED_VERTEX_SHADER,
buffers: [VertexInput::vertex_buffer_layout(vertex_input)],
constants: Default::default(),
}
}
If I move dummy_instanced_vertex_shader to be before dummy_vertex_shader in that file, I then get a VERTEX_ATTRIBUTES and vertex_buffer_layout for both VertexInput and InstanceInput. However, now dummy_vertex_shader_entry is incorrect:
pub fn dummy_instanced_vertex_shader_entry(
vertex_input: wgpu::VertexStepMode,
instance_input: wgpu::VertexStepMode,
) -> VertexEntry<2> {
VertexEntry {
entry_point: ENTRY_DUMMY_INSTANCED_VERTEX_SHADER,
buffers: [
VertexInput::vertex_buffer_layout(vertex_input),
InstanceInput::vertex_buffer_layout(instance_input),
],
constants: Default::default(),
}
}
pub fn dummy_vertex_shader_entry(
vertex_input: wgpu::VertexStepMode,
instance_input: wgpu::VertexStepMode,
) -> VertexEntry<2> {
VertexEntry {
entry_point: ENTRY_DUMMY_VERTEX_SHADER,
buffers: [
VertexInput::vertex_buffer_layout(vertex_input),
InstanceInput::vertex_buffer_layout(instance_input),
],
constants: Default::default(),
}
}
So it seems like wgsl_bindgen assumes that every vertex shader in a file shares the same input as the first vertex shader.
Should be fairly straightforward to fix. Will take a look. Been a bit busy with other stuff.
