Template

Version of vulkano: main
OS: windows
GPU (the selected PhysicalDevice): gtx 4090
GPU Driver: TODO
Upload of a reasonably minimal complete main.rs file that demonstrates the issue: TODO

Issue

I have two definitions of push constants, one from my vertex shader, and one from my fragment shader. I'd like to use the types provided by the shader macro with each occupying different push constant memory. It's my understanding that to do this, I have to do something like the following:

  .push_constants(
      self.layout.clone(),
      0,
      SkinnedVertPushConstants { mvp },
  )?
  .push_constants(
      self.layout.clone(),
      std::mem::size_of::<SkinnedVertPushConstants>() as u32,
      DefaultFragPushConstants {
          fog_origin: [0.0, 0.0, 0.0, 0.0],
          fog_color: [1.0, 1.0, 1.0],
          fog_intensity: 1.0,
      },
  )?;

  ...

  let layout_create_info = PipelineDescriptorSetLayoutCreateInfo {
    flags: PipelineLayoutCreateFlags::empty(),
    set_layouts: vec![DescriptorSetLayoutCreateInfo {
        bindings: BTreeMap::from([(0, layout_binding)]),
        ..Default::default()
    }],
    push_constant_ranges: vec![
        PushConstantRange {
            stages: ShaderStages::VERTEX,
            offset: 0,
            size: std::mem::size_of::<SkinnedVertPushConstants>() as u32,
        },
        PushConstantRange {
            stages: ShaderStages::FRAGMENT,
            offset: std::mem::size_of::<SkinnedVertPushConstants>() as u32,
            size: std::mem::size_of::<DefaultFragPushConstants>() as u32,
        },
    ],
};

layout(push_constant) uniform PushConstants {
    layout(offset = 64) vec4 fog_origin;
    vec3 fog_color;
    float fog_intensity;
} constants;

note that the offset is defined for the zeroth field in this screenshot from https://docs.vulkan.org/guide/latest/push_constants.html#pc-offsets

relevant code is here https://github.com/vulkano-rs/vulkano/blob/42e4d0b7c3ff742d81339cadfd291257ee864110/vulkano-shaders/src/structs.rs#L850

The shader macro errors out when a shader contains push constants with the zeroth field is decorated with offset. Am I misunderstanding something here or is this a bug?

vulkano-rs / vulkano

Push constants don't support first field offset decorations #2534

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Issue