Description
Description
When using the Microsoft Basic Render Driver Adapter, it seems Queue::write_buffer() does not work correctly.
All other backends (on my machine Vulkan and DX12, both on NVIDIA and Intel hardware) do function as expected.
I guess this could be an issue in my code, in wgpu-rs or in the Microsoft Basic Render Driver.
Repro steps
This repo contains a sample app and explains the issue.
Basically, the following code
// Phase 1 : update constant buffers.
for e in &entities {
queue.write_buffer(&e.constant_buffer, 0, &e.constant_data); // (1)
}
// Phase 2 : draw all entities.
let mut encoder = device.create_command_encoder(/*...*/);
{
let mut render_pass = encoder.begin_render_pass(/*...*/);
render_pass.set_pipeline(&render_pipeline);
for e in &entities {
render_pass.set_bind_group(0, &e.bind_group, &[]); // (2)
render_pass.set_vertex_buffer(0, e.vertex_buffer.slice(..));
render_pass.set_index_buffer(e.index_buffer.slice(..), IndexFormat::Uint32);
render_pass.draw_indexed(0..e.num_indices, 0, 0..1);
}
}
queue.submit(iter::once(encoder.finish()));
does not work as expected when using Microsoft Basic Render Driver (so on DX12).
Expected vs observed behavior
All entities have their constant buffer updated in phase (1) and bound to a RenderPass in phase (2).
But they all are rendered with the same constant data - as far as I can tell, always the last one written in (1).
Extra materials
The sample app draws a bunch of quads. Each of them uses a color from its own constant buffer.
The expected result which is what I get on all Adapters, except for Microsoft Basic Render Driver:
The incorrect result when using Microsoft Basic Render Driver:
API trace (also available in the sample repo):
api_trace.zip
Platform
I'm running this on Windows 10, using wgpu 0.11.0