A Slang vertex and fragment shader draw a triangle into an image with dynamic rendering (no
render pass object: the pipeline names its colour format), image barriers move it to the
attachment and transfer layouts, and vkCmdCopyImageToBuffer reads it back into a PPM. It is
the path the Vulkan renderer's passes and screenshots take.
The corner comes from SV_VulkanVertexID: Slang compiles SV_VertexID to gl_VertexIndex -
gl_BaseVertex, which declares the draw-parameters capability.
Validation-clean and VKTRIANGLE OK on the RTX 3070 Ti (Windows) and the M4 Pro (MoltenVK),
13824 pixels covered on both.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
