examples/Sponza no longer built natively (#164). Its closest-hit declared a
descriptor_heap sampler2D, which glslang has rejected since c8253623
("Reject descriptor_heap combined image samplers"), and main.cpp wrote it
through VkResourceDescriptorDataEXT::pCombinedImageSampler, which that union
no longer has: the descriptor heap has no combined image samplers. Both went
unnoticed because nothing builds the examples.
Sponza
- closesthit.glsl declares texture2D and sampler heap arrays and joins them
where it samples, as ui-shared.glsl and HeapDynamicIndexHit do. The
sampler slot is a second spec constant beside the image slot, so the
shader assumes nothing about where the host put it, and a constant index
keeps the example running on NVIDIA 610.43.02 (see its README). The
comment no longer says the image slot is offset by bufferStartElement;
only buffer slots are.
- main.cpp gives the heap a sampler slot, writes the albedo as a
SAMPLED_IMAGE from a view create-info, and writes the sampler into the
sampler heap from a VkSamplerCreateInfo with vkWriteSamplerDescriptorsEXT,
as UIRenderer::RegisterSampler does. SamplerVulkan's VkSampler had no use
left. The sampler keeps its linear filtering and repeat addressing and
drops anisotropy, which a hit shader cannot use: it samples at LOD 0,
without derivatives.
Docs
- README.md and examples/Sponza/README.md quote the new declarations, and
the Sponza README says why the texture and the sampler are two
descriptors. Its texture2DArray materials pattern declared a
descriptor_heap sampler2DArray, which glslang rejects as well; it now
joins a texture2DArray and a sampler.
- examples/SponzaBench/README.md drops its caveat that Sponza does not
compile.
Tests
- ExampleShaders compiles every GLSL shader under examples/ with glslang as
crafter-build does for the example (Vulkan rules, SPIR-V 1.4, shaders/ on
the include path, and the descriptor-set build where the example
registers one), so a glslang that starts rejecting one fails a test
rather than an example build nobody runs. It fails on Sponza's old
closest-hit and needs glslang only.
Closes#164.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Jorijn van der Graaf
6e94cc6209