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>
Device
- Device::Initialize(required, optional) takes DeviceFeatures, the five
core feature structs vulkan10 to vulkan14. The library enables only what
its own shaders and code use. Device::enabledFeatures says what was
enabled, supportedFeatures what the GPU has, apiVersion the version in
use.
- shaderInt16, shaderFloat16, storageBuffer16BitAccess, scalarBlockLayout
and the uniform-buffer, storage-buffer and storage-image non-uniform
indexing bits are no longer enabled for everyone. An application whose
shaders take uint16_t spec constants passes
{.vulkan10 = {.shaderInt16 = VK_TRUE}}. scalarBlockLayout stays on with
the NVIDIA workaround, whose TLAS address may sit in a struct's tail
padding.
- Every GPU is weighed before one is chosen: Vulkan 1.3, the swapchain and,
below 1.4, maintenance5 extensions, the library's needs, the required
features. One that can't run the application is skipped, saying why when
it ranks higher. A CPU device runs it only when nothing else is listed,
and CRAFTER_GRAPHICS_DEVICE never falls back. A GPU two drivers both list
is tried through each.
- When no GPU qualifies, Initialize throws naming each GPU's gaps. It
destroys the instance it made, before any Wayland connection, so it can
be called again asking for less.
- maintenance5 is vulkan14's on a 1.4 GPU and VK_KHR_maintenance5's below.
CRAFTER_GRAPHICS_NO_VULKAN_1_4 runs as a 1.3 application, to exercise
that path on a 1.4 GPU.
- VK_KHR_spirv_1_4 and VK_KHR_shader_float_controls, core since 1.2, are no
longer enabled, nor VK_EXT_shader_atomic_float, which was enabled without
its feature struct. memoryDecompression's feature bit is queried before
it is enabled.
Shaders
- VulkanShader checks a module's capabilities, declared directly or
implicitly, against the enabled core features, the GPU's subgroup
operations and the optional groups, and throws naming the field to pass,
or saying the GPU lacks it. The tables are generated from vk.xml and
SPIR-V's grammar.
- WorkaroundNvidiaAS::Patch sized a row-major matrix push member by its
columns, so the TLAS address could land inside it.
Window
- The swapchain format is one whose own feature flags allow storage reads
and writes without a format, which since Vulkan 1.3 each format says for
itself; shaderStorageImageRead/WriteWithoutFormat are no longer required.
Tests
- DeviceFeatures: ResolveFeatures, ChooseDevice and CheckShaderCapabilities,
without a GPU.
- FeatureRequests: required and optional features end to end, the 1.3
path, and a retry after a refusal.
- PushConstantRewrite: a row-major mat3x4 push member.
- HeapASRead, HeapDynamicIndexHit, RTPassPushData and the ray-tracing
examples ask for the features their shaders use.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
The heap acceleration-structure read still needs the rewrite on
615.78.08; the READMEs say so and point at HeapASRead --no-workaround
for checking a newer driver. Dynamic descriptor indexing in hit shaders
is fixed there, which the README and the Sponza and SponzaBench notes
now say, and the VulkanTriangle investigation no longer contradicts
itself about llvmpipe, which advertises VK_EXT_descriptor_heap now.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Headless benchmark around the native Sponza RT scene: times setup and a
measured Render() loop over the full multi-mesh atrium, prints BENCH
metrics, and exits. Includes run-bench.sh and a README documenting the
methodology and the measured net gain from #40 to current master.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
