feat(device): applications ask for the device features their shaders use

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>
This commit is contained in:
Jorijn van der Graaf 2026-10-31 06:40:02 +01:00
commit bcdc885de8
Signed by: jorijnvdgraaf
GPG key ID: 2937E59CDCC1BCFB
18 changed files with 1721 additions and 333 deletions

View file

@ -93,7 +93,7 @@ constexpr std::string_view kHeader =
"layout(descriptor_heap) uniform writeonly image2D image[];\n"
"layout(location = 0) rayPayloadEXT vec3 hitValue;\n";
const std::array<Case, 5> kCases = {{
const std::array<Case, 6> kCases = {{
// No push constant at all → Patch synthesizes a fresh single-member block at offset 0.
{ "no-push-constant", std::string_view{
""
@ -114,6 +114,12 @@ const std::array<Case, 5> kCases = {{
"layout(push_constant) uniform PC { vec4 v[2]; uint f; } pc;\n"
}, true, true, 40 },
// Existing block {row-major mat3x4 @0}: 3 columns of 4 rows, stored as 4
// rows 16 bytes apart, so it ends at 64, not at the 48 its 3 columns give.
{ "merge-row-major-mat3x4", std::string_view{
"layout(push_constant) uniform PC { layout(row_major) mat3x4 m; } pc;\n"
}, true, true, 64 },
// Push constant but NO acceleration-structure read → Patch is a no-op; the
// single user block must survive untouched and still validate.
{ "push-constant-no-as", std::string_view{
@ -133,7 +139,9 @@ std::string BuildSource(const Case& c) {
// Reference the push constant so glslang keeps the block in the module.
std::string_view g = c.glsl;
std::string extra = "vec4(hitValue, 1.0)";
if (g.find("mat4 m;") != std::string_view::npos)
if (g.find("mat3x4 m;") != std::string_view::npos)
extra = "vec4(hitValue, 1.0) + pc.m[2]";
else if (g.find("mat4 m;") != std::string_view::npos)
extra = "pc.m * vec4(hitValue, 1.0) + vec4(pc.l, float(pc.f))";
else if (g.find("uint f; } pc;") != std::string_view::npos && g.find("vec4 v[2]") != std::string_view::npos)
extra = "vec4(hitValue, 1.0) + pc.v[0] + pc.v[1] + vec4(float(pc.f))";