The lavapipe job did the thing it was built to do on its first attempt.
It accepted a Cpu device at API 1.4, created a device and read pixels
back, captured a real frame, and exited 4 when a feature was forced
unsupported. Three other things were red, and none of them were the
Vulkan backend.
The shader-freshness step aborted for two separate Linux faults in the
compiler tool. Disposing the Silk.NET API container unloads the native
module, and dlclose-ing libshaderc_shared.so leaves glslang's
process-level teardown running against unmapped code. Bisected with a
four-mode probe on Ubuntu 24.04: GetApi, CompilerInitialize and
CompilerRelease each exit 0, and adding only the container Dispose turns
the exit into SIGSEGV. That is the 134 CI reported. shaderc's own handles
are still released; the container is not, because the module's lifetime
is the process's and the process is one statement from returning.
Separately, a portable dotnet build leaves the native under
runtimes/linux-x64/native/ and makes reaching it Silk.NET's probing
problem, which it solved on a local Ubuntu 24.04 and did not solve on the
runner. The script now publishes the tool for the host RID, so the native
sits beside the assembly where AppContext.BaseDirectory finds it, and
checks for it by name so a regression says which file is missing rather
than which names failed.
With both fixed, the question section 5.5.20 left open has an answer:
Linux shaderc and Windows shaderc agree byte-for-byte at the pinned Silk
2.23.0. Eighteen of eighteen .spv identical, manifest identical. The byte
comparison stays a byte comparison.
The Windows leg of portable-headless was running sudo apt-get. That step
is older than this campaign - it is red in the 2026-07-27 main run too -
and it was misplaced rather than mis-conditioned. Nothing in that job
opens a display or links GL, and the graphical jobs that do call xvfb-run
take it from the runner image, so the step is deleted rather than
guarded. Every remaining step in the two-operating-system matrix is pwsh;
every bash step now lives in an ubuntu-only job.
The last failure was ours in a quieter way. WaitForCharacterLogOff-
Confirmation expressed its deadline only as a CancellationTokenSource,
whose timeout is published from a thread-pool timer callback, so on a
saturated pool the token stays unsignalled past the deadline while the
loop keeps draining items that are already queued. That is the case the
method exists to bound. Reproduced by pinning the suite to two CPUs on
Linux, which failed 2 of 6 where four CPUs and sixteen were clean, and
where CI failed 3 of 3. The drain now reads the deadline off the
monotonic clock as well; the token still bounds the asynchronous wait.
Ten of ten clean under the same pin. The test is untouched. Filed as
Release build green. App tests 4,152 / 3 skipped against the same 4,152 /
3 measured at base 32f9bcfa. Core.Net 600 / 600.
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
The first CI job in this project's history that renders a frame.
The whole row rests on a decision V6g already made and paid for. When
section 5.5.8 cut set 0 from ten dynamic storage descriptors to four, four
was not merely under the RX 9070 XT's eight - it is Vulkan's guaranteed
minimum, so no conformant device can fail the layout. That is what makes a
software-device row possible at all. Every other requirement was then
checked against Mesa's lvp_device.c rather than assumed, and all seventeen
features the gate demands are true on lavapipe - including
samplerAnisotropy, which V7 made load-bearing eight commits ago and which a
software rasterizer would have been entirely within its rights to decline.
Three things had to exist before the job could:
1. The harness could not stop. VulkanBringUpHost presents until its window
closes, which is right at a desk and impossible in CI, where nothing ever
closes a window. ACDREAM_VULKAN_PROBE_FRAMES gives it a budget; unset or
malformed is zero, which keeps the interactive behaviour, so no existing
invocation changes. The budget never cuts the capture short - the loop
stays open until the screenshot has been attempted - because a run whose
entire product is a PNG must not be able to exit green with an empty
artifact directory. The decision is a pure static method, tested without
a window or a driver.
2. tools/compile-shaders.ps1 was Windows-only and nobody had noticed,
because nothing had ever run it anywhere else. It built its paths from
embedded 'src\AcDream.App\...' literals; a backslash is a separator on
Windows and an ordinary filename character everywhere else, so on Linux
that is one long nonexistent file name.
3. The report's jq paths were invisible to the compiler. Renaming a record
property or swapping the enum converter would have left every test green
and turned CI red on someone else's branch days later, with a failure
that reads like a driver problem. VulkanCapabilityReportContractTests
pins the exact strings the job greps and pins its packed-version
arithmetic against VulkanApiVersion's own unpacking.
The job, eleven steps: install lavapipe and Xvfb; record vulkaninfo as
evidence; publish linux-x64; run the Gpu.Vk tests on a second operating
system; probe the gate under a 24-bit Xvfb screen (the default is 8-bit,
which leaves the X11 WSI without a usable visual) and assert an accepting
verdict on a Cpu device at API >= 1.3 with a clean active probe; assert the
captured PNG is a real frame by IHDR dimensions and byte count; re-run with
ACDREAM_VULKAN_FORCE_UNSUPPORTED=timelineSemaphore and assert exit 4 with an
actionable refusal; recompile the shaders and compare. Artifacts upload on
always(), so a red run ships its own diagnosis.
The .spv step is what ties the committed binaries to their sources. The
existing App test hashes GLSL against the manifest, which catches "edited a
shader, forgot to recompile"; nothing caught a stale or hand-edited .spv.
Verified on Windows before shipping: 19/19 artifacts byte-identical to a
fresh compile, zero drift.
No GL-versus-Vulkan pixel compare, for two independent reasons recorded in
section 5.5.20: linux-graphical asserts exit 4, so there is no left-hand
side, and the probe renders synthetic scenes rather than the DAT world CI
cannot have. The two jobs now say something sharper than a pixel diff would
have - on the same software Mesa stack, GL is refused and Vulkan is accepted
and draws. Physical Linux GPU and Wayland rows stay deferred on the Slice L
precedent; no hosted runner offers either.
Gates: Release build green, zero errors. App tests 4,152 / 3 skipped against
a 4,134 / 3 baseline at this branch's base (9b7f4343) - eighteen new, all
from this slice. Workflow validated by a real YAML parse plus an Actions
schema check and bash -n over all nine extracted run blocks; no actionlint
was available locally and none was downloaded. The job itself has not run:
its first execution is the CI run this commit triggers, and the V9 row stays
partial until that is green.
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
The last of V6's three commits, and the one that makes the backend render.
Plan sections: 4.5 (pipelines and the persisted cache), 4.6 (shaders and the
committed .spv), 4.7 and 3.3 (clip space, the Y flip and winding), 4.9 and 4.10
(swapchain format and the scissor convention), 4.11 (the probe shader V5
deferred), 5.4 (Target: null means the swapchain image, literally).
WHAT RUNS. ACDREAM_RENDER_BACKEND=vulkan now renders a real scene through the
whole RHI on the RX 9070 XT: 60,000-plus frames per twelve-second run, 4x MSAA
resolving into a B8G8R8A8_UNORM swapchain, GPU timer scopes resolving, a
screenshot taken through IGpuDevice.CaptureBackbuffer, and a clean
CloseMainWindow exit with the allocator reporting three device-memory objects.
WHAT IT DRAWS, AND WHY IT IS NOT THE GAME. V6's milestone is "a full game frame
on Vulkan" and on this branch that cannot be the game's own frame. V4c and V4d
are parked by 5.5.5 so the world renderers are still raw GL; and the two
renderers that DO speak the RHI - TextRenderer and DebugLineRenderer, ported at
V4a - both throw for any device that is not a GlGpuDevice, because their loose
uniforms and their classic texture-unit sprite binding have no home in the
pinned contract yet. Converting them is a V4-class change with its own GL pixel
gate, outside this slice's file list.
So the backend is exercised through the contract by a scene of our own, and it
is not a toy. It uses a device-local mesh arena filled through the staging ring,
instance and batch data written straight into mapped ring memory, an offscreen
render target whose colour is registered into the global texture table and
sampled by a later pass, a BC1 texture with a CPU-built mip chain beside an
uncompressed one with a vkCmdBlitImage chain, one multi-draw-indirect covering
five quads with gl_DrawID selecting per-draw batch data, a second pipeline with
line-list topology bound mid-pass, dynamic cull/front-face/depth-write, push
constants, timer scopes, and an MSAA colour attachment resolving into the
swapchain image.
ORIENTATION, BY INSPECTION. Slice V5's screenshot was a uniform clear and its
orientation was right "by construction" - which a uniform clear cannot show. The
scene is therefore deliberately asymmetric in both axes: a quadrant card that is
red top-left, green top-right, blue bottom-left and white bottom-right, four
differently tinted markers at four different corners, and an open L of lines
whose short stub rises at its right end. The captured PNG reads correctly in
every one of those, including a miniature of the same card in the bottom-right
whose own quadrants are also the right way up. The negative viewport height, the
front-face inversion and the capture path agree.
THE SHADER TOOLCHAIN, AND WHAT IT FOUND. tools/compile-shaders.ps1 drives
tools/ShaderCompiler, a small out-of-solution .NET tool over Silk.NET.Shaderc -
the same shaderc glslc is built on, through the already-pinned Silk 2.23.0
family. glslc is preferred when a Vulkan SDK is present and reported when it is;
neither this machine nor CI has one, and requiring a 500 MB manual install
between a contributor and a working checkout is not a reasonable price for a
build step. The GLSL sources stay the single source of truth: the Vulkan dialect
arrives as a preamble injected after the #version line - ACDREAM_UBO_SET becomes
"set = 1,", the texture table becomes a set-2 descriptor array with a required
nonuniformEXT accessor, and the shared 96-byte push block is declared with each
loose uniform name defined onto its member. The only edits to a shader BODY are
mechanical and dialect-level: dropping default-block uniform declarations, which
Vulkan GLSL has no such thing as, and assigning explicit varying locations BY
NAME across a pair, because ordinal assignment would look identical today and
silently swap varyings the first time an author reordered a line.
Run over the eight production pairs, exactly one thing happened: none of them
compiled, and every failure is a specific source-level fact belonging to a
renderer-port slice that has not landed. debug_line needs uView/uProjection
converged into one uViewProjection - two matrices are 128 bytes and the shared
block is 96. mesh_modern and particle still pass a uvec2 bindless handle as a
varying, which is V4t's GpuTextureSlot retype. sky has ten loose uniforms and
wants a UBO. ui_text needs uScreenSize/uUseTexture/uTex. particle_mesh needs
uTextureIndex to become uTextureIndexA. terrain_modern needs V4d-1's matrix
convergence. mesh is the legacy pair with no RHI consumer at all. That inventory
is committed as shaders.manifest.json, with each source's SHA-256 and the
compiler's own message, and a test re-hashes it so an edited shader that never
got recompiled fails a build rather than shipping a stale binary.
vk_probe is the pair that does compile, and it is the shader 4.11 already asked
for: V5 recorded "build one real pipeline from the committed .spv" as its single
deliberate deviation because no toolchain existed. It is Vulkan-dialect only and
no GL renderer draws with it, so it forks nothing; it retires when the ported
world renderers become the backend's own proof.
DESCRIPTORS. Sets 0 and 1 are DYNAMIC buffer descriptors bound per flight slot,
so a per-draw range change costs a dynamic offset in vkCmdBindDescriptorSets
rather than a vkUpdateDescriptorSets in the hot path - which is what keeps 4.4's
zero-writes-per-frame property true for buffers as well as for textures. Ten
dynamic storage descriptors is above Vulkan's guaranteed minimum of four, so it
is a real requirement rather than a free choice, it fails loudly at layout
creation on a device that cannot serve it, and V9's lavapipe row must confirm
it. Unused bindings point at a shared dummy range so there is ONE set layout and
one pipeline layout; that is why binding a second pipeline mid-pass costs
nothing and disturbs neither the descriptors nor the push constants.
THE ONE MAPPING FUNCTION. VulkanViewportMapping holds the whole coordinate
reconciliation: negative viewport height, the front-face inversion that pairs
with it, and - separately - the scissor flip, which the viewport sign does NOT
perform. The V3 audit flagged that as a concrete V6 acceptance item and it is
the subtle one: vkCmdSetScissor is always top-left-origin, NdcScissorRect emits
GL bottom-left rectangles, and getting it wrong clips a doorway aperture from
the wrong edge in a scene that has one. Clip space needs nothing, as 4.7
concluded: the cameras already build [0,1]-convention projections.
CONTRACT GAP, RECORDED NOT PAPERED OVER. GpuPipelineDescription cannot name its
colour-attachment format, and Vulkan bakes that into a pipeline. Offscreen
targets therefore adopt the swapchain's B8G8R8A8_UNORM rather than a literal
RGBA order - invisible above the API, because an image is sampled through its
format's component mapping and the one CPU readback swizzles explicitly. The
honest fix is a colour-format field added in a reviewed contract commit, exactly
as GpuBlendMode.InverseAlpha and GpuVertexFormat.UByte4UInt were added when V4c
and V4d met the same wall. It is documented at
VulkanTextureFormatMapping.CanonicalColorAttachmentFormat.
The pipeline cache is persisted to the cache directory and validated by its
32-byte header against this device's vendor, device and cache UUID before use.
Drivers are required to ignore incompatible blobs, but "required to" is a poor
foundation for something that runs before anything else in the process, and the
check costs 32 bytes of comparison. Two consecutive launches report "cold" then
"reused".
Gates: Release build clean; App suite 4056 passed / 3 skipped (4037 at V6b plus
19 new); offline pixel gate PASS at a differing fraction of 5.15e-05 with a
same-commit control immediately after it at 2.84e-05 - 29 and 16 pixels of
563,200, the same class of ambient variation the campaign's 15-23 band records,
and roughly 19x under the 0.001 threshold on a commit that changes no GL code
path.
Validation layers could not be run: this machine has no Vulkan SDK, no
HKLM\SOFTWARE\Khronos\Vulkan\ExplicitLayers key, no VK_LAYER_PATH and no
VkLayer_khronos_validation.json anywhere on disk. Plan 7 already requires one
validation-clean run at V7; it needs the SDK installed first and is reported
rather than assumed here.
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
Erik