Campaign V slice V6d, commit 2 of 3. TextRenderer and DebugLineRenderer were the only two renderers speaking the RHI, and both refused any device that was not a GlGpuDevice. They now refuse nothing: this is the first production rendering acdream can do on Vulkan.
Three things had to go.
The loose uniforms. debug_line declared uView and uProjection separately and DebugLineRenderer set them straight against the compiled GL program, because the pinned push-constant block carries one combined matrix and IGpuPassEncoder has no verb for arbitrary named uniforms. That was never portable — Vulkan has no default uniform block at all — so the shader converged on uViewProjection and Flush multiplies on the CPU. System.Numerics is row-vector convention while GLSL reads the floats column-major, which transposes, so the CPU equivalent of the old per-vertex uProjection * uView is view * projection. The product now rounds once per frame rather than once per vertex; these lines only draw when collision wireframes are switched on, so the offline gate sees nothing of it. ui_text's uScreenSize became the block's two spare scalars, uParamA and uParamB, with the same two divisions and the same NDC mapping around them.
The sampling mode. uUseTexture selected between font coverage, RGBA modulate and flat colour, and no field of the 96-byte block means that. It did not need one: which of the two texture-table slots is assigned IS the mode. uTextureIndexB assigned means a single-channel coverage source, uTextureIndexA assigned means an RGBA colour source, neither assigned means the vertex colour alone. GpuTextureSlot.Unassigned is already a loud sentinel for exactly this kind of question, and both branches guard so it never reaches a sampler. That also retired the 1x1 white fill texture: DrawFill routed solid quads through the sprite bucket relying on white times colour, and the untextured branch produces the same value with no texture at all. Multiplying by 1.0 changes no bits, and the gate agrees.
The texture binding. The classic glActiveTexture/glBindTexture path survived V4a because DrawSprite takes an arbitrary texture from sixty-odd widget call sites. But TextureCache had already registered every one of those into the device's table — the classic path was consuming the raw GL name that registration also produced. The UI's currency is now UiTextureTableHandle, a one-based table index whose zero is the same "no texture" every widget already guards on; a raw slot index would have turned all of those guards into silent false negatives, since slot 0 is perfectly valid. One-based rather than the slot itself because GpuTextureSlot is internal to the pinned contract while UiRenderContext.DrawSprite, TextureCache.GetOrUploadRenderSurface and a dozen widget properties are public, and neither publishing a contract type nor converting the retained UI to internal belongs in this slice.
Two consequences worth stating. The two backends disagree about what a 2-D table entry is — GL reconstructs a sampler2D from the bindless handle, Vulkan reads layer 0 of its sampler2DArray descriptor array — and ACDREAM_SAMPLE_2D is the one place that lives. Keeping GL on sampler2D is what leaves the UI's textures exactly as they are, including the paperdoll/appraisal FBO colour texture, which is an externally-owned GL_TEXTURE_2D from the §7.1 transitional seam and cannot become an array before V4g. On the Vulkan side, sampled views are now always layered, which also removes a latent invalid usage V6c shipped: it registered a Type2D offscreen view into a descriptor array whose element type is sampler2DArray.
And one real fix. Sampling through the table means a bound sampler object overrides the texture's own parameters. Nearest-requested UI art used to get its point filtering from a glTexParameter applied before the bindless handle went resident, so registering it with the stock WorldRepeat sampler would have made every retail icon and dat-font glyph silently bilinear. Those now register with a nearest-and-repeat sampler.
Supporting moves: GlGpuDevice.CreatePipeline splices common.glsl the same way Shader does, since an RHI shader that reads the table needs the table declared; GlGpuPassEncoder binds the device's table with the pipeline, which is the GL analogue of Vulkan binding descriptor set 2 per draw, and has to be per-bind because every raw-GL world renderer puts its own privately-numbered table at that binding; and the encoder derives GL_MULTISAMPLE from the pass's SampleCount, which is where the retained UI's hand-rolled glDisable belonged all along. TextRenderGlStateScope is deleted — the encoder's ambient capture restored a strict superset of it — and its failure-safety test follows the guarantee to GlAmbientCapabilityState, which gains a fakeable seam and, with it, the multisample-dimension coverage #249 recorded as missing.
App tests 4,057 passed / 3 skipped, unchanged from commit 1. Offline pixel gate against 871c406b: differing fraction 2.31e-05, 13 pixels of 563,200 compared — below the documented 15-23 pixel same-commit noise band, on a change that redraws every pixel of the retained UI through a different sampling path. The capture was inspected: vitals, spell bar, radar, toolbar icons and slot digits, chat window and Send button all present and correctly placed. Both new .spv pairs compile; the manifest records ui_text and debug_line as Vulkan-ready, leaving six pairs blocked on the world-renderer slices.
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
The second of V6's three commits: everything the fragment stage samples. Plan
sections 4.3 (textures and mip generation) and 4.4 (descriptors).
The descriptor table is the piece that retires GL_ARB_bindless_texture. One
update-after-bind, partially-bound, variable-count combined-image-sampler array
of 16384; registration appends exactly one vkUpdateDescriptorSets and nothing is
written at draw time, so steady state is zero descriptor writes per frame. A
slot is a (view, sampler) pair, exactly like a bindless handle, which is why the
CPU data model needs no change at all - GpuTextureSlot already carries the index
and V2 already moved every batch onto it.
Eviction is retirement-gated and the slot is scrubbed on the way out. Returning
a slot the moment a texture is deleted would let the LRU alias a live draw onto
a new texture, so the release is filed through the ledger; and when it runs the
slot is first overwritten with the default 1x1 white. A stale view descriptor
sitting in a partially-bound array is legal right up until something reads it,
at which point it is a use-after-free with no error attached. Writing the dummy
makes that impossible rather than unlikely.
The CPU block-compression codec is the slice's other substantial piece, and it
exists because Vulkan cannot blit into a compressed image. DAT surfaces arrive
as DXT1/3/5 with no mips, so the chain has to be decoded, box filtered and
re-encoded here. That is not merely a substitute for the missing blit: the GL
path calls glGenerateMipmap on compressed array textures, whose result is
explicitly implementation-defined, so this is the first time that part of the
pipeline has had a defined answer.
Two properties matter more than quality, and both are tested. It is
deterministic - integer arithmetic end to end, endpoints from the block's
bounding box, nearest-palette selection, no dithering and no iterative fit -
because the offline pixel gate compares captures from separate processes and a
chain that varied run to run would make every textured surface look like a
regression. And it preserves BC1's one-bit cut-out: a block containing any texel
below the alpha threshold is encoded in three-colour mode, because retail's
foliage and grates ARE that mode and quantising those texels to an opaque colour
would fill in every leaf. Plan 4.3's escape hatch stands if quality ever trips a
gate: store the affected textures as RGBA8 and blit their mips.
Uncompressed images do take the blit chain, added to the upload queue. Each
source level moves to TRANSFER_SRC for its blit and back to TRANSFER_DST
afterwards; leaving the chain in mixed layouts would be one barrier cheaper and
would then force the batch's final shader-read transition to name a different
old layout per level, so ending every level the same way is what keeps that
transition one barrier per image.
The upload queue now records the layout each image is in on ENTRY to a batch
rather than always naming UNDEFINED. UNDEFINED lets the driver discard existing
contents, which is right for a fresh image and wrong for the incremental
array-layer fills that mirror ManagedGLTextureArray - discarding there would
erase every layer uploaded earlier.
Render targets are single-sampled per the contract and carry SAMPLED usage
alongside COLOR_ATTACHMENT, so a paperdoll or appraisal view can be registered
into the table and drawn by the retained UI the moment its pass ends.
VulkanBackbufferAttachments owns the two attachments the swapchain does not: the
multisampled colour scratch that resolves into the swapchain image, and the
transient depth/stencil. Both are TRANSIENT_ATTACHMENT because nothing reads
either after the frame. Stencil is not optional - issue #117's portal punch
needs the aspect, which is why the V5 gate prefers D32_SFLOAT_S8_UINT over a
depth-only format.
Every format stays UNORM, and that is the V3 audit's finding rather than a
default. The plan previously specified an sRGB swapchain "matching the GL
FramebufferSrgb contract"; that contract does not exist, the renderer is plain
UNORM end to end, and shipping _SRGB would have brightened every frame and
passed silently until V7.
VulkanPipelineLayouts is extracted from V5's capability probe rather than
written beside it, and the probe now calls it. The probe's whole value is
proving the layouts the live backend builds can be built on this device; two
similar-looking definitions would have quietly ended that the first time one of
them changed.
Gates: Release build clean, App suite 4037 passed / 3 skipped (4014 at V6a plus
23 new), offline pixel gate PASS against the parent baseline at a differing
fraction of 4.26e-05 - 24 pixels of 563,200, one above the campaign's recorded
15-23 same-commit noise band and about 23x under the 0.001 threshold, on a
commit that changes no GL code path.
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
Erik