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>
Moves the mesh/EnvCell draw path's per-batch texture representation from a
64-bit ARB_bindless_texture handle to a small integer table index, entirely
on the still-shipping GL backend, with zero pixel change. This is the CPU-side
half of the eventual Vulkan descriptor-array indexing model: a table index is
the backend-neutral form (Vulkan indexes a descriptor array with it directly),
while a raw bindless handle is GL-only. Landing the data-model change now, on
GL, under a strict self-differential pixel gate, keeps it separate from V4c's
much larger RHI-plumbing change (see docs/plans/2026-07-27-vulkan-campaign.md
section 5.2 for why the table cannot be device-owned yet).
Mechanism: mesh_modern.vert's BatchData struct carries `textureIndex` (a slot)
instead of `textureHandle` (uvec2); the vertex shader looks the slot up in a
new binding=9 storage buffer (GpuBindingModel.StorageTextureTable) and passes
the reconstructed uvec2 handle to the fragment shader exactly as before, so
mesh_modern.frag needed no change at all beyond the UBO-set macro below. The
16-byte std430 stride is unchanged (GpuBindingModel.GpuBatchDataStrideBytes);
textureLayer/flags keep their offsets, so every existing CPU writer's layout
is untouched.
The handle->slot table (GlBindlessHandleTable, new, pure C#) is owned
separately by WbDrawDispatcher and EnvCellRenderer rather than shared through
a single TextureCache-owned instance: EnvCellRenderer never had a TextureCache
dependency, and nothing requires index agreement between renderers since each
rebinds its own binding=9 buffer immediately before its own draw call. This
avoided threading a new constructor parameter through EnvCellRenderer (and its
six test call sites) for no behavioral benefit. TextureCache and
CompositeTextureArrayCache turned out to need no changes at all: they only
ever produce raw ulong handles, and that production path is unaffected -
the new indirection is entirely a WbDrawDispatcher/EnvCellRenderer-side
concern, added exactly where each already assembles its per-batch GPU struct
(ToInput, the copy-back loop, PrepareDeferredAlphaDraws for the
RetailAlphaQueue path, and EnvCellRenderer's ModernBatchData construction).
The table itself is a single non-ring buffer (unlike the per-frame
triple-buffered SSBOs) because a genuinely new handle is rare - new dat
surfaces/composite overrides, not every frame - so it flushes only when
GlBindlessHandleTable.Dirty is set, mirroring how the existing texture caches
already upload infrequently.
Shader-side, introduced Rendering/Shaders/common.glsl as the shared preamble
GL has no #include for: Shader.cs gained an `includeCommonPreamble` overload
that splices the file's text in after the leading #version/#extension block
(GLSL requires #version first). It declares the binding=9 table plus the
ACDREAM_TEXTURE_HANDLE(idx) lookup macro, and a scaffolding ACDREAM_UBO_SET
macro (a no-op under GL today, redefined to `set = 1,` when the Vulkan
toolchain compiles this same source at V6+, per the campaign doc's set-1 UBO
note) applied to both SceneLighting UBO declarations now so no later slice
needs to touch them again.
Tests: WbDrawDispatcherIndirectBuilderTests updated for the renamed
IndirectGroupInput/BatchDataPublic fields; new ModernBatchDataLayoutTests
(mirrors ClipFrameLayoutTests' role, but for EnvCellRenderer's GPU struct) and
GlBindlessHandleTableTests (pure-CPU allocator behavior, including the
zero-handle case, which is registered like any other handle rather than
special-cased, since that's what reproduces the pre-V2 sampling result
bit-for-bit).
Gate: dotnet build -c Release green, dotnet test
tests/AcDream.App.Tests -c Release green (3843 passed / 3 skipped, +9 over
the 3834/3 baseline), and tools/run-offline-pixel-gate.ps1 passed with a
2.84e-05 differing-pixel fraction against the parent commit - within the
documented ~33x same-commit noise margin. No divergence-register row: this
introduces no retail behavior deviation.
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
Erik