Adds the GPU mechanism to clip drawing to a per-cell screen-space convex
region via gl_ClipDistance, consumed by the mesh + terrain vertex shaders.
This is the MECHANISM only — every instance defaults to slot 0 (no-clip /
pass-all) and terrain to count 0, so the running game renders IDENTICALLY to
pre-U.3 (verified: offline launch compiles both shaders and reaches steady
state; no GL errors). U.4 populates real clip data from portal visibility.
Binding contract (define once, both sides obey):
- mesh_modern.vert: SSBO binding=2 CellClip[] (shared per-frame regions, slot 0
reserved no-clip) + SSBO binding=3 uint[] per-instance slot, indexed by the
IDENTICAL gl_BaseInstanceARB+gl_InstanceID used for binding=0. binding=0/1
untouched.
- terrain_modern.vert: UBO binding=2 TerrainClip { int count; vec4 planes[8]; }
for the single OutsideView region (UBO namespace; SceneLighting is UBO
binding=1, so binding=2 is free and does not collide with the mesh SSBO
binding=2). count 0 = ungated.
- Both redeclare out gl_PerVertex { vec4 gl_Position; float gl_ClipDistance[8]; }
and set unused planes (i >= count) to +1.0 so they pass everything.
CellClip std430 layout (144 bytes/slot): count@0, 3 pad uints@4/8/12,
planes[8]@16 (vec4 stride 16). Terrain UBO std140: count@0 (padded to 16),
planes[8]@16 → 144 bytes. Verified by ClipFrameLayoutTests (8 new tests).
Pieces:
- ClipFrame: per-frame container + uploader for the SHARED clip data (binding=2
SSBO + terrain UBO). NoClip() = slot 0 + terrain count 0. AppendSlot /
SetTerrainClip pack std430/std140 bytes for U.4. UploadShared binds both.
- WbDrawDispatcher + EnvCellRenderer: each owns its binding=3 zero buffer
(all-zeros sized to its instance count → slot 0), re-binds binding=2 from the
shared ClipFrame id (or an internal no-clip fallback if unwired) before MDI.
gl_ClipDistance is per-vertex, so the single glMultiDrawElementsIndirect per
group is preserved — no draw splitting.
- TerrainModernRenderer: binds the terrain clip UBO (shared or no-clip fallback)
before its draw.
- GameWindow: glEnable(GL_CLIP_DISTANCE0..7) once at init (unused planes pass-all
so always-on avoids per-draw thrash); per frame builds ClipFrame.NoClip(),
UploadShared, and hands the buffer ids to the three renderers (tiny diff; U.4
swaps NoClip() for the real portal-visibility frame).
Gate: dotnet build green; App suite 134/134; offline launch confirms both
shaders compile + link with no GL errors.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
GameWindow.OnLoad resolves QualitySettings.From(_persistedDisplay.Quality)
+ WithEnvOverrides() immediately after LoadAndApplyPersistedSettings, stores
result in _resolvedQuality field. All six quality dimensions applied:
- NearRadius / FarRadius: replace old T16 env-var-only block; preset drives
the radii, legacy ACDREAM_STREAM_RADIUS override still honoured.
- MsaaSamples: WindowOptions.Samples reads from startup quality resolution
in Run() (pre-window-create read from SettingsStore). MSAA cannot change
at runtime; ReapplyQualityPreset logs a restart-required warning if the
new preset would change it.
- AnisotropicLevel: TerrainAtlas.SetAnisotropic() called after Build() and
again in ReapplyQualityPreset. Temporarily removes bindless residency
before the GL TexParameter call, re-makes resident after.
- AlphaToCoverage: WbDrawDispatcher.AlphaToCoverage property gates the
glEnable/glDisable(SampleAlphaToCoverage) pair around the opaque pass.
- MaxCompletionsPerFrame: set on StreamingController after construction
and after each mid-session restart.
ReapplyQualityPreset(QualityPreset) method handles mid-session changes
(Settings panel Quality dropdown Save): rebuilds streamer + controller for
radius changes, toggles A2C and aniso immediately, logs MSAA restart caveat.
onSaveDisplay callback updated to call ReapplyQualityPreset when Quality
field changes.
TerrainModernRenderer.Atlas property added to expose the atlas for
mid-session aniso updates.
991 tests passing, 8 pre-existing failures unchanged.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
T13 routes worker-built meshes from LandblockStreamResult.Loaded.MeshData
into the renderer. AddLandblockWithMesh accepts a prebuilt mesh + origin
and delegates to the existing AddLandblock(uint, LandblockMeshData, Vector3)
so both paths share one upload path (Approach B -- AddLandblock already
takes a prebuilt mesh; no inline build to extract).
GameWindow's T16 lambda captures liveCenterX/Y and passes the derived
origin; the renderer stays origin-agnostic.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
Symptom: terrain renders pure black in modern path (legacy renderer
correct). Diagnostic at TerrainModernRenderer.Draw showed:
glProgramUniformHandle(prog=4, loc=5, handle=0x100251xxx) → GL_INVALID_OPERATION (0x0502)
on both terrain and alpha sampler uniforms.
Root cause: the `uniform sampler2DArray` + glProgramUniformHandleARB
combination is rejected by the NVIDIA Windows driver in this configuration.
The handle is valid and resident; the uniform location is valid; the
program is valid; but the driver refuses to bind a 64-bit handle to a
sampler uniform via the program-uniform path.
Fix: switch to N.5's mesh_modern pattern — pass each 64-bit handle as a
`uniform uvec2` (low + high 32-bit halves) and construct the sampler at
the use site via the GLSL `sampler2DArray(handle)` constructor. This
form is what ARB_bindless_texture documents as universally supported and
is what N.5 already uses successfully.
Files:
- terrain_modern.frag: replace `uniform sampler2DArray uTerrain/uAlpha`
with `uniform uvec2 uTerrainHandle/uAlphaHandle` + `#define`s
- TerrainModernRenderer.cs: cache uvec2 uniform locations; set via
`glProgramUniform2(program, loc, low32, high32)` per frame
- BindlessSupport.cs: remove now-unused `SetSamplerHandleUniform`,
leave a comment noting why the helper was retired
- GameWindow.cs: also strip the temporary [TERRAIN-DBG] cursor-wrap
print added during the perf-baseline investigation
Build green; 114/114 tests in N.5+N.5b filter still pass; user-verified
terrain renders correctly in modern path post-fix. Captured fresh perf
baseline:
- Legacy: cpu_us median 1.5 / p95 3.0 (1 chunk = 1 glDrawElements)
- Modern: cpu_us median 6.4-7.0 / p95 9-14 (51 visible LBs, 1 MDI call)
Modern is ~4× slower on CPU at radius=5 because the chunked legacy path
already collapsed the scene to one draw call. The architectural wins
(zero glBindTexture/frame; constant-cost dispatch as A.5 raises radius)
will be documented in T10's perf baseline doc; the spec's
"≥10% lower CPU" acceptance criterion is invalid at radius=5 and needs
revision.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
Code review (Important #1): AddLandblock validated Vertices.Length but
not Indices.Length. The indices loop indexes meshData.Indices[0..383]
unconditionally — out-of-range input would throw IndexOutOfRangeException
instead of the clearer ArgumentException the vertex check raises. Today
LandblockMesh.Build always produces 384/384, so this is defensive
forward-compat for future mesh sources.
Code review (Important #2): The shader (terrain_modern.vert:gl_VertexID
% 6) only correctly picks the cell-corner index because we bake
`slot * VertsPerLandblock` into indices and 384 is a multiple of 6.
That invariant is now documented in a comment near the constant — anyone
changing it must audit the shader.
Build green: 0 errors / 0 warnings.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
The new terrain dispatcher. Single global VBO/EBO with a slot
allocator (one slot per landblock, 384 verts × 40 bytes per slot).
Per-frame: build DEIC array from visible slots, upload, dispatch
via glMultiDrawElementsIndirect. Atlas textures bound via bindless
handles set per-frame as sampler uniforms.
Total ~6-8 GL calls per frame for terrain regardless of visible
landblock count (vs today's per-LB binds at radius=2 → ~25 calls,
radius=5 → ~121 calls).
API mirrors TerrainChunkRenderer so GameWindow integration in T8 is
a drop-in field+ctor swap.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
