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>
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>
Code quality review caught:
- Silent failure when ARB_bindless_texture absent — the && short-circuit
meant the most common fallback case (no bindless on the GPU) had no
log, while ARB_shader_draw_parameters absent did log. Restructured to
three nested ifs so each failure path logs symmetrically.
- Redundant `bindless is not null` guard removed (TryCreate's non-null
guarantee covers it; the nested-if structure makes this implicit).
- HasShaderDrawParameters in BindlessSupport.cs replaced its manual
GL_NUM_EXTENSIONS scan with `gl.IsExtensionPresent(...)` — same
pattern WB uses, less code.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
Code quality review caught three related issues:
- _gl field stored but never used (TreatWarningsAsErrors=true would
catch this on a clean build, but better to fix it before it bites)
- GL constructor parameter became unused after dropping _gl
- IsAvailable => true is misleading: TryCreate's out parameter is
the canonical signal, the property carries no information
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
Adds Silk.NET.OpenGL.Extensions.ARB 2.23.0 package and a thin
BindlessSupport wrapper exposing GetResidentHandle / MakeNonResident /
HasShaderDrawParameters. TryCreate returns false if the bindless
extension isn't present, letting WbFoundationFlag fall back to legacy.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
