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webgl2

6 posts

verification

5 min read

Verified only where the bug showed: a hot-path fix that shipped a zoom-in regression

A WebGL2 flicker fix (#1139) was render-parity-verified on exactly one scenario — the zoom-OUT hold-tiles case that reproduced the original flicker, retained-content 0.19 → 0.79 matching WebGPU — and never on zoom-in or per-frame cost. It shipped an unmemoized per-frame classifyTile run twice per tile plus synchronous uploads, and stuttered with progressively-black fills on a Seoul zoom-in. Reverted 36 minutes later (#1140). A hot-path fix must be verified in its worst regime, not the one that showed the original bug.

performance webgl2 rendering

webgl2

8 min read

Two renderers, one truth: all four globe bugs lived in the hand-maintained twin

A displaced vector layer, a red/blue checkerboard ocean, a 16-gon planet, and intermittent flicker — four user-visible globe defects on WebGL2, and not one root cause in shared code. Every camera rendered correctly on WebGPU. On why a hand-maintained backend twin is scaffolding that must die, and the 20.7 km test witness that keeps its seam from drifting while it lives.

rendering architecture debugging

gpu

8 min read

The 4-second timeout that lost to a 2-second GPU reset

Ticking 'include stress battery' on a conformance page froze an RTX 2080 desktop so hard the window's own close button stopped responding. The df64 stress shaders over-ran the 2 s Windows TDR, and a 4 s JS compile timeout couldn't help — you can't cancel a GPU op you already submitted.

webgl2 angle shader-dsl

webgl2

5 min read

The no-op that hid a hundred fences

A recursive no-op Proxy let a WebGPU-typed engine boot on WebGL2 by making every native GPU call return a harmless dummy. It also silently swallowed every place a fence was missing. Replacing it with a fail-loud stub — and what the stub screamed about.

architecture debugging rhi

webgl2

4 min read

Porting a WebGPU-first engine to WebGL2

The program index for X-GIS's WebGL2 port: package-enforced backend neutrality, a single shader IR emitting both WGSL and GLSL, and pixel gates instead of promises — with links to the per-subsystem deep-dives. Shared shader math still can't stop pipeline state and target conventions from diverging.

rhi shader-dsl architecture