Tag
11 posts
gpu
8 min read
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.
precision
6 min read
Making the line outline's projection precise, but not its polygon fill, turned a shared invisible jitter into a ~3px fill≠outline seam at deep zoom. The fix isn't more f64 — it's the same camera-relative reframe, which the linear term needs no emulation for.
shader-dsl
9 min read
After a texel-fetched guard fixed the fast-math collapse, isolated df64 ops passed on the reporter's phone but composed ones still broke. There are two failure classes, not one — and the second lives in the ALU, where no value you thread into the shader can reach it. df64 is per-vendor, and our CI's SwiftShader is structurally blind to half of it.
shader-dsl
6 min read
Emitted WGSL/GLSL ships to gl.shaderSource with its authored vocabulary intact — no JS minifier reaches it. A Vite/Webpack-style emit-plugin pass (mangle + minify) that compacts and obfuscates the shader text, the ABI boundary it must never cross, and why compile-and-link is not enough to trust it.
shader-dsl
6 min read
The emit path of @xgis/shader-dsl grew a Vite/Webpack-style plugin seam so ship-time transforms compose without weighing on the core — and a build-only subpath so runtime-emit consumers bundle zero bytes of them. The test: dropping in a third transform (call-graph inlining) that touched no core line.
shader-dsl
5 min read
The verification stack behind shader-dsl's fp64: a correctly-rounding f32 machine built from Math.fround, a metamorphic oracle gate, byte goldens, and discriminative real-GPU known answers.
shader-dsl
4 min read
Incident report: the fp64 demo alternated between correct and f32-collapsed frames under byte-identical inputs. Inferred cause: driver pipeline re-optimization specializing on uniform values. Fixes: render-on-demand and a texel-fetched guard.
shader-dsl
6 min read
f64 and vecN<f64> as first-class shader-dsl types, emulated as two-f32 double-float pairs — same authoring syntax as f32, one lowering pass, ~48 significand bits.
shader-dsl
5 min read
We rebuilt ten classic ShaderToy effects in X-GIS's typed shader DSL. The renders were the easy part: authoring them surfaced eleven concrete DX issues — an elliptical sun no gate could see, a reversed smoothstep every GPU hides — each closed with a gate so it stays fixed.
compiler
6 min read
How a declarative map style becomes GPU work: lexer → parser → a Scene IR → optimization passes → codegen that emits typed shader-dsl IR (never WGSL strings), per-feature compute kernels for match(), and a gradient atlas for zoom-dependent paint.
webgl2
4 min read
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.
