shader-programming

shader-programming is a cross-engine game-development skill that teaches writing GPU shaders from portable fundamentals — the vertex→fragment pipeline, coordinate spaces, UV math, and how common 2D/3D effects are built — in GLSL with HLSL equivalents. It solves the recurring confusion of shader authoring by grounding the reader in concepts that port across engines, where only the language dialect and built-in variable names change, and it defers to engine-specific docs (godot-shaders, Unity/Unreal material docs) for exact syntax.

The core workflow covers knowing which pipeline stage you're in, tracking coordinate spaces (model → world → view → clip), driving effects with UVs and a time uniform, working per-pixel with branch-light math (mix, step, smoothstep, clamp) rather than divergent if-branches, passing data via uniforms and varyings while keeping texture samples few, and verifying visually on target hardware. It provides annotated GLSL fragment patterns — texture sampling and tint, frame-rate-independent UV scrolling, dissolve with a glowing edge from a noise threshold, and a Fresnel rim light — each with HLSL notes. A references/effects.md file adds full outline, vignette, and color-grading shaders, a GLSL↔HLSL function/type mapping table, and per-engine notes. A dedicated Pitfalls section calls out mixing coordinate spaces, forgetting to normalize interpolated vectors, cross-engine UV flips, heavy branching, discard defeating early-Z, and mobile precision issues.

The target users are game developers and technical artists who want to understand or write vertex/fragment shaders, build effects like tint, scroll, dissolve, outline, rim light, and vignette, or translate a shader between GLSL, HLSL, and engines. It is a concept-and-reference skill focused on transferable knowledge rather than any single engine's toolchain.