shader demo

Signed in as __USERNAME__. Shader experiment sandbox, forked from seelie-app-sandbox: Odin + raylib compiled to WebAssembly via emscripten. The experiments: the world renders at the native 640×480 as per-pixel palette indices with a per-pixel light level, then the SVM pass (the Seelie Virtual Machine: SNES semantics with infinite memory and compute - 4 layers at 8bpp, no sprite limits, resolution agnostic) maps (index, level) through a per-frame 256×16 ramp atlas - per-color cel ramps with black/white-out ends, census-weighted shadow/highlight stops, clustered light hues - and adds the smooth fog/rain sub screen with 15-bit color math, before a CRT present pass (aperture grille, scanlines, phosphor bleed) paints it onto the 2560×1440 canvas. Controls as in the sandbox: QWE/AD/ZSC or the left stick walk the 8 compass directions; Numpad +/− adjusts speed; the right stick or arrow keys override facing; [/] or D-pad cycles the character; the mouse wheel steps integer zoom, R resets; N toggles day/night, T the torch, U the tuning panel.