Illumination Buffer

A real-time graphics utility that intercepts and caches the final composite lightmap from Foundry VTT's lighting render pass. Using a low-level WebGL intercept and a direct GPU-to-GPU copy (blit), this module provides a persistent, scene-sized PIXI.RenderTexture updated on each lighting refresh with minimal performance overhead. The resulting texture is exposed via a simple API, designed to be fed directly into custom PIXI.Filters and shaders as a sampler2D uniform. This enables developers to create sophisticated, real-time visual effects that react dynamically to the scene's illumination.