Shader Module Pipeline

Shaders/ShaderModule.cs

A GLava "module" is a directory of numbered fragment passes (1.frag, 2.frag, ...). ShaderModule loads them in order, wraps each in a shared trivial vertex shader (a fullscreen triangle, no vertex buffer needed), and compiles/links each into its own program. A pass containing GLava's #error __disablestage sentinel (e.g. bars/2.frag is a no-op unless USE_ALPHA=1) is recognized and skipped rather than treated as a compile failure, and its predecessor's output passes straight through to the next real pass.

At render time, passes ping-pong between two offscreen FBOs (_fboA/ _fboB), each one receiving the previous enabled pass's output (as whatever uniform name that pass declared via #request uniform "prev" <name>, see Shader Preprocessing), plus the two audio spectrum textures as audio_l/audio_r. The last enabled pass (not necessarily the last file — a trailing disabled pass shouldn't swallow the real output) renders directly to the default framebuffer.

ShaderModule also resolves module directories from a second, sibling location — see GlavaSharp-Original Modules — so --module waterfall works exactly like --module bars without callers needing to know which shader tree it actually lives under.