Avoid redundant OpenGL state changes during a draw - #47
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renderPbrPrimitive re-uploaded every uniform, rebound all texture units, and re-toggled blend/depth/cull for every primitive, then reset that state after each draw - ~55 GL calls per primitive. A glTF model with many primitives (the common case) pays this per primitive even when the frame constants and material are unchanged. This caches within one ctx.draw: - Uniform values are per-program GL state, so a PbrPassValues shadow dirty-checks the frame-level block (view/proj/lightSpace, lighting, fog, camera, tint, debugView, env) and uploads only on change. - The seven sampler-unit uniforms move to setupPbr (set once). - Material uniforms upload only when the material or its version changes; texture binds key on the actual GL id (so a late texture upload is still caught) with an epoch guard against ids recycled by glDeleteTextures. - Blend/depth-mask/cull/front-face go through an enable-state shadow. The binding/enable caches reset at the start of each ctx.draw (foreign GL between draws may have changed them) and after the library's own shadow/skybox passes; the uniform value cache is per-program and persists. Submission order, per-draw back-to-front blended flush, and post-draw GL state are unchanged, so output is identical. No API change. Measured on a dense scene (~1300 primitives, macOS GL): per-primitive uniform+bind cost drops from the bulk of renderPbrPrimitive's self time to noise; ~5 GL calls for an opaque same-material primitive vs ~55.
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What changed
The OpenGL PBR renderer now skips unchanged uniforms, material settings, texture binds, and enable state within one
ctx.drawcall. State is reset at the draw boundary, so the public API and behavior stay the same.Result
In a dense scene, an opaque primitive using the same material drops from about 55 GL calls to about 5.
Checks
Upstream CI passes on every backend.