refactor(shaders): extract oct-normal encode/decode into math/normal snippet

New src/shaders/math/normal.wgsl: oct_encode, oct_decode, oct_encode_unorm,
oct_decode_unorm. Registered in InitShaderComposer as "math/normal".
Removed inline copies from gbuf_raster.wgsl and gbuf_pack.wgsl.
18/18 tests passing.

1 files changed, 1 insertions, 0 deletions

diff --git a/src/effects/shaders.cc b/src/effects/shaders.cc
index 7a68e5f..a6c1b64 100644
--- a/src/effects/shaders.cc
+++ b/src/effects/shaders.cc
@@ -35,6 +35,7 @@ void InitShaderComposer() {
   register_if_exists("math/common_utils",
                      AssetId::ASSET_SHADER_MATH_COMMON_UTILS);
   register_if_exists("math/noise", AssetId::ASSET_SHADER_MATH_NOISE);
+  register_if_exists("math/normal", AssetId::ASSET_SHADER_MATH_NORMAL);
   register_if_exists("render/shadows", AssetId::ASSET_SHADER_RENDER_SHADOWS);
   register_if_exists("render/scene_query_bvh",
                      AssetId::ASSET_SHADER_RENDER_SCENE_QUERY_BVH);