2 files changed, 4 insertions, 25 deletions
diff --git a/cnn_v3/shaders/gbuf_pack.wgsl b/cnn_v3/shaders/gbuf_pack.wgsl
index 71d8471..333589c 100644
--- a/cnn_v3/shaders/gbuf_pack.wgsl
+++ b/cnn_v3/shaders/gbuf_pack.wgsl
@@ -1,4 +1,5 @@
 // G-buffer pack compute shader for CNN v3
+#include "math/normal"
 // Pass 4: Pack all G-buffer channels into two rgba32uint feature textures (32 bytes/pixel)
 // Output feat_tex0 holds 8×f16 geometric channels; feat_tex1 holds 12×u8 context channels.
 
@@ -44,15 +45,6 @@ fn box4(tl: vec2i) -> vec3f {
     return acc * (1.0 / 16.0);
 }
 
-// Decode oct-normal from [0,1] storage → [-1,1] encoded xy → reconstruct z.
-fn decode_oct_normal(rg: vec2f) -> vec3f {
-    let f = rg * 2.0 - vec2f(1.0);
-    var n = vec3f(f.x, f.y, 1.0 - abs(f.x) - abs(f.y));
-    let t = max(-n.z, 0.0);
-    n.x += select(t, -t, n.x >= 0.0);
-    n.y += select(t, -t, n.y >= 0.0);
-    return normalize(n);
-}
 
 @compute @workgroup_size(8, 8)
 fn pack_features(@builtin(global_invocation_id) id: vec3u) {
@@ -73,7 +65,7 @@ fn pack_features(@builtin(global_invocation_id) id: vec3u) {
 
     // Normal: stored as oct-encoded [0,1] in RG; extract just the encoded xy for feat_tex0
     let normal_enc = nm.rg; // already in [0,1] — decode to get the xy for CNN input
-    let n3         = decode_oct_normal(normal_enc);
+    let n3         = oct_decode_unorm(normal_enc);
     // Store oct-encoded in [-1,1] remapped back to what CNN expects (the [-1,1] oct xy)
     let oct_xy     = normal_enc * 2.0 - vec2f(1.0); // remap [0,1] → [-1,1]
 
diff --git a/cnn_v3/shaders/gbuf_raster.wgsl b/cnn_v3/shaders/gbuf_raster.wgsl
index c762db2..a5eb921 100644
--- a/cnn_v3/shaders/gbuf_raster.wgsl
+++ b/cnn_v3/shaders/gbuf_raster.wgsl
@@ -3,6 +3,7 @@
 // Uses GlobalUniforms, ObjectData, ObjectsBuffer from common_uniforms.
 
 #include "common_uniforms"
+#include "math/normal"
 
 @group(0) @binding(0) var<uniform> globals: GlobalUniforms;
 @group(0) @binding(1) var<storage, read> object_data: ObjectsBuffer;
@@ -15,20 +16,6 @@ struct VertexOutput {
     @location(3) @interpolate(flat) instance_index: u32,
 }
 
-// Octahedral encoding: maps unit normal to [-1,1]^2
-fn oct_encode(n: vec3f) -> vec2f {
-    let inv_l1 = 1.0 / (abs(n.x) + abs(n.y) + abs(n.z));
-    var p = n.xy * inv_l1;
-    // Fold lower hemisphere
-    if (n.z < 0.0) {
-        let s = vec2f(
-            select(-1.0, 1.0, p.x >= 0.0),
-            select(-1.0, 1.0, p.y >= 0.0)
-        );
-        p = (1.0 - abs(p.yx)) * s;
-    }
-    return p; // in [-1, 1]
-}
 
 @vertex
 fn vs_main(
@@ -96,7 +83,7 @@ fn fs_main(in: VertexOutput) -> GBufOutput {
     let mat_id = f32(in.instance_index) / 255.0;
 
     // Oct-encode world normal, remap [-1,1] → [0,1] for storage
-    let oct = oct_encode(normalize(in.world_normal)) * 0.5 + vec2f(0.5);
+    let oct = oct_encode_unorm(normalize(in.world_normal));
 
     var out: GBufOutput;
     out.albedo     = vec4f(in.color.rgb, 1.0);