From 398064aef06d64baf464ea22f8238d0c38effd4f Mon Sep 17 00:00:00 2001
From: mars <mars@tebibyte.media>
Date: Thu, 30 Jun 2022 09:53:02 -0600
Subject: [PATCH] Improve mesh debug colors

---
 shaders/mesh_forward.wgsl | 10 +++++++++-
 1 file changed, 9 insertions(+), 1 deletion(-)

diff --git a/shaders/mesh_forward.wgsl b/shaders/mesh_forward.wgsl
index bc2a3a1..6ab86d9 100644
--- a/shaders/mesh_forward.wgsl
+++ b/shaders/mesh_forward.wgsl
@@ -11,11 +11,16 @@ struct VertexInput {
 struct VertexOutput {
   [[builtin(position)]] clip_position: vec4<f32>;
   [[location(0)]] position: vec3<f32>;
+  [[location(1)]] color: vec3<f32>;
 };
 
 [[group(0), binding(0)]]
 var<uniform> camera: CameraUniform;
 
+fn random(seed: u32, salt: f32) -> f32 {
+  return abs(sin((f32(seed & u32(0x11111)) * 0.7071 + salt) * 78.233));
+}
+
 [[stage(vertex)]]
 fn vs_main(
   [[builtin(instance_index)]] mesh_idx: u32,
@@ -27,6 +32,9 @@ fn vs_main(
   var out: VertexOutput;
   out.clip_position = camera.vp * vec4<f32>(world_pos, 1.0);
   out.position = world_pos;
+  out.color.r = random(vertex_idx, f32(1.0) + world_pos.x);
+  out.color.g = random(vertex_idx, f32(2.0) + world_pos.y);
+  out.color.b = random(vertex_idx, f32(3.0) + world_pos.z);
   return out;
 }
 
@@ -34,5 +42,5 @@ fn vs_main(
 fn fs_main(
   frag: VertexOutput,
 ) -> [[location(0)]] vec4<f32> {
-  return vec4<f32>(sin(frag.position) * vec3<f32>(0.5) + vec3<f32>(0.5), 1.0);
+  return vec4<f32>(frag.color, 1.0);
 }