From b8cc592235b47657910127df97d9d815bce9c109 Mon Sep 17 00:00:00 2001
From: Verox001 <verox@cimeyclust.com>
Date: Thu, 16 Jan 2025 13:18:43 +0100
Subject: [PATCH] Finished Ray Tracing lighting

---
 src/lib.rs      |  9 ++++++---
 src/shader.wgsl | 11 +++++++++--
 2 files changed, 15 insertions(+), 5 deletions(-)

diff --git a/src/lib.rs b/src/lib.rs
index d39814b..f3c9d18 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -56,19 +56,23 @@ impl Camera {
 }
 
 #[repr(C)]
-#[derive(Debug, Copy, Clone, bytemuck::Pod, bytemuck::Zeroable)]
+#[derive(Copy, Clone, bytemuck::Pod, bytemuck::Zeroable)]
 struct CameraUniform {
+    view_position: [f32; 4],
     view_proj: [[f32; 4]; 4],
 }
 
 impl CameraUniform {
     fn new() -> Self {
         Self {
+            view_position: [0.0; 4],
             view_proj: cgmath::Matrix4::identity().into(),
         }
     }
 
     fn update_view_proj(&mut self, camera: &Camera) {
+        // We're using Vector4 because of the uniforms 16 byte spacing requirement
+        self.view_position = camera.eye.to_homogeneous().into();
         self.view_proj = (OPENGL_TO_WGPU_MATRIX * camera.build_view_projection_matrix()).into();
     }
 }
@@ -467,7 +471,7 @@ impl<'a> State<'a> {
             device.create_bind_group_layout(&wgpu::BindGroupLayoutDescriptor {
                 entries: &[wgpu::BindGroupLayoutEntry {
                     binding: 0,
-                    visibility: wgpu::ShaderStages::VERTEX,
+                    visibility: wgpu::ShaderStages::VERTEX | wgpu::ShaderStages::FRAGMENT,
                     ty: wgpu::BindingType::Buffer {
                         ty: wgpu::BufferBindingType::Uniform,
                         has_dynamic_offset: false,
@@ -634,7 +638,6 @@ impl<'a> State<'a> {
         self.camera_controller.update_camera(&mut self.camera);
         log::info!("{:?}", self.camera);
         self.camera_uniform.update_view_proj(&self.camera);
-        log::info!("{:?}", self.camera_uniform);
         self.queue.write_buffer(
             &self.camera_buffer,
             0,
diff --git a/src/shader.wgsl b/src/shader.wgsl
index 5c33ddb..39ba767 100644
--- a/src/shader.wgsl
+++ b/src/shader.wgsl
@@ -8,6 +8,7 @@ struct Light {
 var<uniform> light: Light;
 
 struct Camera {
+    view_pos: vec4<f32>,
     view_proj: mat4x4<f32>,
 }
 @group(1) @binding(0)
@@ -74,14 +75,20 @@ fn fs_main(in: VertexOutput) -> @location(0) vec4<f32> {
 
     let light_dir = normalize(light.position - in.world_position);
 
+    let view_dir = normalize(camera.view_pos.xyz - in.world_position);
+    let half_dir = normalize(view_dir + light_dir);
+
+    let specular_strength = pow(max(dot(in.world_normal, half_dir), 0.0), 32.0);
+    let specular_color = specular_strength * light.color;
+
     let diffuse_strength = max(dot(in.world_normal, light_dir), 0.0);
     let diffuse_color = light.color * diffuse_strength;
 
     // We don't need (or want) much ambient light, so 0.1 is fine
-    let ambient_strength = 0.1;
+    let ambient_strength = 0.03;
     let ambient_color = light.color * ambient_strength;
 
-    let result = (ambient_color + diffuse_color) * object_color.xyz;
+    let result = (ambient_color + diffuse_color + specular_color) * object_color.xyz;
 
     return vec4<f32>(result, object_color.a);
 }
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