client: normal maps

1 files changed, 22 insertions, 7 deletions

diff --git a/client/src/shader.wgsl b/client/src/shader.wgsl
index 993c9b5..e8d3276 100644
--- a/client/src/shader.wgsl
+++ b/client/src/shader.wgsl
@@ -16,39 +16,54 @@
 struct VertexIn {
     @location(0) position: vec3<f32>,
     @location(1) normal: vec3<f32>,
-    @location(2) texcoord: vec2<f32>,
+    @location(2) tangent: vec3<f32>, // TODO maybe compress this
+    @location(3) texcoord: vec2<f32>,
 }
 struct VertexOut {
     @builtin(position) clip: vec4<f32>,
     @location(0) normal: vec3<f32>,
-    @location(1) texcoord: vec2<f32>,
+    @location(1) tangent: vec3<f32>,
+    @location(2) texcoord: vec2<f32>,
+}
+
+struct PushConst {
+    modelview: mat4x4<f32>,
+    model_basis: mat3x3<f32>,
 }
 
 @group(0) @binding(0) var tex_albedo: texture_2d<f32>;
 @group(0) @binding(1) var tex_albedo_sampler: sampler;
 @group(1) @binding(0) var tex_normal: texture_2d<f32>;
 @group(1) @binding(1) var tex_normal_sampler: sampler;
-var<push_constant> project: mat4x4<f32>;
+                      var<push_constant> pc: PushConst;
 
 const LIGHT: vec3<f32> = vec3(0.64, 0.64, 0.64);
 
 @vertex
 fn vs_main(vi: VertexIn) -> VertexOut {
-    var clip = project * vec4(vi.position, 1.);
-    let vo = VertexOut(clip, vi.normal, vi.texcoord);
+    let clip = pc.modelview * vec4(vi.position, 1.);
+    let vo = VertexOut(
+        clip,
+        normalize(pc.model_basis * vi.normal),
+        normalize(pc.model_basis * vi.tangent),
+        vi.texcoord
+    );
     return vo;
 }
+
 @fragment
 fn fs_main(vo: VertexOut) -> @location(0) vec4<f32> {
     let t_albedo = textureSample(tex_albedo, tex_albedo_sampler, vo.texcoord);
     let t_normal = textureSample(tex_normal, tex_normal_sampler, vo.texcoord);
 
+    let tangent_basis = mat3x3(vo.tangent, cross(vo.tangent, vo.normal), vo.normal);
+    let normal = tangent_basis * normalize(t_normal.rgb * 2. - 1.);
 
-    let lighting = mix(1., saturate(dot(LIGHT, vo.normal)), 0.9);
+    let lighting = mix(1., saturate(dot(LIGHT, normal)), 0.9);
 
     let alpha = t_albedo.a;
     let color = t_albedo.rgb * lighting;
-    // let color = vo.normal + t_normal.rgb;
+    // let color = normal * 0.5 + 0.5;
 
     if fract(dot(sin(vo.clip * 123.) * 1213., vec4(3., 2., 1., 4.))) > alpha {
         discard;