fix(engine): prevent buggy specular light when material shininess is 0

1 files changed, 7 insertions, 0 deletions

diff --git a/engine/res/default_shader.slang b/engine/res/default_shader.slang
index e42b83a..1f79dbe 100644
--- a/engine/res/default_shader.slang
+++ b/engine/res/default_shader.slang
@@ -164,6 +164,13 @@ struct BlinnPhongLighting
         in float2 texture_coords
     )
     {
+        // The result of the below pow is undefined if both arguments is 0. This stops
+        // that problem. This prevents buggy specular light when shininess is 0.
+        if (this.material.shininess == 0.0) {
+            return light_phong.specular *
+                   (specular_map.Sample(texture_coords).xyz * this.material.specular);
+        }
+
         float3 view_direction = normalize(this.view_pos - frag_pos);
 
         float3 halfway_direction = normalize(light_dir + view_direction);