diff --git a/Terrain2/ShaderTypes.h b/Terrain2/ShaderTypes.h
index 6a45da6..3ea3f57 100644
--- a/Terrain2/ShaderTypes.h
+++ b/Terrain2/ShaderTypes.h
@@ -62,6 +62,28 @@ typedef NS_ENUM(NSInteger, GeneratorTextureIndex) {
     GeneratorTextureIndexOut = 1,
 };
 
+typedef struct {
+    bool enabled;
+#ifdef __METAL_VERSION__
+    simd::float4 position;
+    simd::float3 color;
+#else
+    simd_float4 position;
+    simd_float3 color;
+#endif
+} Light;
+
+struct Material {
+#ifdef __METAL_VERSION__
+    simd::float3 diffuseColor;
+    simd::float3 specularColor;
+#else
+    simd_float3 diffuseColor;
+    simd_float3 specularColor;
+#endif
+    float specularExponent;
+};
+
 typedef struct {
     matrix_float4x4 projectionMatrix;
     matrix_float4x4 modelViewMatrix;