Env update

Engine/Shaders/Common/Transformation.h

@@ -8,3 +8,7 @@
 
 metal::float3x3 extractRotation(metal::float4x4 transformation);
 metal::float4 extractPosition(metal::float4x4 transformation);
+simd::float4x4 perspectiveProjection(float fovYRadians,
+                                     float aspect,
+                                     float nearZ,
+                                     float farZ);

Engine/Shaders/Common/Transformation.metal

@@ -13,5 +13,22 @@ float3x3 extractRotation(float4x4 transformation) {
 }
 
 float4 extractPosition(float4x4 transformation) {
-    return transformation * float4(0, 0, 0, 1);
+    return transformation.columns[3];
+}
+
+simd::float4x4 perspectiveProjection(float fovYRadians,
+                                     float aspect,
+                                     float nearZ,
+                                     float farZ)
+{
+    float ys = 1.0f / tan(fovYRadians * 0.5f);
+    float xs = ys / aspect;
+    float zs = farZ / (farZ - nearZ);
+
+    return simd::float4x4{
+        simd::float4(xs,  0,   0,   0),
+        simd::float4( 0, ys,   0,   0),
+        simd::float4( 0,  0,  zs,   1),
+        simd::float4( 0,  0, -zs * nearZ, 0)
+    };
 }

Engine/Shaders/EnvironmentMapper.metal

@@ -23,9 +23,10 @@ struct RasterizedData {
 vertex RasterizedData environmentVertexShader(VertexP in [[stage_in]],
                                               constant CameraUniforms & camera [[buffer(kAttributeEnvironmentVertexShaderBufferCameraUniforms)]],
                                               constant ModelUniforms * modelUniforms [[buffer(kAttributeEnvironmentVertexShaderBufferModelUniforms)]]) {
+    float4x4 projectionMatrix = perspectiveProjection(30.0f, 16.0f/9.0f, 0.01f, 100.0f);
     float3x3 extractedRotation = extractRotation(modelUniforms[camera.index].modelMatrixInverse);
     return RasterizedData {
-        camera.projectionMatrix * float4(extractedRotation * in.position, 1),
+        projectionMatrix * float4(extractedRotation * in.position, 1),
         in.position
     };
 }