Pass in the faceNormals

Terrain2/Renderer.swift

@@ -279,7 +279,8 @@ class Renderer: NSObject, MTKViewDelegate {
                     renderEncoder.setDepthStencilState(depthState)
 
                     renderEncoder.setTriangleFillMode(drawLines ? .lines : .fill)
-                    
+
+                    renderEncoder.setVertexBuffer(terrain.faceNormalsBuffer, offset: 0, index: BufferIndex.faceNormals.rawValue)
                     renderEncoder.setVertexBuffer(dynamicUniformBuffer, offset:uniformBufferOffset, index: BufferIndex.uniforms.rawValue)
                     renderEncoder.setFragmentBuffer(dynamicUniformBuffer, offset:uniformBufferOffset, index: BufferIndex.uniforms.rawValue)
                     

Terrain2/ShaderTypes.h

@@ -26,7 +26,8 @@ typedef NS_ENUM(NSInteger, BufferIndex)
     BufferIndexMeshPositions  = 0,
     BufferIndexNormals        = 1,
     BufferIndexMeshGenerics   = 2,
-    BufferIndexUniforms       = 3,
+    BufferIndexFaceNormals    = 3,
+    BufferIndexUniforms       = 4,
 };
 
 typedef NS_ENUM(NSInteger, VertexAttribute)

Terrain2/Shaders/Shaders.metal

@@ -33,6 +33,7 @@ typedef struct
 #pragma mark - Geometry Shaders
 
 vertex ColorInOut vertexShader(Vertex in [[stage_in]],
+                               constant packed_float3 *faceNormals [[buffer(BufferIndexFaceNormals)]],
                                constant Uniforms &uniforms [[buffer(BufferIndexUniforms)]])
 {
     ColorInOut out;