Metal shader generation

hecl/include/HECL/Backend/Metal.hpp

@@ -0,0 +1,47 @@
+#ifndef HECLBACKEND_METAL_HPP
+#define HECLBACKEND_METAL_HPP
+#if __APPLE__
+
+#include "ProgrammableCommon.hpp"
+#include <Availability.h>
+
+#if __MAC_OS_X_VERSION_MAX_ALLOWED >= 101100
+#define HECL_HAS_METAL 1
+
+namespace HECL
+{
+namespace Backend
+{
+    
+struct Metal : ProgrammableCommon
+{
+    void reset(const IR& ir, Diagnostics& diag);
+    std::string makeVert(unsigned col, unsigned uv, unsigned w,
+                         unsigned skinSlots, unsigned texMtxs) const;
+    std::string makeFrag(const ShaderFunction& lighting=ShaderFunction()) const;
+    std::string makeFrag(const ShaderFunction& lighting,
+                         const ShaderFunction& post) const;
+    
+private:
+    std::string GenerateVertInStruct(unsigned col, unsigned uv, unsigned w) const;
+    std::string GenerateVertToFragStruct() const;
+    std::string GenerateVertUniformStruct(unsigned skinSlots, unsigned texMtxs) const;
+    
+    std::string EmitVec3(const atVec4f& vec) const
+    {
+        return HECL::Format("float3(%g,%g,%g)", vec.vec[0], vec.vec[1], vec.vec[2]);
+    }
+    
+    std::string EmitTexGenSource2(TexGenSrc src, int uvIdx) const;
+    std::string EmitTexGenSource4(TexGenSrc src, int uvIdx) const;
+};
+    
+}
+}
+
+#else
+#define HECL_HAS_METAL 0
+#endif
+
+#endif // __APPLE__
+#endif // HECLBACKEND_METAL_HPP