GPU/HW: Split shadergen to seperate class

src/core/gpu_hw_shadergen.h

@@ -0,0 +1,34 @@
+#pragma once
+#include <sstream>
+#include <string>
+#include "gpu_hw.h"
+
+class GPU_HW_ShaderGen
+{
+public:
+  enum class Backend
+  {
+    OpenGL
+  };
+
+public:
+  GPU_HW_ShaderGen(Backend backend, u32 resolution_scale, bool true_color);
+  ~GPU_HW_ShaderGen();
+
+  void Init(Backend backend, u32 resolution_scale, bool true_color);
+
+  std::string GenerateBatchVertexShader(bool textured);
+  std::string GenerateBatchFragmentShader(GPU_HW::BatchRenderMode transparency, GPU::TextureMode texture_mode, bool dithering);
+  std::string GenerateScreenQuadVertexShader();
+  std::string GenerateFillFragmentShader();
+  std::string GenerateDisplayFragmentShader(bool depth_24bit, bool interlaced);
+  std::string GenerateVRAMWriteFragmentShader();
+
+  Backend m_backend;
+  u32 m_resolution_scale;
+  bool m_true_color;
+
+private:
+  void GenerateShaderHeader(std::stringstream& ss);
+  void GenerateBatchUniformBuffer(std::stringstream& ss);
+};