Implement OGL sampler cache. Allows binding a texture multiple times with different parameters. Also possibly gives a very small speed improvement.

Source/Plugins/Plugin_VideoOGL/Src/SamplerCache.h

@@ -0,0 +1,80 @@
+
+#ifndef INCLUDE_SAMPLER_CACHE_H_
+#define INCLUDE_SAMPLER_CACHE_H_
+
+#include <map>
+
+#include "Render.h"
+#include "GLUtil.h"
+
+namespace OGL
+{
+
+class SamplerCache : NonCopyable
+{
+public:
+	SamplerCache();
+	~SamplerCache();
+	
+	void SetSamplerState(int stage, const TexMode0& tm0, const TexMode1& tm1);
+	void Clear();
+	
+private:
+	struct Params
+	{
+		union
+		{
+			struct
+			{
+				TexMode0 tm0;
+				TexMode1 tm1;
+			};
+			
+			u64 hex;
+		};
+		
+		Params()
+			: hex()
+		{}
+		
+		Params(const TexMode0& _tm0, const TexMode1& _tm1)
+			: tm0(_tm0)
+			, tm1(_tm1)
+		{
+			static_assert(sizeof(Params) == 8, "Assuming I can treat this as a 64bit int.");
+		}
+		
+		bool operator<(const Params& other) const
+		{
+			return hex < other.hex;
+		}
+		
+		bool operator!=(const Params& other) const
+		{
+			return hex != other.hex;
+		}
+	};
+	
+	struct Value
+	{
+		Value()
+			: sampler_id()
+		//	, last_frame_used()
+		{}
+		
+		GLuint sampler_id;
+		//int last_frame_used;
+	};
+	
+	void SetParameters(GLuint sampler_id, const Params& params);
+	std::pair<Params, Value> GetEntry(const Params& params);
+
+	std::map<Params, Value> m_cache;
+	std::pair<Params, Value> m_active_samplers[8];
+	
+	int m_last_max_anisotropy;
+};
+
+}
+
+#endif