BansheeEngine/Source/BansheeCore/Include/BsGpuParams.h

//********************************** Banshee Engine (www.banshee3d.com) **************************************************//
//**************** Copyright (c) 2016 Marko Pintera ([email protected]). All rights reserved. **********************//
#pragma once

#include "BsCorePrerequisites.h"
#include "BsGpuParam.h"
#include "BsCoreObject.h"
#include "BsIResourceListener.h"
#include "BsVectorNI.h"
#include "BsMatrixNxM.h"

namespace BansheeEngine
{
	/** @addtogroup Implementation
	 *  @{
	 */

	/**	Helper structure whose specializations convert an engine data type into a GPU program data parameter type.  */
	template<class T> struct TGpuDataParamInfo { };
	template<> struct TGpuDataParamInfo < float > { enum { TypeId = GPDT_FLOAT1 }; };
	template<> struct TGpuDataParamInfo < Vector2 > { enum { TypeId = GPDT_FLOAT2 }; };
	template<> struct TGpuDataParamInfo < Vector3 > { enum { TypeId = GPDT_FLOAT3 }; };
	template<> struct TGpuDataParamInfo < Vector4 > { enum { TypeId = GPDT_FLOAT4 }; };
	template<> struct TGpuDataParamInfo < int > { enum { TypeId = GPDT_INT1 }; };
	template<> struct TGpuDataParamInfo < Vector2I > { enum { TypeId = GPDT_INT2 }; };
	template<> struct TGpuDataParamInfo < Vector3I > { enum { TypeId = GPDT_INT3 }; };
	template<> struct TGpuDataParamInfo < Vector4I > { enum { TypeId = GPDT_INT4 }; };
	template<> struct TGpuDataParamInfo < Matrix2 > { enum { TypeId = GPDT_MATRIX_2X2 }; };
	template<> struct TGpuDataParamInfo < Matrix2x3 > { enum { TypeId = GPDT_MATRIX_2X3 }; };
	template<> struct TGpuDataParamInfo < Matrix2x4 > { enum { TypeId = GPDT_MATRIX_2X3 }; };
	template<> struct TGpuDataParamInfo < Matrix3 > { enum { TypeId = GPDT_MATRIX_3X3 }; };
	template<> struct TGpuDataParamInfo < Matrix3x2 > { enum { TypeId = GPDT_MATRIX_3X2 }; };
	template<> struct TGpuDataParamInfo < Matrix3x4 > { enum { TypeId = GPDT_MATRIX_3X4 }; };
	template<> struct TGpuDataParamInfo < Matrix4 > { enum { TypeId = GPDT_MATRIX_4X4 }; };
	template<> struct TGpuDataParamInfo < Matrix4x2 > { enum { TypeId = GPDT_MATRIX_4X2 }; };
	template<> struct TGpuDataParamInfo < Matrix4x3 > { enum { TypeId = GPDT_MATRIX_4X3 }; };
	template<> struct TGpuDataParamInfo < Color > { enum { TypeId = GPDT_COLOR }; };

	/** Helper structure used for initializing GpuParams. */
	struct GPU_PARAMS_DESC
	{
		SPtr<GpuParamDesc> fragmentParams;
		SPtr<GpuParamDesc> vertexParams;
		SPtr<GpuParamDesc> geometryParams;
		SPtr<GpuParamDesc> hullParams;
		SPtr<GpuParamDesc> domainParams;
		SPtr<GpuParamDesc> computeParams;
	};

	/** Contains functionality common for both sim and core thread version of GpuParams. */
	class BS_CORE_EXPORT GpuParamsBase
	{
	public:
		virtual ~GpuParamsBase();

		// Note: Disallow copy/assign because it would require some care when copying (copy internal data shared_ptr and
		// all the internal buffers too). Trivial to implement but not needed at this time. Un-delete and implement if necessary.
		GpuParamsBase(const GpuParamsBase& other) = delete;
		GpuParamsBase& operator=(const GpuParamsBase& rhs) = delete;

		/** Returns a description of all stored parameters. */
		SPtr<GpuParamDesc> getParamDesc(GpuProgramType type) const { return mParamDescs[(int)type]; }

		/**
		 * Returns the size of a data parameter with the specified name, in bytes. Returns 0 if such parameter doesn't exist.
		 */
		UINT32 getDataParamSize(GpuProgramType type, const String& name) const;

		/** Checks if parameter with the specified name exists. */
		bool hasParam(GpuProgramType type, const String& name) const;

		/**	Checks if texture parameter with the specified name exists. */
		bool hasTexture(GpuProgramType type, const String& name) const;

		/**	Checks if load/store texture parameter with the specified name exists. */
		bool hasLoadStoreTexture(GpuProgramType type, const String& name) const;

		/**	Checks if buffer parameter with the specified name exists. */
		bool hasBuffer(GpuProgramType type, const String& name) const;

		/**	Checks if sampler state parameter with the specified name exists. */
		bool hasSamplerState(GpuProgramType type, const String& name) const;

		/** Checks if a parameter block with the specified name exists. */
		bool hasParamBlock(GpuProgramType type, const String& name) const;

		/**	Gets a descriptor for a parameter block buffer with the specified name. */
		GpuParamBlockDesc* getParamBlockDesc(GpuProgramType type, const String& name) const;

		/** Marks the sim thread object as dirty, causing it to sync its contents with its core thread counterpart. */
		virtual void _markCoreDirty() { }

		/** @copydoc IResourceListener::markListenerResourcesDirty */
		virtual void _markResourcesDirty() { }

	protected:
		GpuParamsBase(const GPU_PARAMS_DESC& desc);

		/**	Gets a descriptor for a data parameter with the specified name. */
		GpuParamDataDesc* getParamDesc(GpuProgramType type, const String& name) const;

		SPtr<GpuParamDesc> mParamDescs[6];
	};

	template<bool Core> struct TGpuParamsTypes { };
	template<> struct TGpuParamsTypes < false >
	{
		typedef GpuParams GpuParamsType;
		typedef HTexture TextureType;
		typedef SPtr<GpuBuffer> BufferType;
		typedef SPtr<SamplerState> SamplerType;
		typedef SPtr<GpuParamBlockBuffer> ParamsBufferType;
	};

	template<> struct TGpuParamsTypes < true >
	{
		typedef GpuParamsCore GpuParamsType;
		typedef SPtr<TextureCore> TextureType;
		typedef SPtr<GpuBufferCore> BufferType;
		typedef SPtr<SamplerStateCore> SamplerType;
		typedef SPtr<GpuParamBlockBufferCore> ParamsBufferType;
	};

	/** Templated version of GpuParams that contains functionality for both sim and core thread versions of stored data. */
	template <bool Core>
	class BS_CORE_EXPORT TGpuParams : public GpuParamsBase
	{
	public:
		typedef typename TGpuParamsTypes<Core>::GpuParamsType GpuParamsType;
		typedef typename TGpuParamsTypes<Core>::TextureType TextureType;
		typedef typename TGpuParamsTypes<Core>::BufferType BufferType;
		typedef typename TGpuParamsTypes<Core>::SamplerType SamplerType;
		typedef typename TGpuParamsTypes<Core>::ParamsBufferType ParamsBufferType;

		virtual ~TGpuParams();

		/**
		 * Returns a handle for the parameter with the specified name. Handle may then be stored and used for quickly 
		 * setting or retrieving values to/from that parameter.
		 *
		 * Throws exception if parameter with that name and type doesn't exist.
		 *
		 * Parameter handles will be invalidated when their parent GpuParams object changes.
		 */
		template<class T> void getParam(GpuProgramType type, const String& name, TGpuDataParam<T, Core>& output) const;

		/** @copydoc getParam */
		void getStructParam(GpuProgramType type, const String& name, TGpuParamStruct<Core>& output) const;

		/** @copydoc getParam */
		void getTextureParam(GpuProgramType type, const String& name, TGpuParamTexture<Core>& output) const;

		/** @copydoc getParam */
		void getLoadStoreTextureParam(GpuProgramType type, const String& name, TGpuParamLoadStoreTexture<Core>& output) const;

		/** @copydoc getParam */
		void getBufferParam(GpuProgramType type, const String& name, TGpuParamBuffer<Core>& output) const;

		/** @copydoc getParam */
		void getSamplerStateParam(GpuProgramType type, const String& name, TGpuParamSampState<Core>& output) const;

		/**	Gets a parameter block buffer from the specified set/slot combination. */
		ParamsBufferType getParamBlockBuffer(UINT32 set, UINT32 slot) const;

		/**	Gets a texture bound to the specified set/slot combination. */
		TextureType getTexture(UINT32 set, UINT32 slot) const;

		/**	Gets a load/store texture bound to the specified set/slot combination. */
		TextureType getLoadStoreTexture(UINT32 set, UINT32 slot) const;

		/**	Gets a buffer bound to the specified set/slot combination. */
		BufferType getBuffer(UINT32 set, UINT32 slot) const;

		/**	Gets a sampler state bound to the specified set/slot combination. */
		SamplerType getSamplerState(UINT32 set, UINT32 slot) const;

		/** Gets information that determines which texture surfaces to bind as load/store parameters. */
		const TextureSurface& getLoadStoreSurface(UINT32 set, UINT32 slot) const;

		/**
		 * Sets the parameter buffer with the specified name. Any following parameter reads or writes that are 
		 * referencing that buffer will use the new buffer.
		 *
		 * @note	
		 * This is useful if you want to share a parameter buffer among multiple GPU programs. You would only set the 
		 * values once and then share the buffer among all other GpuParams.
		 * @note
		 * It is up to the caller to guarantee the provided buffer matches parameter block descriptor for this slot.
		 */
		void setParamBlockBuffer(GpuProgramType type, const String& name, const ParamsBufferType& paramBlockBuffer);

		/**
		 * Binds a new parameter buffer to the specified slot. Any following parameter reads or writes that are referencing
		 * that buffer slot will use the new buffer.
		 *
		 * @note	
		 * This is useful if you want to share a parameter buffer among multiple GPU programs. You would only set the 
		 * values once and then share the buffer among all other GpuParams.
		 * @note
		 * It is up to the caller to guarantee the provided buffer matches parameter block descriptor for this slot.
		 */
		virtual void setParamBlockBuffer(UINT32 set, UINT32 slot, const ParamsBufferType& paramBlockBuffer);

		/**	Sets a texture at the specified set/slot combination. */
		virtual void setTexture(UINT32 set, UINT32 slot, const TextureType& texture);

		/**	Sets a load/store texture at the specified set/slot combination. */
		virtual void setLoadStoreTexture(UINT32 set, UINT32 slot, const TextureType& texture, const TextureSurface& surface);

		/**	Sets a buffer at the specified set/slot combination. */
		virtual void setBuffer(UINT32 set, UINT32 slot, const BufferType& buffer);

		/**	Sets a sampler state at the specified set/slot combination. */
		virtual void setSamplerState(UINT32 set, UINT32 slot, const SamplerType& sampler);

		/**	Sets information that determines which texture surfaces to bind	as load/store parameters. */
		virtual void setLoadStoreSurface(UINT32 set, UINT32 slot, const TextureSurface& surface);

	protected:
		/** Type of elements stored in this object. */
		enum class ElementType
		{
			ParamBlock, Texture, LoadStoreTexture, Buffer, SamplerState, Count
		};

		TGpuParams(const GPU_PARAMS_DESC& desc);

		/** @copydoc CoreObject::getThisPtr */
		virtual SPtr<GpuParamsType> _getThisPtr() const = 0;

		/** 
		 * Converts a set/slot combination into a global slot. If the set or slot is out of valid range, the method logs
		 * an error and returns -1. Only performs range checking in debug mode.
		 */
		UINT32 getGlobalSlot(ElementType type, UINT32 set, UINT32 slot) const;

		UINT32 mNumSets[(int)ElementType::Count];
		UINT32 mNumElements[(int)ElementType::Count];
		UINT32* mOffsets[(int)ElementType::Count];

		ParamsBufferType* mParamBlockBuffers = nullptr;
		TextureType* mTextures = nullptr;
		TextureType* mLoadStoreTextures = nullptr;
		TextureSurface* mLoadStoreSurfaces = nullptr;
		BufferType* mBuffers = nullptr;
		SamplerType* mSamplerStates = nullptr;
	};

	/** @} */

	/** @addtogroup RenderAPI-Internal
	 *  @{
	 */

	/**
	 * Core thread version of GpuParams.
	 *
	 * @note	Core thread only.
	 */
	class BS_CORE_EXPORT GpuParamsCore : public CoreObjectCore, public TGpuParams<true>
	{
	public:
		virtual ~GpuParamsCore() { }

		/** 
		 * @copydoc GpuParams::create 
		 * @param[in]	deviceMask		Mask that determines on which GPU devices should the buffer be created on.
		 */
		static SPtr<GpuParamsCore> create(const GPU_PARAMS_DESC& desc, GpuDeviceFlags deviceMask = GDF_DEFAULT);

	protected:
		friend class GpuParams;
		friend class HardwareBufferCoreManager;

		GpuParamsCore(const GPU_PARAMS_DESC& desc, GpuDeviceFlags deviceMask);

		/** @copydoc CoreObject::getThisPtr */
		SPtr<GpuParamsCore> _getThisPtr() const override;

		/** @copydoc CoreObjectCore::syncToCore */
		void syncToCore(const CoreSyncData& data) override;
	};

	/** @} */
	/** @addtogroup RenderAPI
	 *  @{
	 */

	/**
	 * Contains descriptions for all parameters in a set of programs (ones for each stage) and allows you to write and read
	 * those parameters. All parameter values are stored internally on the CPU, and are only submitted to the GPU once the
	 * parameters are bound to the pipeline.
	 *
	 * @note	Sim thread only.
	 */
	class BS_CORE_EXPORT GpuParams : public CoreObject, public TGpuParams<false>, public IResourceListener
	{
	public:
		~GpuParams() { }

		/** Retrieves a core implementation of a mesh usable only from the core thread. */
		SPtr<GpuParamsCore> getCore() const;

		/**
		 * Creates new GpuParams object using the specified parameter descriptions.
		 *
		 * @param[in]	desc	Object containing parameter descriptions for all relevant GPU program stages.
		 */
		static SPtr<GpuParams> create(const GPU_PARAMS_DESC& desc);

		/** Contains a lookup table for sizes of all data parameters. Sizes are in bytes. */
		const static GpuDataParamInfos PARAM_SIZES;

		/** @name Internal
		 *  @{
		 */

		/** @copydoc GpuParamsBase::_markCoreDirty */
		void _markCoreDirty() override;

		/** @copydoc IResourceListener::markListenerResourcesDirty */
		void _markResourcesDirty() override;

		/** @} */
	protected:
		friend class HardwareBufferManager;

		GpuParams(const GPU_PARAMS_DESC& desc);

		/** @copydoc CoreObject::getThisPtr */
		SPtr<GpuParams> _getThisPtr() const override;

		/** @copydoc CoreObject::createCore */
		SPtr<CoreObjectCore> createCore() const override;

		/** @copydoc CoreObject::syncToCore */
		CoreSyncData syncToCore(FrameAlloc* allocator) override;

		/** @copydoc IResourceListener::getListenerResources */
		void getListenerResources(Vector<HResource>& resources) override;

		/** @copydoc IResourceListener::notifyResourceLoaded */
		void notifyResourceLoaded(const HResource& resource) override { markCoreDirty(); }

		/** @copydoc IResourceListener::notifyResourceChanged */
		void notifyResourceChanged(const HResource& resource) override { markCoreDirty(); }
	};

	/** @} */
}