/** 
 * @file llimagegl.h
 * @brief Object for managing images and their textures
 *
 * $LicenseInfo:firstyear=2001&license=viewerlgpl$
 * Second Life Viewer Source Code
 * Copyright (C) 2010, Linden Research, Inc.
 * 
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation;
 * version 2.1 of the License only.
 * 
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 * 
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
 * 
 * Linden Research, Inc., 945 Battery Street, San Francisco, CA  94111  USA
 * $/LicenseInfo$
 */


#ifndef LL_LLIMAGEGL_H
#define LL_LLIMAGEGL_H

#include "llimage.h"

#include "llgltypes.h"
#include "llpointer.h"
#include "llrefcount.h"
#include "v2math.h"
#include "llunits.h"

#include "llrender.h"

#define BYTES_TO_MEGA_BYTES(x) ((x) >> 20)
#define MEGA_BYTES_TO_BYTES(x) ((x) << 20)

//============================================================================
class LLImageGL : public LLRefCount
{
	friend class LLTexUnit;
	friend class GLTextureName;
public:
	struct AllocationInfo;
private:
	// These 2 functions replace glGenTextures() and glDeleteTextures()
	static void generateTextures(S32 numTextures, U32 *textures);
	static void deleteTextures(S32 numTextures, U32 *textures, const std::vector<AllocationInfo>& allocationData);
	static void texMemoryAllocated(const AllocationInfo& entry);
	static void texMemoryDeallocated(const AllocationInfo& entry);
public:
	static void deleteDeadTextures();

	struct AllocationInfo
	{
		AllocationInfo(S32Bytes& _size, U8 _components, U32 _category) :
			size(_size), components(_components), category(_category)
		{}
		S32Bytes size;
		U8 components;
		U32 category;
	};
	// Singu Note:
	// The topology of GLImageGL is wrong. As a result, tex names are shared across multiple LLImageGL 
	// instances. To avoid redundant glDelete calls gl tex names have been wrapped in GLTextureName,
	// which is refcounted via std::shared_ptr.
	class GLTextureNameInstance {
	public:
		GLTextureNameInstance(U32 size = 1) : mTexCount(size)
		{
			mTexNames.resize(mTexCount, 0);
			LLImageGL::generateTextures(1, mTexNames.data());
		}
		~GLTextureNameInstance()
		{
			LLImageGL::deleteTextures(1, mTexNames.data(), mAllocationData);
		}
		GLuint getTexName(U32 idx = 0) const
		{
			return mTexNames[idx];
		}
		void addAllocatedMemory(S32Bytes size, U8 components, U32 category)
		{
			mAllocationData.emplace_back(size, components, category);
			LLImageGL::texMemoryAllocated(mAllocationData.back());
		}
		const std::vector<AllocationInfo>& getAllocatedMemoryInfo() const
		{
			return mAllocationData;
		}
	private:
		const size_t mTexCount;
		std::vector<GLuint> mTexNames;
		std::vector<AllocationInfo> mAllocationData;
	};
	typedef std::shared_ptr<GLTextureNameInstance> GLTextureName;

	static GLTextureName createTextureName(U32 size = 0) {
		return std::make_shared<GLTextureNameInstance>();
	}

	// Size calculation
	static S32 dataFormatBits(S32 dataformat);
	static S32 dataFormatBytes(S32 dataformat, S32 width, S32 height);
	static S32 dataFormatComponents(S32 dataformat);

	BOOL updateBindStats(S32Bytes tex_mem) const ;
	F32 getTimePassedSinceLastBound();
	void forceUpdateBindStats(void) const;

	// needs to be called every frame
	static void updateStats(F32 current_time);

	// Save off / restore GL textures
	static void destroyGL(BOOL save_state = TRUE);
	static void restoreGL();
	static void dirtyTexOptions();

	// Sometimes called externally for textures not using LLImageGL (should go away...)	
	static S32 updateBoundTexMem(const S32Bytes mem, const S32 ncomponents, S32 category) ;
	
	static bool checkSize(S32 width, S32 height);

	//for server side use only.
	// Not currently necessary for LLImageGL, but required in some derived classes,
	// so include for compatability
	static BOOL create(LLPointer<LLImageGL>& dest, BOOL usemipmaps = TRUE);
	static BOOL create(LLPointer<LLImageGL>& dest, U32 width, U32 height, U8 components, BOOL usemipmaps = TRUE);
	static BOOL create(LLPointer<LLImageGL>& dest, const LLImageRaw* imageraw, BOOL usemipmaps = TRUE);
		
public:
	LLImageGL(BOOL usemipmaps = TRUE, bool allow_compression = false);
	LLImageGL(U32 width, U32 height, U8 components, BOOL usemipmaps = TRUE, bool allow_compression = false);
	LLImageGL(const LLImageRaw* imageraw, BOOL usemipmaps = TRUE, bool allow_compression = false);
	
protected:
	virtual ~LLImageGL();

	void analyzeAlpha(const void* data_in, U32 w, U32 h);
	void calcAlphaChannelOffsetAndStride();

public:
	virtual void dump();	// debugging info to llinfos
	
	void setSize(S32 width, S32 height, S32 ncomponents, S32 discard_level = -1);
	void setComponents(S32 ncomponents) { mComponents = (S8)ncomponents ;}
	void setAllowCompression(bool allow) { mAllowCompression = allow; }

	static bool setManualImage(U32 target, S32 miplevel, S32 intformat, S32 width, S32 height, U32 pixformat, U32 pixtype, const void *pixels = nullptr, bool allow_compression = false);

	BOOL createGLTexture() ;
	BOOL createGLTexture(S32 discard_level, const LLImageRaw* imageraw, GLTextureName* usename = nullptr, BOOL to_create = TRUE,
		S32 category = sMaxCategories-1);
	BOOL createGLTexture(S32 discard_level, const U8* data, BOOL data_hasmips = FALSE, GLTextureName* usename = nullptr);
	void setImage(const LLImageRaw* imageraw);
	void setImage(const U8* data_in, BOOL data_hasmips = FALSE);
	BOOL setSubImage(const LLImageRaw* imageraw, S32 x_pos, S32 y_pos, S32 width, S32 height, BOOL force_fast_update = FALSE);
	BOOL setSubImage(const U8* datap, S32 data_width, S32 data_height, S32 x_pos, S32 y_pos, S32 width, S32 height, BOOL force_fast_update = FALSE);
	BOOL setSubImageFromFrameBuffer(S32 fb_x, S32 fb_y, S32 x_pos, S32 y_pos, S32 width, S32 height);

	// Read back a raw image for this discard level, if it exists
	BOOL readBackRaw(S32 discard_level, LLImageRaw* imageraw, bool compressed_ok); 
	void destroyGLTexture();
	void forceToInvalidateGLTexture();

	void setExplicitFormat(LLGLint internal_format, LLGLenum primary_format, LLGLenum type_format = 0, BOOL swap_bytes = FALSE);
	void setComponents(S8 ncomponents) { mComponents = ncomponents; }

	S32	 getDiscardLevel() const		{ return mCurrentDiscardLevel; }
	S32	 getMaxDiscardLevel() const		{ return mMaxDiscardLevel; }

	S32  getCurrentWidth() const { return mWidth ;}
	S32  getCurrentHeight() const { return mHeight ;}
	S32	 getWidth(S32 discard_level = -1) const;
	S32	 getHeight(S32 discard_level = -1) const;
	U8	 getComponents() const { return mComponents; }
	S32  getBytes(S32 discard_level = -1) const;
	S32  getMipBytes(S32 discard_level = -1) const;
	BOOL getBoundRecently() const;
	BOOL isJustBound() const;
	LLGLenum getPrimaryFormat() const { return mFormatPrimary; }
	LLGLenum getFormatType() const { return mFormatType; }

	BOOL getHasGLTexture() const { return mTexName != nullptr; }
	LLGLuint getTexName() const { return mTexName ? mTexName->getTexName() : 0; }

	BOOL getIsAlphaMask(const F32 max_rmse, const F32 max_mid) const { return mNeedsAlphaAndPickMask && (max_rmse < 0.f ? (bool)mIsMask : (mMaskRMSE <= max_rmse && mMaskMidPercentile <= max_mid)); }

	BOOL getIsResident(BOOL test_now = FALSE); // not const

	void setTarget(const LLGLenum target, const LLTexUnit::eTextureType bind_target);

	LLTexUnit::eTextureType getTarget(void) const { return mBindTarget; }
	bool isGLTextureCreated(void) const { return mGLTextureCreated ; }
	void setGLTextureCreated (bool initialized) { mGLTextureCreated = initialized; }

	BOOL getUseMipMaps() const { return mUseMipMaps; }
	void setUseMipMaps(BOOL usemips) { mUseMipMaps = usemips; }	

	void updatePickMask(S32 width, S32 height, const U8* data_in);
	BOOL getMask(const LLVector2 &tc);

	void checkTexSize(bool forced = false) const ;
	
	// Sets the addressing mode used to sample the texture 
	//  (such as wrapping, mirrored wrapping, and clamp)
	// Note: this actually gets set the next time the texture is bound.
	void setAddressMode(LLTexUnit::eTextureAddressMode mode);
	LLTexUnit::eTextureAddressMode getAddressMode(void) const { return mAddressMode; }

	// Sets the filtering options used to sample the texture 
	//  (such as point sampling, bilinear interpolation, mipmapping, and anisotropic filtering)
	// Note: this actually gets set the next time the texture is bound.
	void setFilteringOption(LLTexUnit::eTextureFilterOptions option);
	LLTexUnit::eTextureFilterOptions getFilteringOption(void) const { return mFilterOption; }

		LLGLenum getTexTarget()const { return mTarget ;}
	void init(BOOL usemipmaps, bool allow_compression);
	virtual void cleanup(); // Clean up the LLImageGL so it can be reinitialized.  Be careful when using this in derived class destructors

	void setNeedsAlphaAndPickMask(BOOL need_mask);
public:
	// Various GL/Rendering options
	S32Bytes mTextureMemory;
	mutable F32  mLastBindTime;	// last time this was bound, by discard level
	
private:
	U32 createPickMask(S32 pWidth, S32 pHeight);
	void freePickMask();

	LLPointer<LLImageRaw> mSaveData; // used for destroyGL/restoreGL
	S32	mSaveDiscardLevel;
	U8* mPickMask;  //downsampled bitmap approximation of alpha channel.  NULL if no alpha channel
	U16 mPickMaskWidth;
	U16 mPickMaskHeight;
	S8 mUseMipMaps;
	S8 mHasExplicitFormat; // If false (default), GL format is f(mComponents)
	S8 mAutoGenMips;

	BOOL mIsMask;
	F32  mMaskRMSE;
	F32  mMaskMidPercentile;
	BOOL mNeedsAlphaAndPickMask;
	S8   mAlphaStride ;
	S8   mAlphaOffset ;
	
	bool     mGLTextureCreated ;
	GLTextureName mTexName;
	U16      mWidth;
	U16      mHeight;	
	S8       mCurrentDiscardLevel;
	
	bool mAllowCompression;
	bool mIsCompressed = false;

protected:
	LLGLenum mTarget;		// Normally GL_TEXTURE2D, sometimes something else (ex. cube maps)
	LLTexUnit::eTextureType mBindTarget;	// Normally TT_TEXTURE, sometimes something else (ex. cube maps)
	bool mHasMipMaps;
	S32 mMipLevels;

	LLGLboolean mIsResident;
	
	S8 mComponents;
	S8 mMaxDiscardLevel;	
	
	bool	mTexOptionsDirty;
	LLTexUnit::eTextureAddressMode		mAddressMode;	// Defaults to TAM_WRAP
	LLTexUnit::eTextureFilterOptions	mFilterOption;	// Defaults to TFO_TRILINEAR

	
	LLGLint  mFormatInternal; // = GL internalformat
	LLGLenum mFormatPrimary;  // = GL format (pixel data format)
	LLGLenum mFormatType;
	BOOL	 mFormatSwapBytes;// if true, use glPixelStorei(GL_UNPACK_SWAP_BYTES, 1)
	
	// STATICS
public:	
	static std::set<LLImageGL*> sImageList;
	static S32 sCount;
	
	static F32 sLastFrameTime;
	
	// Global memory statistics
	static S64Bytes sGlobalTextureMemory;	// Tracks main memory texmem
	static S64Bytes sBoundTextureMemory;	// Tracks bound texmem for last completed frame
	static S64Bytes sCurBoundTextureMemory;		// Tracks bound texmem for current frame
	static U32 sBindCount;					// Tracks number of texture binds for current frame
	static U32 sUniqueCount;				// Tracks number of unique texture binds for current frame
	static BOOL sGlobalUseAnisotropic;
	static LLImageGL* sDefaultGLTexture ;	
 	static bool sCompressTextures;			//use GL texture compression

#if DEBUG_MISS
	BOOL mMissed; // Missed on last bind?
	BOOL getMissed() const { return mMissed; };
#else
	BOOL getMissed() const { return FALSE; };
#endif

public:
	static void initClass(S32 num_catagories) ;
	static void cleanupClass() ;
private:
	static S32 sMaxCategories ;

	//the flag to allow to call readBackRaw(...).
	//can be removed if we do not use that function at all.
	static BOOL sAllowReadBackRaw ;
//
// ****************************************************************************************************
//The below for texture auditing use only
// ****************************************************************************************************
private:
	S32 mCategory ;
public:		
	void setCategory(S32 category) ;
	S32  getCategory()const {return mCategory ;}

	//for debug use: show texture size distribution 
	//----------------------------------------
	static LLPointer<LLImageGL> sHighlightTexturep; //default texture to replace normal textures
	static std::vector<S32> sTextureLoadedCounter ;
	static std::vector<S32> sTextureBoundCounter ;
	static std::vector<S32> sTextureCurBoundCounter ;
	static S32 sCurTexSizeBar ;
	static S32 sCurTexPickSize ;

	static void setHighlightTexture(S32 category) ;
	static S32 getTextureCounterIndex(U32 val) ;
	static void incTextureCounter(S32Bytes val, S32 ncomponents, S32 category) ;
	static void decTextureCounter(S32Bytes val, S32 ncomponents, S32 category) ;
	static void setCurTexSizebar(S32 index, BOOL set_pick_size = TRUE) ;
	static void resetCurTexSizebar();
	//----------------------------------------

	//for debug use: show texture category distribution 
	//----------------------------------------		
	
	static std::vector<S64Bytes> sTextureMemByCategory;
	static std::vector<S64Bytes> sTextureMemByCategoryBound ;
	static std::vector<S64Bytes> sTextureCurMemByCategoryBound ;
	//----------------------------------------	
// ****************************************************************************************************
//End of definitions for texture auditing use only
// ****************************************************************************************************

};

extern BOOL gAuditTexture;
#endif // LL_LLIMAGEGL_H