/** 
 * @file llimage.h
 * @brief Object for managing images and their textures.
 *
 * $LicenseInfo:firstyear=2000&license=viewergpl$
 * 
 * Copyright (c) 2000-2009, Linden Research, Inc.
 * 
 * Second Life Viewer Source Code
 * The source code in this file ("Source Code") is provided by Linden Lab
 * to you under the terms of the GNU General Public License, version 2.0
 * ("GPL"), unless you have obtained a separate licensing agreement
 * ("Other License"), formally executed by you and Linden Lab.  Terms of
 * the GPL can be found in doc/GPL-license.txt in this distribution, or
 * online at http://secondlifegrid.net/programs/open_source/licensing/gplv2
 * 
 * There are special exceptions to the terms and conditions of the GPL as
 * it is applied to this Source Code. View the full text of the exception
 * in the file doc/FLOSS-exception.txt in this software distribution, or
 * online at http://secondlifegrid.net/programs/open_source/licensing/flossexception
 * 
 * By copying, modifying or distributing this software, you acknowledge
 * that you have read and understood your obligations described above,
 * and agree to abide by those obligations.
 * 
 * ALL LINDEN LAB SOURCE CODE IS PROVIDED "AS IS." LINDEN LAB MAKES NO
 * WARRANTIES, EXPRESS, IMPLIED OR OTHERWISE, REGARDING ITS ACCURACY,
 * COMPLETENESS OR PERFORMANCE.
 * $/LicenseInfo$
 */

#ifndef LL_LLIMAGE_H
#define LL_LLIMAGE_H

#include "lluuid.h"
#include "llstring.h"
#include "llmemory.h"
#include "llthread.h"

const S32 MIN_IMAGE_MIP =  2; // 4x4, only used for expand/contract power of 2
const S32 MAX_IMAGE_MIP = 11; // 2048x2048
const S32 MAX_DISCARD_LEVEL = 5;

const S32 MIN_IMAGE_SIZE = (1<<MIN_IMAGE_MIP); // 4, only used for expand/contract power of 2
const S32 MAX_IMAGE_SIZE = (1<<MAX_IMAGE_MIP); // 2048
const S32 MIN_IMAGE_AREA = MIN_IMAGE_SIZE * MIN_IMAGE_SIZE;
const S32 MAX_IMAGE_AREA = MAX_IMAGE_SIZE * MAX_IMAGE_SIZE;
const S32 MAX_IMAGE_COMPONENTS = 8;
const S32 MAX_IMAGE_DATA_SIZE = MAX_IMAGE_AREA * MAX_IMAGE_COMPONENTS;

// Note!  These CANNOT be changed without invalidating the viewer VFS files, I think?
const S32 FIRST_PACKET_SIZE = 600;
const S32 MAX_IMG_PACKET_SIZE = 1000;

// Base classes for images.
// There are two major parts for the image:
// The compressed representation, and the decompressed representation.

class LLImageFormatted;
class LLImageRaw;
class LLColor4U;
class LLWorkerThread;

typedef enum e_image_codec
{
	IMG_CODEC_INVALID  = 0,
	IMG_CODEC_RGB  = 1,
	IMG_CODEC_J2C  = 2,
	IMG_CODEC_BMP  = 3,
	IMG_CODEC_TGA  = 4,
	IMG_CODEC_JPEG = 5,
	IMG_CODEC_DXT  = 6,
	IMG_CODEC_PNG  = 7,
	IMG_CODEC_EOF  = 8
} EImageCodec;

//============================================================================
// library initialization class

class LLImage
{
public:
	static void initClass(LLWorkerThread* workerthread);
	static void cleanupClass();

	static const std::string& getLastError();
	static void setLastError(const std::string& message);
	
protected:
	static LLMutex* sMutex;
	static std::string sLastErrorMessage;
};

//============================================================================
// Image base class

class LLImageBase : public LLThreadSafeRefCount
{
protected:
	virtual ~LLImageBase();
	
public:
	LLImageBase();

	enum
	{
		TYPE_NORMAL = 0,
		TYPE_AVATAR_BAKE = 1,
	};

	virtual void deleteData();
	virtual U8* allocateData(S32 size = -1);
	virtual U8* reallocateData(S32 size = -1);

	virtual void dump();
	virtual void sanityCheck();

	U16 getWidth() const		{ return mWidth; }
	U16 getHeight() const		{ return mHeight; }
	S8	getComponents() const	{ return mComponents; }
	S32 getDataSize() const		{ return mDataSize; }

	const U8 *getData() const	;
	U8 *getData()				;
	BOOL isBufferInvalid() ;

	void setSize(S32 width, S32 height, S32 ncomponents);
	U8* allocateDataSize(S32 width, S32 height, S32 ncomponents, S32 size = -1); // setSize() + allocateData()

protected:
	// special accessor to allow direct setting of mData and mDataSize by LLImageFormatted
	void setDataAndSize(U8 *data, S32 size) { mData = data; mDataSize = size; };
	
public:
	static void generateMip(const U8 *indata, U8* mipdata, int width, int height, S32 nchannels);
	
	// Function for calculating the download priority for textures
	// <= 0 priority means that there's no need for more data.
	static F32 calc_download_priority(F32 virtual_size, F32 visible_area, S32 bytes_sent);

	static void setSizeOverride(BOOL enabled) { sSizeOverride = enabled; }

	static EImageCodec getCodecFromExtension(const std::string& exten);
	
private:
	U8 *mData;
	S32 mDataSize;

	U16 mWidth;
	U16 mHeight;

	S8 mComponents;

	BOOL mBadBufferAllocation ;

public:
	S16 mMemType; // debug
	
	static BOOL sSizeOverride;
};

// Raw representation of an image (used for textures, and other uncompressed formats
class LLImageRaw : public LLImageBase
{
protected:
	/*virtual*/ ~LLImageRaw();
	
public:
	LLImageRaw();
	LLImageRaw(U16 width, U16 height, S8 components);
	LLImageRaw(U8 *data, U16 width, U16 height, S8 components);
	// Construct using createFromFile (used by tools)
	LLImageRaw(const std::string& filename, bool j2c_lowest_mip_only = false);

	/*virtual*/ void deleteData();
	/*virtual*/ U8* allocateData(S32 size = -1);
	/*virtual*/ U8* reallocateData(S32 size);
	
	BOOL resize(U16 width, U16 height, S8 components);

	U8 * getSubImage(U32 x_pos, U32 y_pos, U32 width, U32 height) const;
	BOOL setSubImage(U32 x_pos, U32 y_pos, U32 width, U32 height,
					 const U8 *data, U32 stride = 0, BOOL reverse_y = FALSE);

	void clear(U8 r=0, U8 g=0, U8 b=0, U8 a=255);

	void verticalFlip();

	void expandToPowerOfTwo(S32 max_dim = MAX_IMAGE_SIZE, BOOL scale_image = TRUE);
	void contractToPowerOfTwo(S32 max_dim = MAX_IMAGE_SIZE, BOOL scale_image = TRUE);
	void biasedScaleToPowerOfTwo(S32 max_dim = MAX_IMAGE_SIZE);
	BOOL scale( S32 new_width, S32 new_height, BOOL scale_image = TRUE );

	// Fill the buffer with a constant color
	void fill( const LLColor4U& color );

	// Copy operations
	
	// Src and dst can be any size.  Src and dst can each have 3 or 4 components.
	void copy( LLImageRaw* src );

	// Src and dst are same size.  Src and dst have same number of components.
	void copyUnscaled( LLImageRaw* src );
	
	// Src and dst are same size.  Src has 4 components.  Dst has 3 components.
	void copyUnscaled4onto3( LLImageRaw* src );

	// Src and dst are same size.  Src has 3 components.  Dst has 4 components.
	void copyUnscaled3onto4( LLImageRaw* src );

	// Src and dst can be any size.  Src and dst have same number of components.
	void copyScaled( LLImageRaw* src );

	// Src and dst can be any size.  Src has 3 components.  Dst has 4 components.
	void copyScaled3onto4( LLImageRaw* src );

	// Src and dst can be any size.  Src has 4 components.  Dst has 3 components.
	void copyScaled4onto3( LLImageRaw* src );


	// Composite operations

	// Src and dst can be any size.  Src and dst can each have 3 or 4 components.
	void composite( LLImageRaw* src );

	// Src and dst can be any size.  Src has 4 components.  Dst has 3 components.
	void compositeScaled4onto3( LLImageRaw* src );

	// Src and dst are same size.  Src has 4 components.  Dst has 3 components.
	void compositeUnscaled4onto3( LLImageRaw* src );

protected:
	// Create an image from a local file (generally used in tools)
	bool createFromFile(const std::string& filename, bool j2c_lowest_mip_only = false);

	void copyLineScaled( U8* in, U8* out, S32 in_pixel_len, S32 out_pixel_len, S32 in_pixel_step, S32 out_pixel_step );
	void compositeRowScaled4onto3( U8* in, U8* out, S32 in_pixel_len, S32 out_pixel_len );

	U8	fastFractionalMult(U8 a,U8 b);

public:
	static S32 sGlobalRawMemory;
	static S32 sRawImageCount;
};

// Compressed representation of image.
// Subclass from this class for the different representations (J2C, bmp)
class LLImageFormatted : public LLImageBase
{
public:
	static LLImageFormatted* createFromType(S8 codec);
	static LLImageFormatted* createFromExtension(const std::string& instring);	

protected:
	/*virtual*/ ~LLImageFormatted();
	
public:
	LLImageFormatted(S8 codec);

	// LLImageBase
	/*virtual*/ void deleteData();
	/*virtual*/ U8* allocateData(S32 size = -1);
	/*virtual*/ U8* reallocateData(S32 size);
	
	/*virtual*/ void dump();
	/*virtual*/ void sanityCheck();

	// New methods
	// subclasses must return a prefered file extension (lowercase without a leading dot)
	virtual std::string getExtension() = 0;
	// calcHeaderSize() returns the maximum size of header;
	//   0 indicates we don't know have a header and have to lead the entire file
	virtual S32 calcHeaderSize() { return 0; };
	// calcDataSize() returns how many bytes to read to load discard_level (including header)
	virtual S32 calcDataSize(S32 discard_level);
	// calcDiscardLevelBytes() returns the smallest valid discard level based on the number of input bytes
	virtual S32 calcDiscardLevelBytes(S32 bytes);
	// getRawDiscardLevel()by default returns mDiscardLevel, but may be overridden (LLImageJ2C)
	virtual S8  getRawDiscardLevel() { return mDiscardLevel; }
	
	BOOL load(const std::string& filename);
	BOOL save(const std::string& filename);

	virtual BOOL updateData() = 0; // pure virtual
 	void setData(U8 *data, S32 size);
 	void appendData(U8 *data, S32 size);

	// Loads first 4 channels.
	virtual BOOL decode(LLImageRaw* raw_image, F32 decode_time) = 0;  
	// Subclasses that can handle more than 4 channels should override this function.
	virtual BOOL decodeChannels(LLImageRaw* raw_image, F32 decode_time, S32 first_channel, S32 max_channel);

	virtual BOOL encode(const LLImageRaw* raw_image, F32 encode_time) = 0;

	S8 getCodec() const;
	BOOL isDecoding() const { return mDecoding ? TRUE : FALSE; }
	BOOL isDecoded()  const { return mDecoded ? TRUE : FALSE; }
	void setDiscardLevel(S8 discard_level) { mDiscardLevel = discard_level; }
	S8 getDiscardLevel() const { return mDiscardLevel; }

	// setLastError needs to be deferred for J2C images since it may be called from a DLL
	virtual void resetLastError();
	virtual void setLastError(const std::string& message, const std::string& filename = std::string());
	
protected:
	BOOL copyData(U8 *data, S32 size); // calls updateData()
	
protected:
	S8 mCodec;
	S8 mDecoding;
	S8 mDecoded;
	S8 mDiscardLevel;
	
public:
	static S32 sGlobalFormattedMemory;
};

#endif