//	GifMaker.h

//	This is the header file for the GifMaker class.

//	By Joe Strout	1/27/96

//	Hearty thanks to:     Sverre H. Huseby
//                            Bjoelsengt. 17
//                            N-0468 Oslo
//                            Norway      
//                            sverrehu@ifi.uio.no

#ifndef GIFMAKER_H
#define GIFMAKER_H

#ifdef macintosh
#include <Types.h>
#endif

#include "Color.h"
#include <stdio.h>

typedef unsigned Word;          /* At least two bytes (16 bits) */
typedef unsigned char Byte;     /* Exactly one byte (8 bits) */
typedef struct {
    Word LocalScreenWidth,
         LocalScreenHeight;
    Byte GlobalColorTableSize : 3,
         SortFlag             : 1,
         ColorResolution      : 3,
         GlobalColorTableFlag : 1;
    Byte BackgroundColorIndex;
    Byte PixelAspectRatio;
} ScreenDescriptor;

typedef struct {
    Byte Separator;
    Word LeftPosition,
         TopPosition;
    Word Width,
         Height;
    Byte LocalColorTableSize : 3,
         Reserved            : 2,
         SortFlag            : 1,
         InterlaceFlag       : 1,
         LocalColorTableFlag : 1;
} ImageDescriptor;

class GifMaker
{
public:
	GifMaker();			// constructor -- sets default values
	int SaveGif( const char *pFilename );		// make the GIF file; return 1 if good

	// functions which must be overridden to make a picture:
	
	virtual RGB GetColor( const int pColorNum )			// get color palette entry
	{ return RGB(0,0,0); }
	virtual int GetPixel( const int pX, const int pY )		// get color number at a location
	{ return 0; }
	
	// public variables:
	int itsWidth;
	int itsHeight;
	int itsQtyColors;
	int itsColorBits;
	#ifdef macintosh
		OSType itsFileCreator;
	#endif
	
	// private parts:
protected:
	enum GIF_Code {
	    GIF_OK,
	    GIF_ERRCREATE,
	    GIF_ERRWRITE,
	    GIF_OUTMEM
	};

	FILE *OutFile;           /* File to write to */
	Byte Buffer[256];        /* There must be one too much !!! */
	int  Index,              /* Current byte in buffer */
         BitsLeft;           /* Bits left to fill in current byte. These
                                   are right-justified */
	Byte *StrChr;
	Word *StrNxt,
            *StrHsh,
            NumStrings;

	int  BitsPrPrimColor,    /* Bits pr primary color */
            NumColors;          /* Number of colors in color table */
	Byte *ColorTable;
	Word ScreenHeight,
            ScreenWidth,
            ImageHeight,
            ImageWidth,
            ImageLeft,
            ImageTop,
            RelPixX, RelPixY;         /* Used by InputByte() -function */

	int Create(const char *filename);
	int Write(void *buf, unsigned len);
	int WriteByte(Byte b);
	int WriteWord(Word w);
	void Close(void);
	void InitBitFile(void);
	int ResetOutBitFile(void);
	int WriteBits(int bits, int numbits);
	void FreeStrtab(void);
	int AllocStrtab(void);
	Word AddCharString(Word index, Byte b);
	Word FindCharString(Word index, Byte b);
	void ClearStrtab(int codesize);
	int LZW_Compress(int codesize );
	int BitsNeeded(Word n);
	int InputByte(void);
	int WriteScreenDescriptor(ScreenDescriptor *sd);
	int WriteImageDescriptor(ImageDescriptor *id);
	int GIF_Create(const char *filename, int width, int height, int numcolors, int colorres);
	void GIF_SetColor(int colornum, int red, int green, int blue);
	int GIF_CompressImage(int left, int top, int width, int height );
	int GIF_Close(void);

};
#endif