HPAVC/HPAVC CD-ROM.iso/pc/MCASM.RAR/MC_ASM.EXE/WROX_ASM/CH12/FORMATS/FORMATS.H

C/C++ Source or Header | 1994-09-18 | 8.1 KB | 303 lines

// This header contains stuctures and classes
// of graphics file formats readers and savers

#ifndef FORMATS_H
#define FORMATS_H

#include "grfile.h"
#include "graph.h"

//----------------------------------- TARGA ----------------------------

typedef struct {    // targa file header
    BYTE ID_field_length;
    char color_map_type;
    BYTE image_type;

    WORD first_colmap_entry;
    WORD colmap_length;
    char colmap_entry_size;

    int x;
    int y;
    int width;
    int height;
    char bitsperpixel;
    BYTE attrbits : 4;
    BYTE right_to_left : 1;
    BYTE top_to_bottom : 1;
    BYTE interleave : 2;
    } targa_header;

typedef colortype targa_palette[256];

class targa_file: public graph_file_reader { // TARGA file reader
private:
    targa_header header;
    int bytesperpixel,counter;
    BOOL rle_comp;
public:
    targa_file(char *fname);     // open file, read headers and palette
                    // allocates source_line
    virtual ~targa_file();
    virtual int get_next_line();    // returns -1 if file is finished
};

class targa_file_saver: public graph_file_saver { // TARGA file saver
private:
    targa_header header;
    int bytesperpixel,counter,count_row;
    BOOL rle_comp;
    int *arr_ofs;
public:
    targa_file_saver(char *fname, image_type dest_type_,
            image_extention_type dest_ext_type_,
            int width_,int height_,BGRpalette* pal,BOOL compress,
            BOOL top_to_bottom_,BOOL left_to_right_);
    virtual void update_palette(BGRpalette *pal);
    virtual int put_next_line(BYTE* line);    // returns -1 if file is finished
    ~targa_file_saver();
};

//----------------------------------- BMP ------------------------------

const WORD BMPSIGNATURE = 'M'*256+'B';

typedef struct {
    WORD bf_type;         //signature
    long bf_size;          //size of file in DWORD
    WORD bf_reserved1, bf_reserved2;
    long bf_offbits;    //image start offset in byte
} bmp_file_header;

typedef struct {
    long bi_size;
    long bi_width;
    long bi_height;
    WORD bi_planes;
    WORD bi_bit_count;
    long bi_compression;
    long bi_size_image;
    long bi_xpels_per_meter;
    long bi_ypels_per_meter;
    long bi_clr_used;
    long bi_clr_important;
} bmp_file_info_header;


class bmp_file: public graph_file_reader  { // bitmap file reader
private:
    bmp_file_header header;
    bmp_file_info_header info;
public:
    bmp_file(char *fname); //open file, check signature, read headers and palette
                   //allocates source_line
    virtual ~bmp_file();
    virtual int get_next_line();    //returns -1 if file is finished
};


void build_bmp_info(bmp_file_info_header &info,
        image_type f_type,    long width,long height);


class bmp_file_saver: public  graph_file_saver{
    bmp_file_info_header info;
    void init(bmp_file_info_header *info_);
        // is called from constructors
public:
    bmp_file_saver(char *fname,image_type dest_type_,
             BGRpalette *palette, bmp_file_info_header *info_);
    bmp_file_saver(char *fname,image_type dest_type_,
            int width_,int height_,BGRpalette * pal);
    virtual void update_palette(BGRpalette *pal);
    virtual int put_next_line(BYTE *line);    //returns -1 if some error occurs
};

//----------------------------------- GIF ------------------------------

#define LZW_BITS    12
#define LZW_TABLE_SIZE    0x1000    // 1 << LZW_BITS
#define HASH_SIZE    5003

const char GIFSIGNATURE[3] = "GIF";

typedef struct {
    char signature[3];        // = "GIF"
    char version[3];        // = "87a" or "89a" (version)
    } gif_header;

typedef struct {
    int width;
    int height;
    BYTE sizeofGCT : 3;        // size of Global Color Table
    BYTE sortflag : 1;        // sort flag
    BYTE colorres : 3;        // color resolution
    BYTE GCTflag : 1;        // Global Color Table flag
    BYTE backcolor;            // background color
    BYTE pixelaspectratio;        // pixel aspect ratio
    } logical_screen_descriptor;

#define IMAGE_DESCRIPTOR 0x2C

typedef struct {
    int x;                // image left position
    int y;                // image top position
    int width;
    int height;
    BYTE sizeofLCT : 3;
    BYTE reserved : 2;
    BYTE sortflag : 1;        // sort flag
    BYTE interlaceflag : 1;        // interlace flag
    BYTE LCTflag : 1;        // Local Color Table flag
    } image_descriptor;

class gif_file: public graph_file_reader { // GIF file reader
private:
    gif_header header;
    logical_screen_descriptor scrdesc;
    image_descriptor imagedesc;
    WORD *prefixcode;
    BYTE *secondbyte;
    BYTE *decodestack;
    BYTE LZW_code_size;
    int num_bits,clear_code,end_of_info,first_code,max_code;

    DWORD bit_buffer;
    int bit_count,counter;
    BYTE blocksize,pixelvalue;
    BOOL clear_flag;
    WORD next_code,new_code,old_code;
    BYTE *stack_top;

    WORD getcode();
    BYTE *decode(BYTE *stack_bottom, WORD code);
    // gif uses papa's buffer in specifical way, so
    // it allocates and disposes it in constructors and destructors
public:
    gif_file(char *fname);         // open file, check signature, read headers and palette
                    // allocates source_line
    virtual ~gif_file();
    virtual void seek_start();     // seek to image itself start (bottom line)
    virtual int get_next_line();    // returns -1 if file is finished
};

class gif_file_saver: public graph_file_saver { // GIF file saver
private:
    gif_header header;
    logical_screen_descriptor scrdesc;
    image_descriptor imagedesc;

    int *code_value;
    WORD *prefixcode;
    BYTE *secondbyte;
    BYTE LZW_code_size;
    int num_bits,clear_code,end_of_info,first_code,max_code;

    DWORD bit_buffer;
    int bit_count;
    WORD next_code,code;
    BOOL first_byte;

    void putcode(WORD code);
    int find_match(int hash_prefix,WORD hash_symbol);
    // gif uses papa's buffer in specifical way, so
    // it allocates and disposes it in constructors and destructors
public:
    gif_file_saver(char *fname, image_type dest_type_,
            int width_,int height_,BGRpalette* pal);
                // open file, write signature, write headers and palette
    virtual void update_palette(BGRpalette *pal);
    virtual ~gif_file_saver();
    virtual int put_next_line(BYTE *line);
};



const char PCXSIGNATURE = 0x0A;

typedef struct {
    char signature;
    char version;
    char encoding;
    char bitsperpixel;
    int x1;
    int y1;
    int x2;
    int y2;
    int Xres,Yres;
    colortype palette[16];
    char reserved;
    char planes;
    int bytesperline;
    int palinterp;
    int videoscrsizex;
    int videoscrsizey;
    char res[54];
    } pcx_header;

class pcx_file: public graph_file_reader { // PCX file reader
private:
    pcx_header header;
    BYTE prev_c,rep,datab;
    int real_len;
public:
    pcx_file(char *fname);         // open file, check signature, read headers and palette
                    // allocates source_line
    virtual ~pcx_file();
    virtual void seek_start();     // seek to image itself start (bottom line)
    virtual int get_next_line();    // returns -1 if file is finished
    long image_size();        // returns estimation of memory required to store image
};

class pcx_file_saver: public graph_file_saver { // PCX file saver
private:
    pcx_header header;
public:
    pcx_file_saver(char *fname, image_type dest_type_,
            image_extention_type dest_ext_type_,
            int width_,int height_,BGRpalette* pal);    // open file, write headers
                    // allocates source_line
    virtual void update_palette(BGRpalette *pal);
    virtual int put_next_line(BYTE *line);
};

/*------------------*/
/* any file opening */

graph_file_reader *open_image_file(char *fname);
// if error occured returns null
// and sets format_file_error in non-zero value

graph_file_saver *open_saver_file(char *fname,
        image_type dest_type,
        image_extention_type dest_ext_type,
        int width, int height,
        BGRpalette* palptr,
        BOOL top_to_bottom, // if possible
        BOOL left_to_right);
// if error occured returns null
// and sets format_file_error in non-zero value

extern int format_file_error;
// 0 - Ok
// 1 - File not found
// 2 - Unknown file format
// 3 - Format header error
// 4 - Disk read / write error

char *format_file_error_report();

void choosevideomode(graph_file_reader *grf_r);
    // set optimal (but 256 color) mode for image

void setpalette_by_BGR(BGRpalette pal);
    // actually sets palette with values pal[i].x/4

// init simple standard palette for 256 colors mode
void stand_palette(VGApalette &pal);

// simplest way to preview truecolor
void put_TC_row(BYTE *rp, BYTE *gp, BYTE *bp,int x,int y,int xcount);

#endif