The Datafile PD-CD 4/DATAFILE_PDCD4.iso/utilities/utilsm/netpbmsca/ppm/c/ppmtosixel

Text File | 1993-10-04 | 5.1 KB | 207 lines

/* ppmtosix.c - read a portable pixmap and produce a color sixel file
**
** Copyright (C) 1991 by Rick Vinci.
**
** Permission to use, copy, modify, and distribute this software and its
** documentation for any purpose and without fee is hereby granted, provided
** that the above copyright notice appear in all copies and that both that
** copyright notice and this permission notice appear in supporting
** documentation.  This software is provided "as is" without express or
** implied warranty.
*/

#include "ppm.h"
#include "ppmcmap.h"

int WriteHeader ARGS((void));
int WriteColorMap ARGS((colorhist_vector chv, int colors, pixval maxval));
int WriteRawImage ARGS((colorhash_table cht, int rows, int cols));
int WritePackedImage ARGS((colorhash_table cht, int rows, int cols));
int WriteEnd ARGS((void));
#define MAXVAL 100
#define MAXCOLORS 256

#define DCS '\220'   /* Device Control String */
#define ST  '\234'   /* String Terminator */
#define CSI '\233'   /* Control String Introducer */
#define ESC '\033'   /* Escape character */

static pixel** pixels;   /* stored ppm pixmap input */
static colorhash_table cht;
int margin;

int
main( argc, argv )
    int argc;
    char* argv[];
    {
    FILE* ifp;
    int argn, rows, cols, colors;
    int Red, Grn, Blue, rownum, colnum;
    int raw;
    pixval maxval;
    colorhist_vector chv;
    char* usage = "[-raw] [-margin] [ppmfile]";


    ppm_init( &argc, argv );

    argn = 1;
    raw = 0;
    margin = 0;

    /* Parse args. */
    while ( argn < argc && argv[argn][0] == '-' && argv[argn][1] != '\0' )
    {
    if ( pm_keymatch( argv[argn], "-raw", 2 ) )
        raw = 1;
    else if ( pm_keymatch( argv[argn], "-margin", 2 ) )
        margin = 1;
    else
        pm_usage( usage );
    ++argn;
    }

    if ( argn < argc )
    {
    ifp = pm_openr( argv[argn] );
    ++argn;
    }
    else
    ifp = stdin;

    if ( argn != argc )
    pm_usage( usage );

    /* Read in the whole ppmfile. */
    pixels = ppm_readppm( ifp, &cols, &rows, &maxval );
    pm_close( ifp );

    /* Print a warning if we're could to lose accuracy when rescaling colors. */
    if ( maxval > MAXVAL )
    pm_message(
        "maxval is not %d - automatically rescaling colors", MAXVAL );

    /* Figure out the colormap. */
    pm_message( "computing colormap..." );
    chv = ppm_computecolorhist( pixels, cols, rows, MAXCOLORS, &colors );
    if ( chv == (colorhist_vector) 0 )
    pm_error( "too many colors - try doing a 'ppmquant %d'", MAXCOLORS );
    pm_message( "%d colors found", colors );

    /* Make a hash table for fast color lookup. */
    cht = ppm_colorhisttocolorhash( chv, colors );

    pm_message( "delivering sixel image..." );
    WriteHeader();
    WriteColorMap( chv, colors, maxval );
    if ( raw == 1 )
    WriteRawImage( cht, rows, cols );
    else
    WritePackedImage( cht, rows, cols );
    WriteEnd();

    exit( 0 );
    }


int
WriteHeader()
    {
    if ( margin == 1 )
    printf( "%c%d;%ds", CSI, 14, 72 );
    printf( "%c", DCS );  /* start with Device Control String */
    printf( "0;0;8q" );   /* Horizontal Grid Size at 1/90" and graphics On */
    printf( "\"1;1\n" );  /* set aspect ratio 1:1 */
    }

int
WriteColorMap( chv, colors, maxval )
    colorhist_vector chv;
    int colors;
    pixval maxval;
    {
    register int colornum;
    pixel p;

    for ( colornum = 0; colornum < colors ; ++colornum )
    {
    p = chv[colornum].color;
    if ( maxval != MAXVAL )
        PPM_DEPTH( p, p, maxval, MAXVAL );
    printf( "#%d;2;%d;%d;%d", colornum,
        (int) PPM_GETR( p ), (int) PPM_GETG( p ), (int) PPM_GETB( p ) );
    }
    printf( "\n" );
    }

int
WriteRawImage( cht, rows, cols )
    colorhash_table cht;
    int rows, cols;
    {
    int rownum, colnum, b;
    char* sixel = "@ACGO_";
    register pixel* pP;

    for ( rownum = 0; rownum < rows; ++rownum )
    {
    b = rownum % 6;
    for ( colnum = 0, pP = pixels[rownum]; colnum < cols; ++colnum, ++pP )
        printf( "#%d%c", ppm_lookupcolor(cht, pP), sixel[b] );
    printf( "$\n" );   /* Carriage Return */
    if ( b == 5 )
        printf( "-\n" );   /* Line Feed (one sixel height) */
    }
    }

int
WritePackedImage( cht, rows, cols )
    colorhash_table cht;
    int rows, cols;
    {
    int rownum, colnum, b, repeat, thiscolor, nextcolor;
    char* sixel = "@ACGO_";
    register pixel* pP;

    for ( rownum = 0; rownum < rows; ++rownum )
    {
    b = rownum % 6;
    repeat = 1;
    for ( colnum = 0, pP = pixels[rownum]; colnum < cols; ++colnum, ++pP )
        {
        thiscolor = ppm_lookupcolor(cht, pP);
        if ( colnum == cols -1 )   /* last pixel in row */
        if ( repeat == 1 )
            printf( "#%d%c", thiscolor, sixel[b] );
        else
            printf( "#%d!%d%c", thiscolor, repeat, sixel[b] );
        else   /* not last pixel in row */
        {
        nextcolor =  ppm_lookupcolor(cht, pP+1);
        if ( thiscolor == nextcolor )
            ++repeat;
        else
            if ( repeat == 1 )
            printf( "#%d%c", thiscolor, sixel[b] );
            else
            {
            printf( "#%d!%d%c", thiscolor, repeat, sixel[b] );
            repeat = 1;
            }
        }
        }   /* end column loop */
    printf( "$\n" );   /* Carriage Return */
    if ( b == 5 )
        printf( "-\n" );   /* Line Feed (one sixel height) */
    }
    }

int
WriteEnd()
    {
    if ( margin == 1 )
    printf ( "%c%d;%ds", CSI, 1, 80 );
    printf( "%c\n", ST );
    }