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/* ppmtopi1.c - read a portable pixmap and write a Degas PI1 file
**
** Copyright (C) 1991 by Steve Belczyk and Jef Poskanzer.
**
** 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"
#define COLS 320
#define ROWS 200
#define MAXVAL 7
#define MAXCOLORS 16
static short screen[ROWS*COLS/4]; /* simulate the ST's video RAM */
int
main( argc, argv )
int argc;
char* argv[];
{
FILE* ifp;
pixel** pixels;
register pixel *pP;
colorhist_vector chv;
colorhash_table cht;
int rows, cols, row, colors, i;
register int col;
pixval maxval;
ppm_init( &argc, argv );
if ( argc > 2 )
pm_usage( "[ppmfile]" );
if ( argc == 2 )
ifp = pm_openr( argv[1] );
else
ifp = stdin;
pixels = ppm_readppm( ifp, &cols, &rows, &maxval );
pm_close( ifp );
if ( (cols > COLS) || (rows > ROWS) )
pm_error( "image is larger than %dx%d - sorry", COLS, ROWS );
pm_message( "computing colormap..." );
chv = ppm_computecolorhist( pixels, cols, rows, MAXCOLORS, &colors );
if ( chv == (colorhist_vector) 0 )
{
pm_message(
"too many colors - try doing a 'pnmquant %d'", MAXCOLORS );
exit( 1 );
}
pm_message( "%d colors found", colors );
/* Write PI1 header - resolution and palette. */
(void) pm_writebigshort( stdout, (short) 0 ); /* low resolution */
for ( i = 0; i < 16; ++i )
{
short w;
if ( i < colors )
{
pixel p;
p = chv[i].color;
if ( maxval != MAXVAL )
PPM_DEPTH( p, p, maxval, MAXVAL );
w = ( (int) PPM_GETR( p ) ) << 8;
w |= ( (int) PPM_GETG( p ) ) << 4;
w |= ( (int) PPM_GETB( p ) );
}
else
w = 0;
(void) pm_writebigshort( stdout, w );
}
if ( maxval > MAXVAL )
pm_message(
"maxval is not %d - automatically rescaling colors", MAXVAL );
/* Convert color vector to color hash table, for fast lookup. */
cht = ppm_colorhisttocolorhash( chv, colors );
ppm_freecolorhist( chv );
/* Clear the screen buffer. */
for ( i = 0; i < ROWS*COLS/4; ++i )
screen[i] = 0;
/* Convert. */
for ( row = 0; row < rows; ++row )
{
for ( col = 0, pP = pixels[row]; col < cols; ++col, ++pP )
{
register int color, ind, b, plane;
color = ppm_lookupcolor( cht, pP );
if ( color == -1 )
pm_error(
"color not found?!? row=%d col=%d r=%d g=%d b=%d",
row, col, PPM_GETR(*pP), PPM_GETG(*pP), PPM_GETB(*pP) );
ind = 80 * row + ( ( col >> 4 ) << 2 );
b = 0x8000 >> (col & 0xf);
for ( plane = 0; plane < 4; ++plane )
if ( color & (1 << plane) )
screen[ind+plane] |= b;
}
}
/* And write out the screen buffer. */
for ( i = 0; i < ROWS*COLS/4; ++i )
(void) pm_writebigshort( stdout, screen[i] );
exit( 0 );
}
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