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- /* sputoppm.c - read an uncompressed Spectrum file and produce a portable pixmap
- **
- ** 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 ROWS 200
- #define COLS 320
- #define MAXVAL 7
-
- static pixel pal[ROWS][48]; /* Spectrum palettes, three per row */
- static short screen[ROWS*COLS/4]; /* simulates the Atari's video RAM */
-
- int
- main( argc, argv )
- int argc;
- char* argv[];
- {
- FILE* ifp;
- int i, j;
- pixel* pixelrow;
- register pixel* pP;
- int row, col;
-
-
- ppm_init( &argc, argv );
-
- /* Check args. */
- if ( argc > 2 )
- pm_usage( "[spufile]" );
-
- if ( argc == 2 )
- ifp = pm_openr( argv[1] );
- else
- ifp = stdin;
-
- /* Read the SPU file */
-
- /* Read the screen data. */
- for ( i = 0; i < ROWS*COLS/4; ++i )
- (void) pm_readbigshort( ifp, &screen[i] );
-
- /* Clear the first palette line. */
- for ( j = 0; j < 48; ++j )
- PPM_ASSIGN( pal[0][j], 0, 0, 0 );
-
- /* Read the palettes. */
- for ( i = 1; i < ROWS; ++i )
- for ( j = 0; j < 48; ++j )
- {
- short k;
- (void) pm_readbigshort( ifp, &k );
- PPM_ASSIGN( pal[i][j],
- ( k & 0x700 ) >> 8,
- ( k & 0x070 ) >> 4,
- ( k & 0x007 ) );
- }
-
- pm_close( ifp );
-
- /* Ok, get set for writing PPM. */
- ppm_writeppminit( stdout, COLS, ROWS, (pixval) MAXVAL, 0 );
- pixelrow = ppm_allocrow( COLS );
-
- /* Now do the conversion. */
- for ( row = 0; row < ROWS; ++row )
- {
- for ( col = 0, pP = pixelrow; col < COLS; ++col, ++pP )
- {
- int c, ind, b, plane, x1;
-
- /* Compute pixel value. */
- ind = 80 * row + ( ( col >> 4 ) << 2 );
- b = 0x8000 >> (col & 0xf);
- c = 0;
- for ( plane = 0; plane < 4; ++plane )
- if ( b & screen[ind+plane] )
- c |= (1 << plane);
-
- /* Compute palette index. */
- x1 = 10 * c;
- if ( c & 1 )
- x1 -= 5;
- else
- ++x1;
- if ( ( col >= x1 ) && ( col < ( x1 + 160 ) ) )
- c += 16;
- if ( col >= ( x1 + 160 ) )
- c += 32;
-
- /* Store the proper color. */
- *pP = pal[row][c];
- }
- ppm_writeppmrow( stdout, pixelrow, COLS, (pixval) MAXVAL, 0 );
- }
-
- pm_close( stdout );
-
- exit( 0 );
- }
-