/* ppm.h - header file for libppm portable pixmap library
*/

#ifndef _PPM_H_
#define _PPM_H_

#include "pgm.h"

typedef gray pixval;

#ifdef PPM_PACKCOLORS

#define PPM_MAXMAXVAL 1023
typedef unsigned long pixel;
#define PPM_GETR(p) (((p) & 0x3ff00000) >> 20)
#define PPM_GETG(p) (((p) & 0xffc00) >> 10)
#define PPM_GETB(p) ((p) & 0x3ff)

/************* added definitions *****************/
#define PPM_PUTR(p, red) ((p) |= (((red) & 0x3ff) << 20))
#define PPM_PUTG(p, grn) ((p) |= (((grn) & 0x3ff) << 10))
#define PPM_PUTB(p, blu) ((p) |= ( (blu) & 0x3ff))
/**************************************************/

#define PPM_ASSIGN(p,red,grn,blu) (p) = ((pixel) (red) << 20) | ((pixel) (grn) << 10) | (pixel) (blu)
#define PPM_EQUAL(p,q) ((p) == (q))

#else /*PPM_PACKCOLORS*/

#define PPM_OVERALLMAXVAL PGM_OVERALLMAXVAL
#define PPM_MAXMAXVAL PGM_MAXMAXVAL
typedef struct
    {
    pixval r, g, b;
    } pixel;
#define PPM_GETR(p) ((p).r)
#define PPM_GETG(p) ((p).g)
#define PPM_GETB(p) ((p).b)

/************* added definitions *****************/
#define PPM_PUTR(p,red) ((p).r = (red))
#define PPM_PUTG(p,grn) ((p).g = (grn))
#define PPM_PUTB(p,blu) ((p).b = (blu))
/**************************************************/

#define PPM_ASSIGN(p,red,grn,blu) do { (p).r = (red); (p).g = (grn); (p).b = (blu); } while ( 0 )
#define PPM_EQUAL(p,q) ( (p).r == (q).r && (p).g == (q).g && (p).b == (q).b )

#endif /*PPM_PACKCOLORS*/


/* Magic constants. */

#define PPM_MAGIC1 'P'
#define PPM_MAGIC2 '3'
#define RPPM_MAGIC2 '6'
#define PPM_FORMAT (PPM_MAGIC1 * 256 + PPM_MAGIC2)
#define RPPM_FORMAT (PPM_MAGIC1 * 256 + RPPM_MAGIC2)
#define PPM_TYPE PPM_FORMAT


/* Macro for turning a format number into a type number. */

#define PPM_FORMAT_TYPE(f) ((f) == PPM_FORMAT || (f) == RPPM_FORMAT ? PPM_TYPE : PGM_FORMAT_TYPE(f))


/* Declarations of routines. */

void ppm_init ARGS(( int* argcP, char* argv[] ));

#define ppm_allocarray( cols, rows ) ((pixel**) pm_allocarray( cols, rows, sizeof(pixel) ))
#define ppm_allocrow( cols ) ((pixel*) pm_allocrow( cols, sizeof(pixel) ))
#define ppm_freearray( pixels, rows ) pm_freearray( (char**) pixels, rows )
#define ppm_freerow( pixelrow ) pm_freerow( (char*) pixelrow )

pixel** ppm_readppm ARGS(( FILE* file, int* colsP, int* rowsP, pixval* maxvalP ));
void ppm_readppminit ARGS(( FILE* file, int* colsP, int* rowsP, pixval* maxvalP, int* formatP ));
void ppm_readppmrow ARGS(( FILE* file, pixel* pixelrow, int cols, pixval maxval, int format ));

void ppm_writeppm ARGS(( FILE* file, pixel** pixels, int cols, int rows, pixval maxval, int forceplain ));
void ppm_writeppminit ARGS(( FILE* file, int cols, int rows, pixval maxval, int forceplain ));
void ppm_writeppmrow ARGS(( FILE* file, pixel* pixelrow, int cols, pixval maxval, int forceplain ));

void
ppm_check(FILE * file, const enum pm_check_type check_type, 
          const int format, const int cols, const int rows, const int maxval,
          enum pm_check_code * const retval_p);

void
ppm_nextimage(FILE *file, int * const eofP);

pixel ppm_parsecolor ( const char* colorname, pixval maxval );

char*
ppm_colorname(const pixel* const colorP, 
              pixval       const maxval, 
              int          const hexok);

/* Color scaling macro -- to make writing ppmtowhatever easier. */

#define PPM_DEPTH(newp,p,oldmaxval,newmaxval) \
    PPM_ASSIGN( (newp), \
	( (int) PPM_GETR(p) * (newmaxval) + (oldmaxval) / 2 ) / (oldmaxval), \
	( (int) PPM_GETG(p) * (newmaxval) + (oldmaxval) / 2 ) / (oldmaxval), \
	( (int) PPM_GETB(p) * (newmaxval) + (oldmaxval) / 2 ) / (oldmaxval) )


/* Luminance, Chrominance macros. */

/* The following are weights of the red, green, and blue components
   respectively in the luminosity of a color
*/
#define PPM_LUMINR (0.2989)
#define PPM_LUMING (0.5866)
#define PPM_LUMINB (0.1145)

#define PPM_LUMIN(p) ( PPM_LUMINR * PPM_GETR(p) \
                       + PPM_LUMING * PPM_GETG(p) \
                       + PPM_LUMINB * PPM_GETB(p) )
#define PPM_CHROM_R(p) ( 0.5 * PPM_GETR(p) \
                         - 0.41869 * PPM_GETG(p) \
                         - 0.08131 * PPM_GETB(p) )
#define PPM_CHROM_B(p) ( -0.16874 * PPM_GETR(p) \
                         - 0.33126 * PPM_GETG(p) \
                         + 0.5 * PPM_GETB(p) )

#endif /*_PPM_H_*/

