#include "xcftools.h"
#include "pixels.h"

Macros
#define	MAX_PALETTE 256

Typedefs
typedef uint8_t	index_t

Functions
void	init_palette_hash (void)

int	lookup_or_intern (rgba color)

int	palettify_row (rgba *row, unsigned ncols)

int	palettify_rows (rgba *rows[], unsigned ncols, unsigned nlines)

Variables
rgba	palette [MAX_PALETTE]

unsigned	paletteSize

Macro Definition Documentation

◆ MAX_PALETTE

#define MAX_PALETTE 256

Definition at line 25 of file palette.h.

Typedef Documentation

◆ index_t

typedef uint8_t index_t

Definition at line 29 of file palette.h.

Function Documentation

◆ init_palette_hash()

void init_palette_hash ( void )

Definition at line 40 of file palette.c.

{
  unsigned i ;
  for( i=0; i<HASH_SIZE; i++ )
    masterhash[i] = -1 ;
  for( i=0; i<MAX_PALETTE; i++ )
    bucketlinks[i] = -1 ;
  paletteSize = 0 ;
}

References bucketlinks, HASH_SIZE, masterhash, MAX_PALETTE, and paletteSize.

◆ lookup_or_intern()

int lookup_or_intern ( rgba color )

inline

Definition at line 51 of file palette.c.

                             {
  int *target = &masterhash[color % HASH_SIZE];
  while( *target >= 0 ) {
    if( palette[*target] == color )
      return *target ;
    target = &bucketlinks[*target] ;
  }
#if 0
  fprintf(stderr,"Palette[%u] = %08x (%u --> %d)\n",paletteSize,color,
          color % HASH_SIZE, *target);
#endif
  if( paletteSize >= MAX_PALETTE )
    return -1 ;
  *target = paletteSize ;
  palette[paletteSize] = color ;
  return paletteSize++ ;
}

References bucketlinks, HASH_SIZE, masterhash, MAX_PALETTE, palette, paletteSize, and target().

◆ palettify_row()

int palettify_row	(	rgba *	row,
		unsigned	ncols )

Definition at line 80 of file palette.c.

{
  index_t *newrow = (index_t*)row ;
  assert(sizeof(index_t) <= sizeof(rgba));
  unsigned i ;
  for( i=0; i<ncols; i++ ) {
    int j = lookup_or_intern(row[i]) ;
    if( j < 0 ) {
      unpalettify_row(row,i);
      return 0 ;
    }
    newrow[i] = j ;
  }
  return 1 ;
}

References lookup_or_intern(), and unpalettify_row().

◆ palettify_rows()

int palettify_rows	(	rgba *	rows[],
		unsigned	ncols,
		unsigned	nlines )

Definition at line 97 of file palette.c.

{
  unsigned i ;
  for( i=0; i<nlines; i++ ) {
    if( !palettify_row(rows[i],ncols) ) {
      while( i-- )
        unpalettify_row(rows[i],ncols);
      return 0 ;
    }
  }
  return 1 ;
}

References palettify_row(), and unpalettify_row().

Variable Documentation

◆ palette

rgba palette[MAX_PALETTE]

extern

Definition at line 35 of file palette.c.

◆ paletteSize

unsigned paletteSize