palette.c File Reference

#include "palette.h"
#include <assert.h>

Go to the source code of this file.

Macros
#define	HASH_SIZE   1711

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)
static void	unpalettify_row (rgba *row, unsigned ncols)

Variables
static int	bucketlinks [MAX_PALETTE]
static int	masterhash [HASH_SIZE]
rgba	palette [MAX_PALETTE]
unsigned	paletteSize

Macro Definition Documentation

HASH_SIZE

#define HASH_SIZE   1711

Definition at line 22 of file palette.c.

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().

unpalettify_row()

static void unpalettify_row ( rgba * row, unsigned ncols )

inlinestatic

Definition at line 70 of file palette.c.

{
  index_t *newrow = (index_t*) row ;
  unsigned i ;
  for( i=ncols; i--; ) {
    row[i] = palette[newrow[i]] ;
  }
}

References palette.

Variable Documentation

bucketlinks

int bucketlinks[MAX_PALETTE]

static

Definition at line 37 of file palette.c.

masterhash

int masterhash[HASH_SIZE]

static

Definition at line 36 of file palette.c.

palette

rgba palette[MAX_PALETTE]

Definition at line 35 of file palette.c.

paletteSize

unsigned paletteSize

Definition at line 34 of file palette.c.