/* Image processing aux functions header file
   Copyright (C) 1998 Jareth Hein

This file is a part of XEmacs

XEmacs is free software; you can redistribute it and/or modify it
under the terms of the GNU General Public License as published by the
Free Software Foundation; either version 2, or (at your option) any
later version.

XEmacs is distributed in the hope that it will be useful, but WITHOUT
ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
for more details.

You should have received a copy of the GNU General Public License
along with XEmacs; see the file COPYING.  If not, write to
the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
Boston, MA 02111-1307, USA.  */

/* Synched up with: Not in FSF. */

/* Original author: Jareth Hein */

#define	MAX_CMAP_SIZE	256
#define	COLOR_DEPTH	8
#define	MAX_COLOR	256

#define	B_DEPTH		5		/* # bits/pixel to use */
#define	B_LEN		(1L<<B_DEPTH)

#define	C_DEPTH		2
#define	C_LEN		(1L<<C_DEPTH)	/* # cells/color to use */

#define	COLOR_SHIFT	(COLOR_DEPTH-B_DEPTH)

typedef	struct colorbox {
	struct	colorbox *next, *prev;
	int	rmin, rmax;
	int	gmin, gmax;
	int	bmin, bmax;
	int	total;
} Colorbox;

typedef struct {
	int	num_ents;
	int	entries[MAX_CMAP_SIZE][2];
} C_cell;

typedef struct {
  unsigned short rm[MAX_CMAP_SIZE], gm[MAX_CMAP_SIZE], bm[MAX_CMAP_SIZE]; /* map values */
  int um[MAX_CMAP_SIZE]; /* usage counts for each mapentry */
  int histogram[B_LEN][B_LEN][B_LEN]; 
  int num_active_colors;
  Colorbox *freeboxes; /* used and freed internally */
  Colorbox *usedboxes; /* used and freed internally */
  C_cell **ColorCells; /* used and freed internally */
} quant_table;

#define QUANT_GET_COLOR(qt,r,g,b) (qt->histogram[r>>COLOR_SHIFT][g>>COLOR_SHIFT][b>>COLOR_SHIFT])

quant_table *build_EImage_quantable(unsigned char *eimage, int width, int height, int num_colors);