/* compress.c: * * compress a colormap by removing unused RGB colors * * jim frost 10.05.89 * * Copyright 1989, 1990 Jim Frost.  See included file "copyright.h" for * complete copyright information. *//* * Hack to speed up the special case  image->pixlen == 1  added by * Rod Johnson, Entropic Research Laboratory, Inc., 90/09/25. */#ifdef SCCS    static char *sccs_id = "@(#)compress.c	1.2  10/14/90";#endif#include "copyright.h"#include "image.h"void compress(image, verbose)     Image        *image;     unsigned int  verbose;{ Pixel        *index;  unsigned int *used;    RGBMap        rgb;  byte         *pixptr;  unsigned int  a, x, y;  Pixel         color;  goodImage(image, "compress");  if (! RGBP(image)) /* we're AT&T */    return;  if (verbose) {    printf("  Compressing colormap...");    fflush(stdout);  }  newRGBMapData(&rgb, image->rgb.size);  index= (Pixel *)lmalloc(sizeof(Pixel) * image->rgb.used);  used= (unsigned int *)lmalloc(sizeof(unsigned int) * image->rgb.used);  for (x= 0; x < image->rgb.used; x++)    *(used + x)= 0;#define DO_A_COLOR \	if (*(used + color) == 0) {					\	  for (a= 0; a < rgb.used; a++)					\	    if ((*(rgb.red + a) == *(image->rgb.red + color)) &&	\	        (*(rgb.green + a) == *(image->rgb.green + color)) &&	\	        (*(rgb.blue + a) == *(image->rgb.blue + color)))	\	      break;							\	  *(index + color)= a;						\	  *(used + color)= 1;						\	  if (a == rgb.used) {						\	    *(rgb.red + a)= *(image->rgb.red + color);			\	    *(rgb.green + a)= *(image->rgb.green + color);		\	    *(rgb.blue + a)= *(image->rgb.blue + color);		\	    rgb.used++;							\	  }								\	}  /*   * When  image->pixlen == 1  the functions  memToVal  and  valToMem  can   * be replaces with casts.   */  pixptr= image->data;  if (image->pixlen == 1) {    for (y= 0; y < image->height; y++)      for (x= 0; x < image->width; x++) {	color = (unsigned long) *pixptr;        DO_A_COLOR	*pixptr = (byte) *(index + color);        pixptr += image->pixlen;      }  }  else {    for (y= 0; y < image->height; y++)      for (x= 0; x < image->width; x++) {        color= memToVal(pixptr, image->pixlen);        DO_A_COLOR        valToMem(*(index + color), pixptr, image->pixlen);        pixptr += image->pixlen;      }  }#undef DO_A_COLOR  if (verbose)    if (rgb.used < image->rgb.used)      printf("%d unique colors of %d\n", rgb.used, image->rgb.used);    else      printf("no improvement\n");  freeRGBMapData(&(image->rgb));  image->rgb= rgb;}