/* * Map an rgb image through the given color map */#include <u.h>#include <libc.h>#include <libg.h>#include <fb.h>main(int argc, char *argv[]){	char *p, *ep;	unsigned char cmap[256][3];	char *inname, *line;	PICFILE *in, *out;	int rgboffs, i;	char *chan;	switch(getflags(argc, argv, "")){	case 3: inname=argv[2]; break;	case 2: inname="IN"; break;	default:usage("colormap [picture]");	}	if(!getcmap(argv[1], (unsigned char *)cmap)){		fprint(2, "%s: can't get color map %s\n", argv[0], argv[1]);		exits("get cmap");	}	in=picopen_r(inname);	if(in==0){		perror(inname);		exits("open input");	}	line=malloc(PIC_WIDTH(in)*PIC_NCHAN(in));	if(line==0){		fprint(2, "%s: no space\n", argv[0]);		exits("no space");	}	chan=in->chan;	for(rgboffs=0;strcmp(chan+rgboffs, "rgb")!=0;rgboffs++){		if(chan[rgboffs]=='\0'){			fprint(2, "%s: %s not rgb (CHAN=%s)\n", argv[0], inname, chan);			exits("not rgb");		}	}	out=picopen_w("OUT", PIC_SAMEARGS(in));	if(out==0){		perror(argv[0]);		exits("create output");	}	for(i=0;i!=PIC_HEIGHT(in);i++){		picread(in, line);		ep=line+rgboffs+PIC_WIDTH(in)*PIC_NCHAN(in);		for(p=line+rgboffs;p!=ep;p+=PIC_NCHAN(in)){			p[0]=cmap[p[0]&255][0];			p[1]=cmap[p[1]&255][1];			p[2]=cmap[p[2]&255][2];		}		picwrite(out, line);	}	exits("");}