/* * int getcmap(char *file, unsigned char *buf) *	Read a colormap from the given file into the buffer. *	Returns 1 on success, 0 otherwise. *	Goes to unglaublich length to figure out what the file name means: *	If the name is "fb", reads the colormap out of the frambuffer *		(binit must have been called for this to work!) *	If the name is "gamma",returns gamma=2.3 colormap *	If the name is "gamma###", returns gamma=#### colormap *	Looks for the file in a list of directories (given below). *	If the file is a picture file, extracts a colormap from it *	If the file is 3*256 bytes long, it's a raw colormap *	If the file is 256 bytes long, it's a monochrome compensation table */#include <u.h>#include <libc.h>#include <libg.h>#include <fb.h>char *cmapdir[]={	"",	"/lib/fb/cmap/",	0};getcmap(char *f, unsigned char *buf){	char name[512], line[256*3+1];	int cmap, i, n;	PICFILE *pf;	double gamma;	RGB p9map[256];	cmap=-1;	for(i=0;cmapdir[i];i++){		sprint(name, "%s%s", cmapdir[i], f);		if((cmap=open(name, OREAD))!=-1) break;	}	if(cmap==-1){ /* could be gamma or gamma<number> or fb */		if(strcmp(f, "fb")==0){			rdcolmap(&screen, p9map);			for(i=0;i!=256;i++){				buf[3*i+0]=p9map[i].red>>24;				buf[3*i+1]=p9map[i].green>>24;				buf[3*i+1]=p9map[i].blue>>24;			}			return 1;		}		if(strncmp(f, "gamma", 5)!=0) return 0;		f+=5;		if(*f=='\0') gamma=2.3;		else{			if(strspn(f, "0123456789.")!=strlen(f)) return 0;			gamma=atof(f);		}		for(i=0;i!=256;i++){			buf[0]=buf[1]=buf[2]=255.*pow(i/255., 1./gamma);			buf+=3;		}		return 1;	}	n=read(cmap, line, 5);	if(n==5 && strncmp(line, "TYPE=", 5)==0){		close(cmap);		pf=picopen_r(name);		if(pf->cmap==0){			picclose(pf);			return 0;		}		memcpy(buf, pf->cmap, 3*256);		return 1;	}	n+=read(cmap, line+5, 256*3-4);	close(cmap);	switch(n){	default: return 0;	case 256*3:	/* real rgb colormap */		memcpy(buf, line, 256*3);		break;	case 256:	/* compensation table */		for(i=0;i!=256;i++){			buf[0]=buf[1]=buf[2]=line[i];			buf+=3;		}		break;	}	return 1;}