/* * picpack -- ansi version * Bugs: *	f and d are non-portable *	could be faster */#include <u.h>#include <libc.h>#include <libg.h>#include <ape/stdarg.h>#include <fb.h>void picpack(PICFILE *f, char *buf, char *fmt, ...){	register char *bp, *cp;	register short *sp;	register long *lp;	register float *fp;	register double *dp;	register char *ebuf;	int nchan;	va_list pvar;	va_start(pvar, fmt);	nchan=f->nchan;	ebuf=buf+f->width*nchan;	for(;*fmt;fmt++) switch(*fmt){	case 'c':		cp=va_arg(pvar, char *);		for(bp=buf;bp!=ebuf;bp+=nchan)			*bp=*cp++;		buf++;		ebuf++;		break;	case 's':		sp=va_arg(pvar, short *);		for(bp=buf;bp!=ebuf;bp+=nchan){			*bp=*sp;			bp[1]=*sp++>>8;		}		buf+=2;		ebuf+=2;		break;	case 'l':		lp=va_arg(pvar, long *);		for(bp=buf;bp!=ebuf;bp+=nchan){			*bp=*lp;			bp[1]=*lp>>8;			bp[2]=*lp>>16;			bp[3]=*lp++>>24;		}		buf+=4;		ebuf+=4;		break;	case 'f':		fp=va_arg(pvar, float *);		for(bp=buf;bp!=ebuf;bp+=nchan){			cp=(char *)fp++;			bp[0]=cp[0];			bp[1]=cp[1];			bp[2]=cp[2];			bp[3]=cp[3];		}		buf+=4;		ebuf+=4;		break;	case 'd':		dp=va_arg(pvar, double *);		for(bp=buf;bp!=ebuf;bp+=nchan){			cp=(char *)dp++;			bp[0]=cp[0];			bp[1]=cp[1];			bp[2]=cp[2];			bp[3]=cp[3];			bp[4]=cp[4];			bp[5]=cp[5];			bp[6]=cp[6];			bp[7]=cp[7];		}		buf+=8;		ebuf+=8;		break;	case '_':		buf++;		ebuf++;		break;	}	va_end(pvar);}