/* Copyright (c) 1992 AT&T - All rights reserved. */
#include <libc.h>
#include <libg.h>
#include "libgint.h"

void
_ldconvert(char *in, int inld, char *out, int outld, int w, int h)
{
	int	a, b, i, j, i1, j1, j2, mask;
	int	ind, inl, outd, outl;
	int	hh, ww;
	char	*p, *q;

	i1 = 8 >> inld;
	j1 = 8 >> outld;
	ind = 1 << inld;
	outd = 1 << outld;
	inl = ((w << inld) + 7)/8;
	outl = ((w << outld) + 7)/8;
	b = 0;

	if (ind > outd) {
		mask = 256 - (256 >> outd);
		for (hh = 0; hh < h; hh++, in += inl, out += outl)
			for (p = in, q = out, ww = 0; ww < w; ww++) {
				for (j = j1; j > 0; ) {
					a = *p++;
					for (i = i1; i > 0; i--, j--) {
						b |= a & mask;
						a <<= ind;
						b <<= outd;
					}
				}
				*q++ = (b >> 8);
			}
	} else {
		j2 = 1 << (outld - inld);
		mask = 256 - (256 >> ind);
		for (hh = 0; hh < h; hh++, in += inl, out += outl)
			for (p = in, q = out, ww = 0; ww < w; ww++) {
				a = *p++;
				for (i = i1; i > 0; ) {
					for (j = j1; j > 0; j--, i--) {
						b |= a & mask;
						a <<= ind;
						b <<= outd;
					}
					for (j = j2; j > 0; j--)
						b |= (b << ind);
					*q++ = (b >> 8);
				}
			}
	}
}