genode/os/src/lib/blit/blit.cc
2013-01-10 21:44:47 +01:00

56 lines
1.2 KiB
C++

/*
* \brief Generic blitting function
* \author Norman Feske
* \date 2007-10-10
*/
/*
* Copyright (C) 2007-2013 Genode Labs GmbH
*
* This file is part of the Genode OS framework, which is distributed
* under the terms of the GNU General Public License version 2.
*/
#include <blit/blit.h>
#include <blit_helper.h>
extern "C" void blit(void *s, unsigned src_w,
void *d, unsigned dst_w,
int w, int h)
{
char *src = (char *)s, *dst = (char *)d;
if (w <= 0 || h <= 0) return;
/* we support blitting only at a granularity of 16bit */
w &= ~1;
/* copy unaligned column */
if (w && ((long)dst & 2)) {
copy_16bit_column(src, src_w, dst, dst_w, h);
w -= 2; src += 2; dst += 2;
}
/* now, we are on a 32bit aligned destination address */
/* copy 32byte chunks */
if (w >> 5) {
copy_block_32byte(src, src_w, dst, dst_w, w >> 5, h);
src += w & ~31;
dst += w & ~31;
w = w & 31;
}
/* copy 32bit chunks */
if (w >> 2) {
copy_block_32bit(src, src_w, dst, dst_w, w >> 2, h);
src += w & ~3;
dst += w & ~3;
w = w & 3;
}
/* handle trailing row */
if (w >> 1) copy_16bit_column(src, src_w, dst, dst_w, h);
}