rockbox/apps/plugins/lib/gray_scroll_down8.c
Jens Arnold 7c6bdd6493 Split grayscale library into several files to make up a real function library. Significantly decreases binary size for plugins using it.
git-svn-id: svn://svn.rockbox.org/rockbox/trunk@4802 a1c6a512-1295-4272-9138-f99709370657
2004-06-23 22:15:50 +00:00

69 lines
2.2 KiB
C

/***************************************************************************
* __________ __ ___.
* Open \______ \ ____ ____ | | _\_ |__ _______ ___
* Source | _// _ \_/ ___\| |/ /| __ \ / _ \ \/ /
* Jukebox | | ( <_> ) \___| < | \_\ ( <_> > < <
* Firmware |____|_ /\____/ \___ >__|_ \|___ /\____/__/\_ \
* \/ \/ \/ \/ \/
* $Id$
*
* Grayscale framework
* gray_scroll_down8() function
*
* This is a generic framework to use grayscale display within Rockbox
* plugins. It obviously does not work for the player.
*
* Copyright (C) 2004 Jens Arnold
*
* All files in this archive are subject to the GNU General Public License.
* See the file COPYING in the source tree root for full license agreement.
*
* This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
* KIND, either express or implied.
*
****************************************************************************/
#ifndef SIMULATOR /* not for simulator by now */
#include "plugin.h"
#ifdef HAVE_LCD_BITMAP /* and also not for the Player */
#include "gray.h"
/*---------------------------------------------------------------------------
Scroll the whole grayscale buffer down by 8 pixels
----------------------------------------------------------------------------
black_border determines if the pixels scrolled in at the top are black
or white
Scrolling up/down by 8 pixels is very fast.
*/
void gray_scroll_down8(bool black_border)
{
int by, d;
unsigned filler;
unsigned char *ptr;
filler = black_border ? 0xFF : 0;
/* Scroll row by row to minimize flicker (byte rows = 8 pixels each) */
for (by = _graybuf->bheight - 1; by > 0; by--)
{
ptr = _graybuf->data + MULU16(_graybuf->width, by);
for (d = 0; d < _graybuf->depth; d++)
{
_gray_rb->memcpy(ptr, ptr - _graybuf->width, _graybuf->width);
ptr += _graybuf->plane_size;
}
}
/* fill first row */
ptr = _graybuf->data;
for (d = 0; d < _graybuf->depth; d++)
{
_gray_rb->memset(ptr, filler, _graybuf->width);
ptr += _graybuf->plane_size;
}
}
#endif // #ifdef HAVE_LCD_BITMAP
#endif // #ifndef SIMULATOR