rockbox/apps/plugins/lib/xlcd.c
Jens Arnold 937725f674 Beginnings of a library complementing the core LCD functions. First function: filled triangle drawing.
git-svn-id: svn://svn.rockbox.org/rockbox/trunk@7128 a1c6a512-1295-4272-9138-f99709370657
2005-07-12 23:50:37 +00:00

109 lines
3 KiB
C

/***************************************************************************
* __________ __ ___.
* Open \______ \ ____ ____ | | _\_ |__ _______ ___
* Source | _// _ \_/ ___\| |/ /| __ \ / _ \ \/ /
* Jukebox | | ( <_> ) \___| < | \_\ ( <_> > < <
* Firmware |____|_ /\____/ \___ >__|_ \|___ /\____/__/\_ \
* \/ \/ \/ \/ \/
* $Id$
*
* Additional LCD routines not present in the core itself
*
* Copyright (C) 2005 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.
*
****************************************************************************/
#include "plugin.h"
#ifdef HAVE_LCD_BITMAP
/*** globals ***/
static struct plugin_api *local_rb = NULL; /* global api struct pointer */
/*** functions ***/
/* library init */
void xlcd_init(struct plugin_api* newrb)
{
local_rb = newrb;
}
/* draw a filled triangle */
void xlcd_filltriangle(int x1, int y1, int x2, int y2, int x3, int y3)
{
int x, y;
long fp_y1, fp_y2, fp_dy1, fp_dy2;
/* sort vertices by increasing x value */
if (x1 > x3)
{
if (x2 < x3) /* x2 < x3 < x1 */
{
x = x1; x1 = x2; x2 = x3; x3 = x;
y = y1; y1 = y2; y2 = y3; y3 = y;
}
else if (x2 > x1) /* x3 < x1 < x2 */
{
x = x1; x1 = x3; x3 = x2; x2 = x;
y = y1; y1 = y3; y3 = y2; y2 = y;
}
else /* x3 <= x2 <= x1 */
{
x = x1; x1 = x3; x3 = x;
y = y1; y1 = y3; y3 = y;
}
}
else
{
if (x2 < x1) /* x2 < x1 <= x3 */
{
x = x1; x1 = x2; x2 = x;
y = y1; y1 = y2; y2 = y;
}
else if (x2 > x3) /* x1 <= x3 < x2 */
{
x = x2; x2 = x3; x3 = x;
y = y2; y2 = y3; y3 = y;
}
/* else already sorted */
}
if (x1 < x3) /* draw */
{
fp_dy1 = ((y3 - y1) << 16) / (x3 - x1);
fp_y1 = (y1 << 16) + (1<<15) + (fp_dy1 >> 1);
if (x1 < x2) /* first part */
{
fp_dy2 = ((y2 - y1) << 16) / (x2 - x1);
fp_y2 = (y1 << 16) + (1<<15) + (fp_dy2 >> 1);
for (x = x1; x < x2; x++)
{
local_rb->lcd_vline(x, fp_y1 >> 16, fp_y2 >> 16);
fp_y1 += fp_dy1;
fp_y2 += fp_dy2;
}
}
if (x2 < x3) /* second part */
{
fp_dy2 = ((y3 - y2) << 16) / (x3 - x2);
fp_y2 = (y2 << 16) + (1<<15) + (fp_dy2 >> 1);
for (x = x2; x < x3; x++)
{
local_rb->lcd_vline(x, fp_y1 >> 16, fp_y2 >> 16);
fp_y1 += fp_dy1;
fp_y2 += fp_dy2;
}
}
}
}
#endif /* HAVE_LCD_BITMAP */