len0rd/rockbox
1
0
Fork 1
mirror of https://github.com/Rockbox/rockbox.git synced 2025-10-14 02:27:39 -04:00
Code Issues Projects Releases Packages Wiki Activity Actions

plugins code cleanup : moved the duplicated fixed point table loockup based sinus/cosinus functions to fixedpoint.c, removed the bmp size definition in the clock.c|-(useless as the size is already defined in a .h generated with every bitmaps ...)

Browse source 
git-svn-id: svn://svn.rockbox.org/rockbox/trunk@14087 a1c6a512-1295-4272-9138-f99709370657
This commit is contained in:
Kevin Ferrare 2007-07-31 04:59:03 +00:00
parent 4e8b171fc4
commit df4f56b2b0
6 changed files with 118 additions and 378 deletions
Download patch file Download diff file Expand all files Collapse all files

66
apps/plugins/lib/fixedpoint.c
View file

@ -60,6 +60,21 @@ static const unsigned long atan_table[] = {
0x00000000, /* +0.000000000 */
};
/* Precalculated sine and cosine * 16384 (2^14) (fixed point 18.14) */
static const short sin_table[91] =
{
0, 285, 571, 857, 1142, 1427, 1712, 1996, 2280, 2563,
2845, 3126, 3406, 3685, 3963, 4240, 4516, 4790, 5062, 5334,
5603, 5871, 6137, 6401, 6663, 6924, 7182, 7438, 7691, 7943,
8191, 8438, 8682, 8923, 9161, 9397, 9630, 9860, 10086, 10310,
10531, 10748, 10963, 11173, 11381, 11585, 11785, 11982, 12175, 12365,
12550, 12732, 12910, 13084, 13254, 13420, 13582, 13740, 13894, 14043,
14188, 14329, 14466, 14598, 14725, 14848, 14967, 15081, 15190, 15295,
15395, 15491, 15582, 15668, 15749, 15825, 15897, 15964, 16025, 16082,
16135, 16182, 16224, 16261, 16294, 16321, 16344, 16361, 16374, 16381,
16384
};
/**
* Implements sin and cos using CORDIC rotation.
*
@ -136,3 +151,54 @@ long fsqrt(long a, unsigned int fracbits)
return b;
}
/**
* Fixed point sinus using a lookup table
* don't forget to divide the result by 16384 to get the actual sinus value
* @param val sinus argument in degree
* @return sin(val)*16384
*/
long sin_int(int val)
{
val = (val+360)%360;
if (val < 181)
{
if (val < 91)/* phase 0-90 degree */
return (long)sin_table[val];
else/* phase 91-180 degree */
return (long)sin_table[180-val];
}
else
{
if (val < 271)/* phase 181-270 degree */
return -(long)sin_table[val-180];
else/* phase 270-359 degree */
return -(long)sin_table[360-val];
}
return 0;
}
/**
* Fixed point cosinus using a lookup table
* don't forget to divide the result by 16384 to get the actual cosinus value
* @param val sinus argument in degree
* @return cos(val)*16384
*/
long cos_int(int val)
{
val = (val+360)%360;
if (val < 181)
{
if (val < 91)/* phase 0-90 degree */
return (long)sin_table[90-val];
else/* phase 91-180 degree */
return -(long)sin_table[val-90];
}
else
{
if (val < 271)/* phase 181-270 degree */
return -(long)sin_table[270-val];
else/* phase 270-359 degree */
return (long)sin_table[val-270];
}
return 0;
}