Tag
Hash :
7e01caf7
Author :
Thomas de Grivel
Date :
2023-05-25T17:38:26
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/* c3
* Copyright 2022,2023 kmx.io <contact@kmx.io>
*
* Permission is hereby granted to use this software granted the above
* copyright notice and this permission paragraph are included in all
* copies and substantial portions of this software.
*
* THIS SOFTWARE IS PROVIDED "AS-IS" WITHOUT ANY GUARANTEE OF
* PURPOSE AND PERFORMANCE. IN NO EVENT WHATSOEVER SHALL THE
* AUTHOR BE CONSIDERED LIABLE FOR THE USE AND PERFORMANCE OF
* THIS SOFTWARE.
*/
#include "sin.h"
s8 sin_u8 (u8 x)
{
s16 i;
u8 n;
u8 side_bits;
s8 y;
side_bits = (sizeof(u8) * 8 - 3);
n = (1 << side_bits) - 1;
switch (x >> side_bits) {
case 0:
i = x & n;
y = i * S8_MAX / n * S8_MAX / sqrt(n * n + i * i / n / n) / S8_MAX;
return y;
case 1:
return 1;
case 2:
return 2;
case 3:
return 3;
case 4:
return 4;
case 5:
return 5;
case 6:
return 6;
case 7:
return 7;
}
assert(! "sin_u8: error");
errx(1, "sin_u8");
return 0;
}