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/*
* Xytronic LF-1600
* Fixed point data type
*
* Copyright (c) 2015-2017 Michael Buesch <m@bues.ch>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License along
* with this program; if not, write to the Free Software Foundation, Inc.,
* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*/
#include "fixpt.h"
fixpt_big_t fixpt_inflate(fixpt_t a)
{
return (fixpt_big_t)a;
}
fixpt_t fixpt_deflate(fixpt_big_t a)
{
if (a >= FIXPT_MAX)
return FIXPT_MAX;
if (a <= FIXPT_MIN)
return FIXPT_MIN;
return (fixpt_t)a;
}
fixpt_big_t _do_int32_to_fixpt_big(int32_t i)
{
return INT_TO_FIXPT_BIG(i);
}
fixpt_t _do_int32_to_fixpt(int32_t i)
{
return fixpt_deflate(INT_TO_FIXPT_BIG(i));
}
int32_t fixpt_big_to_int(fixpt_big_t p)
{
int32_t i;
if (p < int_to_fixpt_big(0)) {
p = -p;
i = ((int32_t)p + (int32_t)(1L << (FIXPT_SHIFT - 1))) >> FIXPT_SHIFT;
i = -i;
} else {
i = ((int32_t)p + (int32_t)(1L << (FIXPT_SHIFT - 1))) >> FIXPT_SHIFT;
}
return i;
}
int32_t fixpt_to_int(fixpt_t p)
{
return fixpt_big_to_int(fixpt_inflate(p));
}
int32_t fixpt_get_int_part(fixpt_t p)
{
if (p >= int_to_fixpt(0))
return (int32_t)p >> FIXPT_SHIFT;
else
return -((-(int32_t)p) >> FIXPT_SHIFT);
}
uint32_t fixpt_get_dec_fract(fixpt_t p, uint8_t nr_digits)
{
uint32_t dec_mask;
uint32_t dec_fract;
/* Mask the fractional part. */
p = fixpt_abs(p) & ((1L << FIXPT_SHIFT) - 1);
/* Calculate the decimal digit mask. */
dec_mask = (uint32_t)pow_int(10, nr_digits);
/* Calculate the decimal fractional. */
dec_fract = (uint32_t)udiv_round((uint32_t)p * dec_mask,
(uint32_t)(1UL << FIXPT_SHIFT));
return dec_fract;
}
fixpt_big_t fixpt_big_add(fixpt_big_t a, fixpt_big_t b)
{
fixpt_big_t tmp;
tmp = a + b;
return tmp;
}
fixpt_big_t fixpt_big_sub(fixpt_big_t a, fixpt_big_t b)
{
fixpt_big_t tmp;
tmp = a - b;
return tmp;
}
fixpt_big_t fixpt_big_mul(fixpt_big_t a, fixpt_big_t b)
{
fixpt_big_t tmp;
/* Multiply */
tmp = a * b;
/* Round */
tmp += (fixpt_big_t)1L << (FIXPT_SHIFT - 1);
/* Scale */
tmp >>= FIXPT_SHIFT;
return tmp;
}
fixpt_big_t fixpt_big_div(fixpt_big_t a, fixpt_big_t b)
{
fixpt_big_t tmp;
if (b == int_to_fixpt_big(0)) {
/* Division by zero. Handle it gracefully. */
if (a < int_to_fixpt_big(0))
tmp = FIXPTBIG_MIN;
else
tmp = FIXPTBIG_MAX;
} else {
/* Scale */
tmp = a << FIXPT_SHIFT;
/* Round */
if ((tmp >= int_to_fixpt_big(0) && b >= int_to_fixpt_big(0)) ||
(tmp < int_to_fixpt_big(0) && b < int_to_fixpt_big(0))) {
tmp += b / 2;
} else {
tmp -= b / 2;
}
/* Divide */
tmp /= b;
}
return tmp;
}
fixpt_big_t fixpt_big_mul_div(fixpt_big_t a, fixpt_big_t b, fixpt_big_t c)
{
fixpt_big_t tmp;
tmp = fixpt_big_mul(a, b);
tmp = fixpt_big_div(tmp, c);
return tmp;
}
fixpt_t fixpt_add(fixpt_t a, fixpt_t b)
{
fixpt_big_t tmp;
tmp = fixpt_big_add(fixpt_inflate(a), fixpt_inflate(b));
return fixpt_deflate(tmp);
}
fixpt_t fixpt_sub(fixpt_t a, fixpt_t b)
{
fixpt_big_t tmp;
tmp = fixpt_big_sub(fixpt_inflate(a), fixpt_inflate(b));
return fixpt_deflate(tmp);
}
fixpt_t fixpt_mul(fixpt_t a, fixpt_t b)
{
fixpt_big_t tmp;
tmp = fixpt_big_mul(fixpt_inflate(a), fixpt_inflate(b));
return fixpt_deflate(tmp);
}
fixpt_t fixpt_div(fixpt_t a, fixpt_t b)
{
fixpt_big_t tmp;
tmp = fixpt_big_div(fixpt_inflate(a), fixpt_inflate(b));
return fixpt_deflate(tmp);
}
fixpt_t fixpt_mul_div(fixpt_t a, fixpt_t b, fixpt_t c)
{
fixpt_big_t tmp;
tmp = fixpt_big_mul_div(fixpt_inflate(a),
fixpt_inflate(b),
fixpt_inflate(c));
return fixpt_deflate(tmp);
}
fixpt_t fixpt_neg(fixpt_t a)
{
if (a <= FIXPT_MIN)
return FIXPT_MAX;
return (fixpt_t)-a;
}
fixpt_t fixpt_abs(fixpt_t a)
{
if (a < int_to_fixpt(0))
return fixpt_neg(a);
return a;
}
fixpt_t fixpt_add_limited(fixpt_t a, fixpt_t b,
fixpt_t lo_lim, fixpt_t hi_lim)
{
fixpt_t ret;
ret = fixpt_add(a, b);
ret = fixpt_clamp(ret, lo_lim, hi_lim);
return ret;
}
fixpt_t fixpt_clamp(fixpt_t a,
fixpt_t lo_lim, fixpt_t hi_lim)
{
if (a < lo_lim)
a = lo_lim;
if (a > hi_lim)
a = hi_lim;
return a;
}
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