82 lines
1.5 KiB
C
82 lines
1.5 KiB
C
/* SPDX-FileCopyrightText: 2001-2002 NaN Holding BV. All rights reserved.
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*
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* SPDX-License-Identifier: GPL-2.0-or-later */
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/** \file
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* \ingroup bli
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*/
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#include "BLI_math_base.h"
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#include "BLI_strict_flags.h" /* Keep last. */
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int pow_i(int base, int exp)
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{
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int result = 1;
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BLI_assert(exp >= 0);
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while (exp) {
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if (exp & 1) {
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result *= base;
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}
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exp >>= 1;
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base *= base;
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}
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return result;
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}
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double double_round(double x, int ndigits)
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{
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/* From Python 3.1 `floatobject.c`. */
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double pow1, pow2, y, z;
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if (ndigits >= 0) {
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pow1 = pow(10.0, (double)ndigits);
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pow2 = 1.0;
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y = (x * pow1) * pow2;
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/* if y overflows, then rounded value is exactly x */
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if (!isfinite(y)) {
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return x;
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}
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}
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else {
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pow1 = pow(10.0, (double)-ndigits);
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pow2 = 1.0; /* unused; silences a gcc compiler warning */
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y = x / pow1;
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}
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z = round(y);
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if (fabs(y - z) == 0.5) {
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/* halfway between two integers; use round-half-even */
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z = 2.0 * round(y / 2.0);
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}
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if (ndigits >= 0) {
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z = (z / pow2) / pow1;
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}
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else {
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z *= pow1;
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}
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/* if computation resulted in overflow, raise OverflowError */
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return z;
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}
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float floor_power_of_10(float f)
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{
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BLI_assert(!(f < 0.0f));
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if (f != 0.0f) {
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return 1.0f / powf(10.0f, ceilf(log10f(1.0f / f)));
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}
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return 0.0f;
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}
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float ceil_power_of_10(float f)
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{
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BLI_assert(!(f < 0.0f));
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if (f != 0.0f) {
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return 1.0f / powf(10.0f, floorf(log10f(1.0f / f)));
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}
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return 0.0f;
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}
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