warzone2100/lib/framework/math-help.h

172 lines
3.7 KiB
C

/*
This file is part of Warzone 2100.
Copyright (C) 1999-2004 Eidos Interactive
Copyright (C) 2005-2007 Warzone Resurrection Project
Warzone 2100 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.
Warzone 2100 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 Warzone 2100; if not, write to the Free Software
Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
*/
/*! \file
* \brief Routines to provide simple math helper functions
*/
#ifndef __INCLUDED_LIB_FRAMEWORK_MATH_HELP_H__
#define __INCLUDED_LIB_FRAMEWORK_MATH_HELP_H__
// Also PERCENT(int,int); // returns a int value 0->100 of the percentage of the first param over the second
#include "wzglobal.h"
#include <math.h>
#define PERCENT(a,b) (((a)*100)/(b))
#define PERNUM(range,a,b) (((a)*range)/(b))
/* conversion macros */
#define RAD_TO_DEG(x) (x * 180.0 / M_PI)
#ifndef M_PI
# define M_PI 3.14159265358979323846
#endif
#if !defined(WZ_C99) && !defined(__cplusplus) && !defined(WZ_CC_GNU)
static inline int roundf(float x)
{
// Ensure that float truncation results in a proper rounding
if (x < 0.0f)
return x - 0.5f;
else
return x + 0.5f;
}
/**
* nearbyint(3) implementation because that function is only available on C99
* compatible C libraries.
*
* This function rounds its argument to an integer value in floating point
* format, using the current rounding direction and without raising an
* @c inexact exception.
*
* @return The rounded integer value. If @c x is integral or infinite, @c x
* itself is returned.
*/
static double nearbyint(double x)
{
if (ceil(x + 0.5) == floor(x + 0.5))
{
if ((int)ceil(x) % 2 == 0)
{
return ceil(x);
}
else
{
return floor(x);
}
}
else
{
return floor(x + 0.5);
}
}
static inline WZ_DECL_CONST double hypot(double x, double y)
{
return sqrt(x * x + y * y);
}
static inline WZ_DECL_CONST float hypotf(float x, float y)
{
return hypot(x, y);
}
#endif
/*!
* Converts x from degrees to radian
* \param x Degree value to convert
* \return Radian value
*/
static inline WZ_DECL_CONST float deg2radf(float x)
{
return x * (float)M_PI / 180.0f;
}
/*!
* Converts x from radian to degrees
* \param x Radian value to convert
* \return Degree value
*/
static inline WZ_DECL_CONST float rad2degf(float x)
{
return x / (float)M_PI * 180.0f;
}
/*!
* Moves x into the range 0 - max
* \param x Value to clip
* \param max Upper range
* \return Value in the range 0 - max
*/
static inline WZ_DECL_CONST int wrap(int x, int max)
{
while(x < 0) x += max;
while(x >= max) x -= max;
return x;
}
/*!
* Moves x into the range 0.0f - max
* \param x Value to clip
* \param max Upper range
* \return Value in the range 0.0f - max
*/
static inline WZ_DECL_CONST float wrapf(float x, float max)
{
while(x < 0.0f) x += max;
while(x >= max) x -= max;
return x;
}
/*!
* Clips x to boundaries
* \param x Value to clip
* \param min Lower bound
* \param max Upper bound
*/
static inline WZ_DECL_CONST int clip(int x, int min, int max)
{
if (x < min) return min;
if (x > max) return max;
return x;
}
/*!
* Clips x to boundaries
* \param x Value to clip
* \param min Lower bound
* \param max Upper bound
*/
static inline WZ_DECL_CONST float clipf(float x, float min, float max)
{
if (x < min) return min;
if (x > max) return max;
return x;
}
#endif // __INCLUDED_LIB_FRAMEWORK_MATH_HELP_H__