(svn r11940) -Codechange: Store short filename once per open file instead of once per sprite cache entry. Not all file types need this, but most of the time no sprite cache entry needed it either.
/* $Id$ */
/** @file math_func.hpp Integer math functions */
#ifndef MATH_FUNC_HPP
#define MATH_FUNC_HPP
#ifdef min
#undef min
#endif
#ifdef max
#undef max
#endif
#ifdef abs
#undef abs
#endif
/**
* Returns the maximum of two values.
*
* This function returns the greater value of two given values.
* If they are equal the value of a is returned.
*
* @param a The first value
* @param b The second value
* @return The greater value or a if equals
*/
template<typename T> static inline T max(const T a, const T b)
{
return (a >= b) ? a : b;
}
/**
* Returns the minimum of two values.
*
* This function returns the smaller value of two given values.
* If they are equal the value of b is returned.
*
* @param a The first value
* @param b The second value
* @return The smaller value or b if equals
*/
template<typename T> static inline T min(const T a, const T b)
{
return (a < b) ? a : b;
}
/**
* Returns the minimum of two integer.
*
* This function returns the smaller value of two given integers.
*
* @param a The first integer
* @param b The second integer
* @return The smaller value
*/
static inline int min(const int a, const int b)
{
return (a < b) ? a : b;
}
/**
* Returns the minimum of two unsigned integers.
*
* This function returns the smaller value of two given unsigned integers.
*
* @param a The first unsigned integer
* @param b The second unsigned integer
* @return The smaller value
*/
static inline uint minu(const uint a, const uint b)
{
return (a < b) ? a : b;
}
/**
* Returns the absolute value of (scalar) variable.
*
* @note assumes variable to be signed
* @param a The value we want to unsign
* @return The unsigned value
*/
template <typename T> static inline T abs(const T a)
{
return (a < (T)0) ? -a : a;
}
/**
* Return the smallest multiple of n equal or greater than x
*
* @note n must be a power of 2
* @param x The min value
* @param n The base of the number we are searching
* @return The smallest multiple of n equal or greater than x
*/
template<typename T> static inline T Align(const T x, uint n)
{
n--;
return (T)((x + n) & ~(n));
}
/**
* Clamp an integer between an interval.
*
* This function returns a value which is between the given interval of
* min and max. If the given value is in this interval the value itself
* is returned otherwise the border of the interval is returned, according
* which side of the interval was 'left'.
*
* @note The min value must be less or equal of max or you get some
* unexpected results.
* @param a The value to clamp/truncate.
* @param min The minimum of the interval.
* @param max the maximum of the interval.
* @returns A value between min and max which is closest to a.
* @see ClampU(uint, uint, uint)
*/
static inline int Clamp(const int a, const int min, const int max)
{
if (a <= min) return min;
if (a >= max) return max;
return a;
}
/**
* Clamp an unsigned integer between an interval.
*
* This function returns a value which is between the given interval of
* min and max. If the given value is in this interval the value itself
* is returned otherwise the border of the interval is returned, according
* which side of the interval was 'left'.
*
* @note The min value must be less or equal of max or you get some
* unexpected results.
* @param a The value to clamp/truncate.
* @param min The minimum of the interval.
* @param max the maximum of the interval.
* @returns A value between min and max which is closest to a.
* @see Clamp(int, int, int)
*/
static inline uint ClampU(const uint a, const uint min, const uint max)
{
if (a <= min) return min;
if (a >= max) return max;
return a;
}
/**
* Reduce a signed 64-bit int to a signed 32-bit one
*
* This function clamps a 64-bit integer to a 32-bit integer.
* If the 64-bit value is smaller than the smallest 32-bit integer
* value 0x80000000 this value is returned (the left one bit is the sign bit).
* If the 64-bit value is greater than the greatest 32-bit integer value 0x7FFFFFFF
* this value is returned. In all other cases the 64-bit value 'fits' in a
* 32-bits integer field and so the value is casted to int32 and returned.
*
* @param a The 64-bit value to clamps
* @return The 64-bit value reduced to a 32-bit value
* @see Clamp(int, int, int)
*/
static inline int32 ClampToI32(const int64 a)
{
if (a <= (int32)0x80000000) return 0x80000000;
if (a >= (int32)0x7FFFFFFF) return 0x7FFFFFFF;
return (int32)a;
}
/**
* Returns the (absolute) difference between two (scalar) variables
*
* @param a The first scalar
* @param b The second scalar
* @return The absolute difference between the given scalars
*/
template <typename T> static inline T Delta(const T a, const T b) {
return (a < b) ? b - a : a - b;
}
/**
* Checks if a value is between a window started at some base point.
*
* This function checks if the value x is between the value of base
* and base+size. If x equals base this returns true. If x equals
* base+size this returns false.
*
* @param x The value to check
* @param base The base value of the interval
* @param size The size of the interval
* @return True if the value is in the interval, false else.
*/
template<typename T> static inline bool IsInsideBS(const T x, const uint base, const uint size)
{
return (uint)(x - base) < size;
}
/**
* Checks if a value is in an interval.
*
* Returns true if a value is in the interval of [min, max).
*
* @param a The value to check
* @param min The minimum of the interval
* @param max The maximum of the interval
* @see IsInsideBS()
*/
template<typename T> static inline bool IsInsideMM(const T x, const uint min, const uint max)
{
return (uint)(x - min) < (max - min);
}
/**
* Type safe swap operation
* @param a variable to swap with b
* @param b variable to swap with a
*/
template<typename T> void Swap(T& a, T& b)
{
T t = a;
a = b;
b = t;
}
#endif /* MATH_FUNC_HPP */