From 737aec4db6e6368939b22d5e4afd3b9822ddc27e Mon Sep 17 00:00:00 2001 From: skidd13 Date: Thu, 22 Nov 2007 18:01:51 +0000 Subject: (svn r11490) -Codechange: Split the math functions to their own header -Codechange: Replace the rest of the math macros with functions --- src/core/math_func.hpp | 229 +++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 229 insertions(+) create mode 100644 src/core/math_func.hpp (limited to 'src/core') diff --git a/src/core/math_func.hpp b/src/core/math_func.hpp new file mode 100644 index 000000000..b47b06482 --- /dev/null +++ b/src/core/math_func.hpp @@ -0,0 +1,229 @@ +/* $Id */ + +/** @file math_func.hpp */ + +#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 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 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 static inline T abs(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 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 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 static inline bool IS_INSIDE_1D(const T x, const int base, const uint size) +{ + return (uint)(x - base) < size; +} + +/** + * Checks if a byte is in an interval. + * + * Returns true if a byte value is in the interval of [min, max). + * + * @param a The byte value to check + * @param min The minimum of the interval + * @param max The maximum of the interval + * @see IS_INSIDE_1D + */ +template static inline bool IS_BYTE_INSIDE(const T x, const byte min, const byte max) +{ + return (byte)(x - min) < (max - min); +} + +/** + * Checks if an int is in an interval. + * + * Returns true if a integer value is in the interval of [min, max). + * + * @param a The integer value to check + * @param min The minimum of the interval + * @param max The maximum of the interval + * @see IS_INSIDE_1D + */ +template static inline bool IS_INT_INSIDE(const T x, const int min, const uint max) +{ + return (uint)(x - min) < (max - min); +} + +#endif /* MATH_FUNC_HPP */ -- cgit v1.2.3-70-g09d2