/* ** Command & Conquer Red Alert(tm) ** Copyright 2025 Electronic Arts Inc. ** ** 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 3 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, see . */ /* $Header: /CounterStrike/FIXED.H 1 3/03/97 10:24a Joe_bostic $ */ /*********************************************************************************************** *** C O N F I D E N T I A L --- W E S T W O O D S T U D I O S *** *********************************************************************************************** * * * Project Name : Command & Conquer * * * * File Name : FIXED.H * * * * Programmer : Joe L. Bostic * * * * Start Date : 06/19/96 * * * * Last Update : June 19, 1996 [JLB] * * * *---------------------------------------------------------------------------------------------* * Functions: * * - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */ #ifndef FIXED_H #define FIXED_H /* ** The "bool" integral type was defined by the C++ committee in ** November of '94. Until the compiler supports this, use the following ** definition. */ #ifndef __BORLANDC__ #ifndef TRUE_FALSE_DEFINED #define TRUE_FALSE_DEFINED enum {false=0,true=1}; typedef int bool; #endif #endif //#pragma warning 604 9 //#pragma warning 595 9 /* ** This is a very simple fixed point class that functions like a regular integral type. However ** it is under certain restrictions. The whole part must not exceed 255. The fractional part is ** limited to an accuracy of 1/256. It cannot represent or properly handle negative values. It ** really isn't all that fast (if an FPU is guaranteed to be present than using "float" might be ** more efficient). It doesn't detect overflow or underflow in mathematical or bit-shift operations. ** ** Take careful note that the normal mathematical operators return integers and not fixed point ** values if either of the components is an integer. This is the normal C auto-upcasting rule ** as it would apply presuming that integers are considered to be of higher precision than ** fixed point numbers. This allows the result of these operators to generate values with greater ** magnitude than is normally possible if the result were coerced into a fixed point number. ** If the result should be fixed point, then ensure that both parameters are fixed point. ** ** Note that although integers are used as the parameters in the mathematical operators, this ** does not imply that negative parameters are supported. The use of integers is as a convenience ** to the programmer -- constant integers are presumed signed. If unsigned parameters were ** specified, then the compiler would have ambiguous conversion situation in the case of constant ** integers (e.g. 1, 10, 32, etc). This is most important for the constructor when dealing with the ** "0" parameter case. In that situation the compiler might interpret the "0" as a null pointer rather ** than an unsigned integer. There should be no adverse consequences of using signed integer parameters ** since the precision/magnitude of these integers far exceeds the fixed point component counterparts. ** ** Note that when integer values are returns from the arithmetic operators, the value is rounded ** to the nearest whole integer value. This differs from normal integer math that always rounds down. */ class fixed { public: // The default constructor must not touch the data members in any way. fixed(void) {} // Convenient constructor if numerator and denominator components are known. fixed(int numerator, int denominator); // Conversion constructor to get fixed point from integer. fixed(int value) {Data.Composite.Fraction = 0;Data.Composite.Whole = (unsigned char)value;} // Constructor if ASCII image of number is known. fixed(char const * ascii); // Convert to integer when implicitly required. operator unsigned (void) const {return(((unsigned)Data.Raw+(256/2)) / 256);} /* ** The standard operators as they apply to in-place operation. */ fixed & operator *= (fixed const & rvalue) {Data.Raw = (unsigned short)(((int)Data.Raw * rvalue.Data.Raw) / 256);return(*this);} fixed & operator *= (int rvalue) {Data.Raw = (unsigned short)(Data.Raw * rvalue);return(*this);} fixed & operator /= (fixed const & rvalue) {if (rvalue.Data.Raw != 0 && rvalue.Data.Raw != 256) Data.Raw = (unsigned short)(((int)Data.Raw * 256) / rvalue);return(*this);} fixed & operator /= (int rvalue) {if (rvalue) Data.Raw = (unsigned short)((unsigned)Data.Raw / rvalue);return(*this);} fixed & operator += (fixed const & rvalue) {Data.Raw += rvalue.Data.Raw;return(*this);} fixed & operator -= (fixed const & rvalue) {Data.Raw -= rvalue.Data.Raw;return(*this);} /* ** The standard "My Dear Aunt Sally" operators. The integer versions of multiply ** and divide are more efficient than using the fixed point counterparts. */ // const fixed operator * (fixed const & rvalue) const {return(fixed(*this) *= rvalue);} const fixed operator * (fixed const & rvalue) const {fixed temp = *this;temp.Data.Raw = (unsigned short)(((int)temp.Data.Raw * (int)rvalue.Data.Raw) / 256);return(temp);} const int operator * (int rvalue) const {return ((((unsigned)Data.Raw * rvalue) + (256/2)) / 256);} // const fixed operator / (fixed const & rvalue) const {return(fixed(*this) /= rvalue);} const fixed operator / (fixed const & rvalue) const {fixed temp = *this;if (rvalue.Data.Raw != 0 && rvalue.Data.Raw != 256) temp.Data.Raw = (unsigned short)(((int)temp.Data.Raw * 256) / rvalue.Data.Raw);return(temp);} const int operator / (int rvalue) const {if (rvalue) return(((unsigned)Data.Raw+(256/2)) / ((unsigned)rvalue*256));return(*this);} // const fixed operator + (fixed const & rvalue) const {return(fixed(*this) += rvalue);} const fixed operator + (fixed const & rvalue) const {fixed temp = *this;temp += rvalue;return(temp);} const int operator + (int rvalue) const {return((((unsigned)Data.Raw+(256/2))/256) + rvalue);} // const fixed operator - (fixed const & rvalue) const {return(fixed(*this) -= rvalue);} const fixed operator - (fixed const & rvalue) const {fixed temp = *this;temp -= rvalue;return(temp);} const int operator - (int rvalue) const {return((((unsigned)Data.Raw+(256/2))/256) - rvalue);} /* ** The Shift operators are more efficient than using multiplies or divides by power-of-2 numbers. */ fixed & operator >>= (unsigned rvalue) {Data.Raw >>= rvalue;return(*this);} fixed & operator <<= (unsigned rvalue) {Data.Raw <<= rvalue;return(*this);} const fixed operator >> (unsigned rvalue) const {fixed temp = *this;temp >>= rvalue;return(temp);} const fixed operator << (unsigned rvalue) const {fixed temp = *this;temp <<= rvalue;return(temp);} /* ** The full set of comparison operators. */ bool operator == (fixed const & rvalue) const {return(Data.Raw == rvalue.Data.Raw);} bool operator != (fixed const & rvalue) const {return(Data.Raw != rvalue.Data.Raw);} bool operator < (fixed const & rvalue) const {return(Data.Raw < rvalue.Data.Raw);} bool operator > (fixed const & rvalue) const {return(Data.Raw > rvalue.Data.Raw);} bool operator <= (fixed const & rvalue) const {return(Data.Raw <= rvalue.Data.Raw);} bool operator >= (fixed const & rvalue) const {return(Data.Raw >= rvalue.Data.Raw);} bool operator ! (void) const {return(Data.Raw == 0);} /* ** Comparison to integers requires consideration of fractional component. */ bool operator < (int rvalue) const {return(Data.Raw < (rvalue*256));} bool operator > (int rvalue) const {return(Data.Raw > (rvalue*256));} bool operator <= (int rvalue) const {return(Data.Raw <= (rvalue*256));} bool operator >= (int rvalue) const {return(Data.Raw >= (rvalue*256));} bool operator == (int rvalue) const {return(Data.Raw == (rvalue*256));} bool operator != (int rvalue) const {return(Data.Raw != (rvalue*256));} /* ** Friend functions to handle the alternate positioning of fixed and integer parameters. */ friend const int operator * (int lvalue, fixed const & rvalue) {return(rvalue * lvalue);} friend const int operator / (int lvalue, fixed const & rvalue) {if (rvalue.Data.Raw == 0 || rvalue.Data.Raw == 256) return (lvalue); return(((unsigned)(lvalue * 256)+(256/2)) / rvalue.Data.Raw);} friend const int operator + (int lvalue, fixed const & rvalue) {return(rvalue + lvalue);} friend const int operator - (int lvalue, fixed const & rvalue) {return((((lvalue*256) - rvalue.Data.Raw) + (256/2)) / 256);} friend bool operator < (unsigned lvalue, fixed const & rvalue) {return((lvalue*256) < rvalue.Data.Raw);} friend bool operator > (unsigned lvalue, fixed const & rvalue) {return((lvalue*256) > rvalue.Data.Raw);} friend bool operator <= (unsigned lvalue, fixed const & rvalue) {return((lvalue*256) <= rvalue.Data.Raw);} friend bool operator >= (unsigned lvalue, fixed const & rvalue) {return((lvalue*256) >= rvalue.Data.Raw);} friend bool operator == (unsigned lvalue, fixed const & rvalue) {return((lvalue*256) == rvalue.Data.Raw);} friend bool operator != (unsigned lvalue, fixed const & rvalue) {return((lvalue*256) != rvalue.Data.Raw);} friend int operator *= (int & lvalue, fixed const & rvalue) {lvalue = lvalue * rvalue;return(lvalue);} friend int operator /= (int & lvalue, fixed const & rvalue) {lvalue = lvalue / rvalue;return(lvalue);} friend int operator += (int & lvalue, fixed const & rvalue) {lvalue = lvalue + rvalue;return(lvalue);} friend int operator -= (int & lvalue, fixed const & rvalue) {lvalue = lvalue - rvalue;return(lvalue);} /* ** Helper functions to handle simple and common operations on fixed point numbers. */ void Round_Up(void) {Data.Raw += (unsigned short)(256-1);Data.Composite.Fraction = 0;} void Round_Down(void) {Data.Composite.Fraction = 0;} void Round(void) {if (Data.Composite.Fraction >= 256/2) Round_Up();Round_Down();} void Saturate(unsigned capvalue) {if (Data.Raw > (capvalue*256)) Data.Raw = (unsigned short)(capvalue*256);} void Saturate(fixed const & capvalue) {if (*this > capvalue) *this = capvalue;} void Sub_Saturate(unsigned capvalue) {if (Data.Raw >= (capvalue*256)) Data.Raw = (unsigned short)((capvalue*256)-1);} void Sub_Saturate(fixed const & capvalue) {if (*this >= capvalue) Data.Raw = (unsigned short)(capvalue.Data.Raw-1);} void Inverse(void) {*this = fixed(1) / *this;} /* ** Friend helper functions that work in the typical C fashion of passing the object to ** be processed as a parameter to the function. */ friend const fixed Round_Up(fixed const & value) {fixed temp = value; temp.Round_Up();return(temp);} friend const fixed Round_Down(fixed const & value) {fixed temp = value; temp.Round_Down();return(temp);} friend const fixed Round(fixed const & value) {fixed temp = value; temp.Round();return(temp);} friend const fixed Saturate(fixed const & value, unsigned capvalue) {fixed temp = value;temp.Saturate(capvalue);return(temp);} friend const fixed Saturate(fixed const & value, fixed const & capvalue) {fixed temp = value;temp.Saturate(capvalue);return(temp);} friend const fixed Sub_Saturate(fixed const & value, unsigned capvalue) {fixed temp = value;temp.Sub_Saturate(capvalue);return(temp);} friend const fixed Sub_Saturate(fixed const & value, fixed const & capvalue) {fixed temp = value;temp.Sub_Saturate(capvalue);return(temp);} friend const fixed Inverse(fixed const & value) {fixed temp = value;temp.Inverse();return(temp);} /* ** Conversion of the fixed point number into an ASCII string. */ int To_ASCII(char * buffer, int maxlen=-1) const; char const * As_ASCII(void) const; /* ** Helper constants that provide some convenient fixed point values. */ static const fixed _1_2; static const fixed _1_3; static const fixed _1_4; static const fixed _3_4; static const fixed _2_3; private: union { struct { #ifdef BIG_ENDIAN unsigned char Whole; unsigned char Fraction; #else unsigned char Fraction; unsigned char Whole; #endif } Composite; unsigned short Raw; } Data; }; #endif