CnC_Red_Alert/CODE/FIXED.CPP

249 lines
11 KiB
C++

/*
** 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 <http://www.gnu.org/licenses/>.
*/
/* $Header: /CounterStrike/FIXED.CPP 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.CPP *
* *
* Programmer : Joe L. Bostic *
* *
* Start Date : 06/20/96 *
* *
* Last Update : July 3, 1996 [JLB] *
* *
*---------------------------------------------------------------------------------------------*
* Functions: *
* fixed::As_ASCII -- Returns a pointer (static) of this number as an ASCII string. *
* fixed::To_ASCII -- Convert a fixed point number into an ASCII string. *
* fixed::fixed -- Constructor for fixed integral from ASCII initializer. *
* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */
#include "fixed.h"
#include <string.h>
#include <stdlib.h>
#include <stdio.h>
#include <ctype.h>
/*
** These are some handy fixed point constants. Using these constants instead of manually
** constructing them is not only faster, but more readable.
*/
const fixed fixed::_1_2(1, 2); // 1/2
const fixed fixed::_1_3(1, 3); // 1/3
const fixed fixed::_1_4(1, 4); // 1/4
const fixed fixed::_3_4(3, 4); // 3/4
const fixed fixed::_2_3(2, 3); // 2/3
fixed::fixed(int numerator, int denominator)
{
if (denominator == 0) {
Data.Raw = 0;
} else {
Data.Raw = (unsigned short)((unsigned)(numerator * 256) / (unsigned)denominator);
}
}
/***********************************************************************************************
* fixed::fixed -- Constructor for fixed integral from ASCII initializer. *
* *
* This will parse the ASCII initialization string into a fixed point number. *
* The source string can be a conventional fixed point representation (e.g., "1.0", ".25") *
* or a percent value (e.g. "100%", "25%", "150%"). For percent values, the trailing "%" *
* is required. *
* *
* INPUT: ascii -- Pointer to the ascii source to translate into a fixed point number. *
* *
* OUTPUT: none *
* *
* WARNINGS: It is possible to specify an ASCII string that has more precision and *
* magnitude than can be represented by the fixed point number. In such a case, *
* the resulting value is undefined. *
* *
* HISTORY: *
* 06/20/1996 JLB : Created. *
*=============================================================================================*/
fixed::fixed(char const * ascii)
{
/*
** If there is no valid pointer, then default to zero value. This takes care of any
** compiler confusion that would call this routine when the programmer wanted the
** integer parameter constructor to be called.
*/
if (ascii == NULL) {
Data.Raw = 0;
return;
}
/*
** The whole part (if any) always starts with the first legal characters.
*/
char const * wholepart = ascii;
/*
** Skip any leading white space.
*/
while (isspace(*ascii)) {
ascii++;
}
/*
** Determine if the number is expressed as a percentage. Detect this by
** seeing if there is a trailing "%" character.
*/
char const * tptr = ascii;
while (isdigit(*tptr)) {
tptr++;
}
/*
** Percentage value is specified as a whole number but is presumed to be
** divided by 100 to get mathematical fixed point percentage value.
*/
if (*tptr == '\%') {
Data.Raw = (unsigned short)((atoi(ascii) * 256) / 100);
} else {
Data.Composite.Whole = Data.Composite.Fraction = 0;
if (wholepart && *wholepart != '.') {
Data.Composite.Whole = (unsigned char)atoi(wholepart);
}
char * fracpart = strchr(ascii, '.');
if (fracpart) fracpart++;
if (fracpart) {
int frac = atoi(fracpart);
int len = 0;
int base = 1;
char const * fptr = fracpart;
while (isdigit(*fptr)) {
fptr++;
len++;
base *= 10;
}
Data.Composite.Fraction = (unsigned char)((256 * frac) / base);
}
}
}
/***********************************************************************************************
* fixed::To_ASCII -- Convert a fixed point number into an ASCII string. *
* *
* Use this routine to convert this fixed point number into an ASCII null terminated *
* string. This is the counterpart to the fixed point constructor that takes an ASCII *
* string. *
* *
* INPUT: buffer -- Pointer to the buffer to hold the fixed point ASCII string. *
* *
* maxlen -- The length of the buffer. *
* *
* OUTPUT: Returns with the number of characters placed in the buffer. The trailing null is *
* not counted in this total. *
* *
* WARNINGS: none *
* *
* HISTORY: *
* 07/03/1996 JLB : Created. *
*=============================================================================================*/
int fixed::To_ASCII(char * buffer, int maxlen) const
{
if (buffer == NULL) return(0);
/*
** Determine the whole and fractional parts of the number. The fractional
** part number is the value in 1000ths.
*/
int whole = Data.Composite.Whole;
int frac = ((int)Data.Composite.Fraction * 1000) / 256;
char tbuffer[32];
/*
** If there number consists only of a whole part, then the number is simply
** printed into the buffer. If there is a fractional part, then there
** will be a decimal place followed by up to three digits of accuracy for the
** fractional component.
*/
if (frac == 0) {
sprintf(tbuffer, "%d", whole);
} else {
sprintf(tbuffer, "%d.%02d", whole, frac);
char * ptr = &tbuffer[strlen(tbuffer)-1];
while (*ptr == '0') {
*ptr = '\0';
ptr--;
}
}
/*
** If no maximum length to the output buffer was specified, then presume the
** output buffer is just long enough to store the number and the trailing
** zero.
*/
if (maxlen == -1) {
maxlen = strlen(tbuffer)+1;
}
/*
** Fill the output buffer with the ASCII number.
*/
strncpy(buffer, tbuffer, maxlen);
/*
** Return with the number of ASCII characters placed into the output buffer.
*/
int len = strlen(tbuffer);
if (len < maxlen-1) return(len);
return(maxlen-1);
}
/***********************************************************************************************
* fixed::As_ASCII -- Returns a pointer (static) of this number as an ASCII string. *
* *
* This number will be converted into an ASCII string (using a static buffer) and the *
* string pointer will be returned. *
* *
* INPUT: none *
* *
* OUTPUT: Returns with a pointer to the ASCII representation of this fixed point number. *
* *
* WARNINGS: As with all static return pointers, the pointer is valid only until such time *
* as this routine is called again. *
* *
* HISTORY: *
* 07/03/1996 JLB : Created. *
*=============================================================================================*/
char const * fixed::As_ASCII(void) const
{
static char buffer[32];
To_ASCII(buffer, sizeof(buffer));
return(buffer);
}