OpenTTD
Functions
math_func.cpp File Reference

Math functions. More...

#include "../stdafx.h"
#include "math_func.hpp"
#include "../safeguards.h"

Go to the source code of this file.

Functions

int LeastCommonMultiple (int a, int b)
 Compute least common multiple (lcm) of arguments a and b, the smallest integer value that is a multiple of both a and b.
int GreatestCommonDivisor (int a, int b)
 Compute greatest common divisor (gcd) of a and b.
int DivideApprox (int a, int b)
 Deterministic approximate division.
uint32 IntSqrt (uint32 num)
 Compute the integer square root.

Detailed Description

Math functions.

Definition in file math_func.cpp.

Function Documentation

int DivideApprox ( int  a,
int  b 
)

Deterministic approximate division.

Cancels out division errors stemming from the integer nature of the division over multiple runs.

Parameters
aDividend.
bDivisor.
Returns
a/b or (a/b)+1.

Definition at line 59 of file math_func.cpp.

References abs().

Referenced by StationViewWindow::BuildCargoList(), and StationViewWindow::EstimateDestinations().

int GreatestCommonDivisor ( int  a,
int  b 
)

Compute greatest common divisor (gcd) of a and b.

Parameters
aFirst number.
bsecond number.
Returns
Greatest common divisor of a and b.

Definition at line 41 of file math_func.cpp.

Referenced by LeastCommonMultiple().

uint32 IntSqrt ( uint32  num)

Compute the integer square root.

Parameters
numRadicand.
Returns
Rounded integer square root.
Note
Algorithm taken from http://en.wikipedia.org/wiki/Methods_of_computing_square_roots

Definition at line 79 of file math_func.cpp.

Referenced by CanalMaintenanceCost(), RailMaintenanceCost(), RoadMaintenanceCost(), SignalMaintenanceCost(), and StationMaintenanceCost().

int LeastCommonMultiple ( int  a,
int  b 
)

Compute least common multiple (lcm) of arguments a and b, the smallest integer value that is a multiple of both a and b.

Parameters
aFirst number.
bsecond number.
Returns
Least common multiple of values a and b.
Note
This function only works for non-negative values of a and b.

Definition at line 26 of file math_func.cpp.

References GreatestCommonDivisor().

Referenced by NWidgetStacked::SetupSmallestSize(), NWidgetHorizontal::SetupSmallestSize(), NWidgetVertical::SetupSmallestSize(), and NWidgetNewGRFDisplay::SetupSmallestSize().