MathCommon.cpp File Reference

Implements common/useful functions. More...

#include <assert.h>
#include <ctime>
#include <SDL_opengl.h>
#include "Math/MathCommon.h"
#include "Common/Globals.h"

Functions
float	ClosestPoints (const Line &l1, const Line &l2, Point2f &out1, Point2f &out2)
	Computes the closest points between the two given lines.
int	Intersect (const Ray &r, const Circle &c, float &t1, float &t2)
	Intersects a Ray with a Circle and finds the enter and exit time.
int	Intersect (const Line &l, const Circle &c, float &t1, float &t2)
	Intersects a Line with a Circle and finds the enter and exit time.
Point2f	ScreenToNormCoords (const Point2f &p)
	Converts a point in absolute Screen coordinates to normalized device coordinates.
Point2f	NormToScreenCoords (const Point2f &p)
	Converts a point in normalized device coordinates to absolute Screen coordinates.
uint	TimeSeed ()
	Computes a pretty good seed for a random number generator using the system time.

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Detailed Description

Implements common/useful functions.

Author:

Joe Forte

Date:

3/27/2008

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Function Documentation

float ClosestPoints	(	const Line &	l1,
		const Line &	l2,
		Point2f &	out1,
		Point2f &	out2
	)

Computes the closest points between the two given lines.

Parameters:

[in]	l1	the first line.
[in]	l2	the second line.
[out]	out1	the closest point on the first line.
[out]	out2	the closest point on the second line.

Returns:

The distance between out1 and out2.

pg 149

int Intersect	(	const Line &	l,
		const Circle &	c,
		float &	t1,
		float &	t2
	)

Intersects a Line with a Circle and finds the enter and exit time.

Parameters:

[in]	l	the Line.
[in]	c	the circle.
[out]	t1	the time the Line l enters the Circle c.
[out]	t2	the time the Line l exits the Circle c.

Returns:

The number of intersections the Line l has with the Circle c. If 0 is returned there where was no intersection. If 1 is returned then there was one intersection and t1 holds the time. If 2 is returned then there were two intersections and the times are in t1 and t2 where t1 < t2.

int Intersect	(	const Ray &	r,
		const Circle &	c,
		float &	t1,
		float &	t2
	)

Intersects a Ray with a Circle and finds the enter and exit time.

Parameters:

[in]	r	the Ray.
[in]	c	the circle.
[out]	t1	the time the Ray r enters the Circle c.
[out]	t2	the time the Ray r exits the Circle c.

Returns:

The number of intersections the Ray r has with the Circle c. If 0 is returned there where was no intersection. If 1 is returned then there was one intersection and t1 holds the time. If 2 is returned then there were two intersections and the times are in t1 and t2 where t1 < t2.

pg 178

Point2f NormToScreenCoords

(

const Point2f &

p

)

Converts a point in normalized device coordinates to absolute Screen coordinates.

Parameters:

[in]

p

the point to convert.

See also:

ScreenToNormCoords

Returns:

The point p in absolute Screen coordinates.

Point2f ScreenToNormCoords

(

const Point2f &

p

)

Converts a point in absolute Screen coordinates to normalized device coordinates.

Parameters:

[in]

p

the point to convert.

See also:

NormToScreenCoords

Returns:

The point p in normalized device coordinates.

uint TimeSeed

(

)

Computes a pretty good seed for a random number generator using the system time.

Returns:

A seed value.