tlp::BoundingBox Struct Reference

#include <BoundingBox.h>

Inherits Array< Vec3f, 2 >.

Public Member Functions
	BoundingBox ()
	BoundingBox (const tlp::Vec3f &min, const tlp::Vec3f &max, bool checkMinMax=false)
Vec3f	center () const
bool	contains (const tlp::Vec3f &coord) const
bool	contains (const tlp::BoundingBox &boundingBox) const
float	depth () const
void	expand (const tlp::Vec3f &coord)
void	expand (const tlp::BoundingBox &bb, bool noCheck=false)
void	getCompleteBB (Vec3f bb[8]) const
float	height () const
bool	intersect (const tlp::BoundingBox &boundingBox) const
bool	intersect (const Vec3f &segStart, const Vec3f &segEnd) const
bool	isValid () const
void	scale (const tlp::Vec3f &factor)
void	translate (const tlp::Vec3f &vec)
float	width () const

Detailed Description

This class represents the 3D bounding box of an object. It is mostly used to determine whether or not two object are in a state of collision.

It is defined by two 3d points, the first one (A) being the lowest point, the second (B) being the highest. As a bounding box is a mathematical entity describing the lowest and highest points, whether these points are in the top-left corner or lower-right corner depends on the axes we use. Below is a crude ASCII-art description of the axes we use in our 3D world and the points where the min and max are thus positioned. Through the rest of this class's documentation, it will be assumed that this is the convention.

     y
    |
    |
    |_____ x
   /
  /
 z

    _________ B
   /        /|
  /        / |
 /________/  |
 |        |  |
 |        |  |
 |        | /
 |________|/
 A

Definition at line 66 of file BoundingBox.h.

Constructor & Destructor Documentation

BoundingBox() [1/2]

tlp::BoundingBox::BoundingBox

(

)

Creates an invalid boundig box. The minimum is (1, 1, 1) and the maximum is (-1, -1, -1).

BoundingBox() [2/2]

tlp::BoundingBox::BoundingBox	(	const tlp::Vec3f &	min,
		const tlp::Vec3f &	max,
		bool	checkMinMax = false
	)

Creates a bounding box that must be valid. Validity is checked in debug mode by an assert.

Parameters

min	The lower left closest point of the box.
max	The higher right most farther point of the box.
compute	indicates whether the bounding box has to be computed with the min/max args

Member Function Documentation

center()

Vec3f tlp::BoundingBox::center ( ) const

inline

Returns the geometrical center of the bounding box. An assertion is raised in debug mode if the BoundingBox is not valid.

Returns

The center of the bounding box :Vec3f

Definition at line 92 of file BoundingBox.h.

contains() [1/2]

bool tlp::BoundingBox::contains

(

const tlp::Vec3f &

coord

)

const

Checks if the given vector is inside the current bounding box. If the bounding box is invalid the result is always false.

Parameters

coord

A point in the 3D space.

Returns

bool Wether coord is in the bounding box.

contains() [2/2]

bool tlp::BoundingBox::contains

(

const tlp::BoundingBox &

boundingBox

)

const

Checks if the given bounding box is inside the current bounding box. If one of the bounding boxes is invalid the result is always false.

Parameters

boundingBox

The bounding box to test inclusion

Returns

bool Wether boundingBox is in the bounding box.

depth()

float tlp::BoundingBox::depth ( ) const

inline

Returns the depth of the bounding box An assertion is raised in debug mode if the bounding box is not valid.

Definition at line 122 of file BoundingBox.h.

expand() [1/2]

void tlp::BoundingBox::expand

(

const tlp::Vec3f &

coord

)

Expands the bounding box to one containing the vector passed as parameter. If the parameter is inside the bounding box, it remains unchanged.

Parameters

coord

A point in the 3D space we want the bounding box to encompass.

Returns

void

expand() [2/2]

void tlp::BoundingBox::expand	(	const tlp::BoundingBox &	bb,
		bool	noCheck = false
	)

Expands the bounding box to one containing the bounding box passed as parameter. If the parameter is inside the bounding box, it remains unchanged.

Parameters

bb	A bounding box.

Returns

void

getCompleteBB()

void tlp::BoundingBox::getCompleteBB

(

Vec3f

bb[8]

)

const

The vector passed as parameter is modified to contain the 8 points of the bounding box. The points are, in order : 0: lower leftmost closest point (the bounding box's minimum) 1: lower rightmost closest point 2: highest rightmost closest point 3: highest leftmost closest point 4: lower rightmost farthest point 5: lower rightmost farthest point 6: highest rightmost farthest point 7: highest leftmost farthest point.

Crude ASCII art again, sorry for your eyes.

   6_________ 7
   /|       /|
  / |      / |
3/__|_____/2 |
 |  |_____|__|
 |  /4    |  /5
 | /      | /
 |/_______|/
 0        1

Parameters

bb	A vector in which to put the points of the bounding box.

Returns

void

height()

float tlp::BoundingBox::height ( ) const

inline

Returns the height of the bounding box An assertion is raised in debug mode if the bounding box is not valid.

Definition at line 112 of file BoundingBox.h.

intersect() [1/2]

bool tlp::BoundingBox::intersect

(

const tlp::BoundingBox &

boundingBox

)

const

Checks if the given bounding box intersect the current one. If one of the bounding box is invalid return false.

Parameters

boundingBox

The bounding box to compare with.

Returns

bool Wether the bounding boxes intersect.

intersect() [2/2]

bool tlp::BoundingBox::intersect	(	const Vec3f &	segStart,
		const Vec3f &	segEnd
	)		const

Checks if the bounding box intersects a given line segment. If the bounding box is invalid the result is always false.

Parameters

segStart	the start point of the line segment on which to check intersection
segEnd	the end point of the line segment on which to check intersection

Returns

bool Wether the line segment intersects the bounding box

isValid()

bool tlp::BoundingBox::isValid

(

)

const

Checks whether the bounding box's lowest point is less than it's highest point. "Less Than" means axis-by-axis comparison, i.e. x1 < x2 && y1 < y2 && z1 < z2.

Returns

bool Whether this bounding box is valid.

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scale()

void tlp::BoundingBox::scale

(

const tlp::Vec3f &

factor

)

Scales the bounding box, i.e. multiplying its components by a vector passed as parameter.

Parameters

factor

The factor vector to scale this bounding box by.

Returns

void

translate()

void tlp::BoundingBox::translate

(

const tlp::Vec3f &

vec

)

Translates the bounding box by the displacement given by the vector passed as parameter.

Parameters

vec	The displacement vector in 3D space to translate this bounding box by.

Returns

void

width()

float tlp::BoundingBox::width ( ) const

inline

Returns the width of the bounding box An assertion is raised in debug mode if the BoundingBox is not valid.

Definition at line 102 of file BoundingBox.h.