SLPlane Class Reference

Defines a plane in 3D space with the equation ax + by + cy + d = 0. More...

#include <SLPlane.h>

Public Member Functions
	SLPlane (const SLVec3f &v1, const SLVec3f &v2, const SLVec3f &v3)
	SLPlane ()
	~SLPlane ()
void	setPoints (const SLVec3f &v1, const SLVec3f &v2, const SLVec3f &v3)
void	setNormalAndPoint (const SLVec3f &N, const SLVec3f &P)
void	setCoefficients (const SLfloat A, const SLfloat B, const SLfloat C, const SLfloat D)
SLfloat	distToPoint (const SLVec3f &p)
	Returns distance between a point P and the plane. More...
void	print (const char *name)

Public Attributes
SLVec3f	N
	plane normal More...
SLfloat	d
	d = -(ax+by+cy) = -normal.dot(point) More...

Detailed Description

Defines a plane in 3D space with the equation ax + by + cy + d = 0.

SLPlane defines a plane in 3D space with the equation ax + by + cy + d = 0 where [a,b,c] is the plane normal and d is the distance from [0,0,0]. The class is used to define the 6 planes of the view frustum.

Definition at line 24 of file SLPlane.h.

Constructor & Destructor Documentation

SLPlane() [1/2]

SLPlane::SLPlane	(	const SLVec3f &	v0,
		const SLVec3f &	v1,
		const SLVec3f &	v2
	)

SLPlane::SLPlane ctor with 3 points

Definition at line 16 of file SLPlane.cpp.

{
    setPoints(v0, v1, v2);
}

SLPlane() [2/2]

SLPlane::SLPlane ( )

inline

Definition at line 30 of file SLPlane.h.

    {
        N.set(0, 0, 1);
        d = 0.0f;
    }

~SLPlane()

SLPlane::~SLPlane ( )

inline

Definition at line 35 of file SLPlane.h.

{ ; }

Member Function Documentation

distToPoint()

SLfloat SLPlane::distToPoint ( const SLVec3f &  p )

inline

Returns distance between a point P and the plane.

Definition at line 51 of file SLPlane.h.

{ return (d + N.dot(p)); }

print()

void SLPlane::print

(

const char *

name

)

SLPlane::print prints the normal and the coefficent d

Definition at line 71 of file SLPlane.cpp.

{
    SLMATH_LOG("Plane(%s: a=%4.3f, b=%4.3f, c=%4.3f)",
               name,
               N.x,
               N.y,
               N.z);
}

setCoefficients()

void SLPlane::setCoefficients	(	const SLfloat	A,
		const SLfloat	B,
		const SLfloat	C,
		const SLfloat	D
	)

SLPlane::setByCoefficients defines the plane by the coefficient A,B,C & D

Definition at line 50 of file SLPlane.cpp.

{
    // set the normal vector
    N.set(A, B, C);
 
    //compute the lenght of the vector
    SLfloat len = N.length();
 
    // normalize the vector
    N.set(N.x / len, N.y / len, N.z / len);
 
    // and divide d by th length as well
    d = D / len;
}

setNormalAndPoint()

void SLPlane::setNormalAndPoint	(	const SLVec3f &	normal,
		const SLVec3f &	P
	)

SLPlane::setByNormalAndPoint defines the plane by a normal N and a point P

Definition at line 40 of file SLPlane.cpp.

{
    N.set(normal);
    N.normalize();
    d = -N.dot(P);
}

setPoints()

void SLPlane::setPoints	(	const SLVec3f &	v0,
		const SLVec3f &	v1,
		const SLVec3f &	v2
	)

SLPlane::setFromPoints set the plane from 3 points

Definition at line 26 of file SLPlane.cpp.

{
    SLVec3f edge1(v1 - v0);
    SLVec3f edge2(v2 - v0);
    N.cross(edge1, edge2);
    N.normalize();
    d = -N.dot(v0);
}

Member Data Documentation

d

SLfloat SLPlane::d

d = -(ax+by+cy) = -normal.dot(point)

Definition at line 38 of file SLPlane.h.

N

SLVec3f SLPlane::N

plane normal

Definition at line 37 of file SLPlane.h.

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The documentation for this class was generated from the following files:

• SLPlane.h
• SLPlane.cpp