Opcode::Triangle Class Reference

#include <Opcode.h>

Public Member Functions
inline_	Triangle ()
	Constructor. More...
inline_	Triangle (const Point &p0, const Point &p1, const Point &p2)
	Constructor. More...
inline_	Triangle (const Triangle &triangle)
	Copy constructor. More...
inline_	~Triangle ()
	Destructor. More...
void	Flip ()
float	Area () const
float	Perimeter () const
float	Compacity () const
void	Normal (Point &normal) const
void	DenormalizedNormal (Point &normal) const
void	Center (Point &center) const
inline_ Plane	PlaneEquation () const
PartVal	TestAgainstPlane (const Plane &plane, float epsilon) const
void	ComputeMoment (Moment &m)
float	MinEdgeLength () const
float	MaxEdgeLength () const
void	ComputePoint (float u, float v, Point &pt, udword *nearvtx=null) const
void	Inflate (float fat_coeff, bool constant_border)

Public Attributes
Point	mVerts [3]
	Vertices. More...

Detailed Description

Definition at line 31 of file Opcode.h.

Constructor & Destructor Documentation

inline_ Opcode::Triangle::Triangle ( )

inline

Constructor.

Definition at line 35 of file Opcode.h.

{

inline_ Opcode::Triangle::Triangle ( const Point &  p0, const Point &  p1, const Point &  p2  )

inline

Constructor.

Definition at line 37 of file Opcode.h.

{

inline_ Opcode::Triangle::Triangle ( const Triangle &  triangle)

inline

Copy constructor.

Definition at line 39 of file Opcode.h.

    {



                                        
        #include "Ice/IceAxes.h" 

inline_ Opcode::Triangle::~Triangle ( )

inline

Destructor.

Definition at line 46 of file Opcode.h.

Member Function Documentation

float Triangle::Area

(

)

const

Computes the triangle area.

Returns

the area

Definition at line 57 of file IceTriangle.cpp.

{
    const Point& p0 = mVerts[0];
    const Point& p1 = mVerts[1];
    const Point& p2 = mVerts[2];
    return ((p0 - p1)^(p0 - p2)).Magnitude() * 0.5f;
}

void Triangle::Center

(

Point &

center)

const

Computes the triangle center.

Parameters

center

[out] the computed center

Definition at line 128 of file IceTriangle.cpp.

Referenced by Inflate().

{
    const Point& p0 = mVerts[0];
    const Point& p1 = mVerts[1];
    const Point& p2 = mVerts[2];
    center = (p0 + p1 + p2)*INV3;
}

float Triangle::Compacity

(

)

const

Computes the triangle compacity.

Returns

the compacity

Definition at line 87 of file IceTriangle.cpp.

{
    float P = Perimeter();
    if(P==0.0f) return 0.0f;
    return (4.0f*PI*Area()/(P*P));
}

void Opcode::Triangle::ComputeMoment

(

Moment &

m)

void Triangle::ComputePoint	(	float	u,
		float	v,
		Point &	pt,
		udword *	nearvtx = null
	)		const

Computes a point on the triangle according to the stabbing information.

Parameters

u,v	[in] point's barycentric coordinates
pt	[out] point on triangle
nearvtx	[out] index of nearest vertex

Definition at line 252 of file IceTriangle.cpp.

{
    // Compute point coordinates
    pt = (1.0f - u - v)*mVerts[0] + u*mVerts[1] + v*mVerts[2];

    // Compute nearest vertex if needed
    if(nearvtx)
    {
        // Compute distance vector
        Point d(mVerts[0].SquareDistance(pt),   // Distance^2 from vertex 0 to point on the face
                mVerts[1].SquareDistance(pt),   // Distance^2 from vertex 1 to point on the face
                mVerts[2].SquareDistance(pt));  // Distance^2 from vertex 2 to point on the face

        // Get smallest distance
        *nearvtx = d.SmallestAxis();
    }
}

void Triangle::DenormalizedNormal

(

Point &

normal)

const

Computes the triangle denormalized normal.

Parameters

normal

[out] the computed normal

Definition at line 114 of file IceTriangle.cpp.

{
    const Point& p0 = mVerts[0];
    const Point& p1 = mVerts[1];
    const Point& p2 = mVerts[2];
    normal = ((p0 - p1)^(p0 - p2));
}

void Triangle::Flip

(

)

Flips the winding order.

Definition at line 44 of file IceTriangle.cpp.

{
    Point Tmp = mVerts[1];
    mVerts[1] = mVerts[2];
    mVerts[2] = Tmp;
}

void Triangle::Inflate	(	float	fat_coeff,
		bool	constant_border
	)

Definition at line 270 of file IceTriangle.cpp.

References Center(), i, mVerts, and Opcode::Point::Normalize().

{
    // Compute triangle center
    Point TriangleCenter;
    Center(TriangleCenter);

    // Don't normalize?
    // Normalize => add a constant border, regardless of triangle size
    // Don't => add more to big triangles
    for(udword i=0;i<3;i++)
    {
        Point v = mVerts[i] - TriangleCenter;

        if(constant_border) v.Normalize();

        mVerts[i] += v * fat_coeff;
    }
}

float Triangle::MaxEdgeLength

(

)

const

Computes the triangle's largest edge length.

Returns

the largest edge length

Definition at line 232 of file IceTriangle.cpp.

{
    float Max = MIN_FLOAT;
    float Length01 = mVerts[0].Distance(mVerts[1]);
    float Length02 = mVerts[0].Distance(mVerts[2]);
    float Length12 = mVerts[1].Distance(mVerts[2]);
    if(Length01 > Max)  Max = Length01;
    if(Length02 > Max)  Max = Length02;
    if(Length12 > Max)  Max = Length12;
    return Max;
}

float Triangle::MinEdgeLength

(

)

const

Computes the triangle moment.

Parameters

m	[out] the moment Computes the triangle's smallest edge length.

Returns

the smallest edge length

Definition at line 214 of file IceTriangle.cpp.

{
    float Min = MAX_FLOAT;
    float Length01 = mVerts[0].Distance(mVerts[1]);
    float Length02 = mVerts[0].Distance(mVerts[2]);
    float Length12 = mVerts[1].Distance(mVerts[2]);
    if(Length01 < Min)  Min = Length01;
    if(Length02 < Min)  Min = Length02;
    if(Length12 < Min)  Min = Length12;
    return Min;
}

void Triangle::Normal

(

Point &

normal)

const

Computes the triangle normal.

Parameters

normal

[out] the computed normal

Definition at line 100 of file IceTriangle.cpp.

{
    const Point& p0 = mVerts[0];
    const Point& p1 = mVerts[1];
    const Point& p2 = mVerts[2];
    normal = ((p0 - p1)^(p0 - p2)).Normalize();
}

float Triangle::Perimeter

(

)

const

Computes the triangle perimeter.

Returns

the perimeter

Definition at line 71 of file IceTriangle.cpp.

{
    const Point& p0 = mVerts[0];
    const Point& p1 = mVerts[1];
    const Point& p2 = mVerts[2];
    return      p0.Distance(p1)
            +   p0.Distance(p2)
            +   p1.Distance(p2);
}

inline_ Plane Opcode::Triangle::PlaneEquation ( ) const

inline

Definition at line 58 of file Opcode.h.

PartVal Triangle::TestAgainstPlane	(	const Plane &	plane,
		float	epsilon
	)		const

Definition at line 136 of file IceTriangle.cpp.

References i, mVerts, Opcode::TRI_FORCEDWORD, Opcode::TRI_INTERSECT, Opcode::TRI_MINUS_SPACE, Opcode::TRI_ON_PLANE, Opcode::TRI_PLUS_SPACE, and VPlaneSideEps().

{
    bool Pos = false, Neg = false;

    // Loop through all vertices
    for(udword i=0;i<3;i++)
    {
        // Compute side:
        sdword Side = VPlaneSideEps(mVerts[i], plane, epsilon);

                if (Side < 0)   Neg = true;
        else    if (Side > 0)   Pos = true;
    }

            if (!Pos && !Neg)   return TRI_ON_PLANE;
    else    if (Pos && Neg)     return TRI_INTERSECT;
    else    if (Pos && !Neg)    return TRI_PLUS_SPACE;
    else    if (!Pos && Neg)    return TRI_MINUS_SPACE;

    // What?!
    return TRI_FORCEDWORD;
}

Member Data Documentation

Point Opcode::Triangle::mVerts[3]

Vertices.

Definition at line 48 of file Opcode.h.

Referenced by Inflate(), and TestAgainstPlane().

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

• src/cmd/collide2/Ice/IceTriangle.h
• src/cmd/collide2/Ice/IceTriangle.cpp