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GAUGE3D::GPolygon Class Reference

Represents a polygon with an arbitrary number of sides. More...

#include <gauge3d/3dmath/polygon.h>

List of all members.

Public Methods
	GPolygon ()
	Creates a polygon with no sides.
	GPolygon (const GTriangle &triangle)
	Creates a polygon equivalent to the given triangle.
	GPolygon (const GPolygon &other)
	Copy constructor.
	GPolygon (GVector vertices[],int num)
	Creates a polygon with the given vertices.
	~GPolygon ()
	Destructor.
void	GetPlane (GPlane *plane)const
	Gets the plane which the polygon is on. More...
void	Resize (int num,bool copy)
	Change the number of vertices. More...
void	Split (GTriangle triangles[])const
	Splits the polygon into triangles. More...
void	Reverse ()
	Reverses the direction of the vertices. More...
bool	Contains (const GVector &point)
	Returns true if the point is on the polygon.
int8	Intersects (const GLine &line)
	Finds whether or not the line intersects the polygon, and from which side if so. More...
int	NumVertices ()const
	The number of vertices in the polygon.
GVector&	operator[] (int index)
	Array-like access to vertices.
const GVector&	operator[] (int index)const
	Array-like access to vertices.
const GPolygon&	operator= (const GPolygon other)
	Assignment operator.

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Detailed Description

Represents a polygon with an arbitrary number of sides.

I recommend against using this class except when other methods are extremely inconvenient. This class uses dynamic memory, which makes it unsuitable for fast math computations.

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Member Function Documentation

void GAUGE3D::GPolygon::GetPlane ( GPlane * plane ) const

Gets the plane which the polygon is on. Parameters: plane   Points to the location to which to write the plane. Note: The plane will face in the direction from which the vertices of the polygon appear clockwise.

void GAUGE3D::GPolygon::Resize ( int num, bool copy )

Change the number of vertices. Parameters: num   New number of vertices in the polygon. copy   True if the old vertices should be copied into the new list.

void GAUGE3D::GPolygon::Split ( GTriangle triangles[] ) const

Splits the polygon into triangles. Parameters: triangles   An array containing at least the number of vertices minus two triangles. These will be overwritten with the triangles that make up the polygon.

void GAUGE3D::GPolygon::Reverse ( )

Reverses the direction of the vertices. Remarks: This does not reverse the order of the vertices. It just swaps two of the vertices so that clockwise becomes counter-clockwise. This also means that the direction that the polygon faces will be reversed, since that direction is the direction from which the vertices appear in clockwise order.

int8 GAUGE3D::GPolygon::Intersects ( const GLine & line )

Finds whether or not the line intersects the polygon, and from which side if so. Parameters: line   The line with which to test for intersection. Returns: 0 if there is no intersection, 1 if the line hits the front of the polygon, or -1 if the line hits the back of the polygon. (the front side is the side from which the vertices of the polygon appear clockwise.) Remarks: This function is very fast. It is actually faster than Contains(), so if you want to find the point of intersection, first call this and then call GPlane::FindIntersection if necessary.

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

• gauge3d/3dmath/polygon.h

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