#include "GeomExport.h"
#include <WTypes.h>
#include "point2.h"
#include "point3.h"

Functions
GEOMEXPORT Point3	BaryCoords (Point3 p0, Point3 p1, Point3 p2, Point3 p)
	Calculates the barycentric coordinates of the point p in 3-dimensional space according to a reference triangle indicated by its three vertices p0, p1 and p2.
GEOMEXPORT Point3	BaryCoords (Point2 p0, Point2 p1, Point2 p2, Point2 p)
	Calculates the barycentric coordinates of the point p in 2-dimensional space according to a reference triangle indicated by its three vertices p0, p1 and p2.
GEOMEXPORT BOOL	RayHitsBox (Ray &ray, Box3 &b)
	Checks if the given ray intersects a three-dimensional box.
GEOMEXPORT float	DistPtToLine (Point2 p0, Point2 p1, Point2 *q)
	Calculates the distance of a given point from a line in two dimensions.
GEOMEXPORT float	Dist3DPtToLine (Point3 p0, Point3 p1, Point3 *q)
	Calculates the distance of a given point from a line in three dimensions.
GEOMEXPORT void	ComputeBumpVectors (const Point3 tv[3], const Point3 v[3], Point3 bvec[3])
GEOMEXPORT void	ComputeBumpVec2D (int axis, const Point3 tv[3], const Point3 v[3], Point3 bvec[2])
	Computes the 2 Bump basis vectors from the UV, VW, or WU at a triangle.
GEOMEXPORT void	ComputeTangentAndBinormal (const Point3 tv[3], const Point3 v[3], Point3 bvec[2])
	Computes the bump basis vector for the U texture channel (called the tangent), and the cross product of the surface normal with the tangent (called the binormal).
GEOMEXPORT ULONG	CompressNormal (Point3 p)
	Low precision compression of a vector from 12 bytes to 4 bytes.
GEOMEXPORT Point3	DeCompressNormal (ULONG n)
	Decompresses a vector that was compressed using CompressNormal().
GEOMEXPORT void	ArbAxis (const Point3 &zAxis, Matrix3 &matrix)
	Creates an arbitrary axis system given an up vector that conforms to the AutoCAD algorithm.

Function Documentation

GEOMEXPORT Point3 BaryCoords	(	Point3	p0,
		Point3	p1,
		Point3	p2,
		Point3	p
	)

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Calculates the barycentric coordinates of the point p in 3-dimensional space according to a reference triangle indicated by its three vertices p0, p1 and p2.

Parameters:

p0,p1,p2	The three vertices of the reference triangle in 3-dimensional space.
p	The point for which the barycentric coordinates should be calculated.

Returns:: Barycentric coordinates of point p.

See also:: BaryCoords(Point2, Point2, Point2, Point2)

GEOMEXPORT Point3 BaryCoords	(	Point2	p0,
		Point2	p1,
		Point2	p2,
		Point2	p
	)

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Calculates the barycentric coordinates of the point p in 2-dimensional space according to a reference triangle indicated by its three vertices p0, p1 and p2.

Parameters:

p0,p1,p2	The three vertices of the reference triangle in 2-dimensional space.
p	The point for which the barycentric coordinates should be calculated.

Returns:: Barycentric coordinates of point p.

See also:: BaryCoords(Point3, Point3, Point3, Point3)

GEOMEXPORT BOOL RayHitsBox	(	Ray &	ray,
		Box3 &	b
	)

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Checks if the given ray intersects a three-dimensional box.

Parameters:

ray	The ray
b	The box

Returns:: true if the ray intersects the box, false otherwise.

GEOMEXPORT float DistPtToLine	(	Point2 *	p0,
		Point2 *	p1,
		Point2 *	q
	)

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Calculates the distance of a given point from a line in two dimensions.

Parameters:

p0,p1	Pointers to the two 2-dimensional points with which the line is defined.
q	Pointer to the 2-dimensional point whose distance from the line should be calculated.

Returns:: The distance of the point from the line.

GEOMEXPORT float Dist3DPtToLine	(	Point3 *	p0,
		Point3 *	p1,
		Point3 *	q
	)

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Calculates the distance of a given point from a line in three dimensions.

Parameters:

p0,p1	Pointers to the two 3-dimensional points with which the line is defined.
q	Pointer to the 3-dimensional point whose distance from the line should be calculated.

Returns:: The distance of the point from the line.

GEOMEXPORT void ComputeBumpVectors	(	const Point3	tv[3],
		const Point3	v[3],
		Point3	bvec[3]
	)

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Deprecated:: Do not use this function.

Use ComputeBumpVec2D() instead. This is here for compatibility only.

Computes the 3 bump basis vectors from the UVW coordinates of the triangle.

Parameters:

	tv	Texture coordinates at 3 triangle vertices
	v	Coordinates of triangle vertices (usually in camera space).
[out]	bvec	The 3 bump basis vectors (normalized) corresponding to the U,V,and W axes.

GEOMEXPORT void ComputeBumpVec2D	(	int	axis,
		const Point3	tv[3],
		const Point3	v[3],
		Point3	bvec[2]
	)

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Computes the 2 Bump basis vectors from the UV, VW, or WU at a triangle.

Parameters:

	axis	Either AXIS_UV, AXIS_VW, or AXIS_WU .
	tv	Texture coordinates at 3 triangle vertices.
	v	Coordinates of triangle vertices (usually in camera space)
[out]	bvec	The 2 normalized bump basis vectors corresponding to the specified axes.

Note:: This is the recommended way to compute bump vectors instead of ComputeBumpVectors() which can give erroneous results.

GEOMEXPORT void ComputeTangentAndBinormal	(	const Point3	tv[3],
		const Point3	v[3],
		Point3	bvec[2]
	)

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Computes the bump basis vector for the U texture channel (called the tangent), and the cross product of the surface normal with the tangent (called the binormal).

These along with the surface normal are used as the basis vectors for normal mapping.

Parameters:

	tv	Texture coordinates at 3 triangle vertices.
	v	Coordinates of triangle vertices (usually in camera space)
[out]	bvec	The 2 normalized bump basis vectors corresponding to the specified axes.

GEOMEXPORT ULONG CompressNormal ( Point3 p )

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Low precision compression of a vector from 12 bytes to 4 bytes.

Only accurate to 1 part in 512. This is commonly used to compress normals. The vector has to be <= 1.0 in length.

Parameters:

p	The decompressed vector.

Returns:: The 4-byte long compressed value of p

See also:: DeCompressNormal(), BMM_CHAN_NORMAL

GEOMEXPORT Point3 DeCompressNormal ( ULONG n )

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Decompresses a vector that was compressed using CompressNormal().

This function may also be used to decompress a surface normal from the G-Buffer using the BMM_CHAN_NORMAL channel. The decompressed vector has absolute error <.001 in each component.

Parameters:

n	A vector compressed using CompressNormal()

Returns:: A normalized decompressed normal vector

See also:: CompressNormal()

GEOMEXPORT void ArbAxis	(	const Point3 &	zAxis,
		Matrix3 &	matrix
	)

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Creates an arbitrary axis system given an up vector that conforms to the AutoCAD algorithm.

Parameters:

	zAxis	The up vector.
[out]	matrix	The new axis system.

gutil.h File Reference

Functions

Function Documentation