gtkradiant/libs/math/line.h
TTimo 12b372f89c ok
git-svn-id: svn://svn.icculus.org/gtkradiant/GtkRadiant@1 8a3a26a2-13c4-0310-b231-cf6edde360e5
2006-02-10 22:01:20 +00:00

151 lines
3.4 KiB
C++

/*
Copyright (C) 2001-2006, William Joseph.
All Rights Reserved.
This file is part of GtkRadiant.
GtkRadiant is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2 of the License, or
(at your option) any later version.
GtkRadiant is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with GtkRadiant; if not, write to the Free Software
Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
*/
#if !defined(INCLUDED_MATH_LINE_H)
#define INCLUDED_MATH_LINE_H
/// \file
/// \brief Line data types and related operations.
#include "math/vector.h"
#include "math/plane.h"
/// \brief A line segment defined by a start point and and end point.
class Line
{
public:
Vector3 start, end;
Line()
{
}
Line(const Vector3& start_, const Vector3& end_) : start(start_), end(end_)
{
}
};
inline Vector3 line_closest_point(const Line& line, const Vector3& point)
{
Vector3 v = line.end - line.start;
Vector3 w = point - line.start;
double c1 = vector3_dot(w,v);
if ( c1 <= 0 )
return line.start;
double c2 = vector3_dot(v,v);
if ( c2 <= c1 )
return line.end;
return Vector3(line.start + v * (c1 / c2));
}
class Segment
{
public:
Vector3 origin, extents;
Segment()
{
}
Segment(const Vector3& origin_, const Vector3& extents_) :
origin(origin_), extents(extents_)
{
}
};
inline Segment segment_for_startend(const Vector3& start, const Vector3& end)
{
Segment segment;
segment.origin = vector3_mid(start, end);
segment.extents = vector3_subtracted(end, segment.origin);
return segment;
}
inline unsigned int segment_classify_plane(const Segment& segment, const Plane3& plane)
{
double distance_origin = vector3_dot(plane.normal(), segment.origin) + plane.dist();
if (fabs(distance_origin) < fabs(vector3_dot(plane.normal(), segment.extents)))
{
return 1; // partially inside
}
else if (distance_origin < 0)
{
return 2; // totally inside
}
return 0; // totally outside
}
class Ray
{
public:
Vector3 origin, direction;
Ray()
{
}
Ray(const Vector3& origin_, const Vector3& direction_) :
origin(origin_), direction(direction_)
{
}
};
inline Ray ray_for_points(const Vector3& origin, const Vector3& p2)
{
return Ray(origin, vector3_normalised(vector3_subtracted(p2, origin)));
}
inline void ray_transform(Ray& ray, const Matrix4& matrix)
{
matrix4_transform_point(matrix, ray.origin);
matrix4_transform_direction(matrix, ray.direction);
}
// closest-point-on-line
inline double ray_squared_distance_to_point(const Ray& ray, const Vector3& point)
{
return vector3_length_squared(
vector3_subtracted(
point,
vector3_added(
ray.origin,
vector3_scaled(
ray.direction,
vector3_dot(
vector3_subtracted(point, ray.origin),
ray.direction
)
)
)
)
);
}
inline double ray_distance_to_plane(const Ray& ray, const Plane3& plane)
{
return -(vector3_dot(plane.normal(), ray.origin) - plane.dist()) / vector3_dot(ray.direction, plane.normal());
}
#endif