gtkradiant/libs/math/aabb.h
spog 0d98822b3c refactored vector classes to avoid reinterpret_cast
git-svn-id: svn://svn.icculus.org/gtkradiant/GtkRadiant/trunk@60 8a3a26a2-13c4-0310-b231-cf6edde360e5
2006-05-09 22:07:29 +00:00

331 lines
10 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_AABB_H)
#define INCLUDED_MATH_AABB_H
/// \file
/// \brief Axis-aligned bounding-box data types and related operations.
#include "math/matrix.h"
#include "math/plane.h"
class AABB
{
public:
Vector3 origin, extents;
AABB() : origin(0, 0, 0), extents(-1,-1,-1)
{
}
AABB(const Vector3& origin_, const Vector3& extents_) :
origin(origin_), extents(extents_)
{
}
};
const float c_aabb_max = FLT_MAX;
inline bool extents_valid(float f)
{
return f >= 0.0f && f <= c_aabb_max;
}
inline bool origin_valid(float f)
{
return f >= -c_aabb_max && f <= c_aabb_max;
}
inline bool aabb_valid(const AABB& aabb)
{
return origin_valid(aabb.origin[0])
&& origin_valid(aabb.origin[1])
&& origin_valid(aabb.origin[2])
&& extents_valid(aabb.extents[0])
&& extents_valid(aabb.extents[1])
&& extents_valid(aabb.extents[2]);
}
inline AABB aabb_for_minmax(const Vector3& min, const Vector3& max)
{
AABB aabb;
aabb.origin = vector3_mid(min, max);
aabb.extents = vector3_subtracted(max, aabb.origin);
return aabb;
}
template<typename Index>
class AABBExtend
{
public:
static void apply(AABB& aabb, const Vector3& point)
{
float displacement = point[Index::VALUE] - aabb.origin[Index::VALUE];
float half_difference = static_cast<float>(0.5 * (fabs(displacement) - aabb.extents[Index::VALUE]));
if(half_difference > 0.0f)
{
aabb.origin[Index::VALUE] += (displacement >= 0.0f) ? half_difference : -half_difference;
aabb.extents[Index::VALUE] += half_difference;
}
}
static void apply(AABB& aabb, const AABB& other)
{
float displacement = other.origin[Index::VALUE] - aabb.origin[Index::VALUE];
float difference = other.extents[Index::VALUE] - aabb.extents[Index::VALUE];
if(fabs(displacement) > fabs(difference))
{
float half_difference = static_cast<float>(0.5 * (fabs(displacement) + difference));
if(half_difference > 0.0f)
{
aabb.origin[Index::VALUE] += (displacement >= 0.0f) ? half_difference : -half_difference;
aabb.extents[Index::VALUE] += half_difference;
}
}
else if(difference > 0.0f)
{
aabb.origin[Index::VALUE] = other.origin[Index::VALUE];
aabb.extents[Index::VALUE] = other.extents[Index::VALUE];
}
}
};
inline void aabb_extend_by_point(AABB& aabb, const Vector3& point)
{
AABBExtend< IntegralConstant<0> >::apply(aabb, point);
AABBExtend< IntegralConstant<1> >::apply(aabb, point);
AABBExtend< IntegralConstant<2> >::apply(aabb, point);
}
inline void aabb_extend_by_point_safe(AABB& aabb, const Vector3& point)
{
if(aabb_valid(aabb))
{
aabb_extend_by_point(aabb, point);
}
else
{
aabb.origin = point;
aabb.extents = Vector3(0, 0, 0);
}
}
class AABBExtendByPoint
{
AABB& m_aabb;
public:
AABBExtendByPoint(AABB& aabb) : m_aabb(aabb)
{
}
void operator()(const Vector3& point) const
{
aabb_extend_by_point_safe(m_aabb, point);
}
};
inline void aabb_extend_by_aabb(AABB& aabb, const AABB& other)
{
AABBExtend< IntegralConstant<0> >::apply(aabb, other);
AABBExtend< IntegralConstant<1> >::apply(aabb, other);
AABBExtend< IntegralConstant<2> >::apply(aabb, other);
}
inline void aabb_extend_by_aabb_safe(AABB& aabb, const AABB& other)
{
if(aabb_valid(aabb) && aabb_valid(other))
{
aabb_extend_by_aabb(aabb, other);
}
else if(aabb_valid(other))
{
aabb = other;
}
}
inline void aabb_extend_by_vec3(AABB& aabb, const Vector3& extension)
{
vector3_add(aabb.extents, extension);
}
template<typename Index>
inline bool aabb_intersects_point_dimension(const AABB& aabb, const Vector3& point)
{
return fabs(point[Index::VALUE] - aabb.origin[Index::VALUE]) < aabb.extents[Index::VALUE];
}
inline bool aabb_intersects_point(const AABB& aabb, const Vector3& point)
{
return aabb_intersects_point_dimension< IntegralConstant<0> >(aabb, point)
&& aabb_intersects_point_dimension< IntegralConstant<1> >(aabb, point)
&& aabb_intersects_point_dimension< IntegralConstant<2> >(aabb, point);
}
template<typename Index>
inline bool aabb_intersects_aabb_dimension(const AABB& aabb, const AABB& other)
{
return fabs(other.origin[Index::VALUE] - aabb.origin[Index::VALUE]) < (aabb.extents[Index::VALUE] + other.extents[Index::VALUE]);
}
inline bool aabb_intersects_aabb(const AABB& aabb, const AABB& other)
{
return aabb_intersects_aabb_dimension< IntegralConstant<0> >(aabb, other)
&& aabb_intersects_aabb_dimension< IntegralConstant<1> >(aabb, other)
&& aabb_intersects_aabb_dimension< IntegralConstant<2> >(aabb, other);
}
inline unsigned int aabb_classify_plane(const AABB& aabb, const Plane3& plane)
{
double distance_origin = vector3_dot(plane.normal(), aabb.origin) + plane.dist();
if(fabs(distance_origin) < (fabs(plane.a * aabb.extents[0])
+ fabs(plane.b * aabb.extents[1])
+ fabs(plane.c * aabb.extents[2])))
{
return 1; // partially inside
}
else if (distance_origin < 0)
{
return 2; // totally inside
}
return 0; // totally outside
}
inline unsigned int aabb_oriented_classify_plane(const AABB& aabb, const Matrix4& transform, const Plane3& plane)
{
double distance_origin = vector3_dot(plane.normal(), aabb.origin) + plane.dist();
if(fabs(distance_origin) < (fabs(aabb.extents[0] * vector3_dot(plane.normal(), vector4_to_vector3(transform.x())))
+ fabs(aabb.extents[1] * vector3_dot(plane.normal(), vector4_to_vector3(transform.y())))
+ fabs(aabb.extents[2] * vector3_dot(plane.normal(), vector4_to_vector3(transform.z())))))
{
return 1; // partially inside
}
else if (distance_origin < 0)
{
return 2; // totally inside
}
return 0; // totally outside
}
inline void aabb_corners(const AABB& aabb, Vector3 corners[8])
{
Vector3 min(vector3_subtracted(aabb.origin, aabb.extents));
Vector3 max(vector3_added(aabb.origin, aabb.extents));
corners[0] = Vector3(min[0], max[1], max[2]);
corners[1] = Vector3(max[0], max[1], max[2]);
corners[2] = Vector3(max[0], min[1], max[2]);
corners[3] = Vector3(min[0], min[1], max[2]);
corners[4] = Vector3(min[0], max[1], min[2]);
corners[5] = Vector3(max[0], max[1], min[2]);
corners[6] = Vector3(max[0], min[1], min[2]);
corners[7] = Vector3(min[0], min[1], min[2]);
}
inline void aabb_corners_oriented(const AABB& aabb, const Matrix4& rotation, Vector3 corners[8])
{
Vector3 x = vector4_to_vector3(rotation.x()) * aabb.extents.x();
Vector3 y = vector4_to_vector3(rotation.y()) * aabb.extents.y();
Vector3 z = vector4_to_vector3(rotation.z()) * aabb.extents.z();
corners[0] = aabb.origin + -x + y + z;
corners[1] = aabb.origin + x + y + z;
corners[2] = aabb.origin + x + -y + z;
corners[3] = aabb.origin + -x + -y + z;
corners[4] = aabb.origin + -x + y + -z;
corners[5] = aabb.origin + x + y + -z;
corners[6] = aabb.origin + x + -y + -z;
corners[7] = aabb.origin + -x + -y + -z;
}
inline void aabb_planes(const AABB& aabb, Plane3 planes[6])
{
planes[0] = Plane3(g_vector3_axes[0], aabb.origin[0] + aabb.extents[0]);
planes[1] = Plane3(vector3_negated(g_vector3_axes[0]), -(aabb.origin[0] - aabb.extents[0]));
planes[2] = Plane3(g_vector3_axes[1], aabb.origin[1] + aabb.extents[1]);
planes[3] = Plane3(vector3_negated(g_vector3_axes[1]), -(aabb.origin[1] - aabb.extents[1]));
planes[4] = Plane3(g_vector3_axes[2], aabb.origin[2] + aabb.extents[2]);
planes[5] = Plane3(vector3_negated(g_vector3_axes[2]), -(aabb.origin[2] - aabb.extents[2]));
}
inline void aabb_planes_oriented(const AABB& aabb, const Matrix4& rotation, Plane3 planes[6])
{
double x = vector3_dot(vector4_to_vector3(rotation.x()), aabb.origin);
double y = vector3_dot(vector4_to_vector3(rotation.y()), aabb.origin);
double z = vector3_dot(vector4_to_vector3(rotation.z()), aabb.origin);
planes[0] = Plane3(vector4_to_vector3(rotation.x()), x + aabb.extents[0]);
planes[1] = Plane3(-vector4_to_vector3(rotation.x()), -(x - aabb.extents[0]));
planes[2] = Plane3(vector4_to_vector3(rotation.y()), y + aabb.extents[1]);
planes[3] = Plane3(-vector4_to_vector3(rotation.y()), -(y - aabb.extents[1]));
planes[4] = Plane3(vector4_to_vector3(rotation.z()), z + aabb.extents[2]);
planes[5] = Plane3(-vector4_to_vector3(rotation.z()), -(z - aabb.extents[2]));
}
const Vector3 aabb_normals[6] = {
Vector3( 1, 0, 0 ),
Vector3( 0, 1, 0 ),
Vector3( 0, 0, 1 ),
Vector3(-1, 0, 0 ),
Vector3( 0,-1, 0 ),
Vector3( 0, 0,-1 ),
};
const float aabb_texcoord_topleft[2] = { 0, 0 };
const float aabb_texcoord_topright[2] = { 1, 0 };
const float aabb_texcoord_botleft[2] = { 0, 1 };
const float aabb_texcoord_botright[2] = { 1, 1 };
inline AABB aabb_for_oriented_aabb(const AABB& aabb, const Matrix4& transform)
{
return AABB(
matrix4_transformed_point(transform, aabb.origin),
Vector3(
static_cast<float>(fabs(transform[0] * aabb.extents[0])
+ fabs(transform[4] * aabb.extents[1])
+ fabs(transform[8] * aabb.extents[2])),
static_cast<float>(fabs(transform[1] * aabb.extents[0])
+ fabs(transform[5] * aabb.extents[1])
+ fabs(transform[9] * aabb.extents[2])),
static_cast<float>(fabs(transform[2] * aabb.extents[0])
+ fabs(transform[6] * aabb.extents[1])
+ fabs(transform[10] * aabb.extents[2]))
)
);
}
inline AABB aabb_for_oriented_aabb_safe(const AABB& aabb, const Matrix4& transform)
{
if(aabb_valid(aabb))
{
return aabb_for_oriented_aabb(aabb, transform);
}
return aabb;
}
inline AABB aabb_infinite()
{
return AABB(Vector3(0, 0, 0), Vector3(c_aabb_max, c_aabb_max, c_aabb_max));
}
#endif