vmap/libs/math/aabb.h
2020-11-17 12:16:16 +01:00

280 lines
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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 );
}
}
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