godot/core/math/aabb.h
2016-01-01 11:50:53 -02:00

379 lines
11 KiB
C++

/*************************************************************************/
/* aabb.h */
/*************************************************************************/
/* This file is part of: */
/* GODOT ENGINE */
/* http://www.godotengine.org */
/*************************************************************************/
/* Copyright (c) 2007-2016 Juan Linietsky, Ariel Manzur. */
/* */
/* Permission is hereby granted, free of charge, to any person obtaining */
/* a copy of this software and associated documentation files (the */
/* "Software"), to deal in the Software without restriction, including */
/* without limitation the rights to use, copy, modify, merge, publish, */
/* distribute, sublicense, and/or sell copies of the Software, and to */
/* permit persons to whom the Software is furnished to do so, subject to */
/* the following conditions: */
/* */
/* The above copyright notice and this permission notice shall be */
/* included in all copies or substantial portions of the Software. */
/* */
/* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, */
/* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF */
/* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.*/
/* IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY */
/* CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, */
/* TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE */
/* SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. */
/*************************************************************************/
#ifndef AABB_H
#define AABB_H
#include "vector3.h"
#include "plane.h"
/**
* AABB / AABB (Axis Aligned Bounding Box)
* This is implemented by a point (pos) and the box size
*/
class AABB {
public:
Vector3 pos;
Vector3 size;
float get_area() const; /// get area
_FORCE_INLINE_ bool has_no_area() const {
return (size.x<=CMP_EPSILON || size.y<=CMP_EPSILON || size.z<=CMP_EPSILON);
}
_FORCE_INLINE_ bool has_no_surface() const {
return (size.x<=CMP_EPSILON && size.y<=CMP_EPSILON && size.z<=CMP_EPSILON);
}
const Vector3& get_pos() const { return pos; }
void set_pos(const Vector3& p_pos) { pos=p_pos; }
const Vector3& get_size() const { return size; }
void set_size(const Vector3& p_size) { size=p_size; }
bool operator==(const AABB& p_rval) const;
bool operator!=(const AABB& p_rval) const;
_FORCE_INLINE_ bool intersects(const AABB& p_aabb) const; /// Both AABBs overlap
_FORCE_INLINE_ bool encloses(const AABB & p_aabb) const; /// p_aabb is completely inside this
AABB merge(const AABB& p_with) const;
void merge_with(const AABB& p_aabb); ///merge with another AABB
AABB intersection(const AABB& p_aabb) const; ///get box where two intersect, empty if no intersection occurs
bool intersects_segment(const Vector3& p_from, const Vector3& p_to,Vector3* r_clip=NULL,Vector3* r_normal=NULL) const;
bool intersects_ray(const Vector3& p_from, const Vector3& p_dir,Vector3* r_clip=NULL,Vector3* r_normal=NULL) const;
_FORCE_INLINE_ bool smits_intersect_ray(const Vector3 &from,const Vector3& p_dir, float t0, float t1) const;
_FORCE_INLINE_ bool intersects_convex_shape(const Plane *p_plane, int p_plane_count) const;
bool intersects_plane(const Plane &p_plane) const;
_FORCE_INLINE_ bool has_point(const Vector3& p_point) const;
_FORCE_INLINE_ Vector3 get_support(const Vector3& p_normal) const;
Vector3 get_longest_axis() const;
int get_longest_axis_index() const;
_FORCE_INLINE_ real_t get_longest_axis_size() const;
Vector3 get_shortest_axis() const;
int get_shortest_axis_index() const;
_FORCE_INLINE_ real_t get_shortest_axis_size() const;
AABB grow(real_t p_by) const;
_FORCE_INLINE_ void grow_by(real_t p_amount);
void get_edge(int p_edge,Vector3& r_from,Vector3& r_to) const;
_FORCE_INLINE_ Vector3 get_endpoint(int p_point) const;
AABB expand(const Vector3& p_vector) const;
_FORCE_INLINE_ void project_range_in_plane(const Plane& p_plane,float &r_min,float& r_max) const;
_FORCE_INLINE_ void expand_to(const Vector3& p_vector); /** expand to contain a point if necesary */
operator String() const;
_FORCE_INLINE_ AABB() {}
inline AABB(const Vector3 &p_pos,const Vector3& p_size) { pos=p_pos; size=p_size; }
};
inline bool AABB::intersects(const AABB& p_aabb) const {
if ( pos.x >= (p_aabb.pos.x + p_aabb.size.x) )
return false;
if ( (pos.x+size.x) <= p_aabb.pos.x )
return false;
if ( pos.y >= (p_aabb.pos.y + p_aabb.size.y) )
return false;
if ( (pos.y+size.y) <= p_aabb.pos.y )
return false;
if ( pos.z >= (p_aabb.pos.z + p_aabb.size.z) )
return false;
if ( (pos.z+size.z) <= p_aabb.pos.z )
return false;
return true;
}
inline bool AABB::encloses(const AABB & p_aabb) const {
Vector3 src_min=pos;
Vector3 src_max=pos+size;
Vector3 dst_min=p_aabb.pos;
Vector3 dst_max=p_aabb.pos+p_aabb.size;
return (
(src_min.x <= dst_min.x) &&
(src_max.x > dst_max.x) &&
(src_min.y <= dst_min.y) &&
(src_max.y > dst_max.y) &&
(src_min.z <= dst_min.z) &&
(src_max.z > dst_max.z) );
}
Vector3 AABB::get_support(const Vector3& p_normal) const {
Vector3 half_extents = size * 0.5;
Vector3 ofs = pos + half_extents;
return Vector3(
(p_normal.x>0) ? -half_extents.x : half_extents.x,
(p_normal.y>0) ? -half_extents.y : half_extents.y,
(p_normal.z>0) ? -half_extents.z : half_extents.z
)+ofs;
}
Vector3 AABB::get_endpoint(int p_point) const {
switch(p_point) {
case 0: return Vector3( pos.x , pos.y , pos.z );
case 1: return Vector3( pos.x , pos.y , pos.z+size.z );
case 2: return Vector3( pos.x , pos.y+size.y , pos.z );
case 3: return Vector3( pos.x , pos.y+size.y , pos.z+size.z );
case 4: return Vector3( pos.x+size.x , pos.y , pos.z );
case 5: return Vector3( pos.x+size.x , pos.y , pos.z+size.z );
case 6: return Vector3( pos.x+size.x , pos.y+size.y , pos.z );
case 7: return Vector3( pos.x+size.x , pos.y+size.y , pos.z+size.z );
};
ERR_FAIL_V(Vector3());
}
bool AABB::intersects_convex_shape(const Plane *p_planes, int p_plane_count) const {
#if 1
Vector3 half_extents = size * 0.5;
Vector3 ofs = pos + half_extents;
for(int i=0;i<p_plane_count;i++) {
const Plane &p=p_planes[i];
Vector3 point(
(p.normal.x>0) ? -half_extents.x : half_extents.x,
(p.normal.y>0) ? -half_extents.y : half_extents.y,
(p.normal.z>0) ? -half_extents.z : half_extents.z
);
point+=ofs;
if (p.is_point_over(point))
return false;
}
return true;
#else
//cache all points to check against!
// #warning should be easy to optimize, just use the same as when taking the support and use only that point
Vector3 points[8] = {
Vector3( pos.x , pos.y , pos.z ),
Vector3( pos.x , pos.y , pos.z+size.z ),
Vector3( pos.x , pos.y+size.y , pos.z ),
Vector3( pos.x , pos.y+size.y , pos.z+size.z ),
Vector3( pos.x+size.x , pos.y , pos.z ),
Vector3( pos.x+size.x , pos.y , pos.z+size.z ),
Vector3( pos.x+size.x , pos.y+size.y , pos.z ),
Vector3( pos.x+size.x , pos.y+size.y , pos.z+size.z ),
};
for (int i=0;i<p_plane_count;i++) { //for each plane
const Plane & plane=p_planes[i];
bool all_points_over=true;
//test if it has all points over!
for (int j=0;j<8;j++) {
if (!plane.is_point_over( points[j] )) {
all_points_over=false;
break;
}
}
if (all_points_over) {
return false;
}
}
return true;
#endif
}
bool AABB::has_point(const Vector3& p_point) const {
if (p_point.x<pos.x)
return false;
if (p_point.y<pos.y)
return false;
if (p_point.z<pos.z)
return false;
if (p_point.x>pos.x+size.x)
return false;
if (p_point.y>pos.y+size.y)
return false;
if (p_point.z>pos.z+size.z)
return false;
return true;
}
inline void AABB::expand_to(const Vector3& p_vector) {
Vector3 begin=pos;
Vector3 end=pos+size;
if (p_vector.x<begin.x)
begin.x=p_vector.x;
if (p_vector.y<begin.y)
begin.y=p_vector.y;
if (p_vector.z<begin.z)
begin.z=p_vector.z;
if (p_vector.x>end.x)
end.x=p_vector.x;
if (p_vector.y>end.y)
end.y=p_vector.y;
if (p_vector.z>end.z)
end.z=p_vector.z;
pos=begin;
size=end-begin;
}
void AABB::project_range_in_plane(const Plane& p_plane,float &r_min,float& r_max) const {
Vector3 half_extents( size.x * 0.5, size.y * 0.5, size.z * 0.5 );
Vector3 center( pos.x + half_extents.x, pos.y + half_extents.y, pos.z + half_extents.z );
float length = p_plane.normal.abs().dot(half_extents);
float distance = p_plane.distance_to( center );
r_min = distance - length;
r_max = distance + length;
}
inline real_t AABB::get_longest_axis_size() const {
real_t max_size=size.x;
if (size.y > max_size ) {
max_size=size.y;
}
if (size.z > max_size ) {
max_size=size.z;
}
return max_size;
}
inline real_t AABB::get_shortest_axis_size() const {
real_t max_size=size.x;
if (size.y < max_size ) {
max_size=size.y;
}
if (size.z < max_size ) {
max_size=size.z;
}
return max_size;
}
bool AABB::smits_intersect_ray(const Vector3 &from,const Vector3& dir, float t0, float t1) const {
float divx=1.0/dir.x;
float divy=1.0/dir.y;
float divz=1.0/dir.z;
Vector3 upbound=pos+size;
float tmin, tmax, tymin, tymax, tzmin, tzmax;
if (dir.x >= 0) {
tmin = (pos.x - from.x) * divx;
tmax = (upbound.x - from.x) * divx;
}
else {
tmin = (upbound.x - from.x) * divx;
tmax = (pos.x - from.x) * divx;
}
if (dir.y >= 0) {
tymin = (pos.y - from.y) * divy;
tymax = (upbound.y - from.y) * divy;
}
else {
tymin = (upbound.y - from.y) * divy;
tymax = (pos.y - from.y) * divy;
}
if ( (tmin > tymax) || (tymin > tmax) )
return false;
if (tymin > tmin)
tmin = tymin;
if (tymax < tmax)
tmax = tymax;
if (dir.z >= 0) {
tzmin = (pos.z - from.z) * divz;
tzmax = (upbound.z - from.z) * divz;
}
else {
tzmin = (upbound.z - from.z) * divz;
tzmax = (pos.z - from.z) * divz;
}
if ( (tmin > tzmax) || (tzmin > tmax) )
return false;
if (tzmin > tmin)
tmin = tzmin;
if (tzmax < tmax)
tmax = tzmax;
return ( (tmin < t1) && (tmax > t0) );
}
void AABB::grow_by(real_t p_amount) {
pos.x-=p_amount;
pos.y-=p_amount;
pos.z-=p_amount;
size.x+=2.0*p_amount;
size.y+=2.0*p_amount;
size.z+=2.0*p_amount;
}
typedef AABB Rect3;
#endif // AABB_H