godot/core/math/face3.h
2016-01-01 11:50:53 -02:00

268 lines
8.7 KiB
C++

/*************************************************************************/
/* face3.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 FACE3_H
#define FACE3_H
#include "vector3.h"
#include "plane.h"
#include "aabb.h"
#include "transform.h"
class Face3 {
public:
enum Side {
SIDE_OVER,
SIDE_UNDER,
SIDE_SPANNING,
SIDE_COPLANAR
};
Vector3 vertex[3];
/**
*
* @param p_plane plane used to split the face
* @param p_res array of at least 3 faces, amount used in functio return
* @param p_is_point_over array of at least 3 booleans, determining which face is over the plane, amount used in functio return
* @param _epsilon constant used for numerical error rounding, to add "thickness" to the plane (so coplanar points can happen)
* @return amount of faces generated by the split, either 0 (means no split possible), 2 or 3
*/
int split_by_plane(const Plane& p_plane,Face3 *p_res,bool *p_is_point_over) const;
Plane get_plane(ClockDirection p_dir=CLOCKWISE) const;
Vector3 get_random_point_inside() const;
Side get_side_of(const Face3& p_face,ClockDirection p_clock_dir=CLOCKWISE) const;
bool is_degenerate() const;
real_t get_area() const;
Vector3 get_median_point() const;
Vector3 get_closest_point_to(const Vector3& p_point) const;
bool intersects_ray(const Vector3& p_from,const Vector3& p_dir,Vector3 * p_intersection=0) const;
bool intersects_segment(const Vector3& p_from,const Vector3& p_dir,Vector3 * p_intersection=0) const;
ClockDirection get_clock_dir() const; ///< todo, test if this is returning the proper clockwisity
void get_support(const Vector3& p_normal,const Transform& p_transform,Vector3 *p_vertices,int* p_count,int p_max) const;
void project_range(const Vector3& p_normal,const Transform& p_transform,float& r_min, float& r_max) const;
AABB get_aabb() const {
AABB aabb( vertex[0], Vector3() );
aabb.expand_to( vertex[1] );
aabb.expand_to( vertex[2] );
return aabb;
}
bool intersects_aabb(const AABB& p_aabb) const;
_FORCE_INLINE_ bool intersects_aabb2(const AABB& p_aabb) const;
operator String() const;
inline Face3() {}
inline Face3(const Vector3 &p_v1,const Vector3 &p_v2,const Vector3 &p_v3) { vertex[0]=p_v1; vertex[1]=p_v2; vertex[2]=p_v3; }
};
bool Face3::intersects_aabb2(const AABB& p_aabb) const {
Vector3 perp = (vertex[0]-vertex[2]).cross(vertex[0]-vertex[1]);
Vector3 half_extents = p_aabb.size * 0.5;
Vector3 ofs = p_aabb.pos + half_extents;
Vector3 sup =Vector3(
(perp.x>0) ? -half_extents.x : half_extents.x,
(perp.y>0) ? -half_extents.y : half_extents.y,
(perp.z>0) ? -half_extents.z : half_extents.z
);
float d = perp.dot(vertex[0]);
float dist_a = perp.dot(ofs+sup)-d;
float dist_b = perp.dot(ofs-sup)-d;
if (dist_a*dist_b > 0)
return false; //does not intersect the plane
#define TEST_AXIS(m_ax)\
{\
float aabb_min=p_aabb.pos.m_ax;\
float aabb_max=p_aabb.pos.m_ax+p_aabb.size.m_ax;\
float tri_min,tri_max;\
for (int i=0;i<3;i++) {\
if (i==0 || vertex[i].m_ax > tri_max)\
tri_max=vertex[i].m_ax;\
if (i==0 || vertex[i].m_ax < tri_min)\
tri_min=vertex[i].m_ax;\
}\
\
if (tri_max<aabb_min || aabb_max<tri_min)\
return false;\
}
TEST_AXIS(x);
TEST_AXIS(y);
TEST_AXIS(z);
#undef TEST_AXIS
Vector3 edge_norms[3]={
vertex[0]-vertex[1],
vertex[1]-vertex[2],
vertex[2]-vertex[0],
};
for (int i=0;i<12;i++) {
Vector3 from,to;
switch(i) {
case 0:{
from=Vector3( p_aabb.pos.x+p_aabb.size.x , p_aabb.pos.y , p_aabb.pos.z );
to=Vector3( p_aabb.pos.x , p_aabb.pos.y , p_aabb.pos.z );
} break;
case 1:{
from=Vector3( p_aabb.pos.x+p_aabb.size.x , p_aabb.pos.y , p_aabb.pos.z+p_aabb.size.z );
to=Vector3( p_aabb.pos.x+p_aabb.size.x , p_aabb.pos.y , p_aabb.pos.z );
} break;
case 2:{
from=Vector3( p_aabb.pos.x , p_aabb.pos.y , p_aabb.pos.z+p_aabb.size.z );
to=Vector3( p_aabb.pos.x+p_aabb.size.x , p_aabb.pos.y , p_aabb.pos.z+p_aabb.size.z );
} break;
case 3:{
from=Vector3( p_aabb.pos.x , p_aabb.pos.y , p_aabb.pos.z );
to=Vector3( p_aabb.pos.x , p_aabb.pos.y , p_aabb.pos.z+p_aabb.size.z );
} break;
case 4:{
from=Vector3( p_aabb.pos.x , p_aabb.pos.y+p_aabb.size.y , p_aabb.pos.z );
to=Vector3( p_aabb.pos.x+p_aabb.size.x , p_aabb.pos.y+p_aabb.size.y , p_aabb.pos.z );
} break;
case 5:{
from=Vector3( p_aabb.pos.x+p_aabb.size.x , p_aabb.pos.y+p_aabb.size.y , p_aabb.pos.z );
to=Vector3( p_aabb.pos.x+p_aabb.size.x , p_aabb.pos.y+p_aabb.size.y , p_aabb.pos.z+p_aabb.size.z );
} break;
case 6:{
from=Vector3( p_aabb.pos.x+p_aabb.size.x , p_aabb.pos.y+p_aabb.size.y , p_aabb.pos.z+p_aabb.size.z );
to=Vector3( p_aabb.pos.x , p_aabb.pos.y+p_aabb.size.y , p_aabb.pos.z+p_aabb.size.z );
} break;
case 7:{
from=Vector3( p_aabb.pos.x , p_aabb.pos.y+p_aabb.size.y , p_aabb.pos.z+p_aabb.size.z );
to=Vector3( p_aabb.pos.x , p_aabb.pos.y+p_aabb.size.y , p_aabb.pos.z );
} break;
case 8:{
from=Vector3( p_aabb.pos.x , p_aabb.pos.y , p_aabb.pos.z+p_aabb.size.z );
to=Vector3( p_aabb.pos.x , p_aabb.pos.y+p_aabb.size.y , p_aabb.pos.z+p_aabb.size.z );
} break;
case 9:{
from=Vector3( p_aabb.pos.x , p_aabb.pos.y , p_aabb.pos.z );
to=Vector3( p_aabb.pos.x , p_aabb.pos.y+p_aabb.size.y , p_aabb.pos.z );
} break;
case 10:{
from=Vector3( p_aabb.pos.x+p_aabb.size.x , p_aabb.pos.y , p_aabb.pos.z );
to=Vector3( p_aabb.pos.x+p_aabb.size.x , p_aabb.pos.y+p_aabb.size.y , p_aabb.pos.z );
} break;
case 11:{
from=Vector3( p_aabb.pos.x+p_aabb.size.x , p_aabb.pos.y , p_aabb.pos.z+p_aabb.size.z );
to=Vector3( p_aabb.pos.x+p_aabb.size.x , p_aabb.pos.y+p_aabb.size.y , p_aabb.pos.z+p_aabb.size.z );
} break;
}
Vector3 e1=from-to;
for (int j=0;j<3;j++) {
Vector3 e2=edge_norms[j];
Vector3 axis=vec3_cross( e1, e2 );
if (axis.length_squared()<0.0001)
continue; // coplanar
//axis.normalize();
Vector3 sup2 =Vector3(
(axis.x>0) ? -half_extents.x : half_extents.x,
(axis.y>0) ? -half_extents.y : half_extents.y,
(axis.z>0) ? -half_extents.z : half_extents.z
);
float maxB = axis.dot(ofs+sup2);
float minB = axis.dot(ofs-sup2);
if (minB>maxB) {
SWAP(maxB,minB);
}
float minT=1e20,maxT=-1e20;
for (int k=0;k<3;k++) {
float d=axis.dot(vertex[k]);
if (d > maxT)
maxT=d;
if (d < minT)
minT=d;
}
if (maxB<minT || maxT<minB)
return false;
}
}
return true;
}
#endif // FACE3_H