virtualx-engine/core/math/plane.cpp
2017-02-14 17:05:16 -03:00

166 lines
4.7 KiB
C++

/*************************************************************************/
/* plane.cpp */
/*************************************************************************/
/* This file is part of: */
/* GODOT ENGINE */
/* http://www.godotengine.org */
/*************************************************************************/
/* Copyright (c) 2007-2017 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. */
/*************************************************************************/
#include "plane.h"
#include "math_funcs.h"
#define _PLANE_EQ_DOT_EPSILON 0.999
#define _PLANE_EQ_D_EPSILON 0.0001
void Plane::set_normal(const Vector3& p_normal) {
normal=p_normal;
}
void Plane::normalize() {
real_t l = normal.length();
if (l==0) {
*this=Plane(0,0,0,0);
return;
}
normal/=l;
d/=l;
}
Plane Plane::normalized() const {
Plane p = *this;
p.normalize();
return p;
}
Vector3 Plane::get_any_point() const {
return get_normal()*d;
}
Vector3 Plane::get_any_perpendicular_normal() const {
static const Vector3 p1 = Vector3(1,0,0);
static const Vector3 p2 = Vector3(0,1,0);
Vector3 p;
if (ABS(normal.dot(p1)) > 0.99) // if too similar to p1
p=p2; // use p2
else
p=p1; // use p1
p-=normal * normal.dot(p);
p.normalize();
return p;
}
/* intersections */
bool Plane::intersect_3(const Plane &p_plane1, const Plane &p_plane2, Vector3 *r_result) const {
const Plane &p_plane0=*this;
Vector3 normal0=p_plane0.normal;
Vector3 normal1=p_plane1.normal;
Vector3 normal2=p_plane2.normal;
real_t denom=vec3_cross(normal0,normal1).dot(normal2);
if (ABS(denom)<=CMP_EPSILON)
return false;
if (r_result) {
*r_result = ( (vec3_cross(normal1, normal2) * p_plane0.d) +
(vec3_cross(normal2, normal0) * p_plane1.d) +
(vec3_cross(normal0, normal1) * p_plane2.d) )/denom;
}
return true;
}
bool Plane::intersects_ray(Vector3 p_from, Vector3 p_dir, Vector3* p_intersection) const {
Vector3 segment=p_dir;
real_t den=normal.dot( segment );
//printf("den is %i\n",den);
if (Math::abs(den)<=CMP_EPSILON) {
return false;
}
real_t dist=(normal.dot( p_from ) - d) / den;
//printf("dist is %i\n",dist);
if (dist>CMP_EPSILON) { //this is a ray, before the emiting pos (p_from) doesnt exist
return false;
}
dist=-dist;
*p_intersection = p_from + segment * dist;
return true;
}
bool Plane::intersects_segment(Vector3 p_begin, Vector3 p_end, Vector3* p_intersection) const {
Vector3 segment= p_begin - p_end;
real_t den=normal.dot( segment );
//printf("den is %i\n",den);
if (Math::abs(den)<=CMP_EPSILON) {
return false;
}
real_t dist=(normal.dot( p_begin ) - d) / den;
//printf("dist is %i\n",dist);
if (dist<-CMP_EPSILON || dist > (1.0 +CMP_EPSILON)) {
return false;
}
dist=-dist;
*p_intersection = p_begin + segment * dist;
return true;
}
/* misc */
bool Plane::is_almost_like(const Plane& p_plane) const {
return (normal.dot( p_plane.normal ) > _PLANE_EQ_DOT_EPSILON && Math::absd(d-p_plane.d) < _PLANE_EQ_D_EPSILON);
}
Plane::operator String() const {
return normal.operator String() + ", " + rtos(d);
}