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godot/core/math/face3.cpp

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/*************************************************************************/
/* face3.cpp */
/*************************************************************************/
/* This file is part of: */
/* GODOT ENGINE */
/* http://www.godotengine.org */
/*************************************************************************/
/* Copyright (c) 2007-2014 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 "face3.h"
#include "geometry.h"
int Face3::split_by_plane(const Plane& p_plane,Face3 p_res[3],bool p_is_point_over[3]) const {
ERR_FAIL_COND_V(is_degenerate(),0);
Vector3 above[4];
int above_count=0;
Vector3 below[4];
int below_count=0;
for (int i=0;i<3;i++) {
if (p_plane.has_point( vertex[i], CMP_EPSILON )) { // point is in plane
ERR_FAIL_COND_V(above_count>=4,0);
above[above_count++]=vertex[i];
ERR_FAIL_COND_V(below_count>=4,0);
below[below_count++]=vertex[i];
} else {
if (p_plane.is_point_over( vertex[i])) {
//Point is over
ERR_FAIL_COND_V(above_count>=4,0);
above[above_count++]=vertex[i];
} else {
//Point is under
ERR_FAIL_COND_V(below_count>=4,0);
below[below_count++]=vertex[i];
}
/* Check for Intersection between this and the next vertex*/
Vector3 inters;
if (!p_plane.intersects_segment( vertex[i],vertex[(i+1)%3],&inters))
continue;
/* Intersection goes to both */
ERR_FAIL_COND_V(above_count>=4,0);
above[above_count++]=inters;
ERR_FAIL_COND_V(below_count>=4,0);
below[below_count++]=inters;
}
}
int polygons_created=0;
ERR_FAIL_COND_V( above_count>=4 && below_count>=4 , 0 ); //bug in the algo
if (above_count>=3) {
p_res[polygons_created]=Face3( above[0], above[1], above[2] );
p_is_point_over[polygons_created]=true;
polygons_created++;
if (above_count==4) {
p_res[polygons_created]=Face3( above[2], above[3], above[0] );
p_is_point_over[polygons_created]=true;
polygons_created++;
}
}
if (below_count>=3) {
p_res[polygons_created]=Face3( below[0], below[1], below[2] );
p_is_point_over[polygons_created]=false;
polygons_created++;
if (below_count==4) {
p_res[polygons_created]=Face3( below[2], below[3], below[0] );
p_is_point_over[polygons_created]=false;
polygons_created++;
}
}
return polygons_created;
}
bool Face3::intersects_ray(const Vector3& p_from,const Vector3& p_dir,Vector3 * p_intersection) const {
return Geometry::ray_intersects_triangle(p_from,p_dir,vertex[0],vertex[1],vertex[2],p_intersection);
}
bool Face3::intersects_segment(const Vector3& p_from,const Vector3& p_dir,Vector3 * p_intersection) const {
return Geometry::segment_intersects_triangle(p_from,p_dir,vertex[0],vertex[1],vertex[2],p_intersection);
}
bool Face3::is_degenerate() const {
Vector3 normal=vec3_cross(vertex[0]-vertex[1], vertex[0]-vertex[2]);
return (normal.length_squared() < CMP_EPSILON2);
}
Face3::Side Face3::get_side_of(const Face3& p_face,ClockDirection p_clock_dir) const {
int over=0,under=0;
Plane plane=get_plane(p_clock_dir);
for (int i=0;i<3;i++) {
const Vector3 &v=p_face.vertex[i];
if (plane.has_point(v)) //coplanar, dont bother
continue;
if (plane.is_point_over(v))
over++;
else
under++;
}
if ( over > 0 && under == 0 )
return SIDE_OVER;
else if (under > 0 && over ==0 )
return SIDE_UNDER;
else if (under ==0 && over == 0)
return SIDE_COPLANAR;
else
return SIDE_SPANNING;
}
Vector3 Face3::get_random_point_inside() const {
float a=Math::random(0,1);
float b=Math::random(0,1);
if (a>b) {
SWAP(a,b);
}
return vertex[0]*a + vertex[1]*(b-a) + vertex[2]*(1.0-b);
}
Plane Face3::get_plane(ClockDirection p_dir) const {
return Plane( vertex[0], vertex[1], vertex[2] , p_dir );
}
Vector3 Face3::get_median_point() const {
return (vertex[0] + vertex[1] + vertex[2])/3.0;
}
real_t Face3::get_area() const {
return vec3_cross(vertex[0]-vertex[1], vertex[0]-vertex[2]).length();
}
ClockDirection Face3::get_clock_dir() const {
Vector3 normal=vec3_cross(vertex[0]-vertex[1], vertex[0]-vertex[2]);
//printf("normal is %g,%g,%g x %g,%g,%g- wtfu is %g\n",tofloat(normal.x),tofloat(normal.y),tofloat(normal.z),tofloat(vertex[0].x),tofloat(vertex[0].y),tofloat(vertex[0].z),tofloat( normal.dot( vertex[0] ) ) );
return ( normal.dot( vertex[0] ) >= 0 ) ? CLOCKWISE : COUNTERCLOCKWISE;
}
bool Face3::intersects_aabb(const AABB& p_aabb) const {
/** TEST PLANE **/
if (!p_aabb.intersects_plane( get_plane() ))
return false;
/** TEST FACE AXIS */
#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);
/** TEST ALL EDGES **/
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;
p_aabb.get_edge(i,from,to);
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();
float minA,maxA,minB,maxB;
p_aabb.project_range_in_plane(Plane(axis,0),minA,maxA);
project_range(axis,Transform(),minB,maxB);
if (maxA<minB || maxB<minA)
return false;
}
}
return true;
}
Face3::operator String() const {
return String()+vertex[0]+", "+vertex[1]+", "+vertex[2];
}
void Face3::project_range(const Vector3& p_normal,const Transform& p_transform,float& r_min, float& r_max) const {
for (int i=0;i<3;i++) {
Vector3 v=p_transform.xform(vertex[i]);
float d=p_normal.dot(v);
if (i==0 || d > r_max)
r_max=d;
if (i==0 || d < r_min)
r_min=d;
}
}
void Face3::get_support(const Vector3& p_normal,const Transform& p_transform,Vector3 *p_vertices,int* p_count,int p_max) const {
#define _FACE_IS_VALID_SUPPORT_TRESHOLD 0.98
#define _EDGE_IS_VALID_SUPPORT_TRESHOLD 0.05
if (p_max<=0)
return;
Vector3 n=p_transform.basis.xform_inv(p_normal);
/** TEST FACE AS SUPPORT **/
if (get_plane().normal.dot(n) > _FACE_IS_VALID_SUPPORT_TRESHOLD) {
*p_count=MIN(3,p_max);
for (int i=0;i<*p_count;i++) {
p_vertices[i]=p_transform.xform(vertex[i]);
}
return;
}
/** FIND SUPPORT VERTEX **/
int vert_support_idx=-1;
float support_max;
for (int i=0;i<3;i++) {
float d=n.dot(vertex[i]);
if (i==0 || d > support_max) {
support_max=d;
vert_support_idx=i;
}
}
/** TEST EDGES AS SUPPORT **/
for (int i=0;i<3;i++) {
if (i!=vert_support_idx && i+1!=vert_support_idx)
continue;
// check if edge is valid as a support
float dot=(vertex[i]-vertex[(i+1)%3]).normalized().dot(n);
dot=ABS(dot);
if (dot < _EDGE_IS_VALID_SUPPORT_TRESHOLD) {
*p_count=MIN(2,p_max);
for (int j=0;j<*p_count;j++)
p_vertices[j]=p_transform.xform(vertex[(j+i)%3]);
return;
}
}
*p_count=1;
p_vertices[0]=p_transform.xform(vertex[vert_support_idx]);
}
Vector3 Face3::get_closest_point_to(const Vector3& p_point) const {
Vector3 edge0 = vertex[1] - vertex[0];
Vector3 edge1 = vertex[2] - vertex[0];
Vector3 v0 = vertex[0] - p_point;
float a = edge0.dot( edge0 );
float b = edge0.dot( edge1 );
float c = edge1.dot( edge1 );
float d = edge0.dot( v0 );
float e = edge1.dot( v0 );
float det = a*c - b*b;
float s = b*e - c*d;
float t = b*d - a*e;
if ( s + t < det )
{
if ( s < 0.f )
{
if ( t < 0.f )
{
if ( d < 0.f )
{
s = CLAMP( -d/a, 0.f, 1.f );
t = 0.f;
}
else
{
s = 0.f;
t = CLAMP( -e/c, 0.f, 1.f );
}
}
else
{
s = 0.f;
t = CLAMP( -e/c, 0.f, 1.f );
}
}
else if ( t < 0.f )
{
s = CLAMP( -d/a, 0.f, 1.f );
t = 0.f;
}
else
{
float invDet = 1.f / det;
s *= invDet;
t *= invDet;
}
}
else
{
if ( s < 0.f )
{
float tmp0 = b+d;
float tmp1 = c+e;
if ( tmp1 > tmp0 )
{
float numer = tmp1 - tmp0;
float denom = a-2*b+c;
s = CLAMP( numer/denom, 0.f, 1.f );
t = 1-s;
}
else
{
t = CLAMP( -e/c, 0.f, 1.f );
s = 0.f;
}
}
else if ( t < 0.f )
{
if ( a+d > b+e )
{
float numer = c+e-b-d;
float denom = a-2*b+c;
s = CLAMP( numer/denom, 0.f, 1.f );
t = 1-s;
}
else
{
s = CLAMP( -e/c, 0.f, 1.f );
t = 0.f;
}
}
else
{
float numer = c+e-b-d;
float denom = a-2*b+c;
s = CLAMP( numer/denom, 0.f, 1.f );
t = 1.f - s;
}
}
return vertex[0] + s * edge0 + t * edge1;
}
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