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456 lines
10 KiB
C++
456 lines
10 KiB
C++
/*************************************************************************/
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/* face3.cpp */
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/*************************************************************************/
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/* This file is part of: */
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/* GODOT ENGINE */
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/* http://www.godotengine.org */
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/*************************************************************************/
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/* Copyright (c) 2007-2016 Juan Linietsky, Ariel Manzur. */
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/* */
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/* Permission is hereby granted, free of charge, to any person obtaining */
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/* a copy of this software and associated documentation files (the */
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/* "Software"), to deal in the Software without restriction, including */
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/* without limitation the rights to use, copy, modify, merge, publish, */
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/* distribute, sublicense, and/or sell copies of the Software, and to */
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/* permit persons to whom the Software is furnished to do so, subject to */
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/* the following conditions: */
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/* */
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/* The above copyright notice and this permission notice shall be */
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/* included in all copies or substantial portions of the Software. */
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/* */
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/* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, */
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/* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF */
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/* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.*/
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/* IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY */
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/* CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, */
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/* TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE */
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/* SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. */
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/*************************************************************************/
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#include "face3.h"
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#include "geometry.h"
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int Face3::split_by_plane(const Plane& p_plane,Face3 p_res[3],bool p_is_point_over[3]) const {
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ERR_FAIL_COND_V(is_degenerate(),0);
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Vector3 above[4];
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int above_count=0;
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Vector3 below[4];
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int below_count=0;
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for (int i=0;i<3;i++) {
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if (p_plane.has_point( vertex[i], CMP_EPSILON )) { // point is in plane
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ERR_FAIL_COND_V(above_count>=4,0);
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above[above_count++]=vertex[i];
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ERR_FAIL_COND_V(below_count>=4,0);
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below[below_count++]=vertex[i];
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} else {
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if (p_plane.is_point_over( vertex[i])) {
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//Point is over
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ERR_FAIL_COND_V(above_count>=4,0);
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above[above_count++]=vertex[i];
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} else {
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//Point is under
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ERR_FAIL_COND_V(below_count>=4,0);
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below[below_count++]=vertex[i];
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}
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/* Check for Intersection between this and the next vertex*/
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Vector3 inters;
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if (!p_plane.intersects_segment( vertex[i],vertex[(i+1)%3],&inters))
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continue;
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/* Intersection goes to both */
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ERR_FAIL_COND_V(above_count>=4,0);
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above[above_count++]=inters;
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ERR_FAIL_COND_V(below_count>=4,0);
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below[below_count++]=inters;
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}
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}
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int polygons_created=0;
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ERR_FAIL_COND_V( above_count>=4 && below_count>=4 , 0 ); //bug in the algo
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if (above_count>=3) {
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p_res[polygons_created]=Face3( above[0], above[1], above[2] );
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p_is_point_over[polygons_created]=true;
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polygons_created++;
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if (above_count==4) {
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p_res[polygons_created]=Face3( above[2], above[3], above[0] );
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p_is_point_over[polygons_created]=true;
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polygons_created++;
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}
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}
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if (below_count>=3) {
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p_res[polygons_created]=Face3( below[0], below[1], below[2] );
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p_is_point_over[polygons_created]=false;
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polygons_created++;
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if (below_count==4) {
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p_res[polygons_created]=Face3( below[2], below[3], below[0] );
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p_is_point_over[polygons_created]=false;
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polygons_created++;
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}
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}
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return polygons_created;
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}
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bool Face3::intersects_ray(const Vector3& p_from,const Vector3& p_dir,Vector3 * p_intersection) const {
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return Geometry::ray_intersects_triangle(p_from,p_dir,vertex[0],vertex[1],vertex[2],p_intersection);
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}
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bool Face3::intersects_segment(const Vector3& p_from,const Vector3& p_dir,Vector3 * p_intersection) const {
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return Geometry::segment_intersects_triangle(p_from,p_dir,vertex[0],vertex[1],vertex[2],p_intersection);
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}
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bool Face3::is_degenerate() const {
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Vector3 normal=vec3_cross(vertex[0]-vertex[1], vertex[0]-vertex[2]);
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return (normal.length_squared() < CMP_EPSILON2);
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}
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Face3::Side Face3::get_side_of(const Face3& p_face,ClockDirection p_clock_dir) const {
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int over=0,under=0;
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Plane plane=get_plane(p_clock_dir);
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for (int i=0;i<3;i++) {
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const Vector3 &v=p_face.vertex[i];
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if (plane.has_point(v)) //coplanar, dont bother
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continue;
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if (plane.is_point_over(v))
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over++;
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else
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under++;
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}
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if ( over > 0 && under == 0 )
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return SIDE_OVER;
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else if (under > 0 && over ==0 )
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return SIDE_UNDER;
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else if (under ==0 && over == 0)
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return SIDE_COPLANAR;
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else
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return SIDE_SPANNING;
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}
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Vector3 Face3::get_random_point_inside() const {
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float a=Math::random(0,1);
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float b=Math::random(0,1);
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if (a>b) {
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SWAP(a,b);
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}
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return vertex[0]*a + vertex[1]*(b-a) + vertex[2]*(1.0-b);
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}
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Plane Face3::get_plane(ClockDirection p_dir) const {
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return Plane( vertex[0], vertex[1], vertex[2] , p_dir );
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}
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Vector3 Face3::get_median_point() const {
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return (vertex[0] + vertex[1] + vertex[2])/3.0;
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}
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real_t Face3::get_area() const {
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return vec3_cross(vertex[0]-vertex[1], vertex[0]-vertex[2]).length();
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}
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ClockDirection Face3::get_clock_dir() const {
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Vector3 normal=vec3_cross(vertex[0]-vertex[1], vertex[0]-vertex[2]);
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//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] ) ) );
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return ( normal.dot( vertex[0] ) >= 0 ) ? CLOCKWISE : COUNTERCLOCKWISE;
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}
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bool Face3::intersects_aabb(const AABB& p_aabb) const {
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/** TEST PLANE **/
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if (!p_aabb.intersects_plane( get_plane() ))
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return false;
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/** TEST FACE AXIS */
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#define TEST_AXIS(m_ax)\
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{\
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float aabb_min=p_aabb.pos.m_ax;\
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float aabb_max=p_aabb.pos.m_ax+p_aabb.size.m_ax;\
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float tri_min,tri_max;\
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for (int i=0;i<3;i++) {\
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if (i==0 || vertex[i].m_ax > tri_max)\
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tri_max=vertex[i].m_ax;\
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if (i==0 || vertex[i].m_ax < tri_min)\
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tri_min=vertex[i].m_ax;\
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}\
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\
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if (tri_max<aabb_min || aabb_max<tri_min)\
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return false;\
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}
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TEST_AXIS(x);
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TEST_AXIS(y);
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TEST_AXIS(z);
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/** TEST ALL EDGES **/
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Vector3 edge_norms[3]={
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vertex[0]-vertex[1],
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vertex[1]-vertex[2],
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vertex[2]-vertex[0],
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};
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for (int i=0;i<12;i++) {
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Vector3 from,to;
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p_aabb.get_edge(i,from,to);
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Vector3 e1=from-to;
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for (int j=0;j<3;j++) {
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Vector3 e2=edge_norms[j];
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Vector3 axis=vec3_cross( e1, e2 );
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if (axis.length_squared()<0.0001)
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continue; // coplanar
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axis.normalize();
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float minA,maxA,minB,maxB;
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p_aabb.project_range_in_plane(Plane(axis,0),minA,maxA);
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project_range(axis,Transform(),minB,maxB);
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if (maxA<minB || maxB<minA)
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return false;
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}
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}
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return true;
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}
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Face3::operator String() const {
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return String()+vertex[0]+", "+vertex[1]+", "+vertex[2];
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}
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void Face3::project_range(const Vector3& p_normal,const Transform& p_transform,float& r_min, float& r_max) const {
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for (int i=0;i<3;i++) {
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Vector3 v=p_transform.xform(vertex[i]);
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float d=p_normal.dot(v);
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if (i==0 || d > r_max)
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r_max=d;
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if (i==0 || d < r_min)
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r_min=d;
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}
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}
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void Face3::get_support(const Vector3& p_normal,const Transform& p_transform,Vector3 *p_vertices,int* p_count,int p_max) const {
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#define _FACE_IS_VALID_SUPPORT_TRESHOLD 0.98
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#define _EDGE_IS_VALID_SUPPORT_TRESHOLD 0.05
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if (p_max<=0)
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return;
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Vector3 n=p_transform.basis.xform_inv(p_normal);
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/** TEST FACE AS SUPPORT **/
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if (get_plane().normal.dot(n) > _FACE_IS_VALID_SUPPORT_TRESHOLD) {
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*p_count=MIN(3,p_max);
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for (int i=0;i<*p_count;i++) {
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p_vertices[i]=p_transform.xform(vertex[i]);
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}
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return;
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}
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/** FIND SUPPORT VERTEX **/
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int vert_support_idx=-1;
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float support_max;
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for (int i=0;i<3;i++) {
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float d=n.dot(vertex[i]);
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if (i==0 || d > support_max) {
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support_max=d;
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vert_support_idx=i;
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}
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}
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/** TEST EDGES AS SUPPORT **/
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for (int i=0;i<3;i++) {
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if (i!=vert_support_idx && i+1!=vert_support_idx)
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continue;
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// check if edge is valid as a support
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float dot=(vertex[i]-vertex[(i+1)%3]).normalized().dot(n);
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dot=ABS(dot);
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if (dot < _EDGE_IS_VALID_SUPPORT_TRESHOLD) {
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*p_count=MIN(2,p_max);
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for (int j=0;j<*p_count;j++)
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p_vertices[j]=p_transform.xform(vertex[(j+i)%3]);
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return;
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}
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}
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*p_count=1;
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p_vertices[0]=p_transform.xform(vertex[vert_support_idx]);
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}
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Vector3 Face3::get_closest_point_to(const Vector3& p_point) const {
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Vector3 edge0 = vertex[1] - vertex[0];
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Vector3 edge1 = vertex[2] - vertex[0];
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Vector3 v0 = vertex[0] - p_point;
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float a = edge0.dot( edge0 );
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float b = edge0.dot( edge1 );
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float c = edge1.dot( edge1 );
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float d = edge0.dot( v0 );
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float e = edge1.dot( v0 );
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float det = a*c - b*b;
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float s = b*e - c*d;
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float t = b*d - a*e;
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if ( s + t < det )
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{
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if ( s < 0.f )
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{
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if ( t < 0.f )
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{
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if ( d < 0.f )
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{
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s = CLAMP( -d/a, 0.f, 1.f );
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t = 0.f;
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}
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else
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{
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s = 0.f;
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t = CLAMP( -e/c, 0.f, 1.f );
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}
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}
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else
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{
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s = 0.f;
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t = CLAMP( -e/c, 0.f, 1.f );
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}
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}
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else if ( t < 0.f )
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{
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s = CLAMP( -d/a, 0.f, 1.f );
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t = 0.f;
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}
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else
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{
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float invDet = 1.f / det;
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s *= invDet;
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t *= invDet;
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}
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}
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else
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{
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if ( s < 0.f )
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{
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float tmp0 = b+d;
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float tmp1 = c+e;
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if ( tmp1 > tmp0 )
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{
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float numer = tmp1 - tmp0;
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float denom = a-2*b+c;
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s = CLAMP( numer/denom, 0.f, 1.f );
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t = 1-s;
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}
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else
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{
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t = CLAMP( -e/c, 0.f, 1.f );
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s = 0.f;
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}
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}
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else if ( t < 0.f )
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{
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if ( a+d > b+e )
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{
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float numer = c+e-b-d;
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float denom = a-2*b+c;
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s = CLAMP( numer/denom, 0.f, 1.f );
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t = 1-s;
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}
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else
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{
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s = CLAMP( -e/c, 0.f, 1.f );
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t = 0.f;
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}
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}
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else
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{
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float numer = c+e-b-d;
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float denom = a-2*b+c;
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s = CLAMP( numer/denom, 0.f, 1.f );
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t = 1.f - s;
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}
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}
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return vertex[0] + s * edge0 + t * edge1;
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}
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