virtualx-engine/core/math/aabb.cpp

/*************************************************************************/
/*  aabb.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:                                             */
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/* 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.*/
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/*************************************************************************/
#include "aabb.h"

#include "print_string.h"

float AABB::get_area() const {

	return size.x*size.y*size.z;

}

bool AABB::operator==(const AABB& p_rval) const {

	return ((pos==p_rval.pos) && (size==p_rval.size));

}
bool AABB::operator!=(const AABB& p_rval) const {

	return ((pos!=p_rval.pos) || (size!=p_rval.size));

}

void AABB::merge_with(const AABB& p_aabb) {

	Vector3 beg_1,beg_2;
	Vector3 end_1,end_2;
        Vector3 min,max;

	beg_1=pos;
	beg_2=p_aabb.pos;
	end_1=Vector3(size.x,size.y,size.z)+beg_1;
	end_2=Vector3(p_aabb.size.x,p_aabb.size.y,p_aabb.size.z)+beg_2;

	min.x=(beg_1.x<beg_2.x)?beg_1.x:beg_2.x;
	min.y=(beg_1.y<beg_2.y)?beg_1.y:beg_2.y;
	min.z=(beg_1.z<beg_2.z)?beg_1.z:beg_2.z;

	max.x=(end_1.x>end_2.x)?end_1.x:end_2.x;
	max.y=(end_1.y>end_2.y)?end_1.y:end_2.y;
	max.z=(end_1.z>end_2.z)?end_1.z:end_2.z;

	pos=min;
	size=max-min;
}

AABB AABB::intersection(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;

	Vector3 min,max;

	if (src_min.x > dst_max.x || src_max.x < dst_min.x )
		return AABB();
	else {

		min.x= ( src_min.x > dst_min.x ) ? src_min.x :dst_min.x;
		max.x= ( src_max.x < dst_max.x ) ? src_max.x :dst_max.x;

	}

	if (src_min.y > dst_max.y || src_max.y < dst_min.y )
		return AABB();
	else {

		min.y= ( src_min.y > dst_min.y ) ? src_min.y :dst_min.y;
		max.y= ( src_max.y < dst_max.y ) ? src_max.y :dst_max.y;

	}

	if (src_min.z > dst_max.z || src_max.z < dst_min.z )
		return AABB();
	else {

		min.z= ( src_min.z > dst_min.z ) ? src_min.z :dst_min.z;
		max.z= ( src_max.z < dst_max.z ) ? src_max.z :dst_max.z;

	}


	return AABB( min, max-min );
}

bool AABB::intersects_ray(const Vector3& p_from, const Vector3& p_dir,Vector3* r_clip,Vector3* r_normal) const {

	Vector3 c1, c2;
	Vector3 end = pos+size;
	float near=-1e20;
	float far=1e20;
	int axis=0;

	for (int i=0;i<3;i++){
		if (p_dir[i] == 0){
			if ((p_from[i] < pos[i]) || (p_from[i] > end[i])) {
				return false;
			}
		} else { // ray not parallel to planes in this direction
			c1[i] = (pos[i] - p_from[i]) / p_dir[i];
			c2[i] = (end[i] - p_from[i]) / p_dir[i];

			if(c1[i] > c2[i]){
				SWAP(c1,c2);
			}
			if (c1[i] > near){
				near = c1[i];
				axis=i;
			}
			if (c2[i] < far){
				far = c2[i];
			}
			if( (near > far) || (far < 0) ){
				return false;
			}
		}
	}

	if (r_clip)
		*r_clip=c1;
	if (r_normal) {
		*r_normal=Vector3();
		(*r_normal)[axis]=p_dir[axis]?-1:1;
	}

	return true;

}


bool AABB::intersects_segment(const Vector3& p_from, const Vector3& p_to,Vector3* r_clip,Vector3* r_normal) const {

	real_t min=0,max=1;
	int axis=0;
	float sign=0;

	for(int i=0;i<3;i++) {
		real_t seg_from=p_from[i];
		real_t seg_to=p_to[i];
		real_t box_begin=pos[i];
		real_t box_end=box_begin+size[i];
		real_t cmin,cmax;
		float csign;

		if (seg_from < seg_to) {

			if (seg_from > box_end || seg_to < box_begin)
				return false;
			real_t length=seg_to-seg_from;
			cmin = (seg_from < box_begin)?((box_begin - seg_from)/length):0;
			cmax = (seg_to > box_end)?((box_end - seg_from)/length):1;
			csign=-1.0;

		} else {

			if (seg_to > box_end || seg_from < box_begin)
				return false;
			real_t length=seg_to-seg_from;
			cmin = (seg_from > box_end)?(box_end - seg_from)/length:0;
			cmax = (seg_to < box_begin)?(box_begin - seg_from)/length:1;
			csign=1.0;
		}

		if (cmin > min) {
			min = cmin;
			axis=i;
			sign=csign;
		}
		if (cmax < max)
			max = cmax;
		if (max < min)
			return false;
	}


	Vector3 rel=p_to-p_from;

	if (r_normal) {
		Vector3 normal;
		normal[axis]=sign;
		*r_normal=normal;
	}

	if (r_clip)
		*r_clip=p_from+rel*min;

	return true;

}


bool AABB::intersects_plane(const Plane &p_plane) const {

	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	),
	};

	bool over=false;
	bool under=false;

	for (int i=0;i<8;i++) {

		if (p_plane.distance_to(points[i])>0)
			over=true;
		else
			under=true;

	}

	return under && over;
}



Vector3 AABB::get_longest_axis() const {

	Vector3 axis(1,0,0);
	real_t max_size=size.x;

	if (size.y > max_size ) {
		axis=Vector3(0,1,0);
		max_size=size.y;
	}

	if (size.z > max_size ) {
		axis=Vector3(0,0,1);
		max_size=size.z;
	}

	return axis;
}
int AABB::get_longest_axis_index() const {

	int axis=0;
	real_t max_size=size.x;

	if (size.y > max_size ) {
		axis=1;
		max_size=size.y;
	}

	if (size.z > max_size ) {
		axis=2;
		max_size=size.z;
	}

	return axis;
}


Vector3 AABB::get_shortest_axis() const {

	Vector3 axis(1,0,0);
	real_t max_size=size.x;

	if (size.y < max_size ) {
		axis=Vector3(0,1,0);
		max_size=size.y;
	}

	if (size.z < max_size ) {
		axis=Vector3(0,0,1);
		max_size=size.z;
	}

	return axis;
}
int AABB::get_shortest_axis_index() const {

	int axis=0;
	real_t max_size=size.x;

	if (size.y < max_size ) {
		axis=1;
		max_size=size.y;
	}

	if (size.z < max_size ) {
		axis=2;
		max_size=size.z;
	}

	return axis;
}

AABB AABB::merge(const AABB& p_with) const {

	AABB aabb=*this;
	aabb.merge_with(p_with);
	return aabb;
}
AABB AABB::expand(const Vector3& p_vector) const {
	AABB aabb=*this;
	aabb.expand_to(p_vector);
	return aabb;

}
AABB AABB::grow(real_t p_by) const {

	AABB aabb=*this;
	aabb.grow_by(p_by);
	return aabb;
}

void AABB::get_edge(int p_edge,Vector3& r_from,Vector3& r_to) const {

	ERR_FAIL_INDEX(p_edge,12);
	switch(p_edge) {

		case 0:{

			r_from=Vector3( pos.x+size.x	, pos.y		, pos.z		);
			r_to=Vector3( pos.x	, pos.y		, pos.z		);
		} break;
		case 1:{

			r_from=Vector3( pos.x+size.x	, pos.y		, pos.z+size.z	);
			r_to=Vector3( pos.x+size.x	, pos.y		, pos.z		);
		} break;
		case 2:{
			r_from=Vector3( pos.x	, pos.y		, pos.z+size.z	);
			r_to=Vector3( pos.x+size.x	, pos.y		, pos.z+size.z	);

		} break;
		case 3:{

			r_from=Vector3( pos.x	, pos.y		, pos.z		);
			r_to=Vector3( pos.x	, pos.y		, pos.z+size.z	);

		} break;
		case 4:{

			r_from=Vector3( pos.x	, pos.y+size.y		, pos.z		);
			r_to=Vector3( pos.x+size.x	, pos.y+size.y		, pos.z		);
		} break;
		case 5:{

			r_from=Vector3( pos.x+size.x	, pos.y+size.y		, pos.z		);
			r_to=Vector3( pos.x+size.x	, pos.y+size.y		, pos.z+size.z	);
		} break;
		case 6:{
			r_from=Vector3( pos.x+size.x	, pos.y+size.y		, pos.z+size.z	);
			r_to=Vector3( pos.x	, pos.y+size.y		, pos.z+size.z	);

		} break;
		case 7:{

			r_from=Vector3( pos.x	, pos.y+size.y		, pos.z+size.z	);
			r_to=Vector3( pos.x	, pos.y+size.y		, pos.z		);

		} break;
		case 8:{

			r_from=Vector3( pos.x	, pos.y		, pos.z+size.z	);
			r_to=Vector3( pos.x	, pos.y+size.y		, pos.z+size.z	);

		} break;
		case 9:{

			r_from=Vector3( pos.x	, pos.y		, pos.z		);
			r_to=Vector3( pos.x	, pos.y+size.y	, pos.z		);

		} break;
		case 10:{

			r_from=Vector3( pos.x+size.x	, pos.y		, pos.z		);
			r_to=Vector3( pos.x+size.x	, pos.y+size.y	, pos.z		);

		} break;
		case 11:{

			r_from=Vector3( pos.x+size.x	, pos.y		, pos.z+size.z		);
			r_to=Vector3( pos.x+size.x	, pos.y+size.y	, pos.z+size.z		);

		} break;

	}

}

AABB::operator String() const {

	return String()+pos +" - "+ size;
}