BoundingSphere.cpp

#include "BoundingSphere.h"
#include <cmath>

BoundingSphere::BoundingSphere(const float& cx, 
								 const float& cy,
								 const float& cz,
								 const float& rad) : _center(cx, cy, cz), _radius(rad)
{
}

BoundingSphere::~BoundingSphere(void)
{
}


void BoundingSphere::setRadius(const float& rad)
{
	_radius = rad;
}

void BoundingSphere::setCenter(const float& cx, const float& cy, const float& cz)
{
	_center.setX(cx);
	_center.setY(cy);
	_center.setZ(cz);
}

void BoundingSphere::setCenter(const QVector3D& cen)
{
	_center = cen;
}

void BoundingSphere::addSphere(const BoundingSphere& other)
{
	if (qFuzzyCompare(_center, other._center) && qFuzzyCompare(_radius, other._radius)) // same sphere
		return;

	float smallerRadius = _radius < other._radius ? _radius : other._radius;
	if (_center.distanceToPoint(other._center) < smallerRadius) // one sphere inside other
	{
		if (_radius == smallerRadius) // this sphere is smaller
		{
			// make other sphere the bounding sphere
			_center = other._center;
			_radius = other._radius;
		}
		else // other sphere is already inside this one, do nothing
			return;
	}
	else // intersecting or touching or spaced
	{
		QVector3D toThisEnd = (_center - other._center).normalized();
		QVector3D toOtherEnd = (other._center - _center).normalized();

		QVector3D thisEndPoint = _center + toThisEnd * _radius;
		QVector3D otherEndPoint = other._center + toOtherEnd * other._radius;

		_radius = thisEndPoint.distanceToPoint(otherEndPoint) / 2;
		_center = thisEndPoint + toOtherEnd * _radius;
	}
}