BansheeEngine/BansheeUtility/Include/BsSphere.h

#pragma once

#include "BsPrerequisitesUtil.h"
#include "BsVector3.h"

namespace BansheeEngine 
{
	/** @addtogroup Math
	 *  @{
	 */

    /** A sphere represented by a center point and a radius. */
    class BS_UTILITY_EXPORT Sphere
    {
    public:
        /** Default constructor. Creates a unit sphere around the origin. */
        Sphere() : mRadius(1.0), mCenter(Vector3::ZERO) 
		{ }

        Sphere(const Vector3& center, float radius)
            :mRadius(radius), mCenter(center) 
		{ }

        /** Returns the radius of the sphere. */
        float getRadius(void) const { return mRadius; }

        /** Sets the radius of the sphere. */
        void setRadius(float radius) { mRadius = radius; }

        /** Returns the center point of the sphere. */
        const Vector3& getCenter(void) const { return mCenter; }

        /** Sets the center point of the sphere. */
        void setCenter(const Vector3& center) { mCenter = center; }

		/** Merges the two spheres, creating a new sphere that encapsulates them both. */
		void merge(const Sphere& rhs);

		/** Expands the sphere so it includes the provided point. */
		void merge(const Vector3& point);

		/** Transforms the sphere by the given matrix. */
		void transform(const Matrix4& matrix);

		/** Returns whether or not this sphere contains the provided point. */
		bool contains(const Vector3& v) const
		{
            return ((v - mCenter).squaredLength() <= Math::sqr(mRadius));
		}

		/** Returns whether or not this sphere intersects another sphere. */
		bool intersects(const Sphere& s) const
		{
            return (s.mCenter - mCenter).squaredLength() <=
                Math::sqr(s.mRadius + mRadius);
		}

		/** Returns whether or not this sphere intersects a box. */
		bool intersects(const AABox& box) const;

		/** Returns whether or not this sphere intersects a plane. */
		bool intersects(const Plane& plane) const;

		/**
		 * Ray/sphere intersection, returns boolean result and distance to nearest intersection.
		 * 			
		 * @param[in]	discardInside	(optional) If true the intersection will be discarded if ray origin
		 * 								is located within the sphere.
		 */
		std::pair<bool, float> intersects(const Ray& ray, bool discardInside = true) const;

	private:
		float mRadius;
		Vector3 mCenter;
    };

	/** @} */

	/** @cond SPECIALIZATIONS */
	BS_ALLOW_MEMCPY_SERIALIZATION(Sphere);
	/** @endcond */
}