xref: /aoo41x/main/basegfx/inc/basegfx/vector/b2dvector.hxx (revision ce9c7ef7)

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#ifndef _BGFX_VECTOR_B2DVECTOR_HXX
#define _BGFX_VECTOR_B2DVECTOR_HXX

#include <basegfx/tuple/b2dtuple.hxx>
#include <basegfx/vector/b2ivector.hxx>
#include <basegfx/vector/b2enums.hxx>

namespace basegfx
{
	// predeclaration
	class B2DHomMatrix;

	/** Base Point class with two double values

		This class derives all operators and common handling for
		a 2D data class from B2DTuple. All necessary extensions
		which are special for 2D Vectors are added here.

		@see B2DTuple
	*/
	class B2DVector : public ::basegfx::B2DTuple
	{
	public:
		/**	Create a 2D Vector

        	The vector is initialized to (0.0, 0.0)
		*/
		B2DVector()
		:	B2DTuple()
		{}

		/**	Create a 2D Vector

			@param fX
			This parameter is used to initialize the X-coordinate
			of the 2D Vector.

			@param fY
			This parameter is used to initialize the Y-coordinate
			of the 2D Vector.
		*/
		B2DVector(double fX, double fY)
		:	B2DTuple(fX, fY)
		{}

		/**	Create a copy of a 2D Vector

			@param rVec
			The 2D Vector which will be copied.
		*/
		B2DVector(const B2DVector& rVec)
		:	B2DTuple(rVec)
		{}

		/**	Create a copy of a 2D Vector

			@param rVec
			The 2D Vector which will be copied.
		*/
		B2DVector(const ::basegfx::B2IVector& rVec)
		:	B2DTuple(rVec)
		{}

		/** constructor with tuple to allow copy-constructing
			from B2DTuple-based classes
		*/
		B2DVector(const ::basegfx::B2DTuple& rTuple)
		:	B2DTuple(rTuple)
		{}

		~B2DVector()
		{}

		/** *=operator to allow usage from B2DVector, too
		*/
		B2DVector& operator*=( const B2DVector& rPnt )
		{
			mfX *= rPnt.mfX;
			mfY *= rPnt.mfY;
			return *this;
		}

		/** *=operator to allow usage from B2DVector, too
		*/
		B2DVector& operator*=(double t)
		{
			mfX *= t;
			mfY *= t;
			return *this;
		}

		/** assignment operator to allow assigning the results
			of B2DTuple calculations
		*/
		B2DVector& operator=( const ::basegfx::B2DTuple& rVec );

		/** Calculate the length of this 2D Vector

			@return The Length of the 2D Vector
		*/
		double getLength() const;

		/** Set the length of this 2D Vector

			@param fLen
			The to be achieved length of the 2D Vector
		*/
		B2DVector& setLength(double fLen);

		/** Normalize this 2D Vector

			The length of the 2D Vector is set to 1.0
		*/
		B2DVector& normalize();

		/** Test if this 2D Vector is normalized

			@return
			true if lenth of vector is equal to 1.0
			false else
		*/
		bool isNormalized() const;

		/** Calculate the Scalar with another 2D Vector

			@param rVec
			The second 2D Vector

			@return
			The Scalar value of the two involved 2D Vectors
		*/
		double scalar( const B2DVector& rVec ) const;

		/** Calculate the length of the cross product with another 2D Vector

            In 2D, returning an actual vector does not make much
            sense here. The magnitude, although, can be readily
            used for tasks such as angle calculations, since for
            the returned value, the following equation holds:
            retVal = getLength(this)*getLength(rVec)*sin(theta),
            with theta being the angle between the two vectors.

			@param rVec
			The second 2D Vector

			@return
			The length of the cross product of the two involved 2D Vectors
		*/
		double cross( const B2DVector& rVec ) const;

		/** Calculate the Angle with another 2D Vector

			@param rVec
			The second 2D Vector

			@return
			The Angle value of the two involved 2D Vectors in -pi/2 < return < pi/2
		*/
		double angle( const B2DVector& rVec ) const;

		/** Transform vector by given transformation matrix.

        	Since this is a vector, translational components of the
        	matrix are disregarded.
		*/
		B2DVector& operator*=( const B2DHomMatrix& rMat );

		static const B2DVector& getEmptyVector();
	};

	// external operators
	//////////////////////////////////////////////////////////////////////////

	/** Calculate the orientation to another 2D Vector

		@param rVecA
		The first 2D Vector

		@param rVecB
		The second 2D Vector

		@return
		The mathematical Orientation of the two involved 2D Vectors
	*/
	B2VectorOrientation getOrientation( const B2DVector& rVecA, const B2DVector& rVecB );

	/** Calculate a perpendicular 2D Vector to the given one

		@param rVec
		The source 2D Vector

		@attention This only works if the given 2D Vector is normalized.

		@return
		A 2D Vector perpendicular to the one given in parameter rVec
	*/
	B2DVector getPerpendicular( const B2DVector& rNormalizedVec );

	/** Calculate a perpendicular 2D Vector to the given one,
		normalize the given one as preparation

		@param rVec
		The source 2D Vector

		@return
		A normalized 2D Vector perpendicular to the one given in parameter rVec
	*/
	B2DVector getNormalizedPerpendicular( const B2DVector& rVec );

	/** Test two vectors which need not to be normalized for parallelism

		@param rVecA
		The first 2D Vector

		@param rVecB
		The second 2D Vector

		@return
		bool if the two values are parallel. Also true if
		one of the vectors is empty.
	*/
	bool areParallel( const B2DVector& rVecA, const B2DVector& rVecB );

	/** Transform vector by given transformation matrix.

		Since this is a vector, translational components of the
    	matrix are disregarded.
	*/
	B2DVector operator*( const B2DHomMatrix& rMat, const B2DVector& rVec );

	/** Test continuity between given vectors.

		The two given vectors are assumed to describe control points on a
    	common point. Calculate if there is a continuity between them.
	*/
	B2VectorContinuity getContinuity( const B2DVector& rBackVector, const B2DVector& rForwardVector );

} // end of namespace basegfx

#endif /* _BGFX_VECTOR_B2DVECTOR_HXX */