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User Documentation |
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Centre for Vision, Speech & Signal Processing |
Comments:
The class represents a point/line in 2 dimensional projective space.
An object contains 3 real numbers which serve as its projective
coordinates. An object can be treated as a point and its dual line
and vice versa in any time. This feature reflects the dual relationship
of points and lines in 2D projective space. The index of coordinates
starts from 0.
Parent Classes:
Derived Classes:
Typedefs:
- typedef Point3dC::CoordT PCoordT;
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A projective coordinate.
- typedef Point3dC::CoordT CCoordT;
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An cartesian coordinate.
Methods:
- PPointLine2dC()
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Constructs the point/line whose coordinates are zeros, eg. non-existing
projective object.
- PPointLine2dC(CCoordT x,CCoordT y)
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Constructs the point/line (x, y, 1). x,y represent either
point Cartesian coordinates or a line normal expressed as vector
Cartesian coordinates.
- PPointLine2dC(const Point2dC & p)
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Constructs the projective point/line (p.X(), p.Y(), 1) related
to the Euclidian point 'p'.
- PPointLine2dC(const Vector2dC & v)
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Constructs the projective point/line (v.X(), v.Y(), 0) related
to the Euclidian direction 'v'.
- PPointLine2dC(PCoordT p1,PCoordT p2,PCoordT p3)
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Constructs the point/line (p1, p2, p3).
- PPointLine2dC(const PPointLine2dC & p0,const PPointLine2dC & p1)
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Constructs the projective point/line determined by two
projective lines/points, resp.
- PPointLine2dC(const PPointLine2dC & p)
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Copy constructor.
- const PPointLine2dC & operator=(const PPointLine2dC & p)
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Assigment of a point/line 'p'.
Access to the object items.
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- const PCoordT & operator[](IndexT i) const
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Returns the value of the i-th coordinate.
- PCoordT & operator[](IndexT i)
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Access the value of the i-th coordinate.
- CCoordT operator()(IndexT i) const
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Returns the value of the i-th Cartesian coordinate.
The function does not check if the point/line is ideal or not or
the range of the index 'i'.
- PCoordT Scale() const
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Returns the value of the last projective coordinate P3().
- const PCoordT & P1() const
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Returns the value of the 1st coordinate.
- const PCoordT & P2() const
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Returns the value of the 2nd coordinate.
- const PCoordT & P3() const
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Returns the value of the 3rd coordinate.
- PCoordT & P1()
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Returns the value of the 1st coordinate.
- PCoordT & P2()
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Returns the value of the 2nd coordinate.
- PCoordT & P3()
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Returns the value of the 3rd coordinate.
- CCoordT X() const
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Returns the value of the 1. Cartesian coordinate. The function
does not check if the point/line is ideal or not.
- CCoordT Y() const
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Returns the value of the 2. Cartesian coordinate. The function
does not check if the point/line is ideal or not.
- const PPointLine2dC & PPointLine2d() const
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Access to this constant object.
- PPointLine2dC & PPointLine2d()
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Access to the point/line.
Logical conditions.
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- BooleanT operator==(const PPointLine2dC & p) const
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Returns TRUE iff 2 points/lines are the same projective point/line.
Two projective points/lines are equal iff their 3D Cartesian
representants are equal.
- BooleanT operator!=(const PPointLine2dC & p) const
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Returns TRUE iff 2 points/lines are different projective points/lines.
Two projective points/lines are different iff they are not
equal in the sense of the operator '=='.
- BooleanT IsIdealPoint() const
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Returns TRUE iff this point/line represents an ideal projective point.
The point is an ideal projective point if the absolute value of
the ratio Scale()/SumAbs() is smaller or equal to
the threshold 'Point3dC::relZero'.
- BooleanT IsIdealLine() const
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Returns TRUE iff this point/line represents an ideal projective plane.
The plane is an ideal projective plane if the absolute value of
the ratio (Abs(P1)+Abs(P2())/Scale() is smaller or equal to
the threshold 'Point3dC::relZero'.
- BooleanT IsValid() const
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Returns TRUE if the sum of absolute values of the projective coordinates
is bigger than the threshold 'Point3dC::zeroDistance'.
Setting of the coordinates.
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- void Set(const PPointLine2dC & p)
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Sets coordinates according to the values of the point/line 'p'.
- void Set(const PCoordT p1,const PCoordT p2,const PCoordT p3)
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Sets the 1-st coordinate to be 'p1', the 2nd one to be 'p2',
and the 3rd one to be 'p3'.
Information about extrems.
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- IndexT MaxIndex() const
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Returns the index of the maximum coordinate.
- IndexT MinIndex() const
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Returns the index of the minimum coordinate.
- IndexT AbsMaxIndex() const
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Returns the index of the maximum coordinate in absolute value.
- IndexT AbsMinIndex() const
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Returns the index of the minimum coordinate in absolute value.
- PCoordT Sum() const
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Returns the sum of coordinates.
- PCoordT SumAbs() const
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Returns the sum of absolute value of coordinates.
Arithmetical operations.
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- const PPointLine2dC & operator+=(const PPointLine2dC & p)
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Adds the values of the coordinates of the 'p' to this point/line.
- const PPointLine2dC & operator-=(const PPointLine2dC & p)
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Subtracts the values of the coordinates of the 'p' from this
point/line.
- const PPointLine2dC & operator*=(const RealT alpha)
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Multiplies all coordinates by 'alpha'.
- const PPointLine2dC & operator/=(const RealT alpha)
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Divides all coordinates by 'alpha'.
- PPointLine2dC operator+(const PPointLine2dC & p) const
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Returns the point/line which is the sum of this point and the 'p'.
- PPointLine2dC operator*(const RealT alpha) const
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Returns the point/line which coordinates are multiplied by 'alpha'.
- PPointLine2dC operator/(const RealT alpha) const
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Returns the point/line which coordinates are divided by 'alpha'.
Geometrical operations.
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- RealT operator&(const PPointLine2dC & p) const
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Returns the sum P1()*p.P1() + P2()*p.P2() + P3()*p.P3().
In 3 dimensional Euclidian vector space the result is equivalent
to dot product of 2 vectors.
- PPointLine2dC PPointLine2d(const PPointLine2dC & p) const
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Returns the projective line/point determined by this point/line
and the point/line 'p'.
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Programmer:Radek Marik, Documentation by CxxDoc: Tue Mar 20 10:48:08 2001
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