RDCode: Transform2D.h Source File

# Transform2D.h

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    00001 //
    00002 //   Copyright (C) 2003-2006 Rational Discovery LLC
    00003 //
    00004 //   @@ All Rights Reserved  @@
    00005 //
    00006 #ifndef __RD_TRANSFORM2D_H__
    00007 #define __RD_TRANSFORM2D_H__
    00008
    00009 #include "Transform.h"
    00010 #include <Numerics/SquareMatrix.h>
    00011
    00012 namespace RDGeom {
    00013   class Point2D;
    00014   const unsigned int DIM_2D=3;
    00015
    00016   class Transform2D : public RDNumeric::SquareMatrix<double> {
    00017   public:
    00018     //! \brief Constructor
    00019     /*!
    00020       Initialize to an identity matrix transformation
    00021       This is a 3x3 matrix that includes the rotation and translation parts
    00022       see Foley's "Introduction to Computer Graphics" for the representation
    00023
    00024       Operator *= and = are provided by the parent class square matrix.
    00025       Operator *= needs some explanation, since the order matters. This transform gets set to
    00026       the combination other and the current state of this transform
    00027       If this_old and this_new are the states of this object before and after this function
    00028       we have
    00029               this_new(point) = this_old(other(point))
    00030     */
    00031     Transform2D() : RDNumeric::SquareMatrix<double>(DIM_2D,0.0) {
    00032       unsigned int i, id;
    00033       for (i = 0; i < DIM_2D; i++) {
    00034         id = i*(DIM_2D+1);
    00035         d_data[id] = 1.0;
    00036       }
    00037     }
    00038
    00039     void setToIdentity();
    00040
    00041     void TransformPoint(Point2D &pt) const;
    00042
    00043     void SetTranslation(const Point2D &pt);
    00044
    00045     /*! \brief Set the tranform so that the specified points are aligned
    00046      *
    00047      * The resulting tranformation will align pt1 with ref1, and rotation
    00048      * pt2 such that the line betweem (pt1, pt2) will align with
    00049      * with the line (ref1, ref2)
    00050      */
    00051     void SetTransform(const Point2D &ref1, const Point2D &ref2,
    00052                       const Point2D &pt1, const Point2D &pt2);
    00053
    00054     /*! \brief Set the trans form to counterclock wise rotation by the specified value around point
    00055      *
    00056      * ARGUMENTS:
    00057      *   - pt : point about which to rotate
    00058      *   - angle : the angle byt which to rotate
    00059      */
    00060     void SetTransform(const Point2D &pt, double angle);
    00061
    00062   private:
    00063
    00064   };
    00065 }
    00066
    00067 /*! \brief Combine two transforms and return the results as a new transform
    00068  *
    00069  * The order is important here, on two transforms t1 and t2
    00070  * t3 = t1*t2
    00071  * The resulting transform t3 has the folliwng effect
    00072  *  t3(point) = t1(t2(point))
    00073  */
    00074 RDGeom::Transform2D operator* (const RDGeom::Transform2D &t1, const RDGeom::Transform2D &t2);
    00075
    00076
    00077 #endif
    00078