binfilter/inc/bf_sch/calculat.hxx

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  30
  31 // header for BOOL
  32 #ifndef _SOLAR_H
  33 #include <tools/solar.h>
  34 #endif
  35
  36 #include <vector>
  37 #include <utility>
  38 class Point;
  39 class Rectangle;
  40 namespace binfilter {
  41
  42 class Line;
  43 class XPolygon;
  44 class XPolyPolygon;
  45
  46 /**     @descr  This class clips single lines and polygons at a given rectangle.
  47         All of it's methods are static, therefore no object has to be created.
  48
  49         It uses the Liang-Biarsky parametric line-clipping algorithm as described in:
  50             Computer Graphics: principles and practice, 2nd ed.,
  51             James D. Foley et al.,
  52             Section 3.12.4 on page 117.
  53 */
  54 class SchCalculationHelper
  55 {
  56 public:
  57     /** like Rectangle::IsInside, but the result is FALSE, if
  58         the Point is on the Border of the Rectangle
  59      */
  60 //      static BOOL IsPointInsideRectangle( const Point& rPoint, const Rectangle& rRect );
  61
  62     /** @descr  The line is clipped at the rectangle.  If the line lies completely or partly
  63              inside the clipping area then TRUE is returned and the line is modified accordingly.
  64              If the line lies completely outside the clipping area then FALSE is returned and the
  65              line remains unmodified.
  66              The line may be degenerate in that both of it's end points have the same
  67              coordinates.
  68         @param  aLine   The line to be clipped.  It is modified to a part that lies completely
  69             inside the clipping area if such a part exists.
  70         @param  rRectangle      The clipping area.
  71         @return TRUE is returned if the line lies completely or partly inside the clipping area.
  72      */
  73
  74     /** @descr  The intersection between an open polygon and a rectangle is
  75             calculated and the resulting lines are placed into the poly-polygon aResult.
  76         @param  rPolygon        The polygon is required to be open, ie. it's start and end point
  77             have different coordinates and that it is continuous, ie. has no holes.
  78         @param  rRectangle      The clipping area.
  79         @param  aResult The resulting lines that are the parts of the given polygon lying inside
  80             the clipping area are stored into aResult whose prior content is deleted first.
  81      */
  82     static void IntersectPolygonWithRectangle( const XPolygon& rPolygon, const Rectangle& rRectangle,
  83                                                XPolyPolygon& aResult );
  84
  85     /** @descr Calculates the intersection between a set of open polygons and a
  86                rectangle.  This function iterates over all polygons contained in
  87                rPolyPolygon and calls IntersectPolygonWithRectangle() for it.
  88                The resulting XPolyPolygons are then put together into aResult.
  89         @param rPolyPolygon  A set of polygons that must be open.
  90         @param rRectangle    The clipping region
  91         @param rOutResult    The resulting lines representing rPolyPolygon clipped
  92                              at rRectangle.
  93      */
  94
  95     /** @descr calculates natural cubic splines for the given set of points.
  96
  97         @param rPoints is a vector of tuples containing x and y coordinate of
  98                points that are to be interpolated.
  99         @param nGranularity The number of interpolation points between two
 100                x-values given in rPoints
 101
 102         @param rOutResult A polygon (split up into more, if the number of points
 103                is too high as to fit into a single XPolygon) that contains all
 104                line segments between the interpolated points.  It should contain
 105                (rPoints.size() * nGranularity) points.
 106
 107         @param nDPIX resolution in x-direction to reduce the number of points.
 108                A value of 0 (default) means do not take into account.
 109
 110         @param nDPIY resolution in y-direction to reduce the number of points.
 111                A value of 0 (default) means do not take into account.
 112      */
 113
 114 private:
 115     /** @descr  The line given by it's two endpoints rP0 and rP1 is clipped at the rectangle
 116             rRectangle.  If there is at least a part of it visible then TRUE is returned and
 117             the endpoints of that part are stored in rP0 and rP1.  The points rP0 and rP1
 118             may have the same coordinates.
 119         @param  rP0 Start point of the line to clip.  Modified to contain a start point inside
 120             the clipping area if possible.
 121         @param  rP1 End point of the line to clip.  Modified to contain an end point inside
 122             the clipping area if possible.
 123         @param  rRectangle Clipping area.
 124         @return If the line lies completely or partly inside the clipping area then TRUE
 125             is returned.  If the line lies completely outside then FALSE is returned and rP0 and
 126             rP1 are left unmodified.
 127     */
 128     static      BOOL    clip2d  (Point & rP0, Point & rP1, const Rectangle& rRectangle);
 129
 130     /** @descr  This is a supporting function for clip2d.  It computes a new parametric
 131             value for an entering (dTE) or leaving (dTL) intersection point with one
 132             of the edges bounding the clipping area.
 133             For explanation of the parameters please refer to the literature reference
 134             given above.
 135     */
 136     static      BOOL    CLIPt   (double fDenom, double fNum, double & fTE, double & fTL);
 137 };
 138
 139 } //namespace binfilter