include/basegfx/polygon/b2dtrapezoid.hxx

   1 /* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
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  19
  20 #pragma once
  21
  22 #include <config_options.h>
  23 #include <basegfx/polygon/b2dpolygon.hxx>
  24 #include <vector>
  25 #include <basegfx/basegfxdllapi.h>
  26
  27
  28 namespace basegfx { class B2DPolyPolygon; }
  29 namespace basegfx { class B2DPoint; }
  30
  31 namespace basegfx
  32 {
  33     // class to hold a single trapezoid
  34     class UNLESS_MERGELIBS(BASEGFX_DLLPUBLIC) B2DTrapezoid
  35     {
  36     private:
  37         // Geometry data. YValues are down-oriented, this means bottom should
  38         // be bigger than top to be below it. The constructor implementation
  39         // guarantees:
  40
  41         // - mfBottomY >= mfTopY
  42         // - mfTopXRight >= mfTopXLeft
  43         // - mfBottomXRight >= mfBottomXLeft
  44         double              mfTopXLeft;
  45         double              mfTopXRight;
  46         double              mfTopY;
  47         double              mfBottomXLeft;
  48         double              mfBottomXRight;
  49         double              mfBottomY;
  50
  51     public:
  52         // constructor
  53         B2DTrapezoid(
  54             const double& rfTopXLeft,
  55             const double& rfTopXRight,
  56             const double& rfTopY,
  57             const double& rfBottomXLeft,
  58             const double& rfBottomXRight,
  59             const double& rfBottomY);
  60
  61         // data read access
  62         const double& getTopXLeft() const { return mfTopXLeft; }
  63         const double& getTopXRight() const { return mfTopXRight; }
  64         const double& getTopY() const { return mfTopY; }
  65         const double& getBottomXLeft() const { return mfBottomXLeft; }
  66         const double& getBottomXRight() const { return mfBottomXRight; }
  67         const double& getBottomY() const { return mfBottomY; }
  68
  69         // convenience method to get content as Polygon
  70         B2DPolygon getB2DPolygon() const;
  71     };
  72
  73     typedef ::std::vector< B2DTrapezoid > B2DTrapezoidVector;
  74
  75 } // end of namespace basegfx
  76
  77
  78 namespace basegfx::utils
  79 {
  80     // convert SourcePolyPolygon to trapezoids. The trapezoids will be appended to
  81     // ro_Result. ro_Result will not be cleared. If SourcePolyPolygon contains curves,
  82     // it's default AdaptiveSubdivision will be used.
  83     // CAUTION: Trapezoids are orientation-dependent in the sense that the upper and lower
  84     // lines have to be parallel to the X-Axis, thus this subdivision is NOT simply usable
  85     // for primitive decompositions. To use it, the shear and rotate parts of the
  86     // involved transformations HAVE to be taken into account.
  87     BASEGFX_DLLPUBLIC void trapezoidSubdivide(
  88         B2DTrapezoidVector& ro_Result,
  89         const B2DPolyPolygon& rSourcePolyPolygon);
  90
  91     // directly create trapezoids from given edge. Depending on the given geometry,
  92     // none up to three trapezoids will be created
  93     void createLineTrapezoidFromEdge(
  94         B2DTrapezoidVector& ro_Result,
  95         const B2DPoint& rPointA,
  96         const B2DPoint& rPointB,
  97         double fLineWidth);
  98
  99     // create trapezoids for all edges of the given polygon. The closed state of
 100     // the polygon is taken into account. If curves are contained, the default
 101     // AdaptiveSubdivision will be used.
 102     void createLineTrapezoidFromB2DPolygon(
 103         B2DTrapezoidVector& ro_Result,
 104         const B2DPolygon& rPolygon,
 105         double fLineWidth);
 106 } // end of namespace basegfx::utils
 107
 108 /* vim:set shiftwidth=4 softtabstop=4 expandtab: */