basegfx/source/workbench/bezierclip.hxx

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  30
  31 #ifndef BASEGFX_BEZIERCLIP_HXX
  32 #define BASEGFX_BEZIERCLIP_HXX
  33
  34 #include <vector>
  35
  36 struct Point2D
  37 {
  38     typedef double value_type;
  39     Point2D( double _x, double _y ) : x(_x), y(_y) {}
  40     Point2D() : x(), y() {}
  41     double x;
  42     double y;
  43 };
  44
  45 struct Bezier
  46 {
  47     Point2D     p0;
  48     Point2D     p1;
  49     Point2D     p2;
  50     Point2D     p3;
  51
  52     Point2D&            operator[]( int i ) { return reinterpret_cast<Point2D*>(this)[i]; }
  53     const Point2D&      operator[]( int i ) const { return reinterpret_cast<const Point2D*>(this)[i]; }
  54 };
  55
  56 struct FatLine
  57 {
  58     // line L through p1 and p4 in normalized implicit form
  59     double a;
  60     double b;
  61     double c;
  62
  63     // the upper and lower distance from this line
  64     double dMin;
  65     double dMax;
  66 };
  67
  68 template <typename DataType> DataType calcLineDistance( const DataType& a,
  69                                                         const DataType& b,
  70                                                         const DataType& c,
  71                                                         const DataType& x,
  72                                                         const DataType& y )
  73 {
  74     return a*x + b*y + c;
  75 }
  76
  77 typedef ::std::vector< Point2D > Polygon2D;
  78
  79 /* little abs template */
  80 template <typename NumType> NumType absval( NumType x )
  81 {
  82     return x<0 ? -x : x;
  83 }
  84
  85 Polygon2D convexHull( const Polygon2D& rPoly );
  86
  87 // TODO: find proper epsilon here (try ::std::numeric_limits<NumType>::epsilon()?)!
  88 #define DBL_EPSILON 1.0e-100
  89
  90 /* little approximate comparions */
  91 template <typename NumType> bool tolZero( NumType n ) { return fabs(n) < DBL_EPSILON; }
  92 template <typename NumType> bool tolEqual( NumType n1, NumType n2 ) { return tolZero(n1-n2); }
  93 template <typename NumType> bool tolLessEqual( NumType n1, NumType n2 ) { return tolEqual(n1,n2) || n1<n2; }
  94 template <typename NumType> bool tolGreaterEqual( NumType n1, NumType n2 ) { return tolEqual(n1,n2) || n1>n2; }
  95
  96 #endif /* BASEGFX_BEZIERCLIP_HXX */