xref: /trunk/main/basegfx/source/workbench/bezierclip.hxx (revision ce9c7ef7bd056b6da7d6eeebb749fbf2160d647b)

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 *
 * Licensed to the Apache Software Foundation (ASF) under one
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 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
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#ifndef BASEGFX_BEZIERCLIP_HXX
#define BASEGFX_BEZIERCLIP_HXX

#include <vector>

struct Point2D
{
    typedef double value_type;
    Point2D( double _x, double _y ) : x(_x), y(_y) {}
    Point2D() : x(), y() {}
    double x;
    double y;
};

struct Bezier
{
    Point2D p0;
    Point2D p1;
    Point2D p2;
    Point2D p3;

    Point2D&        operator[]( int i ) { return reinterpret_cast<Point2D*>(this)[i]; }
    const Point2D&  operator[]( int i ) const { return reinterpret_cast<const Point2D*>(this)[i]; }
};

struct FatLine
{
    // line L through p1 and p4 in normalized implicit form
    double a;
    double b;
    double c;

    // the upper and lower distance from this line
    double dMin;
    double dMax;
};

template <typename DataType> DataType calcLineDistance( const DataType& a,
                                                        const DataType& b,
                                                        const DataType& c,
                                                        const DataType& x,
                                                        const DataType& y )
{
    return a*x + b*y + c;
}

typedef ::std::vector< Point2D > Polygon2D;

/* little abs template */
template <typename NumType> NumType absval( NumType x )
{
    return x<0 ? -x : x;
}

Polygon2D convexHull( const Polygon2D& rPoly );

// TODO: find proper epsilon here (try ::std::numeric_limits<NumType>::epsilon()?)!
#define DBL_EPSILON 1.0e-100

/* little approximate comparions */
template <typename NumType> bool tolZero( NumType n ) { return fabs(n) < DBL_EPSILON; }
template <typename NumType> bool tolEqual( NumType n1, NumType n2 ) { return tolZero(n1-n2); }
template <typename NumType> bool tolLessEqual( NumType n1, NumType n2 ) { return tolEqual(n1,n2) || n1<n2; }
template <typename NumType> bool tolGreaterEqual( NumType n1, NumType n2 ) { return tolEqual(n1,n2) || n1>n2; }

#endif /* BASEGFX_BEZIERCLIP_HXX */