geom-curves.h

#ifndef INKSCAPE_HELPER_GEOM_CURVES_H
#define INKSCAPE_HELPER_GEOM_CURVES_H

/**
 * Specific curve type functions for Inkscape, not provided by lib2geom.
 *
 * Author:
 *   Johan Engelen <goejendaagh@zonnet.nl>
 *
 * Copyright (C) 2008-2009 Johan Engelen
 *
 * Released under GNU GPL
 */

#include <2geom/hvlinesegment.h>
#include <2geom/line.h>
#include <2geom/bezier-curve.h>

/// \todo un-inline this function
inline bool is_straight_curve(Geom::Curve const & c) {
    if( dynamic_cast<Geom::LineSegment const*>(&c) ||
        dynamic_cast<Geom::HLineSegment const*>(&c) ||
        dynamic_cast<Geom::VLineSegment const*>(&c) )
    {
        return true;
    }
    // the curve can be a quad/cubic bezier, but could still be a perfect straight line
    // if the control points are exactly on the line connecting the initial and final points.
    else if ( Geom::QuadraticBezier const *quad = dynamic_cast<Geom::QuadraticBezier const*>(&c) ) {
        Geom::Line line( quad->initialPoint(), quad->finalPoint() );
        if ( are_near((*quad)[1], line) ) {
            return true;
        }
    }
    else if ( Geom::CubicBezier const *cubic = dynamic_cast<Geom::CubicBezier const*>(&c) ) {
        Geom::Line line( cubic->initialPoint(), cubic->finalPoint() );
        if ( are_near((*cubic)[1], line) && are_near((*cubic)[2], line) ) {
            return true;
        }
    }

    return false;
}

#endif  // INKSCAPE_HELPER_GEOM_CURVES_H

/*
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  mode:c++
  c-file-style:"stroustrup"
  c-file-offsets:((innamespace . 0)(inline-open . 0)(case-label . +))
  indent-tabs-mode:nil
  fill-column:99
  End:
*/
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