inkscape/src/sp-spiral.h

	sp-spiral.h revision d74e415b7dd25ccb70d40a9f11ec99f23b57ed63
#ifndef SEEN_SP_SPIRAL_H
#define SEEN_SP_SPIRAL_H
/*
 * Authors:
 *   Mitsuru Oka <oka326@parkcity.ne.jp>
 *   Lauris Kaplinski <lauris@kaplinski.com>
 *
 * Copyright (C) 1999-2002 Lauris Kaplinski
 * Copyright (C) 2000-2001 Ximian, Inc.
 *
 * Released under GNU GPL, read the file 'COPYING' for more information
 */

#include "sp-shape.h"

#define noSPIRAL_VERBOSE

#define SP_EPSILON       1e-5
#define SP_EPSILON_2     (SP_EPSILON * SP_EPSILON)
#define SP_HUGE          1e5

#define SPIRAL_TOLERANCE 3.0
#define SAMPLE_STEP      (1.0/4.0) ///< step per 2PI
#define SAMPLE_SIZE      8         ///< sample size per one bezier


#define SP_SPIRAL(obj) ((SPSpiral*)obj)
#define SP_IS_SPIRAL(obj) (dynamic_cast<const SPSpiral*>((SPObject*)obj) != NULL)

/**
 * A spiral Shape.
 *
 * The Spiral shape is defined as:
 * \verbatim
   x(t) = rad * t^exp cos(2 * Pi * revo*t + arg) + cx
   y(t) = rad * t^exp sin(2 * Pi * revo*t + arg) + cy    \endverbatim
 * where spiral curve is drawn for {t | t0 <= t <= 1}. The  rad and arg
 * parameters can also be represented by transformation.
 *
 * \todo Should I remove these attributes?
 */
class SPSpiral : public SPShape {
public:
    SPSpiral();
    virtual ~SPSpiral();

    float cx, cy;
    float exp;  ///< Spiral expansion factor
    float revo; ///< Spiral revolution factor
    float rad;  ///< Spiral radius
    float arg;  ///< Spiral argument
    float t0;

    /* Lowlevel interface */
    void setPosition(gdouble cx, gdouble cy, gdouble exp, gdouble revo, gdouble rad, gdouble arg, gdouble t0);

    Geom::Point getXY(gdouble t) const;

    void getPolar(gdouble t, gdouble* rad, gdouble* arg) const;

    bool isInvalid() const;

//private:
    Geom::Point getTangent(gdouble t) const;

    void fitAndDraw(SPCurve* c, double dstep, Geom::Point darray[], Geom::Point const& hat1, Geom::Point& hat2, double* t) const;

    virtual void build(SPDocument* doc, Inkscape::XML::Node* repr);
    virtual Inkscape::XML::Node* write(Inkscape::XML::Document *xml_doc, Inkscape::XML::Node *repr, guint flags);
    virtual void update(SPCtx *ctx, guint flags);
    virtual void set(unsigned int key, gchar const* value);

    virtual void snappoints(std::vector<Inkscape::SnapCandidatePoint> &p, Inkscape::SnapPreferences const *snapprefs);
    virtual gchar* description();

    virtual void set_shape();
    virtual void update_patheffect(bool write);
};

#endif // SEEN_SP_SPIRAL_H