sp-spiral.h

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// SPDX-License-Identifier: GPL-2.0-or-later
#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 v2+, 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) 
#define SAMPLE_SIZE      8         
 
class SPSpiral final : public SPShape {
public:
    SPSpiral();
    ~SPSpiral() override;
    int tag() const override { return tag_of<decltype(*this)>; }
 
    float cx, cy;
    float exp;  
    float revo; 
    float rad;  
    float arg;  
    float t0;
 
    /* Lowlevel interface */
    void setPosition(double cx, double cy, double exp, double revo, double rad, double arg, double t0);
    Geom::Affine set_transform(Geom::Affine const& xform) override;
 
    Geom::Point getXY(double t) const;
 
    void getPolar(double t, double* rad, double* arg) const;
 
    bool isInvalid() const;
 
    void build(SPDocument* doc, Inkscape::XML::Node* repr) override;
    Inkscape::XML::Node* write(Inkscape::XML::Document *xml_doc, Inkscape::XML::Node *repr, unsigned int flags) override;
    void update(SPCtx *ctx, unsigned int flags) override;
    void set(SPAttr key, char const* value) override;
 
    void snappoints(std::vector<Inkscape::SnapCandidatePoint> &p, Inkscape::SnapPreferences const *snapprefs) const override;
    const char* typeName() const override;
    const char* displayName() const override;
    char* description() const override;
    void update_patheffect(bool write) override;
    void set_shape() override;
 
private:
    Geom::Point getTangent(double t) const;
    void fitAndDraw(Geom::Path &c, double dstep, Geom::Point darray[], Geom::Point const& hat1, Geom::Point& hat2, double* t) const;
};
 
#endif // SEEN_SP_SPIRAL_H