1 files changed, 82 insertions, 0 deletions
diff --git a/src/object/sp-spiral.h b/src/object/sp-spiral.h
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+++ b/src/object/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) ///< step per 2PI
+#define SAMPLE_SIZE      8         ///< sample size per one bezier
+
+
+/**
+ * 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();
+	~SPSpiral() override;
+
+	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(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(SPCurve* c, double dstep, Geom::Point darray[], Geom::Point const& hat1, Geom::Point& hat2, double* t) const;
+};
+
+MAKE_SP_OBJECT_DOWNCAST_FUNCTIONS(SP_SPIRAL, SPSpiral)
+MAKE_SP_OBJECT_TYPECHECK_FUNCTIONS(SP_IS_SPIRAL, SPSpiral)
+
+#endif // SEEN_SP_SPIRAL_H