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#ifndef __SP_SPIRAL_H__
#define __SP_SPIRAL_H__
/** \file
* SPSpiral: <sodipodi:spiral> implementation
*
* 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_TYPE_SPIRAL (sp_spiral_get_type ())
#define SP_SPIRAL(obj) (G_TYPE_CHECK_INSTANCE_CAST ((obj), SP_TYPE_SPIRAL, SPSpiral))
#define SP_SPIRAL_CLASS(klass) (G_TYPE_CHECK_CLASS_CAST ((klass), SP_TYPE_SPIRAL, SPSpiralClass))
#define SP_IS_SPIRAL(obj) (G_TYPE_CHECK_INSTANCE_TYPE ((obj), SP_TYPE_SPIRAL))
#define SP_IS_SPIRAL_CLASS(klass) (G_TYPE_CHECK_CLASS_TYPE ((klass), SP_TYPE_SPIRAL))
class SPSpiral;
class SPSpiralClass;
/**
* 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?
*/
struct SPSpiral : public SPShape {
float cx, cy;
float exp; ///< Spiral expansion factor
float revo; ///< Spiral revolution factor
float rad; ///< Spiral radius
float arg; ///< Spiral argument
float t0;
};
/// The SPSpiral vtable.
struct SPSpiralClass {
SPShapeClass parent_class;
};
/* Standard Gtk function */
GType sp_spiral_get_type (void);
/* Lowlevel interface */
void sp_spiral_position_set (SPSpiral *spiral,
gdouble cx,
gdouble cy,
gdouble exp,
gdouble revo,
gdouble rad,
gdouble arg,
gdouble t0);
Geom::Point sp_spiral_get_xy (SPSpiral const *spiral,
gdouble t);
void sp_spiral_get_polar (SPSpiral const *spiral,
gdouble t,
gdouble *rad,
gdouble *arg);
bool sp_spiral_is_invalid (SPSpiral const *spiral);
#endif
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