1 files changed, 91 insertions, 0 deletions
diff --git a/src/sp-spiral.h b/src/sp-spiral.h
new file mode 100644
index 000000000..62c916e82
--- /dev/null
+++ b/src/sp-spiral.h
@@ -0,0 +1,91 @@
+#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);
+
+NR::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