1 files changed, 131 insertions, 0 deletions
diff --git a/libs/canvas/polygon.cc b/libs/canvas/polygon.cc
new file mode 100644
index 0000000000..2e81823616
--- /dev/null
+++ b/libs/canvas/polygon.cc
@@ -0,0 +1,131 @@
+/*
+    Copyright (C) 2011-2013 Paul Davis
+    Author: Carl Hetherington <cth@carlh.net>
+
+    This program is free software; you can redistribute it and/or modify
+    it under the terms of the GNU General Public License as published by
+    the Free Software Foundation; either version 2 of the License, or
+    (at your option) any later version.
+
+    This program is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with this program; if not, write to the Free Software
+    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+*/
+
+#include "canvas/polygon.h"
+
+using namespace ArdourCanvas;
+
+Polygon::Polygon (Group* parent)
+	: Item (parent)
+	, PolyItem (parent)
+	, Fill (parent)
+	, multiple (0)
+	, constant (0)
+	, cached_size (0)
+{
+
+}
+
+Polygon::~Polygon ()
+{
+	delete [] multiple;
+	delete [] constant;
+}
+
+void
+Polygon::render (Rect const & area, Cairo::RefPtr<Cairo::Context> context) const
+{
+	if (_outline) {
+		setup_outline_context (context);
+		render_path (area, context);
+		
+		if (!_points.empty ()) {
+			/* close path */
+			Duple p = item_to_window (Duple (_points.front().x, _points.front().y));
+			context->move_to (p.x, p.y);
+		}
+
+		context->stroke_preserve ();
+	}
+
+	if (_fill) {
+		setup_fill_context (context);
+		context->fill ();
+	}
+}
+
+void 
+Polygon::cache_shape_computation () const
+{
+	Points::size_type npoints = _points.size();
+
+	if (npoints == 0) {
+		return;
+	}
+
+	Points::size_type i;
+	Points::size_type j = npoints -1;
+
+	if (cached_size < npoints) {
+		cached_size = npoints;
+		delete [] multiple;
+		multiple = new float[cached_size];
+		delete [] constant;
+		constant = new float[cached_size];
+	}
+
+	for (i = 0; i < npoints; i++) {
+		if (_points[j].y == _points[i].y) {
+			constant[i] = _points[i].x;
+			multiple[i] = 0; 
+		} else {
+			constant[i] = _points[i].x-(_points[i].y*_points[j].x)/(_points[j].y-_points[i].y)+(_points[i].y*_points[i].x)/(_points[j].y-_points[i].y);
+			multiple[i] = (_points[j].x-_points[i].x)/(_points[j].y-_points[i].y); 
+		}
+
+		j = i; 
+	}
+}
+
+bool 
+Polygon::covers (Duple const & point) const
+{
+	Duple p = canvas_to_item (point);
+
+	Points::size_type npoints = _points.size();
+
+	if (npoints == 0) {
+		return false;
+	}
+
+	Points::size_type i;
+	Points::size_type j = npoints -1;
+	bool oddNodes = false;
+	
+	if (_bounding_box_dirty) {
+		compute_bounding_box ();
+	}
+	
+	for (i = 0; i < npoints; i++) {
+		if (((_points[i].y < p.y && _points[j].y >= p.y) || (_points[j].y < p.y && _points[i].y >= p.y))) {
+			oddNodes ^= (p.y * multiple[i] + constant[i] < p.x); 
+		}
+		j = i; 
+	}
+
+	return oddNodes; 
+} 
+
+void
+Polygon::compute_bounding_box () const
+{
+	PolyItem::compute_bounding_box ();
+	cache_shape_computation ();
+}
+