X-Git-Url: https://main.carlh.net/gitweb/?a=blobdiff_plain;f=libs%2Fcanvas%2Fpoly_line.cc;h=7118e47555d1e74d0f03752e5855ffe8fbd2d8c5;hb=7914d45f2713341ca5246913c3bef7391f51c9bc;hp=e48082817dfc2187cc6d8ca438ab036d27dd9331;hpb=6ae4f104371ed433a79c8845de97428d964edd8b;p=ardour.git

diff --git a/libs/canvas/poly_line.cc b/libs/canvas/poly_line.cc
index e48082817d..7118e47555 100644
--- a/libs/canvas/poly_line.cc
+++ b/libs/canvas/poly_line.cc
@@ -1,5 +1,27 @@
-#include "pbd/xml++.h"
+/*
+    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 <algorithm>
+
 #include "canvas/poly_line.h"
+#include "canvas/canvas.h"
+#include "canvas/utils.h"
 
 using namespace ArdourCanvas;
 
@@ -20,19 +42,54 @@ PolyLine::render (Rect const & area, Cairo::RefPtr<Cairo::Context> context) cons
 	}
 }
 
-
-XMLNode *
-PolyLine::get_state () const
+bool
+PolyLine::covers (Duple const & point) const
 {
-	XMLNode* node = new XMLNode ("PolyLine");
-	add_poly_item_state (node);
-	add_outline_state (node);
-	return node;
-}
+	Duple p = canvas_to_item (point);
 
-void
-PolyLine::set_state (XMLNode const * node)
-{
-	set_poly_item_state (node);
-	set_outline_state (node);
+	const Points::size_type npoints = _points.size();
+	
+	if (npoints < 2) {
+		return false;
+	}
+
+	Points::size_type i;
+	Points::size_type j;
+
+	/* repeat for each line segment */
+
+	const Rect visible (_canvas->visible_area());
+	static const double threshold = 2.0;
+
+	for (i = 1, j = 0; i < npoints; ++i, ++j) {
+
+		Duple at;
+		double t;
+		Duple a (_points[j]);
+		Duple b (_points[i]);
+		
+		/*
+		  Clamp the line endpoints to the visible area of the canvas. If we do
+		  not do this, we may have a line segment extending to COORD_MAX and our
+		  math goes wrong.
+		*/
+		
+		a.x = std::min (a.x, visible.x1);
+		a.y = std::min (a.y, visible.y1);
+		b.x = std::min (b.x, visible.x1);
+		b.y = std::min (b.y, visible.y1);
+		
+		double d = distance_to_segment_squared (p, a, b, t, at);
+		
+		if (t < 0.0 || t > 1.0) {
+			return false;
+		}
+		
+		if (d < threshold) {
+			return true;
+		}
+		
+	}
+	
+	return false;
 }