1 files changed, 59 insertions, 0 deletions
diff --git a/src/helper/geom-nodetype.cpp b/src/helper/geom-nodetype.cpp
new file mode 100644
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+++ b/src/helper/geom-nodetype.cpp
@@ -0,0 +1,59 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Specific nodetype geometry functions for Inkscape, not provided my lib2geom.
+ *
+ * Author:
+ *   Johan Engelen <goejendaagh@zonnet.nl>
+ *
+ * Copyright (C) 2008 Johan Engelen
+ *
+ * Released under GNU GPL v2+, read the file 'COPYING' for more information.
+ */
+
+#include "helper/geom-nodetype.h"
+
+#include <2geom/curve.h>
+
+namespace Geom {
+
+/*
+ * NOTE: THIS METHOD NEVER RETURNS "NODE_SYMM".
+ * Returns the nodetype between c_incoming and c_outgoing. Location of the node is
+ * at c_incoming.pointAt(1) == c_outgoing.pointAt(0). If these two are unequal, 
+ * the returned type is NODE_NONE.
+ * Comparison is based on the unitTangent, does not work for NODE_SYMM!
+ */
+NodeType get_nodetype(Curve const &c_incoming, Curve const &c_outgoing)
+{
+    if ( !are_near(c_incoming.pointAt(1), c_outgoing.pointAt(0)) )
+        return NODE_NONE;
+
+    Geom::Curve *crv = c_incoming.reverse();
+    Geom::Point deriv_1 = -crv->unitTangentAt(0);
+    delete crv;
+    Geom::Point deriv_2 = c_outgoing.unitTangentAt(0);
+    double this_angle_L2 = Geom::L2(deriv_1);
+    double next_angle_L2 = Geom::L2(deriv_2);
+    double both_angles_L2 = Geom::L2(deriv_1 + deriv_2);
+    if ( (this_angle_L2 > 1e-6) &&
+         (next_angle_L2 > 1e-6) &&
+         ((this_angle_L2 + next_angle_L2 - both_angles_L2) < 1e-3) )
+    {
+        return NODE_SMOOTH;
+    }
+
+    return NODE_CUSP;
+}
+
+} // end namespace Geom
+
+/*
+  Local Variables:
+  mode:c++
+  c-file-style:"stroustrup"
+  c-file-offsets:((innamespace . 0)(inline-open . 0)(case-label . +))
+  indent-tabs-mode:nil
+  fill-column:99
+  End:
+*/
+// vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4:fileencoding=utf-8:textwidth=99 :