1 files changed, 83 insertions, 0 deletions
diff --git a/src/live_effects/lpe-path_length.cpp b/src/live_effects/lpe-path_length.cpp
new file mode 100644
index 0000000..3a4ca88
--- /dev/null
+++ b/src/live_effects/lpe-path_length.cpp
@@ -0,0 +1,83 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/** \file
+ * LPE <path_length> implementation.
+ */
+/*
+ * Authors:
+ *   Maximilian Albert <maximilian.albert@gmail.com>
+ *   Johan Engelen
+ *
+ * Copyright (C) 2007-2008 Authors
+ *
+ * Released under GNU GPL v2+, read the file 'COPYING' for more information.
+ */
+
+#include "live_effects/lpe-path_length.h"
+#include "util/units.h"
+// TODO due to internal breakage in glibmm headers, this must be last:
+#include <glibmm/i18n.h>
+
+namespace Inkscape {
+namespace LivePathEffect {
+
+LPEPathLength::LPEPathLength(LivePathEffectObject *lpeobject) :
+    Effect(lpeobject),
+    scale(_("Scale:"), _("Scaling factor"), "scale", &wr, this, 1.0),
+    info_text(this),
+    unit(_("Unit:"), _("Unit"), "unit", &wr, this),
+    display_unit(_("Display unit"), _("Print unit after path length"), "display_unit", &wr, this, true)
+{
+    registerParameter(&scale);
+    registerParameter(&info_text);
+    registerParameter(&unit);
+    registerParameter(&display_unit);
+}
+
+LPEPathLength::~LPEPathLength()
+= default;
+
+Geom::Piecewise<Geom::D2<Geom::SBasis> >
+LPEPathLength::doEffect_pwd2 (Geom::Piecewise<Geom::D2<Geom::SBasis> > const & pwd2_in)
+{
+    using namespace Geom;
+
+    /* convert the measured length to the correct unit ... */
+    double lengthval = Geom::length(pwd2_in) * scale;
+    lengthval = Inkscape::Util::Quantity::convert(lengthval, "px", unit.get_abbreviation());
+
+    /* ... set it as the canvas text ... */
+    gchar *arc_length = g_strdup_printf("%.2f %s", lengthval,
+                                        display_unit ? unit.get_abbreviation() : "");
+    info_text.param_setValue(arc_length);
+    g_free(arc_length);
+
+    info_text.setPosAndAnchor(pwd2_in, 0.5, 10);
+
+    // TODO: how can we compute the area (such that cw turns don't count negative)?
+    //       should we display the area here, too, or write a new LPE for this?
+    Piecewise<D2<SBasis> > A = integral(pwd2_in);
+    Point c;
+    double area;
+    if (centroid(pwd2_in, c, area)) {
+        //g_print ("Area is zero\n");
+    }
+    //g_print ("Area: %f\n", area);
+    if (!this->isVisible()) {
+        info_text.param_setValue("");
+    }
+    return pwd2_in;
+}
+
+} //namespace LivePathEffect
+} /* namespace Inkscape */
+
+/*
+  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 :