1 files changed, 183 insertions, 0 deletions
diff --git a/src/live_effects/lpe-perp_bisector.cpp b/src/live_effects/lpe-perp_bisector.cpp
new file mode 100644
index 0000000..edc7057
--- /dev/null
+++ b/src/live_effects/lpe-perp_bisector.cpp
@@ -0,0 +1,183 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/** \file
+ * LPE <perp_bisector> implementation.
+ */
+/*
+ * Authors:
+ *   Maximilian Albert
+ *   Johan Engelen
+ *
+ * Copyright (C) Johan Engelen 2007 <j.b.c.engelen@utwente.nl>
+ * Copyright (C) Maximilin Albert 2008 <maximilian.albert@gmail.com>
+ *
+ * Released under GNU GPL v2+, read the file 'COPYING' for more information.
+ */
+#include "live_effects/lpe-perp_bisector.h"
+#include "display/curve.h"
+#include "line-geometry.h"
+
+#include "object/sp-path.h"
+
+#include "ui/knot/knot-holder.h"
+#include "ui/knot/knot-holder-entity.h"
+
+// TODO due to internal breakage in glibmm headers, this must be last:
+#include <glibmm/i18n.h>
+
+namespace Inkscape {
+namespace LivePathEffect {
+namespace PB {
+
+class KnotHolderEntityEnd : public LPEKnotHolderEntity {
+public:
+    KnotHolderEntityEnd(LPEPerpBisector *effect) : LPEKnotHolderEntity(effect) {};
+    void bisector_end_set(Geom::Point const &p, guint state, bool left = true);
+};
+
+class KnotHolderEntityLeftEnd : public KnotHolderEntityEnd {
+public:
+    KnotHolderEntityLeftEnd(LPEPerpBisector *effect) : KnotHolderEntityEnd(effect) {};
+    void knot_set(Geom::Point const &p, Geom::Point const &origin, guint state) override;
+    Geom::Point knot_get() const override;
+};
+
+class KnotHolderEntityRightEnd : public KnotHolderEntityEnd {
+public:
+    KnotHolderEntityRightEnd(LPEPerpBisector *effect) : KnotHolderEntityEnd(effect) {};
+    void knot_set(Geom::Point const &p, Geom::Point const &origin, guint state) override;
+    Geom::Point knot_get() const override;
+};
+
+Geom::Point
+KnotHolderEntityLeftEnd::knot_get() const {
+    LPEPerpBisector const* lpe = dynamic_cast<LPEPerpBisector const*>(_effect);
+    return Geom::Point(lpe->C);
+}
+
+Geom::Point
+KnotHolderEntityRightEnd::knot_get() const {
+    LPEPerpBisector const* lpe = dynamic_cast<LPEPerpBisector const*>(_effect);
+    return Geom::Point(lpe->D);
+}
+
+void
+KnotHolderEntityEnd::bisector_end_set(Geom::Point const &p, guint state, bool left) {
+    LPEPerpBisector *lpe = dynamic_cast<LPEPerpBisector *>(_effect);
+    if (!lpe) return;
+
+    Geom::Point const s = snap_knot_position(p, state);
+
+    double lambda = Geom::nearest_time(s, lpe->M, lpe->perp_dir);
+    if (left) {
+        lpe->C = lpe->M + lpe->perp_dir * lambda;
+        lpe->length_left.param_set_value(lambda);
+    } else {
+        lpe->D = lpe->M + lpe->perp_dir * lambda;
+        lpe->length_right.param_set_value(-lambda);
+    }
+
+    // FIXME: this should not directly ask for updating the item. It should write to SVG, which triggers updating.
+    sp_lpe_item_update_patheffect (SP_LPE_ITEM(item), true, true);
+}
+
+void
+KnotHolderEntityLeftEnd::knot_set(Geom::Point const &p, Geom::Point const &/*origin*/, guint state) {
+    bisector_end_set(p, state);
+}
+
+void
+KnotHolderEntityRightEnd::knot_set(Geom::Point const &p, Geom::Point const &/*origin*/, guint state) {
+    bisector_end_set(p, state, false);
+}
+
+} //namescape PB
+
+LPEPerpBisector::LPEPerpBisector(LivePathEffectObject *lpeobject) :
+    Effect(lpeobject),
+    length_left(_("Length left:"), _("Specifies the left end of the bisector"), "length-left", &wr, this, 200),
+    length_right(_("Length right:"), _("Specifies the right end of the bisector"), "length-right", &wr, this, 200),
+    A(0,0), B(0,0), M(0,0), C(0,0), D(0,0), perp_dir(0,0)
+{
+    show_orig_path = true;
+    _provides_knotholder_entities = true;
+
+    // register all your parameters here, so Inkscape knows which parameters this effect has:
+    registerParameter(&length_left);
+    registerParameter(&length_right);
+}
+
+LPEPerpBisector::~LPEPerpBisector()
+= default;
+
+void
+LPEPerpBisector::doOnApply (SPLPEItem const*/*lpeitem*/)
+{
+    /* make the path a straight line */
+    /**
+    SPCurve* curve = sp_path_getCurveForEdit (SP_PATH(lpeitem)); // TODO: Should we use sp_shape_get_curve()?
+
+    Geom::Point A(curve->first_point());
+    Geom::Point B(curve->last_point());
+
+    SPCurve *c = new SPCurve();
+    c->moveto(A);
+    c->lineto(B);
+    // TODO: Why doesn't sp_path_set_curve_before_LPE(SP_PATH(lpeitem), c, TRUE, true) work?
+    SP_PATH(lpeitem)->original_curve = c->ref();
+    c->unref();
+    **/
+}
+
+
+Geom::Piecewise<Geom::D2<Geom::SBasis> >
+LPEPerpBisector::doEffect_pwd2 (Geom::Piecewise<Geom::D2<Geom::SBasis> > const & pwd2_in)
+{
+    using namespace Geom;
+
+    Piecewise<D2<SBasis> > output;
+
+    A = pwd2_in.firstValue();
+    B = pwd2_in.lastValue();
+    M = (A + B)/2;
+
+    perp_dir = unit_vector((B - A).ccw());
+
+    C = M + perp_dir * length_left;
+    D = M - perp_dir * length_right;
+
+    output = Piecewise<D2<SBasis> >(D2<SBasis>(SBasis(C[X], D[X]), SBasis(C[Y], D[Y])));
+
+    return output;
+}
+
+void
+LPEPerpBisector::addKnotHolderEntities(KnotHolder *knotholder, SPDesktop *desktop, SPItem *item) {
+    {
+        KnotHolderEntity *e = new PB::KnotHolderEntityLeftEnd(this);
+        e->create(desktop, item, knotholder, Inkscape::CANVAS_ITEM_CTRL_TYPE_LPE, "LPE:PerpBisectorLeftEnd",
+                  _("Adjust the \"left\" end of the bisector"));
+knotholder->add(e);
+    }
+    {
+        KnotHolderEntity *e = new PB::KnotHolderEntityRightEnd(this);
+        e->create(desktop, item, knotholder, Inkscape::CANVAS_ITEM_CTRL_TYPE_LPE, "LPE:PerpBisectorRightEnd",
+                  _("Adjust the \"right\" end of the bisector"));
+        knotholder->add(e);
+    }
+};
+
+/* ######################## */
+
+} //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 :