Adding upstream version 1.2.2.upstream/1.2.2upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 1189 insertions, 0 deletions

diff --git a/src/ui/tools/pencil-tool.cpp b/src/ui/tools/pencil-tool.cpp
new file mode 100644
index 0000000..055f581
--- /dev/null
+++ b/src/ui/tools/pencil-tool.cpp
@@ -0,0 +1,1189 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/** \file
+ * Pencil event context implementation.
+ */
+
+/*
+ * Authors:
+ *   Lauris Kaplinski <lauris@kaplinski.com>
+ *   bulia byak <buliabyak@users.sf.net>
+ *   Jon A. Cruz <jon@joncruz.org>
+ *
+ * Copyright (C) 2000 Lauris Kaplinski
+ * Copyright (C) 2000-2001 Ximian, Inc.
+ * Copyright (C) 2002 Lauris Kaplinski
+ * Copyright (C) 2004 Monash University
+ *
+ * Released under GNU GPL v2+, read the file 'COPYING' for more information.
+ */
+
+#include <numeric> // For std::accumulate
+#include <gdk/gdkkeysyms.h>
+#include <glibmm/i18n.h>
+
+#include <2geom/bezier-utils.h>
+#include <2geom/circle.h>
+#include <2geom/sbasis-to-bezier.h>
+#include <2geom/svg-path-parser.h>
+
+#include "pencil-tool.h"
+
+#include "context-fns.h"
+#include "desktop.h"
+#include "desktop-style.h"
+#include "layer-manager.h"
+#include "message-context.h"
+#include "message-stack.h"
+#include "selection-chemistry.h"
+#include "selection.h"
+#include "snap.h"
+
+#include "display/curve.h"
+#include "display/control/canvas-item-bpath.h"
+#include "display/control/snap-indicator.h"
+
+#include "livarot/Path.h"  // Simplify paths
+
+#include "live_effects/lpe-powerstroke-interpolators.h"
+#include "live_effects/lpe-powerstroke.h"
+#include "live_effects/lpe-simplify.h"
+#include "live_effects/lpeobject.h"
+
+#include "object/sp-lpe-item.h"
+#include "object/sp-path.h"
+#include "path/path-boolop.h"
+#include "style.h"
+
+#include "svg/svg.h"
+
+#include "ui/draw-anchor.h"
+#include "ui/tool/event-utils.h"
+
+#include "xml/node.h"
+#include "xml/sp-css-attr.h"
+
+namespace Inkscape {
+namespace UI {
+namespace Tools {
+
+static Geom::Point pencil_drag_origin_w(0, 0);
+static bool pencil_within_tolerance = false;
+
+static bool in_svg_plane(Geom::Point const &p) { return Geom::LInfty(p) < 1e18; }
+const double HANDLE_CUBIC_GAP = 0.01;
+
+PencilTool::PencilTool(SPDesktop *desktop)
+    : FreehandBase(desktop, "/tools/freehand/pencil", "pencil.svg")
+    , p()
+    , _npoints(0)
+    , _state(SP_PENCIL_CONTEXT_IDLE)
+    , _req_tangent(0, 0)
+    , _is_drawing(false)
+    , sketch_n(0)
+    , _pressure_curve(nullptr)
+{
+    Inkscape::Preferences *prefs = Inkscape::Preferences::get();
+    if (prefs->getBool("/tools/freehand/pencil/selcue")) {
+        this->enableSelectionCue();
+    }
+    this->_pressure_curve = std::make_unique<SPCurve>();
+    this->_is_drawing = false;
+    this->anchor_statusbar = false;
+}
+
+PencilTool::~PencilTool() {
+}
+
+void PencilTool::_extinput(GdkEvent *event) {
+    if (gdk_event_get_axis (event, GDK_AXIS_PRESSURE, &this->pressure)) {
+        this->pressure = CLAMP (this->pressure, DDC_MIN_PRESSURE, DDC_MAX_PRESSURE);
+        is_tablet = true;
+    } else {
+        this->pressure = DDC_DEFAULT_PRESSURE;
+        is_tablet = false;
+    }
+}
+
+/** Snaps new node relative to the previous node. */
+void PencilTool::_endpointSnap(Geom::Point &p, guint const state) {
+    if ((state & GDK_CONTROL_MASK)) { //CTRL enables constrained snapping
+        if (this->_npoints > 0) {
+            spdc_endpoint_snap_rotation(this, p, this->p[0], state);
+        }
+    } else {
+        if (!(state & GDK_SHIFT_MASK)) { //SHIFT disables all snapping, except the angular snapping above
+                                         //After all, the user explicitly asked for angular snapping by
+                                         //pressing CTRL
+            std::optional<Geom::Point> origin = this->_npoints > 0 ? this->p[0] : std::optional<Geom::Point>();
+            spdc_endpoint_snap_free(this, p, origin, state);
+        } else {
+            _desktop->snapindicator->remove_snaptarget();
+        }
+    }
+}
+
+/**
+ * Callback for handling all pencil context events.
+ */
+bool PencilTool::root_handler(GdkEvent* event) {
+    bool ret = false;
+    this->_extinput(event);
+    switch (event->type) {
+        case GDK_BUTTON_PRESS:
+            ret = this->_handleButtonPress(event->button);
+            break;
+
+        case GDK_MOTION_NOTIFY:
+            ret = this->_handleMotionNotify(event->motion);
+            break;
+
+        case GDK_BUTTON_RELEASE:
+            ret = this->_handleButtonRelease(event->button);
+            break;
+
+        case GDK_KEY_PRESS:
+            ret = this->_handleKeyPress(event->key);
+            break;
+
+        case GDK_KEY_RELEASE:
+            ret = this->_handleKeyRelease(event->key);
+            break;
+
+        default:
+            break;
+    }
+    if (!ret) {
+        ret = FreehandBase::root_handler(event);
+    }
+
+    return ret;
+}
+
+bool PencilTool::_handleButtonPress(GdkEventButton const &bevent) {
+    bool ret = false;
+    if ( bevent.button == 1) {
+        Inkscape::Selection *selection = _desktop->getSelection();
+
+        if (Inkscape::have_viable_layer(_desktop, defaultMessageContext()) == false) {
+            return true;
+        }
+
+        /* Grab mouse, so release will not pass unnoticed */
+        grabCanvasEvents();
+
+        Geom::Point const button_w(bevent.x, bevent.y);
+
+        /* Find desktop coordinates */
+        Geom::Point p = _desktop->w2d(button_w);
+
+        /* Test whether we hit any anchor. */
+        SPDrawAnchor *anchor = spdc_test_inside(this, button_w);
+        if (tablet_enabled) {
+            anchor = nullptr;
+        }
+        pencil_drag_origin_w = Geom::Point(bevent.x,bevent.y);
+        pencil_within_tolerance = true;
+        Inkscape::Preferences *prefs = Inkscape::Preferences::get();
+        tablet_enabled = prefs->getBool("/tools/freehand/pencil/pressure", false);
+        switch (this->_state) {
+            case SP_PENCIL_CONTEXT_ADDLINE:
+                /* Current segment will be finished with release */
+                ret = true;
+                break;
+            default:
+                /* Set first point of sequence */
+                SnapManager &m = _desktop->namedview->snap_manager;
+                if (bevent.state & GDK_CONTROL_MASK) {
+                    m.setup(_desktop, true);
+                    if (!(bevent.state & GDK_SHIFT_MASK)) {
+                        m.freeSnapReturnByRef(p, Inkscape::SNAPSOURCE_NODE_HANDLE);
+                      }
+                    spdc_create_single_dot(this, p, "/tools/freehand/pencil", bevent.state);
+                    m.unSetup();
+                    ret = true;
+                    break;
+                }
+                if (anchor) {
+                    p = anchor->dp;
+                    //Put the start overwrite curve always on the same direction
+                    if (anchor->start) {
+                        this->sa_overwrited = anchor->curve->create_reverse();
+                    } else {
+                        this->sa_overwrited = anchor->curve->copy();
+                    }
+                    _desktop->messageStack()->flash(Inkscape::NORMAL_MESSAGE, _("Continuing selected path"));
+                } else {
+                    m.setup(_desktop, true);
+                    if (tablet_enabled) {
+                        // This is the first click of a new curve; deselect item so that
+                        // this curve is not combined with it (unless it is drawn from its
+                        // anchor, which is handled by the sibling branch above)
+                        selection->clear();
+                        _desktop->messageStack()->flash(Inkscape::NORMAL_MESSAGE, _("Creating new path"));
+                    } else if (!(bevent.state & GDK_SHIFT_MASK)) {
+                        // This is the first click of a new curve; deselect item so that
+                        // this curve is not combined with it (unless it is drawn from its
+                        // anchor, which is handled by the sibling branch above)
+                        selection->clear();
+                        _desktop->messageStack()->flash(Inkscape::NORMAL_MESSAGE, _("Creating new path"));
+                        m.freeSnapReturnByRef(p, Inkscape::SNAPSOURCE_NODE_HANDLE);
+                    } else if (selection->singleItem() && SP_IS_PATH(selection->singleItem())) {
+                        _desktop->messageStack()->flash(Inkscape::NORMAL_MESSAGE, _("Appending to selected path"));
+                        m.freeSnapReturnByRef(p, Inkscape::SNAPSOURCE_NODE_HANDLE);
+                    }
+                    m.unSetup();
+                }
+                if (!tablet_enabled) {
+                    this->sa = anchor;
+                }
+                this->_setStartpoint(p);
+                ret = true;
+                break;
+        }
+
+        set_high_motion_precision();
+        this->_is_drawing = true;
+    }
+    return ret;
+}
+
+bool PencilTool::_handleMotionNotify(GdkEventMotion const &mevent) {
+    if ((mevent.state & GDK_CONTROL_MASK) && (mevent.state & GDK_BUTTON1_MASK)) {
+        // mouse was accidentally moved during Ctrl+click;
+        // ignore the motion and create a single point
+        this->_is_drawing = false;
+        return true;
+    }
+    bool ret = false;
+
+    if ((mevent.state & GDK_BUTTON2_MASK)) {
+        // allow scrolling
+        return ret;
+    }
+
+    /* Test whether we hit any anchor. */
+    SPDrawAnchor *anchor = spdc_test_inside(this, pencil_drag_origin_w);
+    if (this->pressure == 0.0 && tablet_enabled && !anchor) {
+        // tablet event was accidentally fired without press;
+        return ret;
+    }
+    
+    if ( ( mevent.state & GDK_BUTTON1_MASK ) && this->_is_drawing) {
+        /* Grab mouse, so release will not pass unnoticed */
+        grabCanvasEvents();
+    }
+
+    /* Find desktop coordinates */
+    Geom::Point p = _desktop->w2d(Geom::Point(mevent.x, mevent.y));
+
+    Inkscape::Preferences *prefs = Inkscape::Preferences::get();
+    if (pencil_within_tolerance) {
+        gint const tolerance = prefs->getIntLimited("/options/dragtolerance/value", 0, 0, 100);
+        if ( Geom::LInfty( Geom::Point(mevent.x,mevent.y) - pencil_drag_origin_w ) < tolerance ) {
+            return false;   // Do not drag if we're within tolerance from origin.
+        }
+    }
+
+    // Once the user has moved farther than tolerance from the original location
+    // (indicating they intend to move the object, not click), then always process the
+    // motion notify coordinates as given (no snapping back to origin)
+    pencil_within_tolerance = false;
+    
+    anchor = spdc_test_inside(this, Geom::Point(mevent.x,mevent.y));
+
+    switch (this->_state) {
+        case SP_PENCIL_CONTEXT_ADDLINE:
+            if (is_tablet) {
+                this->_state = SP_PENCIL_CONTEXT_FREEHAND;
+                return false;
+            }
+            /* Set red endpoint */
+            if (anchor) {
+                p = anchor->dp;
+            } else {
+                Geom::Point ptnr(p);
+                this->_endpointSnap(ptnr, mevent.state);
+                p = ptnr;
+            }
+            this->_setEndpoint(p);
+            ret = true;
+            break;
+        default:
+            /* We may be idle or already freehand */
+            if ( (mevent.state & GDK_BUTTON1_MASK) && this->_is_drawing ) {
+                if (this->_state == SP_PENCIL_CONTEXT_IDLE) {
+                    this->discard_delayed_snap_event();
+                }
+                this->_state = SP_PENCIL_CONTEXT_FREEHAND;
+
+                if ( !this->sa && !this->green_anchor ) {
+                    /* Create green anchor */
+                    this->green_anchor.reset(new SPDrawAnchor(this, this->green_curve.get(), TRUE, this->p[0]));
+                }
+                if (anchor) {
+                    p = anchor->dp;
+                }
+                if ( this->_npoints != 0) { // buttonpress may have happened before we entered draw context!
+                    if (this->ps.empty()) {
+                        // Only in freehand mode we have to add the first point also to this->ps (apparently)
+                        // - We cannot add this point in spdc_set_startpoint, because we only need it for freehand
+                        // - We cannot do this in the button press handler because at that point we don't know yet
+                        //   whether we're going into freehand mode or not
+                        this->ps.push_back(this->p[0]);
+                        if (tablet_enabled) {
+                            this->_wps.emplace_back(0, 0);
+                        }
+                    }
+                    this->_addFreehandPoint(p, mevent.state, false);
+                    ret = true;
+                }
+                if (anchor && !this->anchor_statusbar) {
+                    this->message_context->set(Inkscape::NORMAL_MESSAGE, _("<b>Release</b> here to close and finish the path."));
+                    this->anchor_statusbar = true;
+                    this->ea = anchor;
+                } else if (!anchor && this->anchor_statusbar) {
+                    this->message_context->clear();
+                    this->anchor_statusbar = false;
+                    this->ea = nullptr;
+                } else if (!anchor) {
+                    this->message_context->set(Inkscape::NORMAL_MESSAGE, _("Drawing a freehand path"));
+                    this->ea = nullptr;
+                }
+
+            } else {
+                if (anchor && !this->anchor_statusbar) {
+                    this->message_context->set(Inkscape::NORMAL_MESSAGE, _("<b>Drag</b> to continue the path from this point."));
+                    this->anchor_statusbar = true;
+                } else if (!anchor && this->anchor_statusbar) {
+                    this->message_context->clear();
+                    this->anchor_statusbar = false;
+                }
+            }
+
+            // Show the pre-snap indicator to communicate to the user where we would snap to if he/she were to
+            // a) press the mousebutton to start a freehand drawing, or
+            // b) release the mousebutton to finish a freehand drawing
+            if (!tablet_enabled && !this->sp_event_context_knot_mouseover()) {
+                SnapManager &m = _desktop->namedview->snap_manager;
+                m.setup(_desktop, true);
+                m.preSnap(Inkscape::SnapCandidatePoint(p, Inkscape::SNAPSOURCE_NODE_HANDLE));
+                m.unSetup();
+            }
+            break;
+    }
+    return ret;
+}
+
+bool PencilTool::_handleButtonRelease(GdkEventButton const &revent) {
+    bool ret = false;
+
+    set_high_motion_precision(false);
+
+    if ( revent.button == 1 && this->_is_drawing) {
+        this->_is_drawing = false;
+
+        /* Find desktop coordinates */
+        Geom::Point p = _desktop->w2d(Geom::Point(revent.x, revent.y));
+
+        /* Test whether we hit any anchor. */
+        SPDrawAnchor *anchor = spdc_test_inside(this, Geom::Point(revent.x, revent.y));
+
+        switch (this->_state) {
+            case SP_PENCIL_CONTEXT_IDLE:
+                /* Releasing button in idle mode means single click */
+                /* We have already set up start point/anchor in button_press */
+                if (!(revent.state & GDK_CONTROL_MASK) && !is_tablet) {
+                    // Ctrl+click creates a single point so only set context in ADDLINE mode when Ctrl isn't pressed
+                    this->_state = SP_PENCIL_CONTEXT_ADDLINE;
+                }
+                /*Or select the down item if we are in tablet mode*/
+                if (is_tablet) {
+                    using namespace Inkscape::LivePathEffect;
+                    SPItem *item = sp_event_context_find_item(_desktop, Geom::Point(revent.x, revent.y), FALSE, FALSE);
+                    if (item && (!this->white_item || item != white_item)) {
+                        if (SP_IS_LPE_ITEM(item)) {
+                            Effect* lpe = SP_LPE_ITEM(item)->getCurrentLPE();
+                            if (lpe) {
+                                LPEPowerStroke* ps = static_cast<LPEPowerStroke*>(lpe);
+                                if (ps) {
+                                    _desktop->selection->clear();
+                                    _desktop->selection->add(item);
+                                }
+                            }
+                        }
+                    }
+                }
+                break;
+            case SP_PENCIL_CONTEXT_ADDLINE:
+                /* Finish segment now */
+                if (anchor) {
+                    p = anchor->dp;
+                } else {
+                    this->_endpointSnap(p, revent.state);
+                }
+                this->ea = anchor;
+                this->_setEndpoint(p);
+                this->_finishEndpoint();
+                this->_state = SP_PENCIL_CONTEXT_IDLE;
+                this->discard_delayed_snap_event();
+                break;
+            case SP_PENCIL_CONTEXT_FREEHAND:
+                if (revent.state & GDK_MOD1_MASK && !tablet_enabled) {
+                    /* sketch mode: interpolate the sketched path and improve the current output path with the new interpolation. don't finish sketch */
+                    this->_sketchInterpolate();
+
+                    this->green_anchor.reset();
+
+                    this->_state = SP_PENCIL_CONTEXT_SKETCH;
+                } else {
+                    /* Finish segment now */
+                    /// \todo fixme: Clean up what follows (Lauris)
+                    if (anchor) {
+                        p = anchor->dp;
+                    } else {
+                        Geom::Point p_end = p;
+                        if (tablet_enabled) {
+                            this->_addFreehandPoint(p_end, revent.state, true);
+                            this->_pressure_curve->reset();
+                        } else {
+                            this->_endpointSnap(p_end, revent.state);
+                            if (p_end != p) {
+                                // then we must have snapped!
+                                this->_addFreehandPoint(p_end, revent.state, true);
+                            }
+                        }
+                    }
+
+                    this->ea = anchor;
+                    /* Write curves to object */
+                    _desktop->messageStack()->flash(Inkscape::NORMAL_MESSAGE, _("Finishing freehand"));
+                    this->_interpolate();
+                    Inkscape::Preferences *prefs = Inkscape::Preferences::get();
+                    if (tablet_enabled) {
+                        gint shapetype = prefs->getInt("/tools/freehand/pencil/shape", 0);
+                        gint simplify = prefs->getInt("/tools/freehand/pencil/simplify", 0);
+                        gint mode = prefs->getInt("/tools/freehand/pencil/freehand-mode", 0);
+                        prefs->setInt("/tools/freehand/pencil/shape", 0);
+                        prefs->setInt("/tools/freehand/pencil/simplify", 0);
+                        prefs->setInt("/tools/freehand/pencil/freehand-mode", 0);
+                        spdc_concat_colors_and_flush(this, FALSE);
+                        prefs->setInt("/tools/freehand/pencil/freehand-mode", mode);
+                        prefs->setInt("/tools/freehand/pencil/simplify", simplify);
+                        prefs->setInt("/tools/freehand/pencil/shape", shapetype);
+                    } else {
+                        spdc_concat_colors_and_flush(this, FALSE);
+                    }
+                    this->points.clear();
+                    this->sa = nullptr;
+                    this->ea = nullptr;
+                    this->ps.clear();
+                    this->_wps.clear();
+                    this->green_anchor.reset();
+                    this->_state = SP_PENCIL_CONTEXT_IDLE;
+                    // reset sketch mode too
+                    this->sketch_n = 0;
+                }
+                break;
+            case SP_PENCIL_CONTEXT_SKETCH:
+            default:
+                break;
+        }
+
+        ungrabCanvasEvents();
+
+        ret = true;
+    }
+    return ret;
+}
+
+void PencilTool::_cancel() {
+    ungrabCanvasEvents();
+
+    this->_is_drawing = false;
+    this->_state = SP_PENCIL_CONTEXT_IDLE;
+    this->discard_delayed_snap_event();
+
+    this->red_curve->reset();
+    this->red_bpath->set_bpath(red_curve.get());
+
+    for (auto path : this->green_bpaths) {
+        delete path;
+    }
+    this->green_bpaths.clear();
+    this->green_curve->reset();
+    this->green_anchor.reset();
+
+    this->message_context->clear();
+    this->message_context->flash(Inkscape::NORMAL_MESSAGE, _("Drawing cancelled"));
+}
+
+bool PencilTool::_handleKeyPress(GdkEventKey const &event) {
+    bool ret = false;
+
+    switch (get_latin_keyval(&event)) {
+        case GDK_KEY_Up:
+        case GDK_KEY_Down:
+        case GDK_KEY_KP_Up:
+        case GDK_KEY_KP_Down:
+            // Prevent the zoom field from activation.
+            if (!Inkscape::UI::held_only_control(event)) {
+                ret = true;
+            }
+            break;
+        case GDK_KEY_Escape:
+            if (this->_npoints != 0) {
+                // if drawing, cancel, otherwise pass it up for deselecting
+                if (this->_state != SP_PENCIL_CONTEXT_IDLE) {
+                    this->_cancel();
+                    ret = true;
+                }
+            }
+            break;
+        case GDK_KEY_z:
+        case GDK_KEY_Z:
+            if (Inkscape::UI::held_only_control(event) && this->_npoints != 0) {
+                // if drawing, cancel, otherwise pass it up for undo
+                if (this->_state != SP_PENCIL_CONTEXT_IDLE) {
+                    this->_cancel();
+                    ret = true;
+                }
+            }
+            break;
+        case GDK_KEY_g:
+        case GDK_KEY_G:
+            if (Inkscape::UI::held_only_shift(event)) {
+                _desktop->selection->toGuides();
+                ret = true;
+            }
+            break;
+        case GDK_KEY_Alt_L:
+        case GDK_KEY_Alt_R:
+        case GDK_KEY_Meta_L:
+        case GDK_KEY_Meta_R:
+            if (this->_state == SP_PENCIL_CONTEXT_IDLE) {
+                _desktop->messageStack()->flash(Inkscape::NORMAL_MESSAGE, _("<b>Sketch mode</b>: holding <b>Alt</b> interpolates between sketched paths. Release <b>Alt</b> to finalize."));
+            }
+            break;
+        default:
+            break;
+    }
+    return ret;
+}
+
+bool PencilTool::_handleKeyRelease(GdkEventKey const &event) {
+    bool ret = false;
+
+    switch (get_latin_keyval(&event)) {
+        case GDK_KEY_Alt_L:
+        case GDK_KEY_Alt_R:
+        case GDK_KEY_Meta_L:
+        case GDK_KEY_Meta_R:
+            if (this->_state == SP_PENCIL_CONTEXT_SKETCH) {
+                spdc_concat_colors_and_flush(this, FALSE);
+                this->sketch_n = 0;
+                this->sa = nullptr;
+                this->ea = nullptr;
+                this->green_anchor.reset();
+                this->_state = SP_PENCIL_CONTEXT_IDLE;
+                this->discard_delayed_snap_event();
+                _desktop->messageStack()->flash(Inkscape::NORMAL_MESSAGE, _("Finishing freehand sketch"));
+                ret = true;
+            }
+            break;
+        default:
+            break;
+    }
+    return ret;
+}
+
+/**
+ * Reset points and set new starting point.
+ */
+void PencilTool::_setStartpoint(Geom::Point const &p) {
+    this->_npoints = 0;
+    this->red_curve_is_valid = false;
+    if (in_svg_plane(p)) {
+        this->p[this->_npoints++] = p;
+    }
+}
+
+/**
+ * Change moving endpoint position.
+ * <ul>
+ * <li>Ctrl constrains to moving to H/V direction, snapping in given direction.
+ * <li>Otherwise we snap freely to whatever attractors are available.
+ * </ul>
+ *
+ * Number of points is (re)set to 2 always, 2nd point is modified.
+ * We change RED curve.
+ */
+void PencilTool::_setEndpoint(Geom::Point const &p) {
+    if (this->_npoints == 0) {
+        return;
+        /* May occur if first point wasn't in SVG plane (e.g. weird w2d transform, perhaps from bad
+         * zoom setting).
+         */
+    }
+    g_return_if_fail( this->_npoints > 0 );
+
+    this->red_curve->reset();
+    if ( ( p == this->p[0] )
+         || !in_svg_plane(p) )
+    {
+        this->_npoints = 1;
+    } else {
+        this->p[1] = p;
+        this->_npoints = 2;
+
+        this->red_curve->moveto(this->p[0]);
+        this->red_curve->lineto(this->p[1]);
+        this->red_curve_is_valid = true;
+        if (!tablet_enabled) {
+            red_bpath->set_bpath(red_curve.get());
+        }
+    }
+}
+
+/**
+ * Finalize addline.
+ *
+ * \todo
+ * fixme: I'd like remove red reset from concat colors (lauris).
+ * Still not sure, how it will make most sense.
+ */
+void PencilTool::_finishEndpoint() {
+    if (this->red_curve->is_unset() || 
+        this->red_curve->first_point() == this->red_curve->second_point())
+    {
+        this->red_curve->reset();
+        if (!tablet_enabled) {
+            red_bpath->set_bpath(nullptr);
+        }
+    } else {
+        /* Write curves to object. */
+        spdc_concat_colors_and_flush(this, FALSE);
+        this->sa = nullptr;
+        this->ea = nullptr;
+    }
+}
+
+static inline double square(double const x) { return x * x; }
+
+
+
+void PencilTool::addPowerStrokePencil()
+{
+    {
+        SPDocument *document = _desktop->doc();
+        if (!document) {
+            return;
+        }
+        using namespace Inkscape::LivePathEffect;
+        Inkscape::Preferences *prefs = Inkscape::Preferences::get();
+        double tol = prefs->getDoubleLimited("/tools/freehand/pencil/base-simplify", 25.0, 0.0, 100.0) * 0.4;
+        double tolerance_sq = 0.02 * square(_desktop->w2d().descrim() * tol) * exp(0.2 * tol - 2);
+        int n_points = this->ps.size();
+        // worst case gives us a segment per point
+        int max_segs = 4 * n_points;
+        std::vector<Geom::Point> b(max_segs);
+        auto curvepressure = std::make_unique<SPCurve>();
+        int const n_segs = Geom::bezier_fit_cubic_r(b.data(), this->ps.data(), n_points, tolerance_sq, max_segs);
+        if (n_segs > 0) {
+            /* Fit and draw and reset state */
+            curvepressure->moveto(b[0]);
+            for (int c = 0; c < n_segs; c++) {
+                curvepressure->curveto(b[4 * c + 1], b[4 * c + 2], b[4 * c + 3]);
+            }
+        }
+        Geom::Affine transform_coordinate = currentLayer()->i2dt_affine().inverse();
+        curvepressure->transform(transform_coordinate);
+        Geom::Path path = curvepressure->get_pathvector()[0];
+
+        if (!path.empty()) {
+            Inkscape::XML::Document *xml_doc = document->getReprDoc();
+            Inkscape::XML::Node *pp = nullptr;
+            pp = xml_doc->createElement("svg:path");
+            pp->setAttribute("d", sp_svg_write_path(path));
+            pp->setAttribute("id", "power_stroke_preview");
+            Inkscape::GC::release(pp);
+
+            SPShape *powerpreview = SP_SHAPE(currentLayer()->appendChildRepr(pp));
+            SPLPEItem *lpeitem = dynamic_cast<SPLPEItem *>(powerpreview);
+            if (!lpeitem) {
+                return;
+            }
+            DocumentUndo::ScopedInsensitive tmp(document);
+            tol = prefs->getDoubleLimited("/tools/freehand/pencil/tolerance", 10.0, 0.0, 100.0) + 30;
+            if (tol > 30) {
+                tol = tol / (130.0 * (132.0 - tol));
+                Inkscape::SVGOStringStream threshold;
+                threshold << tol;
+                Effect::createAndApply(SIMPLIFY, document, lpeitem);
+                Effect *lpe = lpeitem->getCurrentLPE();
+                Inkscape::LivePathEffect::LPESimplify *simplify =
+                    static_cast<Inkscape::LivePathEffect::LPESimplify *>(lpe);
+                if (simplify) {
+                    sp_lpe_item_enable_path_effects(lpeitem, false);
+                    Glib::ustring pref_path = "/live_effects/simplify/smooth_angles";
+                    bool valid = prefs->getEntry(pref_path).isValid();
+                    if (!valid) {
+                        lpe->getRepr()->setAttribute("smooth_angles", "0");
+                    }
+                    pref_path = "/live_effects/simplify/helper_size";
+                    valid = prefs->getEntry(pref_path).isValid();
+                    if (!valid) {
+                        lpe->getRepr()->setAttribute("helper_size", "0");
+                    }
+                    pref_path = "/live_effects/simplify/step";
+                    valid = prefs->getEntry(pref_path).isValid();
+                    if (!valid) {
+                        lpe->getRepr()->setAttribute("step", "1");
+                    }
+                    lpe->getRepr()->setAttribute("threshold", threshold.str());
+                    lpe->getRepr()->setAttribute("simplify_individual_paths", "false");
+                    lpe->getRepr()->setAttribute("simplify_just_coalesce", "false");
+                    sp_lpe_item_enable_path_effects(lpeitem, true);
+                }
+                sp_lpe_item_update_patheffect(lpeitem, false, true);
+                SPCurve const *curvepressure = powerpreview->curve();
+                if (curvepressure->is_empty()) {
+                    return;
+                }
+                path = curvepressure->get_pathvector()[0];
+            }
+            powerStrokeInterpolate(path);
+            Inkscape::Preferences *prefs = Inkscape::Preferences::get();
+            Glib::ustring pref_path_pp = "/live_effects/powerstroke/powerpencil";
+            prefs->setBool(pref_path_pp, true);
+            Effect::createAndApply(POWERSTROKE, document, lpeitem);
+            Effect *lpe = lpeitem->getCurrentLPE();
+            Inkscape::LivePathEffect::LPEPowerStroke *pspreview = static_cast<LPEPowerStroke *>(lpe);
+            if (pspreview) {
+                sp_lpe_item_enable_path_effects(lpeitem, false);
+                Glib::ustring pref_path = "/live_effects/powerstroke/interpolator_type";
+                bool valid = prefs->getEntry(pref_path).isValid();
+                if (!valid) {
+                    pspreview->getRepr()->setAttribute("interpolator_type", "CentripetalCatmullRom");
+                }
+                pref_path = "/live_effects/powerstroke/linejoin_type";
+                valid = prefs->getEntry(pref_path).isValid();
+                if (!valid) {
+                    pspreview->getRepr()->setAttribute("linejoin_type", "spiro");
+                }
+                pref_path = "/live_effects/powerstroke/interpolator_beta";
+                valid = prefs->getEntry(pref_path).isValid();
+                if (!valid) {
+                    pspreview->getRepr()->setAttribute("interpolator_beta", "0.75");
+                }
+                gint cap = prefs->getInt("/live_effects/powerstroke/powerpencilcap", 2);
+                pspreview->getRepr()->setAttribute("start_linecap_type", LineCapTypeConverter.get_key(cap));
+                pspreview->getRepr()->setAttribute("end_linecap_type", LineCapTypeConverter.get_key(cap));
+                pspreview->getRepr()->setAttribute("sort_points", "true");
+                pspreview->getRepr()->setAttribute("not_jump", "true");
+                pspreview->offset_points.param_set_and_write_new_value(this->points);
+                sp_lpe_item_enable_path_effects(lpeitem, true);
+                sp_lpe_item_update_patheffect(lpeitem, false, true);
+                pp->setAttribute("style", "fill:#888888;opacity:1;fill-rule:nonzero;stroke:none;");
+            }
+            prefs->setBool(pref_path_pp, false);
+        }
+    }
+}
+
+/**
+ * Add a virtual point to the future pencil path.
+ *
+ * @param p the point to add.
+ * @param state event state
+ * @param last the point is the last of the user stroke.
+ */
+void PencilTool::_addFreehandPoint(Geom::Point const &p, guint /*state*/, bool last)
+{
+    g_assert( this->_npoints > 0 );
+    g_return_if_fail(unsigned(this->_npoints) < G_N_ELEMENTS(this->p));
+
+    double distance = 0;
+    if ( ( p != this->p[ this->_npoints - 1 ] )
+         && in_svg_plane(p) )
+    {
+        this->p[this->_npoints++] = p;
+        this->_fitAndSplit();
+        if (tablet_enabled) {
+            distance = Geom::distance(p, this->ps.back()) + this->_wps.back()[Geom::X];
+        }
+        this->ps.push_back(p);
+    }
+    if (tablet_enabled && in_svg_plane(p)) {
+        Inkscape::Preferences *prefs = Inkscape::Preferences::get();
+        double min = prefs->getIntLimited("/tools/freehand/pencil/minpressure",  0, 0, 100) / 100.0;
+        double max = prefs->getIntLimited("/tools/freehand/pencil/maxpressure", 30, 0, 100) / 100.0;
+        if (min > max) {
+            min = max;
+        }
+        double dezoomify_factor = 0.05 * 1000 / _desktop->current_zoom();
+        double const pressure_shrunk = pressure * (max - min) + min; // C++20 -> use std::lerp()
+        double pressure_computed = std::abs(pressure_shrunk * dezoomify_factor);
+        double pressure_computed_scaled = std::abs(pressure_computed * _desktop->getDocument()->getDocumentScale().inverse()[Geom::X]);
+        if (p != this->p[this->_npoints - 1]) {
+            this->_wps.emplace_back(distance, pressure_computed_scaled);
+        }
+        if (pressure_computed) {
+            Geom::Circle pressure_dot(p, pressure_computed);
+            Geom::Piecewise<Geom::D2<Geom::SBasis>> pressure_piecewise;
+            pressure_piecewise.push_cut(0);
+            pressure_piecewise.push(pressure_dot.toSBasis(), 1);
+            Geom::PathVector pressure_path = Geom::path_from_piecewise(pressure_piecewise, 0.1);
+            Geom::PathVector previous_presure = this->_pressure_curve->get_pathvector();
+            if (!pressure_path.empty() && !previous_presure.empty()) {
+                pressure_path = sp_pathvector_boolop(pressure_path, previous_presure, bool_op_union, fill_nonZero, fill_nonZero);
+            }
+            this->_pressure_curve->set_pathvector(pressure_path);
+            red_bpath->set_bpath(_pressure_curve.get());
+        }
+        if (last) {
+            this->addPowerStrokePencil();
+        }
+    }
+}
+
+void PencilTool::powerStrokeInterpolate(Geom::Path const path)
+{
+    size_t ps_size = this->ps.size();
+    if ( ps_size <= 1 ) {
+        return;
+    }
+
+    using Geom::X;
+    using Geom::Y;
+    gint path_size = path.size();
+    std::vector<Geom::Point> tmp_points;
+    Geom::Point previous = Geom::Point(Geom::infinity(), 0);
+    bool increase = false;
+    size_t i = 0;
+    double dezoomify_factor = 0.05 * 1000 / _desktop->current_zoom();
+    double limit = 6 * dezoomify_factor;
+    double max =
+        std::max(this->_wps.back()[Geom::X] - (this->_wps.back()[Geom::X] / 10), this->_wps.back()[Geom::X] - limit);
+    double min = std::min(this->_wps.back()[Geom::X] / 10, limit);
+    double original_lenght = this->_wps.back()[Geom::X];
+    double max10 = 0;
+    double min10 = 0;
+    for (auto wps : this->_wps) {
+        i++;
+        Geom::Coord pressure = wps[Geom::Y];
+        max10 = max10  > pressure ? max10 : pressure;
+        min10 = min10 <= pressure ? min10 : pressure;
+        if (!original_lenght || wps[Geom::X] > max) {
+            break;
+        }
+        if (wps[Geom::Y] == 0 || wps[Geom::X] < min) {
+            continue;
+        }
+        if (previous[Geom::Y] < (max10 + min10) / 2.0) {
+            if (increase && tmp_points.size() > 1) {
+                tmp_points.pop_back();
+            }
+            wps[Geom::Y] = max10;
+            tmp_points.push_back(wps);
+            increase = true;
+        } else {
+            if (!increase && tmp_points.size() > 1) {
+                tmp_points.pop_back();
+            }
+            wps[Geom::Y] = min10;
+            tmp_points.push_back(wps);
+            increase = false;
+        }
+        previous = wps;
+        max10 = 0;
+        min10 = 999999999;
+    }
+    this->points.clear();
+    double prev_pressure = 0;
+    for (auto point : tmp_points) {
+        point[Geom::X] /= (double)original_lenght;
+        point[Geom::X] *= path_size;
+        if (std::abs(point[Geom::Y] - prev_pressure) > point[Geom::Y] / 10.0) {
+            this->points.push_back(point);
+            prev_pressure = point[Geom::Y];
+        }
+    }
+    if (points.empty() && !_wps.empty()) {
+        // Synthesize a pressure data point based on the average pressure
+        double average_pressure = std::accumulate(_wps.begin(), _wps.end(), 0.0,
+            [](double const &sum_so_far, Geom::Point const &point) -> double {
+                return sum_so_far + point[Geom::Y];
+        }) / (double)_wps.size();
+        points.emplace_back(0.5 * path.size(), /* place halfway along the path */
+                            2.0 * average_pressure /* 2.0 - for correct average thickness of a kite */);
+    }
+}
+
+void PencilTool::_interpolate() {
+    size_t ps_size = this->ps.size();
+    if ( ps_size <= 1 ) {
+        return;
+    }
+    using Geom::X;
+    using Geom::Y;
+    Inkscape::Preferences *prefs = Inkscape::Preferences::get();
+    double tol = prefs->getDoubleLimited("/tools/freehand/pencil/tolerance", 10.0, 0.0, 100.0) * 0.4;
+    bool simplify = prefs->getInt("/tools/freehand/pencil/simplify", 0);
+    if(simplify){
+        double tol2 = prefs->getDoubleLimited("/tools/freehand/pencil/base-simplify", 25.0, 0.0, 100.0) * 0.4;
+        tol = std::min(tol,tol2);
+    }
+    this->green_curve->reset();
+    this->red_curve->reset();
+    this->red_curve_is_valid = false;
+
+    double tolerance_sq = 0.02 * square(_desktop->w2d().descrim() * tol) * exp(0.2 * tol - 2);
+
+    g_assert(is_zero(this->_req_tangent) || is_unit_vector(this->_req_tangent));
+
+    int n_points = this->ps.size();
+
+    // worst case gives us a segment per point
+    int max_segs = 4 * n_points;
+
+    std::vector<Geom::Point> b(max_segs);
+    int const n_segs = Geom::bezier_fit_cubic_r(b.data(), this->ps.data(), n_points, tolerance_sq, max_segs);
+    if (n_segs > 0) {
+        /* Fit and draw and reset state */
+        this->green_curve->moveto(b[0]);
+        Inkscape::Preferences *prefs = Inkscape::Preferences::get();
+        guint mode = prefs->getInt("/tools/freehand/pencil/freehand-mode", 0);
+        for (int c = 0; c < n_segs; c++) {
+            // if we are in BSpline we modify the trace to create adhoc nodes 
+            if (mode == 2) {
+                Geom::Point point_at1 = b[4 * c + 0] + (1./3) * (b[4 * c + 3] - b[4 * c + 0]);
+                point_at1 = Geom::Point(point_at1[X] + HANDLE_CUBIC_GAP, point_at1[Y] + HANDLE_CUBIC_GAP);
+                Geom::Point point_at2 = b[4 * c + 3] + (1./3) * (b[4 * c + 0] - b[4 * c + 3]);
+                point_at2 = Geom::Point(point_at2[X] + HANDLE_CUBIC_GAP, point_at2[Y] + HANDLE_CUBIC_GAP);
+                this->green_curve->curveto(point_at1,point_at2,b[4*c+3]);
+            } else {
+                if (!tablet_enabled || c != n_segs - 1) {
+                    this->green_curve->curveto(b[4 * c + 1], b[4 * c + 2], b[4 * c + 3]);
+                } else {
+                    std::optional<Geom::Point> finalp = this->green_curve->last_point();
+                    if (this->green_curve->nodes_in_path() > 4 && Geom::are_near(*finalp, b[4 * c + 3], 10.0)) {
+                        this->green_curve->backspace();
+                        this->green_curve->curveto(*finalp, b[4 * c + 3], b[4 * c + 3]);
+                    } else {
+                        this->green_curve->curveto(b[4 * c + 1], b[4 * c + 3], b[4 * c + 3]);
+                    }
+                }
+            }
+        }
+        if (!tablet_enabled) {
+            red_bpath->set_bpath(green_curve.get());
+        }
+
+        /* Fit and draw and copy last point */
+        g_assert(!this->green_curve->is_empty());
+
+        /* Set up direction of next curve. */
+        {
+            Geom::Curve const * last_seg = this->green_curve->last_segment();
+            g_assert( last_seg );      // Relevance: validity of (*last_seg)
+            this->p[0] = last_seg->finalPoint();
+            this->_npoints = 1;
+            Geom::Curve *last_seg_reverse = last_seg->reverse();
+            Geom::Point const req_vec( -last_seg_reverse->unitTangentAt(0) );
+            delete last_seg_reverse;
+            this->_req_tangent = ( ( Geom::is_zero(req_vec) || !in_svg_plane(req_vec) )
+                                ? Geom::Point(0, 0)
+                                : Geom::unit_vector(req_vec) );
+        }
+    }
+}
+
+
+/* interpolates the sketched curve and tweaks the current sketch interpolation*/
+void PencilTool::_sketchInterpolate() {
+    if ( this->ps.size() <= 1 ) {
+        return;
+    }
+
+    Inkscape::Preferences *prefs = Inkscape::Preferences::get();
+    double tol = prefs->getDoubleLimited("/tools/freehand/pencil/tolerance", 10.0, 1.0, 100.0) * 0.4;
+    bool simplify = prefs->getInt("/tools/freehand/pencil/simplify", 0);
+    if(simplify){
+        double tol2 = prefs->getDoubleLimited("/tools/freehand/pencil/base-simplify", 25.0, 1.0, 100.0) * 0.4;
+        tol = std::min(tol,tol2);
+    }
+    double tolerance_sq = 0.02 * square(_desktop->w2d().descrim() * tol) * exp(0.2 * tol - 2);
+
+    bool average_all_sketches = prefs->getBool("/tools/freehand/pencil/average_all_sketches", true);
+
+    g_assert(is_zero(this->_req_tangent) || is_unit_vector(this->_req_tangent));
+
+    this->red_curve->reset();
+    this->red_curve_is_valid = false;
+
+    int n_points = this->ps.size();
+
+    // worst case gives us a segment per point
+    int max_segs = 4 * n_points;
+
+    std::vector<Geom::Point> b(max_segs);
+
+    int const n_segs = Geom::bezier_fit_cubic_r(b.data(), this->ps.data(), n_points, tolerance_sq, max_segs);
+
+    if (n_segs > 0) {
+        Geom::Path fit(b[0]);
+
+        for (int c = 0; c < n_segs; c++) {
+            fit.appendNew<Geom::CubicBezier>(b[4 * c + 1], b[4 * c + 2], b[4 * c + 3]);
+        }
+
+        Geom::Piecewise<Geom::D2<Geom::SBasis> > fit_pwd2 = fit.toPwSb();
+
+        if (this->sketch_n > 0) {
+            double t;
+
+            if (average_all_sketches) {
+                // Average = (sum of all) / n
+                //         = (sum of all + new one) / n+1
+                //         = ((old average)*n + new one) / n+1
+                t = this->sketch_n / (this->sketch_n + 1.);
+            } else {
+                t = 0.5;
+            }
+
+            this->sketch_interpolation = Geom::lerp(t, fit_pwd2, this->sketch_interpolation);
+
+            // simplify path, to eliminate small segments
+            Path path;
+            path.LoadPathVector(Geom::path_from_piecewise(this->sketch_interpolation, 0.01));
+            path.Simplify(0.5);
+
+            Geom::PathVector pathv = path.MakePathVector();
+            this->sketch_interpolation = pathv[0].toPwSb();
+        } else {
+            this->sketch_interpolation = fit_pwd2;
+        }
+
+        this->sketch_n++;
+
+        this->green_curve->reset();
+        this->green_curve->set_pathvector(Geom::path_from_piecewise(this->sketch_interpolation, 0.01));
+        if (!tablet_enabled) {
+            red_bpath->set_bpath(green_curve.get());
+        }
+        /* Fit and draw and copy last point */
+        g_assert(!this->green_curve->is_empty());
+
+        /* Set up direction of next curve. */
+        {
+            Geom::Curve const * last_seg = this->green_curve->last_segment();
+            g_assert( last_seg );      // Relevance: validity of (*last_seg)
+            this->p[0] = last_seg->finalPoint();
+            this->_npoints = 1;
+            Geom::Curve *last_seg_reverse = last_seg->reverse();
+            Geom::Point const req_vec( -last_seg_reverse->unitTangentAt(0) );
+            delete last_seg_reverse;
+            this->_req_tangent = ( ( Geom::is_zero(req_vec) || !in_svg_plane(req_vec) )
+                                ? Geom::Point(0, 0)
+                                : Geom::unit_vector(req_vec) );
+        }
+    }
+
+    this->ps.clear();
+    this->points.clear();
+    this->_wps.clear();
+}
+
+void PencilTool::_fitAndSplit() {
+    g_assert( this->_npoints > 1 );
+
+    double const tolerance_sq = 0;
+
+    Geom::Point b[4];
+    g_assert(is_zero(this->_req_tangent)
+             || is_unit_vector(this->_req_tangent));
+    Geom::Point const tHatEnd(0, 0);
+    Inkscape::Preferences *prefs = Inkscape::Preferences::get();
+    int const n_segs = Geom::bezier_fit_cubic_full(b, nullptr, this->p, this->_npoints,
+                                                this->_req_tangent, tHatEnd,
+                                                tolerance_sq, 1);
+    if ( n_segs > 0
+         && unsigned(this->_npoints) < G_N_ELEMENTS(this->p) )
+    {
+        /* Fit and draw and reset state */
+
+        this->red_curve->reset();
+        this->red_curve->moveto(b[0]);
+        using Geom::X;
+        using Geom::Y;
+            // if we are in BSpline we modify the trace to create adhoc nodes
+        guint mode = prefs->getInt("/tools/freehand/pencil/freehand-mode", 0);
+        if(mode == 2){
+            Geom::Point point_at1 = b[0] + (1./3)*(b[3] - b[0]);
+            point_at1 = Geom::Point(point_at1[X] + HANDLE_CUBIC_GAP, point_at1[Y] + HANDLE_CUBIC_GAP);
+            Geom::Point point_at2 = b[3] + (1./3)*(b[0] - b[3]);
+            point_at2 = Geom::Point(point_at2[X] + HANDLE_CUBIC_GAP, point_at2[Y] + HANDLE_CUBIC_GAP);
+            this->red_curve->curveto(point_at1,point_at2,b[3]);
+        }else{
+            this->red_curve->curveto(b[1], b[2], b[3]);
+        }
+        if (!tablet_enabled) {
+            red_bpath->set_bpath(red_curve.get());
+        }
+        this->red_curve_is_valid = true;
+    } else {
+        /* Fit and draw and copy last point */
+
+        g_assert(!this->red_curve->is_empty());
+
+        /* Set up direction of next curve. */
+        {
+            Geom::Curve const * last_seg = this->red_curve->last_segment();
+            g_assert( last_seg );      // Relevance: validity of (*last_seg)
+            this->p[0] = last_seg->finalPoint();
+            this->_npoints = 1;
+            Geom::Curve *last_seg_reverse = last_seg->reverse();
+            Geom::Point const req_vec( -last_seg_reverse->unitTangentAt(0) );
+            delete last_seg_reverse;
+            this->_req_tangent = ( ( Geom::is_zero(req_vec) || !in_svg_plane(req_vec) )
+                                ? Geom::Point(0, 0)
+                                : Geom::unit_vector(req_vec) );
+        }
+
+        green_curve->append_continuous(*red_curve);
+        auto curve = this->red_curve->copy();
+
+        /// \todo fixme:
+
+        auto layer = _desktop->layerManager().currentLayer();
+        this->highlight_color = layer->highlight_color();
+        if((unsigned int)prefs->getInt("/tools/nodes/highlight_color", 0xff0000ff) == this->highlight_color){
+            this->green_color = 0x00ff007f;
+        } else {
+            this->green_color = this->highlight_color;
+        }
+
+        auto cshape = new Inkscape::CanvasItemBpath(_desktop->getCanvasSketch(), curve.get(), true);
+        cshape->set_stroke(green_color);
+        cshape->set_fill(0x0, SP_WIND_RULE_NONZERO);
+
+        this->green_bpaths.push_back(cshape);
+
+        this->red_curve_is_valid = false;
+    }
+}
+
+}
+}
+}
+
+/*
+  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 :