tweak-tool.cpp

Go to the documentation of this file.

// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * tweaking paths without node editing
 *
 * Authors:
 *   bulia byak
 *   Jon A. Cruz <jon@joncruz.org>
 *   Abhishek Sharma
 *
 * Copyright (C) 2007 authors
 *
 * Released under GNU GPL v2+, read the file 'COPYING' for more information.
 */
 
#include "tweak-tool.h"
 
#include <gdk/gdkkeysyms.h>
#include <glibmm/i18n.h>
 
#include <2geom/circle.h>
 
#include "context-fns.h"
#include "desktop-style.h"
#include "desktop.h"
#include "document-undo.h"
#include "document.h"
#include "filter-chemistry.h"
#include "gradient-chemistry.h"
#include "message-context.h"
#include "path-chemistry.h"
#include "selection.h"
#include "style.h"
 
#include "display/control/canvas-item-bpath.h"
 
#include "livarot/Path.h"
#include "livarot/Shape.h"
 
#include "object/box3d.h"
#include "object/filters/gaussian-blur.h"
#include "object/sp-flowtext.h"
#include "object/sp-linear-gradient.h"
#include "object/sp-mesh-gradient.h"
#include "object/sp-path.h"
#include "object/sp-radial-gradient.h"
#include "object/sp-stop.h"
#include "object/sp-text.h"
 
#include "path/path-util.h"
 
#include "ui/icon-names.h"
#include "ui/toolbar/tweak-toolbar.h"
#include "ui/widget/events/canvas-event.h"
 
 
using Inkscape::DocumentUndo;
 
#define DDC_RED_RGBA 0xff0000ff
 
#define DYNA_MIN_WIDTH 1.0e-6
 
namespace Inkscape::UI::Tools {
 
TweakTool::TweakTool(SPDesktop *desktop)
    : ToolBase(desktop, "/tools/tweak", "tweak-push.svg")
    , pressure(TC_DEFAULT_PRESSURE)
    , usepressure(false)
    , usetilt(false)
    , width(0.2)
    , force(0.2)
    , fidelity(0)
    , mode(0)
    , is_drawing(false)
    , is_dilating(false)
    , has_dilated(false)
    , do_h(true)
    , do_s(true)
    , do_l(true)
    , do_o(false)
{
    dilate_area = make_canvasitem<CanvasItemBpath>(desktop->getCanvasSketch());
    dilate_area->set_stroke(0xff9900ff);
    dilate_area->set_fill(0x0, SP_WIND_RULE_EVENODD);
    dilate_area->set_visible(false);
 
    sp_event_context_read(this, "width");
    sp_event_context_read(this, "mode");
    sp_event_context_read(this, "fidelity");
    sp_event_context_read(this, "force");
    sp_event_context_read(this, "usepressure");
    sp_event_context_read(this, "doh");
    sp_event_context_read(this, "dol");
    sp_event_context_read(this, "dos");
    sp_event_context_read(this, "doo");
 
    style_set_connection = desktop->connectSetStyle( // catch style-setting signal in this tool
        sigc::hide(sigc::mem_fun(*this, &TweakTool::set_style))
    );
    
    Inkscape::Preferences *prefs = Inkscape::Preferences::get();
    if (prefs->getBool("/tools/tweak/selcue")) {
        enableSelectionCue();
    }
    if (prefs->getBool("/tools/tweak/gradientdrag")) {
        enableGrDrag();
    }
}
 
TweakTool::~TweakTool()
{
    enableGrDrag(false);
}
 
static bool is_transform_mode (gint mode)
{
    return (mode == TWEAK_MODE_MOVE || 
            mode == TWEAK_MODE_MOVE_IN_OUT || 
            mode == TWEAK_MODE_MOVE_JITTER || 
            mode == TWEAK_MODE_SCALE || 
            mode == TWEAK_MODE_ROTATE || 
            mode == TWEAK_MODE_MORELESS);
}
 
static bool is_color_mode(gint mode)
{
    return mode == TWEAK_MODE_COLORPAINT || mode == TWEAK_MODE_COLORJITTER || mode == TWEAK_MODE_BLUR;
}
 
void TweakTool::update_cursor (bool with_shift) {
    guint num = 0;
    gchar *sel_message = nullptr;
 
    if (!_desktop->getSelection()->isEmpty()) {
        num = (guint)boost::distance(_desktop->getSelection()->items());
        sel_message = g_strdup_printf(ngettext("<b>%i</b> object selected","<b>%i</b> objects selected",num), num);
    } else {
        sel_message = g_strdup_printf("%s", _("<b>Nothing</b> selected"));
    }
 
   switch (this->mode) {
       case TWEAK_MODE_MOVE:
           this->message_context->setF(Inkscape::NORMAL_MESSAGE, _("%s. Drag to <b>move</b>."), sel_message);
           this->set_cursor("tweak-move.svg");
           break;
       case TWEAK_MODE_MOVE_IN_OUT:
           this->message_context->setF(Inkscape::NORMAL_MESSAGE, _("%s. Drag or click to <b>move in</b>; with Shift to <b>move out</b>."), sel_message);
           if (with_shift) {
               this->set_cursor("tweak-move-out.svg");
           } else {
               this->set_cursor("tweak-move-in.svg");
           }
           break;
       case TWEAK_MODE_MOVE_JITTER:
           this->message_context->setF(Inkscape::NORMAL_MESSAGE, _("%s. Drag or click to <b>move randomly</b>."), sel_message);
            this->set_cursor("tweak-move-jitter.svg");
           break;
       case TWEAK_MODE_SCALE:
           this->message_context->setF(Inkscape::NORMAL_MESSAGE, _("%s. Drag or click to <b>scale down</b>; with Shift to <b>scale up</b>."), sel_message);
           if (with_shift) {
               this->set_cursor("tweak-scale-up.svg");
           } else {
               this->set_cursor("tweak-scale-down.svg");
           }
           break;
       case TWEAK_MODE_ROTATE:
           this->message_context->setF(Inkscape::NORMAL_MESSAGE, _("%s. Drag or click to <b>rotate clockwise</b>; with Shift, <b>counterclockwise</b>."), sel_message);
           if (with_shift) {
               this->set_cursor("tweak-rotate-counterclockwise.svg");
           } else {
               this->set_cursor("tweak-rotate-clockwise.svg");
           }
           break;
       case TWEAK_MODE_MORELESS:
           this->message_context->setF(Inkscape::NORMAL_MESSAGE, _("%s. Drag or click to <b>duplicate</b>; with Shift, <b>delete</b>."), sel_message);
           if (with_shift) {
               this->set_cursor("tweak-less.svg");
           } else {
               this->set_cursor("tweak-more.svg");
           }
           break;
       case TWEAK_MODE_PUSH:
           this->message_context->setF(Inkscape::NORMAL_MESSAGE, _("%s. Drag to <b>push paths</b>."), sel_message);
           this->set_cursor("tweak-push.svg");
           break;
       case TWEAK_MODE_SHRINK_GROW:
           this->message_context->setF(Inkscape::NORMAL_MESSAGE, _("%s. Drag or click to <b>inset paths</b>; with Shift to <b>outset</b>."), sel_message);
           if (with_shift) {
               this->set_cursor("tweak-outset.svg");
           } else {
               this->set_cursor("tweak-inset.svg");
           }
           break;
       case TWEAK_MODE_ATTRACT_REPEL:
           this->message_context->setF(Inkscape::NORMAL_MESSAGE, _("%s. Drag or click to <b>attract paths</b>; with Shift to <b>repel</b>."), sel_message);
           if (with_shift) {
               this->set_cursor("tweak-repel.svg");
           } else {
               this->set_cursor("tweak-attract.svg");
           }
           break;
       case TWEAK_MODE_ROUGHEN:
           this->message_context->setF(Inkscape::NORMAL_MESSAGE, _("%s. Drag or click to <b>roughen paths</b>."), sel_message);
           this->set_cursor("tweak-roughen.svg");
           break;
       case TWEAK_MODE_COLORPAINT:
           this->message_context->setF(Inkscape::NORMAL_MESSAGE, _("%s. Drag or click to <b>paint objects</b> with color."), sel_message);
           this->set_cursor("tweak-color.svg");
           break;
       case TWEAK_MODE_COLORJITTER:
           this->message_context->setF(Inkscape::NORMAL_MESSAGE, _("%s. Drag or click to <b>randomize colors</b>."), sel_message);
           this->set_cursor("tweak-color.svg");
           break;
       case TWEAK_MODE_BLUR:
           this->message_context->setF(Inkscape::NORMAL_MESSAGE, _("%s. Drag or click to <b>increase blur</b>; with Shift to <b>decrease</b>."), sel_message);
           this->set_cursor("tweak-color.svg");
           break;
   }
   g_free(sel_message);
}
 
bool TweakTool::set_style(const SPCSSAttr* css) {
    if (this->mode == TWEAK_MODE_COLORPAINT) { // intercept color setting only in this mode
        // we cannot store properties with uris
        css = sp_css_attr_unset_uris(const_cast<SPCSSAttr *>(css));
        Inkscape::Preferences *prefs = Inkscape::Preferences::get();
        prefs->setStyle("/tools/tweak/style", const_cast<SPCSSAttr *>(css));
        return true;
    }
 
    return false;
}
 
void TweakTool::set(const Inkscape::Preferences::Entry& val) {
    Glib::ustring path = val.getEntryName();
 
    if (path == "width") {
        this->width = CLAMP(val.getDouble(0.1), -1000.0, 1000.0);
    } else if (path == "mode") {
        this->mode = val.getInt();
        this->update_cursor(false);
    } else if (path == "fidelity") {
        this->fidelity = CLAMP(val.getDouble(), 0.0, 1.0);
    } else if (path == "force") {
        this->force = CLAMP(val.getDouble(1.0), 0, 1.0);
    } else if (path == "usepressure") {
        this->usepressure = val.getBool();
    } else if (path == "doh") {
        this->do_h = val.getBool();
    } else if (path == "dos") {
        this->do_s = val.getBool();
    } else if (path == "dol") {
        this->do_l = val.getBool();
    } else if (path == "doo") {
        this->do_o = val.getBool();
    }
}
 
static void sp_tweak_extinput(TweakTool *tc, ExtendedInput const &ext)
{
    if (ext.pressure) {
        tc->pressure = std::clamp(*ext.pressure, TC_MIN_PRESSURE, TC_MAX_PRESSURE);
    } else {
        tc->pressure = TC_DEFAULT_PRESSURE;
    }
}
 
static double
get_dilate_radius (TweakTool *tc)
{
    // 10 times the pen width:
    return 500 * tc->width/tc->getDesktop()->current_zoom();
}
 
static double
get_path_force (TweakTool *tc)
{
    double force = 8 * (tc->usepressure? tc->pressure : TC_DEFAULT_PRESSURE)
        /sqrt(tc->getDesktop()->current_zoom());
    if (force > 3) {
        force += 4 * (force - 3);
    }
    return force * tc->force;
}
 
static double
get_move_force (TweakTool *tc)
{
    double force = (tc->usepressure? tc->pressure : TC_DEFAULT_PRESSURE);
    return force * tc->force;
}
 
static bool
sp_tweak_dilate_recursive (Inkscape::Selection *selection, SPItem *item, Geom::Point p, Geom::Point vector, gint mode, double radius, double force, double fidelity, bool reverse)
{
    bool did = false;
 
    {
        auto box = cast<SPBox3D>(item);
        if (box && !is_transform_mode(mode) && !is_color_mode(mode)) {
            // convert 3D boxes to ordinary groups before tweaking their shapes
            item = box->convert_to_group();
            selection->add(item);
        }
    }
 
    if (is<SPText>(item) || is<SPFlowtext>(item)) {
        std::vector<SPItem*> items;
        items.push_back(item);
        std::vector<SPItem*> selected;
        std::vector<Inkscape::XML::Node*> to_select;
        SPDocument *doc = item->document;
        sp_item_list_to_curves (items, selected, to_select);
        SPObject* newObj = doc->getObjectByRepr(to_select[0]);
        item = cast<SPItem>(newObj);
        g_assert(item != nullptr);
        selection->add(item);
    }
 
    if (is<SPGroup>(item) && !is<SPBox3D>(item)) {
        std::vector<SPItem *> children;
        for (auto& child: item->children) {
            if (is<SPItem>(&child)) {
                children.push_back(cast<SPItem>(&child));
            }
        }
 
        for (auto i = children.rbegin(); i!= children.rend(); ++i) {
            SPItem *child = *i; 
            g_assert(child != nullptr);
            if (sp_tweak_dilate_recursive (selection, child, p, vector, mode, radius, force, fidelity, reverse)) {
                did = true;
            }
        }
    } else {
        if (mode == TWEAK_MODE_MOVE) {
 
            Geom::OptRect a = item->documentVisualBounds();
            if (a) {
                double x = Geom::L2(a->midpoint() - p)/radius;
                if (a->contains(p)) x = 0;
                if (x < 1) {
                    Geom::Point move = force * 0.5 * (cos(M_PI * x) + 1) * vector;
                    item->move_rel(Geom::Translate(move * selection->desktop()->doc2dt().withoutTranslation()));
                    did = true;
                }
            }
 
        } else if (mode == TWEAK_MODE_MOVE_IN_OUT) {
 
            Geom::OptRect a = item->documentVisualBounds();
            if (a) {
                double x = Geom::L2(a->midpoint() - p)/radius;
                if (a->contains(p)) x = 0;
                if (x < 1) {
                    Geom::Point move = force * 0.5 * (cos(M_PI * x) + 1) * 
                        (reverse? (a->midpoint() - p) : (p - a->midpoint()));
                    item->move_rel(Geom::Translate(move * selection->desktop()->doc2dt().withoutTranslation()));
                    did = true;
                }
            }
 
        } else if (mode == TWEAK_MODE_MOVE_JITTER) {
 
            Geom::OptRect a = item->documentVisualBounds();
            if (a) {
                double dp = g_random_double_range(0, M_PI*2);
                double dr = g_random_double_range(0, radius);
                double x = Geom::L2(a->midpoint() - p)/radius;
                if (a->contains(p)) x = 0;
                if (x < 1) {
                    Geom::Point move = force * 0.5 * (cos(M_PI * x) + 1) * Geom::Point(cos(dp)*dr, sin(dp)*dr);
                    item->move_rel(Geom::Translate(move * selection->desktop()->doc2dt().withoutTranslation()));
                    did = true;
                }
            }
 
        } else if (mode == TWEAK_MODE_SCALE) {
 
            Geom::OptRect a = item->documentVisualBounds();
            if (a) {
                double x = Geom::L2(a->midpoint() - p)/radius;
                if (a->contains(p)) x = 0;
                if (x < 1) {
                    double scale = 1 + (reverse? force : -force) * 0.05 * (cos(M_PI * x) + 1);
                    item->scale_rel(Geom::Scale(scale, scale));
                    did = true;
                }
            }
 
        } else if (mode == TWEAK_MODE_ROTATE) {
 
            Geom::OptRect a = item->documentVisualBounds();
            if (a) {
                double x = Geom::L2(a->midpoint() - p)/radius;
                if (a->contains(p)) x = 0;
                if (x < 1) {
                    double angle = (reverse? force : -force) * 0.05 * (cos(M_PI * x) + 1) * M_PI;
                    angle *= -selection->desktop()->yaxisdir();
                    item->rotate_rel(Geom::Rotate(angle));
                    did = true;
                }
            }
 
        } else if (mode == TWEAK_MODE_MORELESS) {
 
            Geom::OptRect a = item->documentVisualBounds();
            if (a) {
                double x = Geom::L2(a->midpoint() - p)/radius;
                if (a->contains(p)) x = 0;
                if (x < 1) {
                    double prob = force * 0.5 * (cos(M_PI * x) + 1);
                    double chance = g_random_double_range(0, 1);
                    if (chance <= prob) {
                        if (reverse) { // delete
                            item->deleteObject(true, true);
                        } else { // duplicate
                            SPDocument *doc = item->document;
                            Inkscape::XML::Document* xml_doc = doc->getReprDoc();
                            Inkscape::XML::Node *old_repr = item->getRepr();
                            SPObject *old_obj = doc->getObjectByRepr(old_repr);
                            Inkscape::XML::Node *parent = old_repr->parent();
                            Inkscape::XML::Node *copy = old_repr->duplicate(xml_doc);
                            parent->appendChild(copy);
                            SPObject *new_obj = doc->getObjectByRepr(copy);
                            if (selection->includes(old_obj)) {
                                selection->add(new_obj);
                            }
                            Inkscape::GC::release(copy);
                        }
                        did = true;
                    }
                }
            }
 
        } else if (is<SPPath>(item) || is<SPShape>(item)) {
 
            Inkscape::XML::Node *newrepr = nullptr;
            gint pos = 0;
            Inkscape::XML::Node *parent = nullptr;
            char const *id = nullptr;
            if (!is<SPPath>(item)) {
                newrepr = sp_selected_item_to_curved_repr(item, 0);
                if (!newrepr) {
                    return false;
                }
 
                // remember the position of the item
                pos = item->getRepr()->position();
                // remember parent
                parent = item->getRepr()->parent();
                // remember id
                id = item->getRepr()->attribute("id");
            }
 
            // skip those paths whose bboxes are entirely out of reach with our radius
            Geom::OptRect bbox = item->documentVisualBounds();
            if (bbox) {
                bbox->expandBy(radius);
                if (!bbox->contains(p)) {
                    return false;
                }
            }
 
            auto orig = Path_for_item(item, false);
            if (!orig) {
                return false;
            }
 
            Path *res = new Path;
            res->SetBackData(false);
 
            Shape *theShape = new Shape;
            Shape *theRes = new Shape;
            Geom::Affine i2doc(item->i2doc_affine());
 
            orig->ConvertWithBackData((0.08 - (0.07 * fidelity)) / i2doc.descrim()); // default 0.059
            orig->Fill(theShape, 0);
 
            SPCSSAttr *css = sp_repr_css_attr(item->getRepr(), "style");
            gchar const *val = sp_repr_css_property(css, "fill-rule", nullptr);
            if (val && strcmp(val, "nonzero") == 0) {
                theRes->ConvertToShape(theShape, fill_nonZero);
            } else if (val && strcmp(val, "evenodd") == 0) {
                theRes->ConvertToShape(theShape, fill_oddEven);
            } else {
                theRes->ConvertToShape(theShape, fill_nonZero);
            }
 
            if (Geom::L2(vector) != 0) {
                vector = 1/Geom::L2(vector) * vector;
            }
 
            bool did_this = false;
            if (mode == TWEAK_MODE_SHRINK_GROW) {
                if (theShape->MakeTweak(tweak_mode_grow, theRes,
                        reverse? force : -force,
                        join_straight, 4.0,
                        true, p, Geom::Point(0,0), radius, &i2doc) == 0) // 0 means the shape was actually changed
                    did_this = true;
            } else if (mode == TWEAK_MODE_ATTRACT_REPEL) {
                if (theShape->MakeTweak(tweak_mode_repel, theRes,
                        reverse? force : -force,
                        join_straight, 4.0,
                        true, p, Geom::Point(0,0), radius, &i2doc) == 0)
                    did_this = true;
            } else if (mode == TWEAK_MODE_PUSH) {
                if (theShape->MakeTweak(tweak_mode_push, theRes,
                        1.0,
                        join_straight, 4.0,
                        true, p, force*2*vector, radius, &i2doc) == 0)
                    did_this = true;
            } else if (mode == TWEAK_MODE_ROUGHEN) {
                if (theShape->MakeTweak(tweak_mode_roughen, theRes,
                        force,
                        join_straight, 4.0,
                        true, p, Geom::Point(0,0), radius, &i2doc) == 0)
                    did_this = true;
            }
 
            // the rest only makes sense if we actually changed the path
            if (did_this) {
                theRes->ConvertToShape(theShape, fill_positive);
 
                res->Reset();
                theRes->ConvertToForme(res);
 
                double th_max = (0.6 - 0.59*sqrt(fidelity)) / i2doc.descrim();
                double threshold = MAX(th_max, th_max*force);
                res->ConvertEvenLines(threshold);
                res->Simplify(threshold / (selection->desktop()->current_zoom()));
 
                if (newrepr) { // converting to path, need to replace the repr
                    bool is_selected = selection->includes(item);
                    if (is_selected) {
                        selection->remove(item);
                    }
 
                    // It's going to resurrect, so we delete without notifying listeners.
                    item->deleteObject(false);
 
                    // restore id
                    newrepr->setAttribute("id", id);
                    // add the new repr to the parent
                    // move to the saved position
                    parent->addChildAtPos(newrepr, pos);
 
                    if (is_selected)
                        selection->add(newrepr);
                }
 
                if (res->descr_cmd.size() > 1) {
                    auto str = res->svg_dump_path();
                    if (newrepr) {
                        newrepr->setAttribute("d", str.c_str());
                    } else {
                        auto lpeitem = cast<SPLPEItem>(item);
                        if (lpeitem && lpeitem->hasPathEffectRecursive()) {
                            item->setAttribute("inkscape:original-d", str.c_str());
                        } else {
                            item->setAttribute("d", str.c_str());
                        }
                    }
                } else {
                    // TODO: if there's 0 or 1 node left, delete this path altogether
                }
 
                if (newrepr) {
                    Inkscape::GC::release(newrepr);
                    newrepr = nullptr;
                }
            }
 
            delete theShape;
            delete theRes;
            delete res;
 
            if (did_this) {
                did = true;
            }
        }
 
    }
 
    return did;
}
 
static Color tweak_color(guint mode, Color const &color, Color const &goal, double force, bool do_h, bool do_s, bool do_l)
{
    // Tweak colors are entirely based on HSL values;
    if (auto hsl = color.converted(Colors::Space::Type::HSL)) {
        unsigned int pin = (do_h * 1) + (do_s * 2) + (do_l * 4);
        if (mode == TWEAK_MODE_COLORPAINT) {
            hsl->average(goal, force, pin);
        } else if (mode == TWEAK_MODE_COLORJITTER) {
            hsl->jitter(force, pin);
        }
        if (auto copy = hsl->converted(color.getSpace()))
            return *copy;
    }
    return color; // Bad conversion
}
 
static void tweak_stop_color(guint mode, SPStop *stop, Color const &goal, double force, bool do_h, bool do_s, bool do_l)
{
    auto copy = stop->getColor();
    tweak_color(mode, copy, goal, force, do_h, do_s, do_l);
    stop->setColor(copy);
}
 
    static void
tweak_opacity (guint mode, SPIScale24 *style_opacity, double opacity_goal, double force)
{
    double opacity = SP_SCALE24_TO_FLOAT (style_opacity->value);
 
    if (mode == TWEAK_MODE_COLORPAINT) {
        double d = opacity_goal - opacity;
        opacity += d * force;
    } else if (mode == TWEAK_MODE_COLORJITTER) {
        opacity += g_random_double_range(-opacity, 1 - opacity) * force;
    }
 
    style_opacity->value = SP_SCALE24_FROM_FLOAT(opacity);
}
 
 
    static double
tweak_profile (double dist, double radius)
{
    if (radius == 0) {
        return 0;
    }
    double x = dist / radius;
    double alpha = 1;
    if (x >= 1) {
        return 0;
    } else if (x <= 0) {
        return 1;
    } else {
        return (0.5 * cos (M_PI * (pow(x, alpha))) + 0.5);
    }
}
 
static void tweak_colors_in_gradient(SPItem *item, Inkscape::PaintTarget fill_or_stroke,
    Color const &goal, Geom::Point p_w, double radius, double force, guint mode,
    bool do_h, bool do_s, bool do_l, bool /*do_o*/)
{
    SPGradient *gradient = getGradient(item, fill_or_stroke);
 
    if (!gradient) {
        return;
    }
 
    Geom::Affine i2d (item->i2doc_affine ());
    Geom::Point p = p_w * i2d.inverse();
    p *= (gradient->gradientTransform).inverse();
    // now p is in gradient's original coordinates
 
    auto lg = cast<SPLinearGradient>(gradient);
    auto rg = cast<SPRadialGradient>(gradient);
    if (lg || rg) {
 
        double pos = 0;
        double r = 0;
 
        if (lg) {
            Geom::Point p1(lg->x1.computed, lg->y1.computed);
            Geom::Point p2(lg->x2.computed, lg->y2.computed);
            Geom::Point pdiff(p2 - p1);
            double vl = Geom::L2(pdiff);
 
            // This is the matrix which moves and rotates the gradient line
            // so it's oriented along the X axis:
            Geom::Affine norm = Geom::Affine(Geom::Translate(-p1)) *
                Geom::Affine(Geom::Rotate(-atan2(pdiff[Geom::Y], pdiff[Geom::X])));
 
            // Transform the mouse point by it to find out its projection onto the gradient line:
            Geom::Point pnorm = p * norm;
 
            // Scale its X coordinate to match the length of the gradient line:
            pos = pnorm[Geom::X] / vl;
            // Calculate radius in length-of-gradient-line units
            r = radius / vl;
 
        }
        if (rg) {
            Geom::Point c (rg->cx.computed, rg->cy.computed);
            pos = Geom::L2(p - c) / rg->r.computed;
            r = radius / rg->r.computed;
        }
 
        // Normalize pos to 0..1, taking into account gradient spread:
        double pos_e = pos;
        if (gradient->getSpread() == SP_GRADIENT_SPREAD_PAD) {
            if (pos > 1) {
                pos_e = 1;
            }
            if (pos < 0) {
                pos_e = 0;
            }
        } else if (gradient->getSpread() == SP_GRADIENT_SPREAD_REPEAT) {
            if (pos > 1 || pos < 0) {
                pos_e = pos - floor(pos);
            }
        } else if (gradient->getSpread() == SP_GRADIENT_SPREAD_REFLECT) {
            if (pos > 1 || pos < 0) {
                bool odd = ((int)(floor(pos)) % 2 == 1);
                pos_e = pos - floor(pos);
                if (odd) {
                    pos_e = 1 - pos_e;
                }
            }
        }
 
        SPGradient *vector = sp_gradient_get_forked_vector_if_necessary(gradient, false);
 
        double offset_l = 0;
        double offset_h = 0;
        SPObject *child_prev = nullptr;
        for (auto& child: vector->children) {
            auto stop = cast<SPStop>(&child);
            if (!stop) {
                continue;
            }
 
            offset_h = stop->offset;
 
            if (child_prev) {
                auto prevStop = cast<SPStop>(child_prev);
                g_assert(prevStop != nullptr);
 
                if (offset_h - offset_l > r && pos_e >= offset_l && pos_e <= offset_h) {
                    // the summit falls in this interstop, and the radius is small,
                    // so it only affects the ends of this interstop;
                    // distribute the force between the two endstops so that they
                    // get all the painting even if they are not touched by the brush
                    tweak_stop_color(mode, stop, goal,
                        force * (pos_e - offset_l) / (offset_h - offset_l),
                        do_h, do_s, do_l);
                    tweak_stop_color(mode, prevStop, goal,
                        force * (offset_h - pos_e) / (offset_h - offset_l),
                        do_h, do_s, do_l);
                    stop->updateRepr();
                    child_prev->updateRepr();
                    break;
                } else {
                    // wide brush, may affect more than 2 stops,
                    // paint each stop by the force from the profile curve
                    if (offset_l <= pos_e && offset_l > pos_e - r) {
                        tweak_stop_color(mode, prevStop, goal,
                            force * tweak_profile (fabs (pos_e - offset_l), r),
                            do_h, do_s, do_l);
                        child_prev->updateRepr();
                    }
 
                    if (offset_h >= pos_e && offset_h < pos_e + r) {
                        tweak_stop_color(mode, prevStop, goal,
                            force * tweak_profile (fabs (pos_e - offset_h), r),
                            do_h, do_s, do_l);
                        stop->updateRepr();
                    }
                }
            }
 
            offset_l = offset_h;
            child_prev = &child;
        }
    } else {
        // Mesh
        auto mg = cast<SPMeshGradient>(gradient);
        if (mg) {
            auto mg_array = cast<SPMeshGradient>(mg->getArray());
            SPMeshNodeArray *array = &(mg_array->array);
            // Every third node is a corner node
            for( unsigned i=0; i < array->nodes.size(); i+=3 ) {
                for( unsigned j=0; j < array->nodes[i].size(); j+=3 ) {
                    SPStop *stop = array->nodes[i][j]->stop;
                    double distance = Geom::L2(Geom::Point(p - array->nodes[i][j]->p)); 
                    tweak_stop_color(mode, stop, goal,
                        force * tweak_profile (distance, radius), do_h, do_s, do_l);
                    stop->updateRepr();
                }
            }
        }
    }
}
 
static bool
sp_tweak_color_recursive (guint mode, SPItem *item, SPItem *item_at_point,
    std::optional<Color> &fill_goal, std::optional<Color> &stroke_goal,
    float opacity_goal, bool do_opacity,
    bool do_blur, bool reverse,
    Geom::Point p, double radius, double force,
    bool do_h, bool do_s, bool do_l, bool do_o)
{
    bool did = false;
 
    if (is<SPGroup>(item)) {
        for (auto& child: item->children) {
            auto childItem = cast<SPItem>(&child);
            if (childItem) {
                if (sp_tweak_color_recursive (mode, childItem, item_at_point,
                        fill_goal, stroke_goal,
                        opacity_goal, do_opacity,
                        do_blur, reverse,
                        p, radius, force, do_h, do_s, do_l, do_o)) {
                    did = true;
                }
            }
        }
 
    } else {
        SPStyle *style = item->style;
        if (!style) {
            return false;
        }
        Geom::OptRect bbox = item->documentGeometricBounds();
        if (!bbox) {
            return false;
        }
 
        Geom::Rect brush(p - Geom::Point(radius, radius), p + Geom::Point(radius, radius));
 
        Geom::Point center = bbox->midpoint();
        double this_force;
 
        // if item == item_at_point, use max force
        if (item == item_at_point) {
            this_force = force;
            // else if no overlap of bbox and brush box, skip:
        } else if (!bbox->intersects(brush)) {
            return false;
            //TODO:
            // else if object > 1.5 brush: test 4/8/16 points in the brush on hitting the object, choose max
            //} else if (bbox->maxExtent() > 3 * radius) {
            //}
            // else if object > 0.5 brush: test 4 corners of bbox and center on being in the brush, choose max
            // else if still smaller, then check only the object center:
    } else {
        this_force = force * tweak_profile (Geom::L2 (p - center), radius);
    }
 
    if (this_force > 0.002) {
 
        if (do_blur) {
            Geom::OptRect bbox = item->documentGeometricBounds();
            if (!bbox) {
                return did;
            }
 
            double blur_now = 0;
            Geom::Affine i2dt = item->i2dt_affine ();
            if (style->filter.set && style->getFilter()) {
                //cycle through filter primitives
                for (auto& primitive_obj: style->getFilter()->children) {
                    auto primitive = cast<SPFilterPrimitive>(&primitive_obj);
                    if (primitive) {
                        //if primitive is gaussianblur
                        auto spblur = cast<SPGaussianBlur>(primitive);
                        if (spblur) {
                            float num = spblur->get_std_deviation().getNumber();
                            blur_now += num * i2dt.descrim(); // sum all blurs in the filter
                        }
                    }
                }
            }
            double perimeter = bbox->dimensions()[Geom::X] + bbox->dimensions()[Geom::Y];
            blur_now = blur_now / perimeter;
 
            double blur_new;
            if (reverse) {
                blur_new = blur_now - 0.06 * force;
            } else {
                blur_new = blur_now + 0.06 * force;
            }
            if (blur_new < 0.0005 && blur_new < blur_now) {
                blur_new = 0;
            }
            if (blur_new == 0) {
                remove_filter(item, false);
            } else {
                double radius = blur_new * perimeter;
                SPFilter *filter = modify_filter_gaussian_blur_from_item(item->document, item, radius);
                sp_style_set_property_url(item, "filter", filter, false);
            }
            return true; // do not do colors, blur is a separate mode
        }
 
        if (fill_goal) {
            if (style->fill.isPaintserver()) {
                tweak_colors_in_gradient(item, Inkscape::FOR_FILL, *fill_goal, p, radius, this_force, mode, do_h, do_s, do_l, do_o);
                did = true;
            } else if (style->fill.isColor()) {
                style->fill.setColor(tweak_color(mode, style->fill.getColor(), *fill_goal, this_force, do_h, do_s, do_l));
                item->updateRepr();
                did = true;
            }
        }
        if (stroke_goal) {
            if (style->stroke.isPaintserver()) {
                tweak_colors_in_gradient(item, Inkscape::FOR_STROKE, *stroke_goal, p, radius, this_force, mode, do_h, do_s, do_l, do_o);
                did = true;
            } else if (style->stroke.isColor()) {
                style->stroke.setColor(tweak_color(mode, style->stroke.getColor(), *stroke_goal, this_force, do_h, do_s, do_l));
                item->updateRepr();
                did = true;
            }
        }
        if (do_opacity && do_o) {
            tweak_opacity (mode, &style->opacity, opacity_goal, this_force);
        }
    }
}
 
return did;
}
 
 
static bool
sp_tweak_dilate (TweakTool *tc, Geom::Point event_p, Geom::Point p, Geom::Point vector, bool reverse)
{
    SPDesktop *desktop = tc->getDesktop();
    Inkscape::Selection *selection = desktop->getSelection();
 
    if (selection->isEmpty()) {
        return false;
    }
 
    bool did = false;
    double radius = get_dilate_radius(tc);
 
    SPItem *item_at_point = tc->getDesktop()->getItemAtPoint(event_p, true);
 
    bool do_opacity = false;
    auto fill_goal = sp_desktop_get_color_tool(desktop, "/tools/tweak", true);
    auto stroke_goal = sp_desktop_get_color_tool(desktop, "/tools/tweak", false);
    double opacity_goal = sp_desktop_get_master_opacity_tool(desktop, "/tools/tweak", &do_opacity);
    if (reverse) {
        if (fill_goal)
            fill_goal->invert();
        if (stroke_goal)
            stroke_goal->invert();
        opacity_goal = 1 - opacity_goal;
    }
 
    double path_force = get_path_force(tc);
    if (radius == 0 || path_force == 0) {
        return false;
    }
    double move_force = get_move_force(tc);
    double color_force = MIN(sqrt(path_force)/20.0, 1);
 
    //    auto items= selection->items();
    std::vector<SPItem*> items(selection->items().begin(), selection->items().end());
    for(auto item : items){
        if (is_color_mode (tc->mode)) {
            if (fill_goal || stroke_goal || do_opacity) {
                if (sp_tweak_color_recursive (tc->mode, item, item_at_point,
                        fill_goal, stroke_goal,
                        opacity_goal, do_opacity,
                        tc->mode == TWEAK_MODE_BLUR, reverse,
                        p, radius, color_force, tc->do_h, tc->do_s, tc->do_l, tc->do_o)) {
                    did = true;
                }
            }
        } else if (is_transform_mode(tc->mode)) {
            if (sp_tweak_dilate_recursive (selection, item, p, vector, tc->mode, radius, move_force, tc->fidelity, reverse)) {
                did = true;
            }
        } else {
            if (sp_tweak_dilate_recursive (selection, item, p, vector, tc->mode, radius, path_force, tc->fidelity, reverse)) {
                did = true;
            }
        }
    }
 
    return did;
}
 
    static void
sp_tweak_update_area (TweakTool *tc)
{
    double radius = get_dilate_radius(tc);
    Geom::Affine const sm (Geom::Scale(radius, radius) * Geom::Translate(tc->getDesktop()->point()));
    
    Geom::PathVector path = Geom::Path(Geom::Circle(0,0,1)); // Unit circle centered at origin.
    path *= sm;
    tc->dilate_area->set_bpath(path);
    tc->dilate_area->set_visible(true);
}
 
    static void
sp_tweak_switch_mode (TweakTool *tc, gint mode, bool with_shift)
{
    auto tb = dynamic_cast<UI::Toolbar::TweakToolbar*>(tc->getDesktop()->get_toolbar_by_name("TweakToolbar"));
 
    if(tb) {
        tb->setMode(mode);
    } else {
        std::cerr << "Could not access Tweak toolbar" << std::endl;
    }
 
    // need to set explicitly, because the prefs may not have changed by the previous
    tc->mode = mode;
    tc->update_cursor(with_shift);
}
 
    static void
sp_tweak_switch_mode_temporarily (TweakTool *tc, gint mode, bool with_shift)
{
    Inkscape::Preferences *prefs = Inkscape::Preferences::get();
    // Juggling about so that prefs have the old value but tc->mode and the button show new mode:
    gint now_mode = prefs->getInt("/tools/tweak/mode", 0);
 
    auto tb = dynamic_cast<UI::Toolbar::TweakToolbar*>(tc->getDesktop()->get_toolbar_by_name("TweakToolbar"));
 
    if(tb) {
        tb->setMode(mode);
    } else {
        std::cerr << "Could not access Tweak toolbar" << std::endl;
    }
 
    // button has changed prefs, restore
    prefs->setInt("/tools/tweak/mode", now_mode);
    // changing prefs changed tc->mode, restore back :
    tc->mode = mode;
    tc->update_cursor(with_shift);
}
 
bool TweakTool::root_handler(CanvasEvent const &event)
{
    bool ret = false;
 
    inspect_event(event,
        [&] (EnterEvent const &event) {
            dilate_area->set_visible(true);
        },
        [&] (LeaveEvent const &event) {
            dilate_area->set_visible(false);
        },
        [&] (ButtonPressEvent const &event) {
            if (event.num_press == 1 && event.button == 1) {
                if (Inkscape::have_viable_layer(_desktop, defaultMessageContext()) == false) {
                    ret = true;
                } else {
 
                    Geom::Point const button_dt(_desktop->w2d(event.pos));
                    last_push = _desktop->dt2doc(button_dt);
 
                    sp_tweak_extinput(this, event.extinput);
 
                    is_drawing = true;
                    is_dilating = true;
                    has_dilated = false;
 
                    ret = true;
                }
            }
        },
        [&] (MotionEvent const &event) {
 
            Geom::Point motion_dt(_desktop->w2d(event.pos));
            Geom::Point motion_doc(_desktop->dt2doc(motion_dt));
            sp_tweak_extinput(this, event.extinput);
 
            // Draw the dilating cursor.
            double radius = get_dilate_radius(this);
            Geom::Affine const sm(Geom::Scale(radius, radius) * Geom::Translate(motion_dt));
            Geom::PathVector path = Geom::Path(Geom::Circle(0,0,1)); // Unit circle centered at origin.
            path *= sm;
            dilate_area->set_bpath(path);
            dilate_area->set_visible(true);
 
            unsigned num = 0;
            if (!_desktop->getSelection()->isEmpty()) {
                num = (unsigned)boost::distance(_desktop->getSelection()->items());
            }
            if (num == 0) {
                message_context->flash(Inkscape::ERROR_MESSAGE, _("<b>Nothing selected!</b> Select objects to tweak."));
            }
 
            // dilating:
            if (is_drawing && ( event.modifiers & GDK_BUTTON1_MASK )) {
                sp_tweak_dilate (this, event.pos, motion_doc, motion_doc - last_push, event.modifiers & GDK_SHIFT_MASK? true : false);
                //this->last_push = motion_doc;
                has_dilated = true;
                // It's slow, so prevent clogging up with events.
                gobble_motion_events(GDK_BUTTON1_MASK);
                ret = true;
            }
        },
        [&] (ButtonReleaseEvent const &event) {
 
            Geom::Point const motion_dt(_desktop->w2d(event.pos));
 
            is_drawing = false;
 
            if (is_dilating && event.button == 1) {
                if (has_dilated) {
                    // If we did not rub, do a light tap.
                    pressure = 0.03;
                    sp_tweak_dilate(this, event.pos, _desktop->dt2doc(motion_dt), Geom::Point(0, 0), event.modifiers & GDK_SHIFT_MASK);
                }
                is_dilating = false;
                has_dilated = false;
                Glib::ustring text;
                switch (mode) {
                    case TWEAK_MODE_MOVE:
                        text = _("Move tweak");
                        break;
                    case TWEAK_MODE_MOVE_IN_OUT:
                        text = _("Move in/out tweak");
                        break;
                    case TWEAK_MODE_MOVE_JITTER:
                        text = _("Move jitter tweak");
                        break;
                    case TWEAK_MODE_SCALE:
                        text = _("Scale tweak");
                        break;
                    case TWEAK_MODE_ROTATE:
                        text = _("Rotate tweak");
                        break;
                    case TWEAK_MODE_MORELESS:
                        text = _("Duplicate/delete tweak");
                        break;
                    case TWEAK_MODE_PUSH:
                        text = _("Push path tweak");
                        break;
                    case TWEAK_MODE_SHRINK_GROW:
                        text = _("Shrink/grow path tweak");
                        break;
                    case TWEAK_MODE_ATTRACT_REPEL:
                        text = _("Attract/repel path tweak");
                        break;
                    case TWEAK_MODE_ROUGHEN:
                        text = _("Roughen path tweak");
                        break;
                    case TWEAK_MODE_COLORPAINT:
                        text = _("Color paint tweak");
                        break;
                    case TWEAK_MODE_COLORJITTER:
                        text = _("Color jitter tweak");
                        break;
                    case TWEAK_MODE_BLUR:
                        text = _("Blur tweak");
                        break;
                }
                DocumentUndo::done(_desktop->getDocument(), text.c_str(), INKSCAPE_ICON("tool-tweak"));
            }
        },
        [&] (KeyPressEvent const &event) {
            switch (get_latin_keyval (event)) {
                case GDK_KEY_m:
                case GDK_KEY_M:
                case GDK_KEY_0:
                    if (mod_shift_only(event)) {
                        sp_tweak_switch_mode(this, TWEAK_MODE_MOVE, mod_shift(event));
                        ret = true;
                    }
                    break;
                case GDK_KEY_i:
                case GDK_KEY_I:
                case GDK_KEY_1:
                    if (mod_shift_only(event)) {
                        sp_tweak_switch_mode(this, TWEAK_MODE_MOVE_IN_OUT, mod_shift(event));
                        ret = true;
                    }
                    break;
                case GDK_KEY_z:
                case GDK_KEY_Z:
                case GDK_KEY_2:
                    if (mod_shift_only(event)) {
                        sp_tweak_switch_mode(this, TWEAK_MODE_MOVE_JITTER, mod_shift(event));
                        ret = true;
                    }
                    break;
                case GDK_KEY_less:
                case GDK_KEY_comma:
                case GDK_KEY_greater:
                case GDK_KEY_period:
                case GDK_KEY_3:
                    if (mod_shift_only(event)) {
                        sp_tweak_switch_mode(this, TWEAK_MODE_SCALE, mod_shift(event));
                        ret = true;
                    }
                    break;
                case GDK_KEY_bracketright:
                case GDK_KEY_bracketleft:
                case GDK_KEY_4:
                    if (mod_shift_only(event)) {
                        sp_tweak_switch_mode(this, TWEAK_MODE_ROTATE, mod_shift(event));
                        ret = true;
                    }
                    break;
                case GDK_KEY_d:
                case GDK_KEY_D:
                case GDK_KEY_5:
                    if (mod_shift_only(event)) {
                        sp_tweak_switch_mode(this, TWEAK_MODE_MORELESS, mod_shift(event));
                        ret = true;
                    }
                    break;
                case GDK_KEY_p:
                case GDK_KEY_P:
                case GDK_KEY_6:
                    if (mod_shift_only(event)) {
                        sp_tweak_switch_mode(this, TWEAK_MODE_PUSH, mod_shift(event));
                        ret = true;
                    }
                    break;
                case GDK_KEY_s:
                case GDK_KEY_S:
                case GDK_KEY_7:
                    if (mod_shift_only(event)) {
                        sp_tweak_switch_mode(this, TWEAK_MODE_SHRINK_GROW, mod_shift(event));
                        ret = true;
                    }
                    break;
                case GDK_KEY_a:
                case GDK_KEY_A:
                case GDK_KEY_8:
                    if (mod_shift_only(event)) {
                        sp_tweak_switch_mode(this, TWEAK_MODE_ATTRACT_REPEL, mod_shift(event));
                        ret = true;
                    }
                    break;
                case GDK_KEY_r:
                case GDK_KEY_R:
                case GDK_KEY_9:
                    if (mod_shift_only(event)) {
                        sp_tweak_switch_mode(this, TWEAK_MODE_ROUGHEN, mod_shift(event));
                        ret = true;
                    }
                    break;
                case GDK_KEY_c:
                case GDK_KEY_C:
                    if (mod_shift_only(event)) {
                        sp_tweak_switch_mode(this, TWEAK_MODE_COLORPAINT, mod_shift(event));
                        ret = true;
                    }
                    break;
                case GDK_KEY_j:
                case GDK_KEY_J:
                    if (mod_shift_only(event)) {
                        sp_tweak_switch_mode(this, TWEAK_MODE_COLORJITTER, mod_shift(event));
                        ret = true;
                    }
                    break;
                case GDK_KEY_b:
                case GDK_KEY_B:
                    if (mod_shift_only(event)) {
                        sp_tweak_switch_mode(this, TWEAK_MODE_BLUR, mod_shift(event));
                        ret = true;
                    }
                    break;
 
                case GDK_KEY_Up:
                case GDK_KEY_KP_Up:
                    if (!mod_ctrl_only(event)) {
                        force += 0.05;
                        if (force > 1.0) {
                            force = 1.0;
                        }
                        _desktop->setToolboxAdjustmentValue("tweak-force", force * 100);
                        ret = true;
                    }
                    break;
                case GDK_KEY_Down:
                case GDK_KEY_KP_Down:
                    if (!mod_ctrl_only(event)) {
                        force -= 0.05;
                        if (force < 0.0) {
                            force = 0.0;
                        }
                        _desktop->setToolboxAdjustmentValue("tweak-force", force * 100);
                        ret = true;
                    }
                    break;
                case GDK_KEY_Right:
                case GDK_KEY_KP_Right:
                    if (!mod_ctrl_only(event)) {
                        width += 0.01;
                        if (width > 1.0) {
                            width = 1.0;
                        }
                        _desktop->setToolboxAdjustmentValue ("tweak-width", width * 100); // the same spinbutton is for alt+x
                        sp_tweak_update_area(this);
                        ret = true;
                    }
                    break;
                case GDK_KEY_Left:
                case GDK_KEY_KP_Left:
                    if (!mod_ctrl_only(event)) {
                        width -= 0.01;
                        if (width < 0.01) {
                            width = 0.01;
                        }
                        _desktop->setToolboxAdjustmentValue("tweak-width", width * 100);
                        sp_tweak_update_area(this);
                        ret = true;
                    }
                    break;
                case GDK_KEY_Home:
                case GDK_KEY_KP_Home:
                    width = 0.01;
                    _desktop->setToolboxAdjustmentValue("tweak-width", width * 100);
                    sp_tweak_update_area(this);
                    ret = true;
                    break;
                case GDK_KEY_End:
                case GDK_KEY_KP_End:
                    width = 1.0;
                    _desktop->setToolboxAdjustmentValue("tweak-width", width * 100);
                    sp_tweak_update_area(this);
                    ret = true;
                    break;
                case GDK_KEY_x:
                case GDK_KEY_X:
                    if (mod_alt_only(event)) {
                        _desktop->setToolboxFocusTo("tweak-width");
                        ret = true;
                    }
                    break;
 
                case GDK_KEY_Shift_L:
                case GDK_KEY_Shift_R:
                    update_cursor(true);
                    break;
 
                case GDK_KEY_Control_L:
                case GDK_KEY_Control_R:
                    sp_tweak_switch_mode_temporarily(this, TWEAK_MODE_SHRINK_GROW, mod_shift(event));
                    break;
                case GDK_KEY_Delete:
                case GDK_KEY_KP_Delete:
                case GDK_KEY_BackSpace:
                    ret = deleteSelectedDrag(mod_ctrl_only(event));
                    break;
 
                default:
                    break;
            }
        },
        [&] (KeyReleaseEvent const &event) {
            Inkscape::Preferences *prefs = Inkscape::Preferences::get();
            switch (get_latin_keyval(event)) {
                case GDK_KEY_Shift_L:
                case GDK_KEY_Shift_R:
                    update_cursor(false);
                    break;
                case GDK_KEY_Control_L:
                case GDK_KEY_Control_R:
                    sp_tweak_switch_mode (this, prefs->getInt("/tools/tweak/mode"), mod_shift(event));
                    message_context->clear();
                    break;
                default:
                    sp_tweak_switch_mode (this, prefs->getInt("/tools/tweak/mode"), mod_shift(event));
                    break;
            }
        },
        [&] (CanvasEvent const &event) {}
    );
 
    return ret || ToolBase::root_handler(event);
}
 
} // namespace Inkscape::UI::Tool
 
/*
  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 :