C++ SPCurve::moveto方法代码示例

static void sp_dropper_context_setup(SPEventContext *ec)
{
    SPDropperContext *dc = SP_DROPPER_CONTEXT(ec);

    if (((SPEventContextClass *) parent_class)->setup) {
        ((SPEventContextClass *) parent_class)->setup(ec);
    }

    /* TODO: have a look at sp_dyna_draw_context_setup where the same is done.. generalize? at least make it an arcto! */
    SPCurve *c = new SPCurve();
    const double C1 = 0.552;
    c->moveto(-1,0);
    c->curveto(-1, C1, -C1, 1, 0, 1 );
    c->curveto(C1, 1, 1, C1, 1, 0 );
    c->curveto(1, -C1, C1, -1, 0, -1 );
    c->curveto(-C1, -1, -1, -C1, -1, 0 );
    c->closepath();
    dc->area = sp_canvas_bpath_new(sp_desktop_controls(ec->desktop), c);
    c->unref();
    sp_canvas_bpath_set_fill(SP_CANVAS_BPATH(dc->area), 0x00000000,(SPWindRule)0);
    sp_canvas_bpath_set_stroke(SP_CANVAS_BPATH(dc->area), 0x0000007f, 1.0, SP_STROKE_LINEJOIN_MITER, SP_STROKE_LINECAP_BUTT);
    sp_canvas_item_hide(dc->area);

    Inkscape::Preferences *prefs = Inkscape::Preferences::get();
    if (prefs->getBool("/tools/dropper/selcue")) {
        ec->enableSelectionCue();
    }

    if (prefs->getBool("/tools/dropper/gradientdrag")) {
        ec->enableGrDrag();
    }
}

void SPPolyLine::set(SPObject *object, unsigned int key, const gchar *value)
{
    SPPolyLine *polyline = SP_POLYLINE(object);

    switch (key) {
	case SP_ATTR_POINTS: {
            SPCurve * curve;
            const gchar * cptr;
            char * eptr;
            gboolean hascpt;

            if (!value) break;
            curve = new SPCurve ();
            hascpt = FALSE;

            cptr = value;
            eptr = NULL;

            while (TRUE) {
                gdouble x, y;

                while (*cptr != '\0' && (*cptr == ',' || *cptr == '\x20' || *cptr == '\x9' || *cptr == '\xD' || *cptr == '\xA')) {
                    cptr++;
                }
                if (!*cptr) break;

                x = g_ascii_strtod (cptr, &eptr);
                if (eptr == cptr) break;
                cptr = eptr;

                while (*cptr != '\0' && (*cptr == ',' || *cptr == '\x20' || *cptr == '\x9' || *cptr == '\xD' || *cptr == '\xA')) {
                    cptr++;
                }
                if (!*cptr) break;

                y = g_ascii_strtod (cptr, &eptr);
                if (eptr == cptr) break;
                cptr = eptr;
                if (hascpt) {
                    curve->lineto(x, y);
                } else {
                    curve->moveto(x, y);
                    hascpt = TRUE;
                }
            }
		
            (SP_SHAPE (polyline))->setCurve (curve, TRUE);
            curve->unref();
            break;
	}
	default:
            if (((SPObjectClass *) SPPolyLineClass::static_parent_class)->set) {
                ((SPObjectClass *) SPPolyLineClass::static_parent_class)->set (object, key, value);
            }
            break;
    }
}

void SPLine::set_shape() {
    SPCurve *c = new SPCurve();

    c->moveto(this->x1.computed, this->y1.computed);
    c->lineto(this->x2.computed, this->y2.computed);

    this->setCurveInsync(c, TRUE); // *_insync does not call update, avoiding infinite recursion when set_shape is called by update
    this->setCurveBeforeLPE(c);

    // LPE's cannot be applied to lines. (the result can (generally) not be represented as SPLine)

    c->unref();
}

static void sp_spray_context_setup(SPEventContext *ec)
{
    SPSprayContext *tc = SP_SPRAY_CONTEXT(ec);

    if (((SPEventContextClass *) parent_class)->setup) {
        ((SPEventContextClass *) parent_class)->setup(ec);
    }

    {
        /* TODO: have a look at sp_dyna_draw_context_setup where the same is done.. generalize? at least make it an arcto! */
        SPCurve *c = new SPCurve();
        const double C1 = 0.552;
        c->moveto(-1,0);
        c->curveto(-1, C1, -C1, 1, 0, 1 );
        c->curveto(C1, 1, 1, C1, 1, 0 );
        c->curveto(1, -C1, C1, -1, 0, -1 );
        c->curveto(-C1, -1, -1, -C1, -1, 0 );
        c->closepath();
        tc->dilate_area = sp_canvas_bpath_new(sp_desktop_controls(ec->desktop), c);
        c->unref();
        sp_canvas_bpath_set_fill(SP_CANVAS_BPATH(tc->dilate_area), 0x00000000,(SPWindRule)0);
        sp_canvas_bpath_set_stroke(SP_CANVAS_BPATH(tc->dilate_area), 0xff9900ff, 1.0, SP_STROKE_LINEJOIN_MITER, SP_STROKE_LINECAP_BUTT);
        sp_canvas_item_hide(tc->dilate_area);
    }

    tc->is_drawing = false;

    tc->_message_context = new Inkscape::MessageContext((ec->desktop)->messageStack());

    sp_event_context_read(ec, "distrib");
    sp_event_context_read(ec, "width");
    sp_event_context_read(ec, "ratio");
    sp_event_context_read(ec, "tilt");
    sp_event_context_read(ec, "rotation_variation");
    sp_event_context_read(ec, "scale_variation");
    sp_event_context_read(ec, "mode");
    sp_event_context_read(ec, "population");
    sp_event_context_read(ec, "force");
    sp_event_context_read(ec, "mean");
    sp_event_context_read(ec, "standard_deviation");
    sp_event_context_read(ec, "usepressure");
    sp_event_context_read(ec, "Scale");

    Inkscape::Preferences *prefs = Inkscape::Preferences::get();
    if (prefs->getBool("/tools/spray/selcue")) {
        ec->enableSelectionCue();
    }
    if (prefs->getBool("/tools/spray/gradientdrag")) {
        ec->enableGrDrag();
    }
}

SPCurve *
SPCurve::new_from_rect(Geom::Rect const &rect, bool all_four_sides)
{
    SPCurve *c =  new SPCurve();

    Geom::Point p = rect.corner(0);
    c->moveto(p);

    for (int i=3; i>=1; i--) {
        c->lineto(rect.corner(i));
    }

    if (all_four_sides) {
        // When _constrained_ snapping to a path, the 2geom::SimpleCrosser will be invoked which doesn't consider the closing segment.
        // of a path. Consequently, in case we want to snap to for example the page border, we must provide all four sides of the
        // rectangle explicitly
        c->lineto(rect.corner(0));
    } else {
        // ... instead of just three plus a closing segment
        c->closepath();
    }

    return c;
}

void SPStar::set_shape() {
    // perhaps we should convert all our shapes into LPEs without source path
    // and with knotholders for parameters, then this situation will be handled automatically
    // by disabling the entire stack (including the shape LPE)
    if (hasBrokenPathEffect()) {
        g_warning ("The star shape has unknown LPE on it! Convert to path to make it editable preserving the appearance; editing it as star will remove the bad LPE");

        if (this->getRepr()->attribute("d")) {
            // unconditionally read the curve from d, if any, to preserve appearance
            Geom::PathVector pv = sp_svg_read_pathv(this->getRepr()->attribute("d"));
            SPCurve *cold = new SPCurve(pv);
            this->setCurveInsync( cold, TRUE);
            this->setCurveBeforeLPE(cold);
            cold->unref();
        }

        return;
    }

    SPCurve *c = new SPCurve ();

    bool not_rounded = (fabs (this->rounded) < 1e-4);

    // note that we pass randomized=true to sp_star_get_xy, because the curve must be randomized;
    // other places that call that function (e.g. the knotholder) need the exact point

    // draw 1st segment
    c->moveto(sp_star_get_xy (this, SP_STAR_POINT_KNOT1, 0, true));

    if (this->flatsided == false) {
        if (not_rounded) {
            c->lineto(sp_star_get_xy (this, SP_STAR_POINT_KNOT2, 0, true));
        } else {
            c->curveto(sp_star_get_curvepoint (this, SP_STAR_POINT_KNOT1, 0, NEXT),
                sp_star_get_curvepoint (this, SP_STAR_POINT_KNOT2, 0, PREV),
                sp_star_get_xy (this, SP_STAR_POINT_KNOT2, 0, true));
        }
    }

    // draw all middle segments
    for (gint i = 1; i < sides; i++) {
        if (not_rounded) {
            c->lineto(sp_star_get_xy (this, SP_STAR_POINT_KNOT1, i, true));
        } else {
            if (this->flatsided == false) {
                c->curveto(sp_star_get_curvepoint (this, SP_STAR_POINT_KNOT2, i - 1, NEXT),
                        sp_star_get_curvepoint (this, SP_STAR_POINT_KNOT1, i, PREV),
                        sp_star_get_xy (this, SP_STAR_POINT_KNOT1, i, true));
            } else {
                c->curveto(sp_star_get_curvepoint (this, SP_STAR_POINT_KNOT1, i - 1, NEXT),
                        sp_star_get_curvepoint (this, SP_STAR_POINT_KNOT1, i, PREV),
                        sp_star_get_xy (this, SP_STAR_POINT_KNOT1, i, true));
            }
        }

        if (this->flatsided == false) {
            if (not_rounded) {
                       c->lineto(sp_star_get_xy (this, SP_STAR_POINT_KNOT2, i, true));
            } else {
                c->curveto(sp_star_get_curvepoint (this, SP_STAR_POINT_KNOT1, i, NEXT),
                    sp_star_get_curvepoint (this, SP_STAR_POINT_KNOT2, i, PREV),
                    sp_star_get_xy (this, SP_STAR_POINT_KNOT2, i, true));
            }
        }
    }

    // draw last segment
	if (!not_rounded) {
		if (this->flatsided == false) {
			c->curveto(sp_star_get_curvepoint (this, SP_STAR_POINT_KNOT2, sides - 1, NEXT),
				sp_star_get_curvepoint (this, SP_STAR_POINT_KNOT1, 0, PREV),
				sp_star_get_xy (this, SP_STAR_POINT_KNOT1, 0, true));
		} else {
			c->curveto(sp_star_get_curvepoint (this, SP_STAR_POINT_KNOT1, sides - 1, NEXT),
				sp_star_get_curvepoint (this, SP_STAR_POINT_KNOT1, 0, PREV),
				sp_star_get_xy (this, SP_STAR_POINT_KNOT1, 0, true));
		}
	}

    c->closepath();

    /* Reset the shape'scurve to the "original_curve"
     * This is very important for LPEs to work properly! (the bbox might be recalculated depending on the curve in shape)*/
    this->setCurveInsync( c, TRUE);
    this->setCurveBeforeLPE( c );

    if (hasPathEffect() && pathEffectsEnabled()) {
        SPCurve *c_lpe = c->copy();
        bool success = this->performPathEffect(c_lpe);

        if (success) {
            this->setCurveInsync( c_lpe, TRUE);
        } 

        c_lpe->unref();
    }

    c->unref();
}

void Box3DSide::set_shape() {
    if (!this->document->getRoot()) {
        // avoid a warning caused by sp_document_height() (which is called from sp_item_i2d_affine() below)
        // when reading a file containing 3D boxes
        return;
    }

    SPObject *parent = this->parent;

    if (!SP_IS_BOX3D(parent)) {
        g_warning("Parent of 3D box side is not a 3D box.\n");
        return;
    }

    SPBox3D *box = SP_BOX3D(parent);

    Persp3D *persp = box3d_side_perspective(this);

    if (!persp) {
        return;
    }

    // TODO: Draw the correct quadrangle here
    //       To do this, determine the perspective of the box, the orientation of the side (e.g., XY-FRONT)
    //       compute the coordinates of the corners in P^3, project them onto the canvas, and draw the
    //       resulting path.

    unsigned int corners[4];
    box3d_side_compute_corner_ids(this, corners);

    SPCurve *c = new SPCurve();

    if (!box3d_get_corner_screen(box, corners[0]).isFinite() ||
        !box3d_get_corner_screen(box, corners[1]).isFinite() ||
        !box3d_get_corner_screen(box, corners[2]).isFinite() ||
        !box3d_get_corner_screen(box, corners[3]).isFinite() )
    {
        g_warning ("Trying to draw a 3D box side with invalid coordinates.\n");
        return;
    }

    c->moveto(box3d_get_corner_screen(box, corners[0]));
    c->lineto(box3d_get_corner_screen(box, corners[1]));
    c->lineto(box3d_get_corner_screen(box, corners[2]));
    c->lineto(box3d_get_corner_screen(box, corners[3]));
    c->closepath();

    /* Reset the this'scurve to the "original_curve"
     * This is very important for LPEs to work properly! (the bbox might be recalculated depending on the curve in shape)*/
    this->setCurveInsync( c, TRUE);

    if (hasPathEffect() && pathEffectsEnabled()) {
        SPCurve *c_lpe = c->copy();
        bool success = this->performPathEffect(c_lpe);

        if (success) {
            this->setCurveInsync(c_lpe, TRUE);
        }

        c_lpe->unref();
    }

    c->unref();
}

void sp_polygon_set(SPObject *object, unsigned int key, const gchar *value)
{
    SPPolygon *polygon = SP_POLYGON(object);

    switch (key) {
        case SP_ATTR_POINTS: {
            if (!value) {
                /* fixme: The points attribute is required.  We should handle its absence as per
                 * http://www.w3.org/TR/SVG11/implnote.html#ErrorProcessing. */
                break;
            }
            SPCurve *curve = new SPCurve();
            gboolean hascpt = FALSE;

            gchar const *cptr = value;
            bool has_error = false;

            while (TRUE) {
                gdouble x;
                if (!polygon_get_value(&cptr, &x)) {
                    break;
                }

                gdouble y;
                if (!polygon_get_value(&cptr, &y)) {
                    /* fixme: It is an error for an odd number of points to be specified.  We
                     * should display the points up to now (as we currently do, though perhaps
                     * without the closepath: the spec isn't quite clear on whether to do a
                     * closepath or not, though I'd guess it's best not to do a closepath), but
                     * then flag the document as in error, as per
                     * http://www.w3.org/TR/SVG11/implnote.html#ErrorProcessing.
                     *
                     * (Ref: http://www.w3.org/TR/SVG11/shapes.html#PolygonElement.) */
                    has_error = true;
                    break;
                }

                if (hascpt) {
                    curve->lineto(x, y);
                } else {
                    curve->moveto(x, y);
                    hascpt = TRUE;
                }
            }

            if (has_error || *cptr != '\0') {
                /* TODO: Flag the document as in error, as per
                 * http://www.w3.org/TR/SVG11/implnote.html#ErrorProcessing. */
            } else if (hascpt) {
                /* We might have done a moveto but no lineto.  I'm not sure how we're supposed to represent
                 * a single-point polygon in SPCurve. TODO: add a testcase with only one coordinate pair */
                curve->closepath();
            }
            sp_shape_set_curve(SP_SHAPE(polygon), curve, TRUE);
            curve->unref();
            break;
        }
        default:
            if (((SPObjectClass *) parent_class)->set) {
                ((SPObjectClass *) parent_class)->set(object, key, value);
            }
            break;
    }
}

void spdc_concat_colors_and_flush(FreehandBase *dc, gboolean forceclosed)
{
    // Concat RBG
    SPCurve *c = dc->green_curve;
    Inkscape::Preferences *prefs = Inkscape::Preferences::get();
    // Green
    dc->green_curve = new SPCurve();
    while (dc->green_bpaths) {
        sp_canvas_item_destroy(SP_CANVAS_ITEM(dc->green_bpaths->data));
        dc->green_bpaths = g_slist_remove(dc->green_bpaths, dc->green_bpaths->data);
    }

    // Blue
    c->append_continuous(dc->blue_curve, 0.0625);
    dc->blue_curve->reset();
    sp_canvas_bpath_set_bpath(SP_CANVAS_BPATH(dc->blue_bpath), NULL);

    // Red
    if (dc->red_curve_is_valid) {
        c->append_continuous(dc->red_curve, 0.0625);
    }
    dc->red_curve->reset();
    sp_canvas_bpath_set_bpath(SP_CANVAS_BPATH(dc->red_bpath), NULL);

    if (c->is_empty()) {
        c->unref();
        return;
    }

    // Step A - test, whether we ended on green anchor
    if ( forceclosed || ( dc->green_anchor && dc->green_anchor->active ) ) {
        // We hit green anchor, closing Green-Blue-Red
        dc->desktop->messageStack()->flash(Inkscape::NORMAL_MESSAGE, _("Path is closed."));
        c->closepath_current();
        // Closed path, just flush
        spdc_flush_white(dc, c);
        c->unref();
        return;
    }

    // Step B - both start and end anchored to same curve
    if ( dc->sa && dc->ea
         && ( dc->sa->curve == dc->ea->curve )
         && ( ( dc->sa != dc->ea )
              || dc->sa->curve->is_closed() ) )
    {
        // We hit bot start and end of single curve, closing paths
        dc->desktop->messageStack()->flash(Inkscape::NORMAL_MESSAGE, _("Closing path."));
        if (dc->sa->start && !(dc->sa->curve->is_closed()) ) {
            c = reverse_then_unref(c);
        }
        if(prefs->getInt(tool_name(dc) + "/freehand-mode", 0) == 1 || 
            prefs->getInt(tool_name(dc) + "/freehand-mode", 0) == 2){
            dc->overwrite_curve->append_continuous(c, 0.0625);
            c->unref();
            dc->overwrite_curve->closepath_current();
            if(dc->sa){
                dc->white_curves = g_slist_remove(dc->white_curves, dc->sa->curve);
                dc->white_curves = g_slist_append(dc->white_curves, dc->overwrite_curve);
            }
        }else{
            dc->sa->curve->append_continuous(c, 0.0625);
            c->unref();
            dc->sa->curve->closepath_current();
        }
        spdc_flush_white(dc, NULL);
        return;
    }

    // Step C - test start
    if (dc->sa) {
        SPCurve *s = dc->sa->curve;
        dc->white_curves = g_slist_remove(dc->white_curves, s);
        if(prefs->getInt(tool_name(dc) + "/freehand-mode", 0) == 1 || 
            prefs->getInt(tool_name(dc) + "/freehand-mode", 0) == 2){
                s = dc->overwrite_curve;
        }
        if (dc->sa->start) {
            s = reverse_then_unref(s);
        }
        s->append_continuous(c, 0.0625);
        c->unref();
        c = s;
    } else /* Step D - test end */ if (dc->ea) {
        SPCurve *e = dc->ea->curve;
        dc->white_curves = g_slist_remove(dc->white_curves, e);
        if (!dc->ea->start) {
            e = reverse_then_unref(e);
        }
        if(prefs->getInt(tool_name(dc) + "/freehand-mode", 0) == 1 || 
            prefs->getInt(tool_name(dc) + "/freehand-mode", 0) == 2){
                e = reverse_then_unref(e);
                Geom::CubicBezier const * cubic = dynamic_cast<Geom::CubicBezier const*>(&*e->last_segment());
                SPCurve *lastSeg = new SPCurve();
                if(cubic){
                    lastSeg->moveto((*cubic)[0]);
                    lastSeg->curveto((*cubic)[1],(*cubic)[3],(*cubic)[3]);
                    if( e->get_segment_count() == 1){
                        e = lastSeg;
                    }else{
//.........这里部分代码省略.........

static void spdc_check_for_and_apply_waiting_LPE(FreehandBase *dc, SPItem *item, SPCurve *curve)
{
    using namespace Inkscape::LivePathEffect;
    Inkscape::Preferences *prefs = Inkscape::Preferences::get();

    if (item && SP_IS_LPE_ITEM(item)) {
        bool simplify = prefs->getInt(tool_name(dc) + "/simplify", 0);
        if(simplify){
            double tol = prefs->getDoubleLimited("/tools/freehand/pencil/tolerance", 10.0, 1.0, 100.0);
            tol = tol/(100.0*(102.0-tol));
            std::ostringstream ss;
            ss << tol;
            spdc_apply_simplify(ss.str(), dc, item);
            sp_lpe_item_update_patheffect(SP_LPE_ITEM(item), false, false);
        }
        if (prefs->getInt(tool_name(dc) + "/freehand-mode", 0) == 1) {
            Effect::createAndApply(SPIRO, dc->desktop->doc(), item);
        }

        if (prefs->getInt(tool_name(dc) + "/freehand-mode", 0) == 2) {
            Effect::createAndApply(BSPLINE, dc->desktop->doc(), item);
        }
        SPShape *sp_shape = dynamic_cast<SPShape *>(item);
        if (sp_shape) {
            curve = sp_shape->getCurve();
        }

        //Store the clipboard path to apply in the future without the use of clipboard
        static Geom::PathVector previous_shape_pathv;

        shapeType shape = (shapeType)prefs->getInt(tool_name(dc) + "/shape", 0);
        bool shape_applied = false;
        SPCSSAttr *css_item = sp_css_attr_from_object(item, SP_STYLE_FLAG_ALWAYS);
        const char *cstroke = sp_repr_css_property(css_item, "stroke", "none");
        static SPItem *bend_item;

#define SHAPE_LENGTH 10
#define SHAPE_HEIGHT 10


        if(shape == LAST_APPLIED){

            shape = previous_shape_type;
            if(shape == CLIPBOARD || shape == BEND_CLIPBOARD){
                shape = LAST_APPLIED;
            }
        }

        switch (shape) {
            case NONE:
                // don't apply any shape
                break;
            case TRIANGLE_IN:
            {
                // "triangle in"
                std::vector<Geom::Point> points(1);
                points[0] = Geom::Point(0., SHAPE_HEIGHT/2);
                spdc_apply_powerstroke_shape(points, dc, item);

                shape_applied = true;
                break;
            }
            case TRIANGLE_OUT:
            {
                // "triangle out"
                guint curve_length = curve->get_segment_count();
                std::vector<Geom::Point> points(1);
                points[0] = Geom::Point((double)curve_length, SHAPE_HEIGHT/2);
                spdc_apply_powerstroke_shape(points, dc, item);

                shape_applied = true;
                break;
            }
            case ELLIPSE:
            {
                // "ellipse"
                SPCurve *c = new SPCurve();
                const double C1 = 0.552;
                c->moveto(0, SHAPE_HEIGHT/2);
                c->curveto(0, (1 - C1) * SHAPE_HEIGHT/2, (1 - C1) * SHAPE_LENGTH/2, 0, SHAPE_LENGTH/2, 0);
                c->curveto((1 + C1) * SHAPE_LENGTH/2, 0, SHAPE_LENGTH, (1 - C1) * SHAPE_HEIGHT/2, SHAPE_LENGTH, SHAPE_HEIGHT/2);
                c->curveto(SHAPE_LENGTH, (1 + C1) * SHAPE_HEIGHT/2, (1 + C1) * SHAPE_LENGTH/2, SHAPE_HEIGHT, SHAPE_LENGTH/2, SHAPE_HEIGHT);
                c->curveto((1 - C1) * SHAPE_LENGTH/2, SHAPE_HEIGHT, 0, (1 + C1) * SHAPE_HEIGHT/2, 0, SHAPE_HEIGHT/2);
                c->closepath();
                spdc_paste_curve_as_freehand_shape(c->get_pathvector(), dc, item);
                c->unref();

                shape_applied = true;
                break;
            }
            case CLIPBOARD:
            {
                // take shape from clipboard;
                Inkscape::UI::ClipboardManager *cm = Inkscape::UI::ClipboardManager::get();
                if(cm->paste(SP_ACTIVE_DESKTOP,true) == true){
                    SPItem * pasted_clipboard = dc->selection->singleItem();
                    if(pasted_clipboard){
                        Inkscape::XML::Node *pasted_clipboard_root = pasted_clipboard->getRepr();
                        Inkscape::XML::Node *path = sp_repr_lookup_name(pasted_clipboard_root, "svg:path", -1); // unlimited search depth
                        if ( path != NULL ) {
//.........这里部分代码省略.........

void
LPESimplify::generateHelperPathAndSmooth(Geom::PathVector &result)
{
    if(steps < 1) {
        return;
    }
    Geom::PathVector tmp_path;
    Geom::CubicBezier const *cubic = NULL;
    for (Geom::PathVector::iterator path_it = result.begin(); path_it != result.end(); ++path_it) {
        if (path_it->empty()) {
            continue;
        }

        Geom::Path::iterator curve_it1 = path_it->begin(); // incoming curve
        Geom::Path::iterator curve_it2 = ++(path_it->begin());// outgoing curve
        Geom::Path::iterator curve_endit = path_it->end_default(); // this determines when the loop has to stop
        SPCurve *nCurve = new SPCurve();
        if (path_it->closed()) {
            // if the path is closed, maybe we have to stop a bit earlier because the
            // closing line segment has zerolength.
            const Geom::Curve &closingline =
                path_it->back_closed(); // the closing line segment is always of type
            // Geom::LineSegment.
            if (are_near(closingline.initialPoint(), closingline.finalPoint())) {
                // closingline.isDegenerate() did not work, because it only checks for
                // *exact* zero length, which goes wrong for relative coordinates and
                // rounding errors...
                // the closing line segment has zero-length. So stop before that one!
                curve_endit = path_it->end_open();
            }
        }
        if(helper_size > 0) {
            drawNode(curve_it1->initialPoint());
        }
        nCurve->moveto(curve_it1->initialPoint());
        Geom::Point start = Geom::Point(0,0);
        while (curve_it1 != curve_endit) {
            cubic = dynamic_cast<Geom::CubicBezier const *>(&*curve_it1);
            Geom::Point point_at1 = curve_it1->initialPoint();
            Geom::Point point_at2 = curve_it1->finalPoint();
            Geom::Point point_at3 = curve_it1->finalPoint();
            Geom::Point point_at4 = curve_it1->finalPoint();

            if(start == Geom::Point(0,0)) {
                start = point_at1;
            }

            if (cubic) {
                point_at1 = (*cubic)[1];
                point_at2 = (*cubic)[2];
            }

            if(path_it->closed() && curve_it2 == curve_endit) {
                point_at4 = start;
            }
            if(curve_it2 != curve_endit) {
                cubic = dynamic_cast<Geom::CubicBezier const *>(&*curve_it2);
                if (cubic) {
                    point_at4 = (*cubic)[1];
                }
            }
            Geom::Ray ray1(point_at2, point_at3);
            Geom::Ray ray2(point_at3, point_at4);
            double angle1 = Geom::deg_from_rad(ray1.angle());
            double angle2 = Geom::deg_from_rad(ray2.angle());
            if((smooth_angles  >= std::abs(angle2 - angle1)) && !are_near(point_at4,point_at3) && !are_near(point_at2,point_at3)) {
                double dist = Geom::distance(point_at2,point_at3);
                Geom::Angle angleFixed = ray2.angle();
                angleFixed -= Geom::Angle::from_degrees(180.0);
                point_at2 =  Geom::Point::polar(angleFixed, dist) + point_at3;
            }
            nCurve->curveto(point_at1, point_at2, curve_it1->finalPoint());
            cubic = dynamic_cast<Geom::CubicBezier const *>(nCurve->last_segment());
            if (cubic) {
                point_at1 = (*cubic)[1];
                point_at2 = (*cubic)[2];
                if(helper_size > 0) {
                    if(!are_near((*cubic)[0],(*cubic)[1])) {
                        drawHandle((*cubic)[1]);
                        drawHandleLine((*cubic)[0],(*cubic)[1]);
                    }
                    if(!are_near((*cubic)[3],(*cubic)[2])) {
                        drawHandle((*cubic)[2]);
                        drawHandleLine((*cubic)[3],(*cubic)[2]);
                    }
                }
            }
            if(helper_size > 0) {
                drawNode(curve_it1->finalPoint());
            }
            ++curve_it1;
            ++curve_it2;
        }
        if (path_it->closed()) {
            nCurve->closepath_current();
        }
        tmp_path.push_back(nCurve->get_pathvector()[0]);
        nCurve->reset();
        delete nCurve;
    }
//.........这里部分代码省略.........