C++ SPCurve::lineto方法代码示例

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();
}

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;
    }
}