Ejemplo n.º 1
0
/*
 * Can be called recursively.
 * If optimize_stroke == false, the view Rect is not used.
 */
static void
feed_curve_to_cairo(cairo_t *cr, Geom::Curve const &c, Geom::Affine const & trans, Geom::Rect view, bool optimize_stroke)
{
    if( is_straight_curve(c) )
    {
        Geom::Point end_tr = c.finalPoint() * trans;
        if (!optimize_stroke) {
            cairo_line_to(cr, end_tr[0], end_tr[1]);
        } else {
            Geom::Rect swept(c.initialPoint()*trans, end_tr);
            if (swept.intersects(view)) {
                cairo_line_to(cr, end_tr[0], end_tr[1]);
            } else {
                cairo_move_to(cr, end_tr[0], end_tr[1]);
            }
        }
    }
    else if(Geom::QuadraticBezier const *quadratic_bezier = dynamic_cast<Geom::QuadraticBezier const*>(&c)) {
        std::vector<Geom::Point> points = quadratic_bezier->points();
        points[0] *= trans;
        points[1] *= trans;
        points[2] *= trans;
        Geom::Point b1 = points[0] + (2./3) * (points[1] - points[0]);
        Geom::Point b2 = b1 + (1./3) * (points[2] - points[0]);
        if (!optimize_stroke) {
            cairo_curve_to(cr, b1[0], b1[1], b2[0], b2[1], points[2][0], points[2][1]);
        } else {
            Geom::Rect swept(points[0], points[2]);
            swept.expandTo(points[1]);
            if (swept.intersects(view)) {
                cairo_curve_to(cr, b1[0], b1[1], b2[0], b2[1], points[2][0], points[2][1]);
            } else {
                cairo_move_to(cr, points[2][0], points[2][1]);
            }
        }
    }
    else if(Geom::CubicBezier const *cubic_bezier = dynamic_cast<Geom::CubicBezier const*>(&c)) {
        std::vector<Geom::Point> points = cubic_bezier->points();
        //points[0] *= trans; // don't do this one here for fun: it is only needed for optimized strokes
        points[1] *= trans;
        points[2] *= trans;
        points[3] *= trans;
        if (!optimize_stroke) {
            cairo_curve_to(cr, points[1][0], points[1][1], points[2][0], points[2][1], points[3][0], points[3][1]);
        } else {
            points[0] *= trans;  // didn't transform this point yet
            Geom::Rect swept(points[0], points[3]);
            swept.expandTo(points[1]);
            swept.expandTo(points[2]);
            if (swept.intersects(view)) {
                cairo_curve_to(cr, points[1][0], points[1][1], points[2][0], points[2][1], points[3][0], points[3][1]);
            } else {
                cairo_move_to(cr, points[3][0], points[3][1]);
            }
        }
    }
//    else if(Geom::SVGEllipticalArc const *svg_elliptical_arc = dynamic_cast<Geom::SVGEllipticalArc *>(c)) {
//        //TODO: get at the innards and spit them out to cairo
//    }
    else {
        //this case handles sbasis as well as all other curve types
        Geom::Path sbasis_path = Geom::cubicbezierpath_from_sbasis(c.toSBasis(), 0.1);

        //recurse to convert the new path resulting from the sbasis to svgd
        for(Geom::Path::iterator iter = sbasis_path.begin(); iter != sbasis_path.end(); ++iter) {
            feed_curve_to_cairo(cr, *iter, trans, view, optimize_stroke);
        }
    }
}
Ejemplo n.º 2
0
/*
 * Can be called recursively.
 * If optimize_stroke == false, the view Rect is not used.
 */
static void
feed_curve_to_cairo(cairo_t *cr, Geom::Curve const &c, Geom::Affine const & trans, Geom::Rect view, bool optimize_stroke)
{
    using Geom::X;
    using Geom::Y;

    unsigned order = 0;
    if (Geom::BezierCurve const* b = dynamic_cast<Geom::BezierCurve const*>(&c)) {
        order = b->order();
    }

    // handle the three typical curve cases
    switch (order) {
    case 1:
    {
        Geom::Point end_tr = c.finalPoint() * trans;
        if (!optimize_stroke) {
            cairo_line_to(cr, end_tr[0], end_tr[1]);
        } else {
            Geom::Rect swept(c.initialPoint()*trans, end_tr);
            if (swept.intersects(view)) {
                cairo_line_to(cr, end_tr[0], end_tr[1]);
            } else {
                cairo_move_to(cr, end_tr[0], end_tr[1]);
            }
        }
    }
    break;
    case 2:
    {
        Geom::QuadraticBezier const *quadratic_bezier = static_cast<Geom::QuadraticBezier const*>(&c);
        std::vector<Geom::Point> points = quadratic_bezier->controlPoints();
        points[0] *= trans;
        points[1] *= trans;
        points[2] *= trans;
        // degree-elevate to cubic Bezier, since Cairo doesn't do quadratic Beziers
        Geom::Point b1 = points[0] + (2./3) * (points[1] - points[0]);
        Geom::Point b2 = b1 + (1./3) * (points[2] - points[0]);
        if (!optimize_stroke) {
            cairo_curve_to(cr, b1[X], b1[Y], b2[X], b2[Y], points[2][X], points[2][Y]);
        } else {
            Geom::Rect swept(points[0], points[2]);
            swept.expandTo(points[1]);
            if (swept.intersects(view)) {
                cairo_curve_to(cr, b1[X], b1[Y], b2[X], b2[Y], points[2][X], points[2][Y]);
            } else {
                cairo_move_to(cr, points[2][X], points[2][Y]);
            }
        }
    }
    break;
    case 3:
    {
        Geom::CubicBezier const *cubic_bezier = static_cast<Geom::CubicBezier const*>(&c);
        std::vector<Geom::Point> points = cubic_bezier->controlPoints();
        //points[0] *= trans; // don't do this one here for fun: it is only needed for optimized strokes
        points[1] *= trans;
        points[2] *= trans;
        points[3] *= trans;
        if (!optimize_stroke) {
            cairo_curve_to(cr, points[1][X], points[1][Y], points[2][X], points[2][Y], points[3][X], points[3][Y]);
        } else {
            points[0] *= trans;  // didn't transform this point yet
            Geom::Rect swept(points[0], points[3]);
            swept.expandTo(points[1]);
            swept.expandTo(points[2]);
            if (swept.intersects(view)) {
                cairo_curve_to(cr, points[1][X], points[1][Y], points[2][X], points[2][Y], points[3][X], points[3][Y]);
            } else {
                cairo_move_to(cr, points[3][X], points[3][Y]);
            }
        }
    }
    break;
    default:
    {
        if (Geom::EllipticalArc const *a = dynamic_cast<Geom::EllipticalArc const*>(&c)) {
            //if (!optimize_stroke || a->boundsFast().intersects(view)) {
                Geom::Affine xform = a->unitCircleTransform() * trans;
                Geom::Point ang(a->initialAngle().radians(), a->finalAngle().radians());

                // Apply the transformation to the current context
                cairo_matrix_t cm;
                cm.xx = xform[0];
                cm.xy = xform[2];
                cm.x0 = xform[4];
                cm.yx = xform[1];
                cm.yy = xform[3];
                cm.y0 = xform[5];

                cairo_save(cr);
                cairo_transform(cr, &cm);

                // Draw the circle
                if (a->sweep()) {
                    cairo_arc(cr, 0, 0, 1, ang[0], ang[1]);
                } else {
                    cairo_arc_negative(cr, 0, 0, 1, ang[0], ang[1]);
                }
                // Revert the current context
                cairo_restore(cr);
            //} else {
            //    Geom::Point f = a->finalPoint() * trans;
            //    cairo_move_to(cr, f[X], f[Y]);
            //}
        } else {
            // handles sbasis as well as all other curve types
            // this is very slow
            Geom::Path sbasis_path = Geom::cubicbezierpath_from_sbasis(c.toSBasis(), 0.1);

            // recurse to convert the new path resulting from the sbasis to svgd
            for (Geom::Path::iterator iter = sbasis_path.begin(); iter != sbasis_path.end(); ++iter) {
                feed_curve_to_cairo(cr, *iter, trans, view, optimize_stroke);
            }
        }
    }
    break;
    }
}