Ejemplo n.º 1
0
/** Reparameterise M to have unit speed.
 \param M the Element.
 \param tol the maximum error allowed.
 \param order the maximum degree to use for approximation
 \relates Piecewise, D2
*/
Piecewise<D2<SBasis> >
Geom::arc_length_parametrization(D2<SBasis> const &M,
                           unsigned order,
                           double tol){
    Piecewise<D2<SBasis> > u;
    u.push_cut(0);

    Piecewise<SBasis> s = arcLengthSb(Piecewise<D2<SBasis> >(M),tol);
    for (unsigned i=0; i < s.size();i++){
        double t0=s.cuts[i],t1=s.cuts[i+1];
        if ( are_near(s(t0),s(t1)) ) {
            continue;
        }
        D2<SBasis> sub_M = compose(M,Linear(t0,t1));
        D2<SBasis> sub_u;
        for (unsigned dim=0;dim<2;dim++){
            SBasis sub_s = s.segs[i];
            sub_s-=sub_s.at0();
            sub_s/=sub_s.at1();
            sub_u[dim]=compose_inverse(sub_M[dim],sub_s, order, tol);
        }
        u.push(sub_u,s(t1));
    }
    return u;
}
Ejemplo n.º 2
0
    void draw(cairo_t *cr, std::ostringstream *notify, int width, int height, bool save) {
        Geom::Point dir(1,-2);

	D2<Piecewise<SBasis> > B = make_cuts_independent(path_a_pw);

	cairo_set_source_rgba (cr, 0., 0.125, 0, 1);

        if(0) {
            D2<Piecewise<SBasis> > tB(cos(B[0]*0.1)*(brush_handle.pos[0]/100) + B[0], 
                                      cos(B[1]*0.1)*(brush_handle.pos[1]/100) + B[1]);
	
            cairo_d2_pw_sb(cr, tB);
        } else  {
            Piecewise<SBasis> r2 = (dot(path_a_pw - brush_handle.pos, path_a_pw - brush_handle.pos));
            Piecewise<SBasis> rc;
            rc.push_cut(0);
            rc.push(SBasis(Linear(1, 1)), 2);
            rc.push(SBasis(Linear(1, 0)), 4);
            rc.push(SBasis(Linear(0, 0)), 30);
            rc *= 10;
            rc.scaleDomain(1000);
            Piecewise<SBasis> swr;
            swr.push_cut(0);
            swr.push(SBasis(Linear(0, 1)), 2);
            swr.push(SBasis(Linear(1, 0)), 4);
            swr.push(SBasis(Linear(0, 0)), 30);
            swr *= 10;
            swr.scaleDomain(1000);
            cairo_pw(cr, swr);// + (height - 100));
            D2<Piecewise<SBasis> >  uB = make_cuts_independent(unitVector(path_a_pw - brush_handle.pos));
        
            D2<Piecewise<SBasis> > tB(compose(rc, (r2))*uB[0] + B[0], 
                                      compose(rc, (r2))*uB[1] + B[1]);
            cairo_d2_pw_sb(cr, tB);
            //path_a_pw = sectionize(tB);
	}
	cairo_stroke(cr);
        
        *notify << path_a_pw.size();
        
        Toy::draw(cr, notify, width, height, save);
    }
Ejemplo n.º 3
0
    void draw( cairo_t *cr,	std::ostringstream *notify,
               int width, int height, bool save )
    {

        Point p = ph.pos;
        Point np = p;
        std::vector<Point> nps;

        cairo_set_line_width (cr, 0.3);
        cairo_set_source_rgb(cr, 0,0,0);
        switch ( choice )
        {
        case '1':
        {
            LineSegment seg(psh.pts[0], psh.pts[1]);
            cairo_move_to(cr, psh.pts[0]);
            cairo_curve(cr, seg);
            double t = seg.nearestPoint(p);
            np = seg.pointAt(t);
            if ( toggles[0].on )
            {
                nps.push_back(np);
            }
            break;
        }
        case '2':
        {
            SVGEllipticalArc earc;
            bool earc_constraints_satisfied = true;
            try
            {
                earc.set(psh.pts[0], 200, 150, 0, true, true, psh.pts[1]);
            }
            catch( RangeError e )
            {
                earc_constraints_satisfied = false;
            }
            if ( earc_constraints_satisfied )
            {
                cairo_d2_sb(cr, earc.toSBasis());
                if ( toggles[0].on )
                {
                    std::vector<double> t = earc.allNearestPoints(p);
                    for ( unsigned int i = 0; i < t.size(); ++i )
                        nps.push_back(earc.pointAt(t[i]));
                }
                else
                {
                    double t = earc.nearestPoint(p);
                    np = earc.pointAt(t);
                }
            }
            break;
        }
        case '3':
        {
            D2<SBasis> A = psh.asBezier();
            cairo_d2_sb(cr, A);
            if ( toggles[0].on )
            {
                std::vector<double> t = Geom::all_nearest_points(p, A);
                for ( unsigned int i = 0; i < t.size(); ++i )
                    nps.push_back(A(t[i]));
            }
            else
            {
                double t = nearest_point(p, A);
                np = A(t);
            }
            break;
        }
        case '4':
        {
            D2<SBasis> A = handles_to_sbasis(psh.pts.begin(), 3);
            D2<SBasis> B = handles_to_sbasis(psh.pts.begin() + 3, 3);
            D2<SBasis> C = handles_to_sbasis(psh.pts.begin() + 6, 3);
            D2<SBasis> D = handles_to_sbasis(psh.pts.begin() + 9, 3);
            cairo_d2_sb(cr, A);
            cairo_d2_sb(cr, B);
            cairo_d2_sb(cr, C);
            cairo_d2_sb(cr, D);
            Piecewise< D2<SBasis> > pwc;
            pwc.push_cut(0);
            pwc.push_seg(A);
            pwc.push_cut(0.25);
            pwc.push_seg(B);
            pwc.push_cut(0.50);
            pwc.push_seg(C);
            pwc.push_cut(0.75);
            pwc.push_seg(D);
            pwc.push_cut(1);
            if ( toggles[0].on )
            {
                std::vector<double> t = Geom::all_nearest_points(p, pwc);
                for ( unsigned int i = 0; i < t.size(); ++i )
                    nps.push_back(pwc(t[i]));
            }
            else
            {
                double t = Geom::nearest_point(p, pwc);
                np = pwc(t);
            }
            break;
        }
        case '5':
        {
            closed_toggle = true;
            BezierCurve<2> A(psh.pts[0], psh.pts[1], psh.pts[2]);
            BezierCurve<3> B(psh.pts[2], psh.pts[3], psh.pts[4], psh.pts[5]);
            BezierCurve<3> C(psh.pts[5], psh.pts[6], psh.pts[7], psh.pts[8]);
            Path path;
            path.append(A);
            path.append(B);
            path.append(C);
            SVGEllipticalArc D;
            bool earc_constraints_satisfied = true;
            try
            {
                D.set(psh.pts[8], 160, 80, 0, true, true, psh.pts[9]);
            }
            catch( RangeError e )
            {
                earc_constraints_satisfied = false;
            }
            if ( earc_constraints_satisfied ) path.append(D);
            if ( toggles[1].on ) path.close(true);

            cairo_path(cr, path);

            if ( toggles[0].on )
            {
                std::vector<double> t = path.allNearestPoints(p);
                for ( unsigned int i = 0; i < t.size(); ++i )
                    nps.push_back(path.pointAt(t[i]));
            }
            else
            {
                double t = path.nearestPoint(p);
                np = path.pointAt(t);
            }
            break;
        }
        case '6':
        {
            closed_toggle = true;
            PathVector pathv = paths_b*Translate(psh.pts[0]-paths_b[0][0].initialPoint());
            //std::cout << pathv.size() << std::endl;

            cairo_path(cr, pathv);

            if ( toggles[0].on )
            {
                std::vector<PathVectorPosition> t = allNearestPoints(pathv, p);
                for ( unsigned int i = 0; i < t.size(); ++i )
                    nps.push_back(pointAt(pathv, t[i]));
            }
            else
            {
                boost::optional<PathVectorPosition> t = nearestPoint(pathv, p);
                if(t)
                    np = pointAt(pathv, *t);
            }
            break;
        }
        default:
        {
            *notify << std::endl;
            for (int i = FIRST_ITEM; i < TOTAL_ITEMS; ++i)
            {
                *notify << "   " << i << " -  " <<  menu_items[i] << std::endl;
            }
            Toy::draw(cr, notify, width, height, save);
            return;
        }
        }

        if ( toggles[0].on )
        {
            for ( unsigned int i = 0; i < nps.size(); ++i )
            {
                cairo_move_to(cr, p);
                cairo_line_to(cr, nps[i]);
            }
        }
        else
        {
            cairo_move_to(cr, p);
            cairo_line_to(cr, np);
        }
        cairo_stroke(cr);

        toggles[0].bounds = Rect( Point(10, height - 50), Point(10, height - 50) + Point(80,25) );
        toggles[0].draw(cr);
        if ( closed_toggle )
        {
            toggles[1].bounds = Rect( Point(100, height - 50), Point(100, height - 50) + Point(80,25) );
            toggles[1].draw(cr);
            closed_toggle = false;
        }

        Toy::draw(cr, notify, width, height, save);
    }