function scara(d1, d2, t1, t2)

R = d1 + d2;
r = d1 - d2;

r1 = [d1 * cos(t1), d1 * sin(t1)];
r2 = r1 + [d2 * cos(t1 + t2), d2 * sin(t1 + t2)];

cr = R / 30;
xmin = -1.1 * R;
xmax = 1.1 * R;
ymin = -0.1 * R;
ymax = 1.1 * R;
aRmin = 180 / %pi * atan(ymin, R);
armin = 180 / %pi * atan(max(-r, ymin), r);
subplot(2, 1, 1);
plot(0, 0);
plot(0, 0);
m = d1 + d2;
isoview
xfarc(-cr, cr, 2 * cr, 2 * cr, 0, 360 * 64);
xfarc(r1(1, 1) - cr, r1(1, 2) + cr, 2 * cr, 2 * cr, 0, 360 * 64);
xfarc(r2(1, 1) - cr, r2(1, 2) + cr, 2 * cr, 2 * cr, 0, 360 * 64);
xarc(-R, R, 2 * R , 2 * R, aRmin * 64, (180 - 2 * aRmin) * 64);
xarc(-r, r, 2 * r , 2 * r, armin * 64, (180 - 2 * armin) * 64);
xgrid;
ax = gca();
ax.font_size = 3;
h1 = ax.children(7).children(1);
h2 = ax.children(6).children(1);
h3 = ax.children(5);
h4 = ax.children(4);
h5 = ax.children(3);
h6 = ax.children(2);
h7 = ax.children(1);
h1.thickness = 10;
h2.thickness = 3;
h2.foreground = 5;
h4.background = 3;
h5.background = 6;
h6.foreground = 14;
h7.foreground = 14;

t1 = 180 * t1 / %pi;
t2 = 180 * t2 / %pi;
tMin =  min([t1; t2]);
tMax =  max([t1; t2]);
tm = ((1:length(t1))-1)' * 0.1;
subplot(2, 1, 2);
plot(tm(1), tMin, tm($), tMax, 0, 0);
xgrid;
h = legend('$\theta_1$', '$\theta_2$');
h.font_size = 5;
ax = gca();
ax.font_size = 3;
g1 = ax.children(2).children(3);
g2 = ax.children(2).children(2);
g3 = ax.children(2).children(1);
g1.thickness = 2;
g2.thickness = 2;
g3.foreground = 6;

realtimeinit(0.1);
for i = 1:size(r1, 1)
    realtime(i);
    h1.data = [0, 0; r1(i, 1), r1(i, 2); r2(i, 1), r2(i, 2)];
    h2.data = [r2(1:i, :)];
    h4.data = [r1(i, 1) - cr, r1(i, 2) + cr, 2 * cr, 2 * cr, 0, 360 * 64];
    h5.data = [r2(i, 1) - cr, r2(i, 2) + cr, 2 * cr, 2 * cr, 0, 360 * 64];
    g1.data = [tm(1:i), t1(1:i)];
    g2.data = [tm(1:i), t2(1:i)];
    g3.data = [tm(i), tMin; tm(i), tMax];
end

endfunction