function bezier
 	p1 = [0;0]
 	p2 = [1;1]
	p3 = [2;1]
	p4 = [1;3]
	plotbezier(p1,p2,p3,p4);
end

function plotbezier(p1,p2,p3,p4)
	npts = 50;
	dt = 1/npts;
	p = zeros(2,npts);
	b = 3*(p2-p1)
	c = 3*(p3-p2)-b;
	d = p4 - p1 - b -c;
	for i=1:npts
		t=i*dt;
		p(1:2,i) = p1 + b*t + c*t^2 + d*t^3;
	end
	plot(p(1,1:npts),p(2,1:npts),'b');
	hold on
	plot([p1(1),p2(1)],[p1(2),p2(2)],'r');
	plot([p3(1),p4(1)],[p3(2),p4(2)],'g');
	hold off
end