Hi! I am making the game planarity in MATLAB, and i am stuck where the program have to determine that is there any lines that are in inscision with each other. Any ideas how could the program find the inscision points. Heres my source for the game:

> clear;
clc;
a=1;
b=10;
x=floor(rand(5,1)*(b-a+1)+a);
y=floor(rand(5,1)*(b-a+1)+a);

fig1=figure;
set(fig1,'Color','w','Position',[100 100 500 500])
plot(x,y,'o','MarkerSize',12,'MarkerFaceColor','r');

axis([0 11 0 11]);
axis off

grid on;
hold on;
FirstPlayerLines=[];
SecondPlayerLines=[];

    for a1=1:+1:2 
        for a2=5:-1:2
            plot([x(a1) x(a2)],[y(a1) y(a2)],'Color','black','LineWidth',3);

        end
    end

waitforbuttonpress