g=10;

AR1x = [3, 3];
AR1y = [2, 4];
AR2x = [10, 10];
AR2y = [5, 7];
FR1x = [4, 5];
FR1y = [4, 4];
FR2x = [7, 9];
FR2y = [5, 5];

hold on;
%plot (AR1x, AR1y, 'g-');
%plot (AR2x, AR2y, 'g-');
%plot (FR1x, FR1y, 'r-');
%plot (FR2x, FR2y, 'r-');

minAlpha = 5;
maxAlpha = 85;
minV = 5;
maxV = 30;

Vs =[];
As =[];


for iteration = [0:1:100000]
    v = rand() * (maxV-minV) + minV;
    alpha = rand() * (maxAlpha-minAlpha) + minAlpha;

    vx = v*cosd(alpha);
    vy = v*sind(alpha);

    t=0;
    y=1;
    xOld=0;
    yOld=0;

    crossesAllowed = 0;
    savedX = [];
    savedY = [];

    good = 0;

    while y > 0
      t = t + 0.01;
      x = vx * t;
      savedX =[savedX, x];
      y = vy * t - (g * t^2) / 2;
      savedY =[savedY, y];



      crossedForbidden = crossesLine(xOld,yOld,x,y, FR1x, FR1y);
      if crossedForbidden == 1
          disp('Hit forbidden line');
          break;
      end;

      crossedForbidden = crossesLine(xOld,yOld,x,y, FR2x, FR2y);
      if crossedForbidden == 1
          disp('Hit forbidden line');
          break;
      end;

      % Green lines
      crossesAllowed = crossesAllowed + crossesLine(xOld,yOld,x,y, AR1x, AR1y);
      crossesAllowed = crossesAllowed + crossesLine(xOld,yOld,x,y, AR2x, AR2y);


      if crossesAllowed == 2
         %good = good + 1;
         disp('OK simulation')
         %hold on
         %grid on
         %xlabel('X');
         %ylabel('Y');

         %plot (savedX, savedY, 'b-');

         %if good == 5
         %    return;
         %end;

         Vs = [Vs, v];
         As = [As, alpha];
         break;

      end;



      xOld = x;
      yOld = y;
    end

      %if (allowedCrosses != 2)

end

hold on
grid on
plot (Vs, As, 'b*');