%Simulate Launched Ball Method
%This method runs the simulink model launched_ball and determines the
%horizontal distance between the target & the launched projectile.
%
%m = mass of the projectile/ball
%g = gravity
%R = resistance force
%Fi = input force magnitude (force is always an impulse)
%theta = angle at which to launch the ball
%t_final = the length of time to run the simulation
function [error,x,y] = sim_launched_ball(m, g, R, target_x, target_y, Fi, theta, t)

sim('launched_ball', t, simset('SrcWorkspace', 'current'));

x = squeeze(sim_x.signals.values);
y = squeeze(sim_y.signals.values);

%determine if the projectile hit the target, otherwise return the distance
for i = (length(y)):-1:1
    if (y(i) > target_y)
        if (i == length(x)) %prevent indexing value outside x array
            error = target_x - x(i);
        else
            error = target_x - x(i+1);
        end
        return
    end
end

error = target_x - x(1); %if no value in y is ever greater than the target y, must set a default error value

end