function [ Hp, Recharge, Time ] = ShieldRegen( HpMax, RechargeTime, Dps, Resist, Duration )
%ShieldRegen( HpMax, RechargeTime, Dps, Resist, Duration, Delta );
%   Plots shield HP as a function of time
%   HpMax = Shield max HP
%   RechargeTime = Shield recharge time (see in game ship fitting window)
%   Dps = incoming dps
%   Resist = Shield resist against incoming dps
%   Duration = Time axis of resulting graph

Delta = 0.01;   %simulation time delta
Eff =1/(1-Resist/100);  %effectiveness from resists
EDps = Dps / Eff;    %Effective DPS

n=1;
Hp(1)=HpMax;
Recharge(1)=0;
Time = 0:Delta:Duration;
ending = nan;

for t=Delta:Delta:Duration;
    n=n+1;
    Hp(n) = min( [ Hp(n-1) + (Recharge(n-1)-EDps)*Delta, HpMax] );

    if Hp(n)>0
        Recharge(n) = 2 * HpMax .* 5 ./ RechargeTime .*( sqrt(Hp(n) ./ HpMax) - (Hp(n) ./ HpMax) );
    else
        Hp(n)=0;
        Recharge(n)=0;
        ending = min(ending, n*Delta);
    end


end


HP = max(Recharge);
PeakEHP = HP*Eff;
HpPercentage = 100*(Hp./HpMax);
endingtime = ending + 50;

figure('name', 'Shield regen');
plot(Time, HpPercentage);
axis([0, endingtime, 0, 100]);
xlabel('Time (s)');
ylabel('Shield Hp %');
grid on;
str = { sprintf('Incoming damage: %d dps', Dps), sprintf('Shield: Max HP %d, resist %.1f %%, recharge time %d s', HpMax, Resist, RechargeTime), sprintf('Max recharge %.0f EHP/s', PeakEHP )}'
title( str );
end