Updating the HUD
As you might expect, we will update the HUD variables in the updated section of our code. However, we will not do so at every frame. The reason for this is that it is unnecessary, and it also slows our game loop down.
As an example, consider the scenario when the player kills a zombie and gets some more points. It doesn’t matter whether the Text object that holds the score is updated in one-thousandth, one-hundredth, or even one-tenth of a second. The player will discern no difference. This means there is no point rebuilding strings that we set for the Text objects every frame.
Therefore, we can time when and how often we update the HUD. Add the following highlighted variables:
// Health bar
RectangleShape healthBar;
healthBar.setFillColor(Color::Red);
healthBar.setPosition(450, 980);
// When did we last update the HUD?
int framesSinceLastHUDUpdate = 0;
// How often (in frames) should we update the HUD
int fpsMeasurementFrameInterval = 1000;
//...
