You know in classic platformers when you get bonked by an enemy, you'll lose some health and then you'll start blinking or flashing. While you're blinking, you're unable to get hit again so that you can get back to safety! This is one example where you would want your player's sprite to blink. In this example, we'll show you how to flicker the sprite of an object in-and-out of visibility.

Demo

Click on the ghost to see it blink.

Prerequisite

Know how objects and events work
Be familiar with GML

Concept

To make the sprite appear and disappear, we'll be manipulating the built-in variable visible. Setting it to false will make the sprite invisible, but the object still run. Setting it to true will make the sprite visible again.

When you click the object, a countdown begins.
If the counter hasn't reached zero, the sprite will turn invisible (if it's visible) or visible (it it's invisible) every 8 frames.
When the counter hits 0, make sure the sprite is visible.

Code

CREATE event in obj_ghost:

blink_counter = 0;

Here we're just defining our counter variable as blink_counter and we'll set it to 0.

STEP event in obj_ghost:

if blink_counter > 0
{
	blink_counter -= 1;

	if (blink_counter mod 8 == 0)
	{
		visible = !visible;	
	}
	
	if (blink_counter = 0)
		visible = true;
}

First we'll check if blink_counter is greater than 0. If it is, we'll assume the countdown is active, and decrease it by 1. if (blink_counter mod 8 == 0) will run every 8th frame, and turn visible to the opposite of what it currently is. If visible is false, it'll set it to true. If it's true, it'll set it to false. After that, we check if blink_counter is 0. If it is, the countdown is over, and we want to make sure the sprite is visible.

MOUSE LEFT PRESSED event in obj_ghost:

blink_counter = 120;

When you click on the ghost, blink_counter is set to 120, so it'll count down 120 frames, or about 2 seconds. After this event, the step event will begin the countdown and make the sprite blink!

...and that's all to it! This is only one simple way to make a sprite blink. There are many other ways, of course, so let's hear your ideas in the comments.

Homework

Make the sprite blink faster. Now make it slower. How does it affect the feeling of the effect?
How would you make the sprite's blink increase as the countdown gets lower?

Blinking Sprite