Question - Code Tile Alpha?

[Victor Wolf]

So I'm working on a game where the player is navigating a maze. The maze is lit when you hold spacebar and unlit when not. The enemies are drawn to you when the light is on.

I'm trying to do this with image alphas for now (trying to avoid lighting while I'm still a beginner).

It's working fine but I'd like to make it take a second to go all the way dark, so it will be more visually pleasing. Right now I'm just drawing a black rectangle over the tile layers when spacebar is not held. Is there a way to actually change the alpha of the tiles themselves? And if so, can I do it gradually?

If not, is there a way I can make the rectangle's alpha decrease before it disappears completely?

Thanks

 

[Perseus]

As far as I'm aware, changing the alpha of individual tiles or the entire tilemap is currently not possible. But manipulating the alpha of the rectangle should be rather easy and a better practice to some extent. Use a variable to store the alpha value for drawing the rectangle. Using the Step event, keep decreasing it by a small amount when the spacebar is held down until it is equal to 0. When the spacebar is not being held down, keep increasing it until it is equal to 1.

if (keyboard_check(vk_space)) {
   rect_alpha = max(rect_alpha - 0.01, 0);
}
else {
   rect_alpha = min(rect_alpha + 0.01, 1);
}

Using draw_set_alpha(), set the drawing alpha to rect_alpha prior to drawing the rectangle.

 

[Victor Wolf]

Thanks! I'll try that out.
EDIT: Works great, thanks again. A little tweaking and it'll be perfect.