How can I create a tile, overlay for a scene in Cocos2d?

Question

I'm new to Cocos2d, but I can't seem to find the answer to this. I want to add an image that is mostly transparent as an overlay to my application. The image is overlayed on the app, and does not respond to screen taps. All gestures should "pass through" to the application.

The overlay image should actually be tiled. It's a small image that should repeat both horizontally and vertically.

How can I do this? In fact, this is an overlay that I would like to display for the duration of the entire application-- not just one specific scene. Is there a simple way to do this?

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The point of my overlay is that I'd like to create a pseudo-scan line affect for a game which has an "8-bit" tone. The scan lines will be generated by applying the overlay to the game. The overlay is non-interactive and should always exist. So, this isn't a "tile based game", but I do need a tiling affect for this functionality.

Answer 1

You should be able to create a layer in each scene, set the zOrder to something large so that it overlays everything else, and set its isTouchEnabled attribute to NO. You can then add whatever you want to the layer, which could be your patterned image. To change the alpha, just set the opacity attribute of your image. The only issue that I can foresee is that the overlay might disable touch events for layers below it.