Access Sprite's RGBA Pixel Values

Hi,

I want to be able to use the alpha channel of my background sprite to hold height data. Is there a way to get access to the RGBA of a pixel in a sprite for use in an Action?

Thanks

You can't access its RGBA data directly, but you can use its height variable, or add an instance variable to the background to store that kind of data.

Thanks for the reply. However, if I understand you correctly, that will not help me. I basically want a heightmap (2d array) for my background image, meaning each pixel will have a value 0-255 for its height and that I can access.

So you want to create a height-map then? Such as the ones used for mapping topography?

You will probably have to create a javascript plugin to do something like that without having tons of sprites. Try asking for help over in the plugins section.

You could use the Canvas plugin

Or use the Array object?

Thanks for the replies all.

It seems some kind of plugin is the way to go.

An array won't help me because the heightmap will be created by the artist who creates the background image and then I'm back to the same problem of trying to access a image's RGBA values.

The use of an array would require some effort before hand. Like making an editor, and exporting a json file to be used as your heightmap.

Aside from that the reason there's not much there for per pixel operations is because it would be way too slow to use on any image of any largish size.

For how the canvas object could be used for this:

http://www.scirra.com/forum/using-pixel-colors-as-reference-for-level-layouts_topic57020.html

http://www.scirra.com/forum/destroy-Objects-parts_topic61035_page2.html