I don't understand the using of RGB in LOVE

[sabino]

Hi,
I've just bought an e-book titled "LOVE for Lua Game Programming".
I've read some page and I found this code as example:

love.graphics.setColor(0,0,0,225)
love.graphics.setBackgroundColor(255,153,0)

Why the first line has 4 numbers (RGB is identified by only 3 numbers)?
Thank you!

[slime]

Hi!

The fourth argument to setColor controls opacity/transparency when drawing. A value of 255 means fully opaque / no transparency, and a value of 0 means fully transparent. Anywhere in between means partial transparency.

[kikito]

It's actually RGBA (the A defaults to 255) http://en.wikipedia.org/wiki/RGBA_color_space

[bartbes]

And of course the background is RGB, instead of RGBA because your background can't be transparent (what would be behind it?)

[Zilarrezko]

And of course the background is RGB, instead of RGBA because your background can't be transparent (what would be behind it?)

Conspiracy theory!

[jjmafiae]

Bartbes, I think there might be a secret cookie factory behind it.

[zorg]

And of course the background is RGB, instead of RGBA because your background can't be transparent (what would be behind it?)

What about "what is behind it.", e.g. the desktop, or another window, or both, or whatever... though i'm sure that there would be some nontrivial (like cross-platform/windowing system) problems in implementing this, assuming it'd even be possible.