Today’s graphics tip is all about optimising alpha transparencies, which are used quite a lot in Dare the Monkey.

Alpha Transparencies

Applying alpha effects to large bitmaps can cripple a game’s performance. This is also true if you over use alpha transparencies on a large number of smaller sprites.


Alpha effects applied to smaller source bitmaps.

In Dare I use alphas sparingly, and when I do use them I reduce the actual source bitmap image down in size then scale it back up at runtime. You can see this used to good effect in the image above, which is from one of the game’s jungle levels.

You’d be surprised at the number of players who’ll never notice that much smaller bitmaps are being used.