An interface for texture effects. Texture effects are two-dimensional effects
applied to a texture. The affected texture has to be converted and uploaded to the
GPU every time the effect will be applied.
Applies the effect. Like init(), this will be called from within the
Texture class. To avoid the construction of a new int for every call,
the resulting image is rendered directly into dest. So if one wants to
implements an effect, take the source bitmap (it's an int containing
the texture in ARGB (0xaarrggbb)-format) and write the modified
source bitmap into the dest bitmap.
dest - the destination bitmap
source - the source bitmap (the unmodified texture)
If this returns true, jPCT assumes that the alpha channel in the returned pixels
is populated and treats it accordingly.