The thing is that:
I need a transparent log on the left top of the jPCT world, and I also notice that some words blitted from a texture look much better if they are in a transparent background.
So Can I blit some parts from a texture( a picture, maybe GIF, JPG or PNG), and set the parts transparent?
It is not the issue about FrameBuffer.TRANSPARENT_BLITTING or FrameBuffer.OPAQUE_BLITTING, when I set the FrameBuffer.TRANSPARENT_BLITTING, the background will be missed if it is black, and if not black, the background will be there. But I need it is transparent.