Commit
3d94fac862c3605d3a0862e8e6f7725483398163
by Sven GothelBug 1234 - GLReadBufferUtil.readPixelsImpl(..) not using [xy] offset in
readTexture.updateSubImage(..)
The passed inX and inY x/y offset for readPixel -> [textureData] buffer,
must be passed to readTexture.updateSubImage(..)'s destination offset.
I.e. the buffer's content starting at beginning is filled via
glReadPixels w/ offset applied.
Hence the texture update must pass the offset as the destination offset,
i.e. to be used for glTexSubImage2D's offset.