- ByteImage *buf
- Parent ByteImage structure from which to make new virtual field byte image.
- 1 or 0. Selects top or bottom field.
Virtual field byte image.
Given a pointer to a Dali ByteImage structure, creates a virtual ByteImage structure from it to represent the top or bottom field (selected based on the value of top_flag). This is done by creating a virtual ByteImage that has the same width, but half the height of the parent byte image and setting the parent width field of the virtual byte image to twice the true parent width value. Thus, routines that correctly use the parent width field of the ByteImage structure to index into the byte image values will properly operate on every other line of the byte image if given a byte field image created with this routine.