NAME
QBSBlit -- Synchronize the blitter request with the video beam.
SYNOPSIS
QBSBlit( bsp )
a1
void QBSBlit( struct bltnode * );
FUNCTION
Call a user routine for use of the blitter, enqueued separately from
the qblit queue. calls the user routine contained in the blit
structure when the video beam is located at a specified position
onscreen. Useful when you are trying to blit into a visible part
of the screen and wish to perform the data move while the beam is
not trying to display that same area. (prevents showing part of
an old display and part of a new display simultaneously). Blitter
requests on the QBSBlit queue take precedence over those on the
regular blitter queue. The beam position is specified in the blitnode.
INPUTS
bsp - pointer to a blit structure. See description in the
Graphics Support section of the manual for more info.
RESULT
User routine is called when the QBSBlit queue reaches this
request AND the video beam is in the specified position.
If there are lots of blits going on and the video beam
has wrapped around back to the top it will call all the
remaining bltnodes as fast as it can to try and catch up.
NOTES
qblit(), and qbsblit() have been rewritten for v39. queued
blits are now handled in FIFO order. Tasks trying to
ownblitter() are now given a fair share of the total
blitter time available. QBSBlit() is no longer queued
separately from nodes added by qblit(). this fixes the
ordering dependencies listed under BUGS in prior autodoc
notes.
BUGS
SEE ALSO
qblit() hardware/blit.h