NAME
QBSBlit -- Synchronize the blitter request with the video beam.
SYNOPSIS
QBSBlit( bsp )
a1
void QBSBlit( struct bltnode * );Links: 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 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.
BUGS Not very smart when getting blits from different tasks. They all get put in same queue so there are unfortunately some interdependencies with the beam syncing.
SEE ALSO