grants@syacus.acus.oz.au (Grant Sayer) (03/09/91)
The problem is to be able to present a coloured image (Mac IIci) and then to remove the image after the monitor's retrace has finished. The colour manipulation is done using a region and AnimateEntry to change the colour index in the CLUT table between the desired colour and the background thus causing the image to disappear. My understanding of the VBL tasks is that an interrupt, occurring at the end of the monitor's rescan forces anything on the VBL queue to be executed. The problem is that VBL tasks cannot be operations that affect the memory manager (I think), as listed in Inside Mac, which of course the quickdraw operations do. Can anyone offer any suggestions as to ways to show an image which only lasts as long as, for example, one frame of the display ? Thanks for any suggestions/help -- Grant Sayer ACSnet : grants@syacus.acus.oz Ph : +61 2 390-1339 Internet : grants@syacus.acus.OZ.AU Fax: +61 2 390-1391 UUCP : uunet!munnari!syacus.acus.oz.au!grants