CompuServe Messages

#Flickerless Scrolls

    01-Aug-90 09:46:38
Fm: jack radigan 76545,201
To: JAMES D. WILLIAMS 72157,3524
Jim, I've thought about using double-buffering for a 16 color display, but I've not actually tried it. My initial reaction would be that blasting text into two bitmaps and scrolling the two bitmaps is going to bring throughput down to its knees. If I'm missing something basic here and don't have to double up on blitter usage I'm sure you'll correct me. 😉 What I have thought of doing so that I can get some good performance is to do copper based scrolling. Of course, it will be unfriendly to Intuition and have to reside in its own screen, but the throughput should be quite nice. Also, take a look at the optimized scroll feature. It minimizes a scroll operation to the minimum bitplanes and width needed to accomplish it. -jack-