CompuServe Thread

Flickerless Scrolls

7 messages in this thread
#115106From: JAMES D. WILLIAMSJul 30, 1990 11:22 PM
'status line indicators'… like the clock, huh? I'll try it. " A 16 color screen is going to flicker when you scroll it, there's no escaping it if you use RKM and Intuition friendly methods." Uhm… that turns out not to be the case. I'm using a _32_ color screen, and my program is quite RKM/Intuition Friendly. You want I should tell you how to double-buffer your display? Should be a lot easier than it was for me (2 screens, 6 windows, gadgets _and_ (&^$^%$) AnimObs)… no sarcasm, btw (well… maybe a _little_ <grin>). Jack, I do NOT want you to give up the CLI/Keyboard based 'interface' at all. I agree, once you get used to a program, in most cases, keyboard shortcuts are more efficiet than a GUI at text applications (like a term)… I would just like to see it 'GUIier' for the novice user. I think you do see my points, so I won't flog a dead horse anymore. I sympathise with your need for time. 24 hours/day is just not enough time to program and lead a life, too. If you care for any advice or help I can give (such as with the double-buffering), please let me know. –Eet– PS almost forgot, it only flickers with certain combinations of colors, obviously dependant on the bitplanes used. Assuming you're using the blitter for the scroll, blitting only the 1 or two planes involved in the scroll may eliminate the flicker. (unless there's some other colors on screen, in which case you can't :). Double-buffering should definitely be only an option, along with the deeper screens. That way, the user could avoid the memory/speed hit that double-buffering would give. Director of Mayhem Extra Terrestrial Imports, Ltd.
#115265From: jack radiganAug 1, 1990 9:46 AM
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-
#115330From: JAMES D. WILLIAMSAug 1, 1990 9:49 PM
Yes, I tried that optimised scroll. It helps with some configurations. double-buffering doesn't slow the scroll noticable, unless you RefreshGadgets() while you do it <grin>. Only problem is the fact that Intuition only knows about 1 bitmap. –Eet– Director of Mayhem Extra Terrestrial Imports, Ltd.
#115511From: jack radiganAug 3, 1990 9:22 AM
Jim, Have you tried a double-buffered, 16 color text set up? My guess is that having to do Text() calls for each bitmap is going to really bog things down. I think the copper solution is better since it will eliminate flicker *and* increase scrolling throughput as well. -jack-
#115386From: Lou BertatoAug 2, 1990 12:06 PM
Hi Jack…. I sent my registration to you a couple of days ago for JRComm. You should be getting it any day now (or you might have it now). Anyways, for scrolling…. I haven't been following this thread, but did you check out req.library, a PD library which is available through CIS$ or other BBS's. I discovered this library in CygnusEd 2.0. req.library has scrolling functions in there that are supurb, plus file requesters. Maybe you should check this out? If you want to check it out, then just take a look at CygnusEd 2.0. Luciano, 73246,1744
#115512From: jack radiganAug 3, 1990 9:22 AM
Luciano, No, haven't recevied it yet, maybe by the weekend. I have CED 2.0, but haven't looked into the req.library. The main reason is that I dismiss any file requester that doesn't allow multiple selections. I haven't been able to look at Khalid's latest incarnation yet, but he made mention that he was thinking about this (I hope)… -jack-
#115519From: Khalid AldoseriAug 3, 1990 10:00 AM
Jack, I am working hard on version 3 of my file requester and have decided to add multiple select across directories. (finally 🙂 I have been a bit, err, preoccupied the last 2 days with the events in the area and haven't been doing any programming… I've put you on my email beta list, so you'll get a beta of what I'm working on pretty soon. Khalid.