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GuyWithDogs
11-05-2006, 03:39 PM
I'm looking into libraries to use with Delphi 7 to try and make a smooth text scrolling application (which I'll possibly try to convert to an ActiveX control for use in a web page). Previous attempts at basic graphics in Delphi don't get a smooth enough scrolling effect - like the news ticker across the bottom of CNN, or a sports ticker on ESPN or your local news. Right to left text ends up not scrolling smoothly - htere are jerks and jumps that bug people who are viewing it. This is getting done on a large scale on a big screen in the lobby of the company I work for, so it's large size text, etc.

Questions in the Delphi newsgroups had someone suggest DirectX as a possible approach, so I started looking at that, and found DelphiX, unDelphiX, and Asphyre mentioned. It looks like Asphyre is dead, though - am I right about that?

From what I read here, it sounds like unDelphiX has had more done to it recently than DelphiX. Is that correct?

Finally - is this even a reasonable approach? Is it overkill for what I want? Or should I just grab an unDelphiX install and start trying it?

Thanks.

User137
11-05-2006, 06:49 PM
If you need only text scrolling and are willing to force program to need DirectX, then good old DelphiX works good for you. New UnDelphiX brings 3D acceleration with it but i guess that is not needed on your case.

Actually smooth scrolling can be achieved even with simple TImage component and its Canvas. (You would have to use Canvas even if you went DelphiX)

GuyWithDogs
11-05-2006, 07:46 PM
Actually smooth scrolling can be achieved even with simple TImage component and its Canvas. (You would have to use Canvas even if you went DelphiX)

If it's not too far off-topic, can you tell me how? I tried a number of different approaches suggested in response to some questions in the borland.delphi.graphics newsgroup, but I still get hesitations in the scrolling. This is with text running thru a form that's 10% the height of the screen.

In those earlier tests, I had taken the suggestions and turned the resulting application into an ActiveX control that was running within Internet Explorer 6. But even as a standalone app, I couldn't get really smooth scrolling.

A brief test with Asphyre last weekend showed that a DirectX approach had some potential, but even that wasn't foolproof. Part of it, I'm sure, was my newbieness to Asphyre.

Thanks.