> BACKGROUND INFORMATION > > The issue is this any X magnification program that I have seen draws the > > magnified area on a window I DO NOT WANT TO DO THIS. I want to write a > > program, which zooms in like a video camera on a particular part of the > > screen what will happen is that the magnified area of the screen will fill > > the entire screen, in simple terms the magnified area will be re-drawn > with > > more pixels to fill the screen. However the X server and clients > shouldn't > > care about this in-fact they shouldn't know.
I think he's talking about the DGA SetMode(), which allows you to change the physical resolution. Like pressing [CTRL] + [ALT] + keypad [+] combination. He could probably do this by initializing DGA, then setmode, and deinitializing DGA. Just a thought. Roger On Tue, 2003-03-11 at 15:10, Sottek, Matthew J wrote: > You could potentially do something with Video4Linux to cause a > portion of the framebuffer to be displayed using a hardware overlay. > This would require a driver that has Xv and Video4Linux support > and a real hardware overlay with on-the-fly scaling (i.e doesn't > require a temporary output) > > The upside is that it would be automatic without any CPU intervention. > anything XFree draws in the framebuffer would automatically be > scaled real-time by the overlay. You would just need to reposition > the overlay when the panning was needed. > > or, > > You could use Xv in a more conventional manner (no video4linux) and > just read the framebuffer contents via a memory map and do an > XvShmPutImage to get the scaled up version on-screen. Some hardware > probably has issues with mmap reading of the FB while rendering so > your mileage may vary. > > -Matt > > > -----Original Message----- > From: Mark Vojkovich [mailto:[EMAIL PROTECTED] > Sent: Tuesday, March 11, 2003 12:59 PM > To: [EMAIL PROTECTED] > Subject: Re: DGA Example Code for Screen Magnification Prog > > > DGA is for fullscreen games and such and takes over the screen making > the rest of the server think it's switched away do another VT. DGA > is mutually exclusive with normal server operation so it can't be > used magnify normal server operation. > > Most hardware can display resolutions as low as 320x240. Isn't > that low enough resolutions for you? In a dual head configuration > with Xinerama, one head could display a blowup of the other > screen. I haven't tried it but one should be able to have a > client that tracks mouse motion on the screen and adjusts the > viewport position of the blownup screen through the vidmode extension. > > > Mark. > > > On Tue, 11 Mar 2003, Kieran O'Sullivan wrote: > > > I am writing an Xlib based screen magnification program for X called > > BlindPenguin (http://www.blindpenguin.org). In great wisdon of great > > folly I have dicided to use DGA to write this program. > > I am looking for DGA code examples I have looked at the dga prog which > > changes your screen colour, but i need more. freshmeat.net has one or two > > games which use DGA and I'm hoping someone here has something? > > > > Setting the mode lines in XF86Config isn't really an option for a person > > with my sight level unless it is possible to set a Mode line which will > > make the screen 8 times its normal size. > > > > BACKGROUND INFORMATION > > The issue is this any X magnification program that I have seen draws the > > magnified area on a window I DO NOT WANT TO DO THIS. I want to write a > > program, which zooms in like a video camera on a particular part of the > > screen what will happen is that the magnified area of the screen will fill > > the entire screen, in simple terms the magnified area will be re-drawn > with > > more pixels to fill the screen. However the X server and clients > shouldn't > > care about this in-fact they shouldn't know. Basically there are 2 > screens > > 1 is the screen that the X server creates and the other is the screen that > > the user sees. As I move the mouse around the X server moves it on the > real > > screen but the user sees the magnified screen moving. To use the video > camera > > analogy again imagine a person walking around a room using the view > finder > > of a video camera turned up to full zoom to see. Their coordinates would > > change relative to the objects in the room but they would see things much > > larger than they are. > > > > > > _______________________________________________ > > Devel mailing list > > [EMAIL PROTECTED] > > http://XFree86.Org/mailman/listinfo/devel > > > > _______________________________________________ > Devel mailing list > [EMAIL PROTECTED] > http://XFree86.Org/mailman/listinfo/devel > _______________________________________________ > Devel mailing list > [EMAIL PROTECTED] > http://XFree86.Org/mailman/listinfo/devel -- roger <[EMAIL PROTECTED]> _______________________________________________ Devel mailing list [EMAIL PROTECTED] http://XFree86.Org/mailman/listinfo/devel
