Path: utzoo!news-server.csri.toronto.edu!rpi!zaphod.mps.ohio-state.edu!sdd.hp.com!hp-pcd!hpcvra.cv.hp.com!everett
From: everett@hpcvra.cv.hp.com. (Everett Kaser)
Newsgroups: comp.os.msdos.programmer
Subject: Re: DOS or MS C Graphics
Message-ID: <31600013@hpcvra.cv.hp.com.>
Date: 18 Mar 91 16:52:48 GMT
References: <65023@eerie.acsu.Buffalo.EDU>
Organization: Hewlett-Packard Co., Corvallis, OR, USA
Lines: 22


 v117gv8r@ubvmsb.cc.buffalo.edu (Thomas E Burnett) / 12:17 pm  Mar 13, 1991 /
>Using MS Quick-C to put images on a screen there are 5 modes available:
>_GOR, _GXOR, _GAND, _GPSET, _GPRESET. Using some combination of these
> modes I would like to be able to put and move images (using two pages)
>so that the image retains its original colors regardless of the background
>that it is put on and then recover the background when the image is
>moved or removed. For instance the image of an airplane moving over
>farmland. 
>Can anyone tell me how to do this using the QC _putimage() function?
>	Thom

About the only way to do this on PC display hardware is to read the current
background image (using _getimage()) into a scratch save buffer, then use
_putimage(,,,_GPSET) to force your new image onto the screen.  Then, when
you want to move your image, you first use _putimage(,,,_GPSET) to replace
the previous background image (using the saved image from the scratch buffer)
and then repeating the previous _getimage()/_putimage() at the new location.

Everett Kaser                   Hewlett-Packard Company
...hplabs!hp-pcd!everett        work: (503) 750-3569   Corvallis, Oregon
everett%hpcvra@hplabs.hp.com    home: (503) 928-5259   Albany, Oregon