Message-ID: <311.990604478048@iw0.mailusenet.com> Date: Thu, 24 May 2001 07:11:25 -0700 (PDT) From: Andrew Zdenek Subject: SVGA scrolling Organization: Self Newsgroups: comp.os.msdos.djgpp Size: 1193 Lines: 18 To: djgpp AT delorie DOT com DJ-Gateway: from newsgroup comp.os.msdos.djgpp Reply-To: djgpp AT delorie DOT com I know this question is not specific to DJGPP, but I have had no luck getting help on other newsgroups and I was hoping there are some people here who have experience with SVGA programming with djgpp. I am trying to write a simple SVGA mode 0x101 driver to display an image larger than 640x480. I first loaded the parts of the image into a linear buffer which is large enough to fit the entire image. Then I tried to create a scrolling effect by using memcpy to blit 640x480 portions of the buffer to video memory. The problem is all the images which are located at a point greater than the screen width wrap around and are plotted back on the currently viewed screen. This same problem does not happen with the vertical plotting. I tried increasing the logical scan line width and setting the logical display start to the position withing the buffer in hopes that the problem was caused by the video memory overlapping, but this did not stop the images from wrapping. Does anyone know why this is happening? Thanks ---- Posted via http://www.etin.com - the FREE public USENET portal on the Web Complete SEARCHING, BROWSING, and POSTING of text and BINARY messages!