Display Rotation and OpenGL

Sorry if this is the wrong place to post this…

I have a singleboard development computer I am playing with that has an S3 Twister graphics adapter (a marriage of the Via chipset and the Pro Savage graphics engine.)

I am running an openGL application on the unit, and it runs fine in landscape mode, but when I rotate the screen orientation to portrait (using the native S3 drivers or the Pivot software), the graphics will not display properly.

Do I need a custom driver to handle the translation from landscape to portrait orientation? Or what?

Thanks for your help.

If portrait mode means physically turning the display 90° left or right, you need

  1. a way to detect that the display has been turned (no idea about that one)
  2. adjust your viewport accordingly, ie swap x and y values
  3. you may need to rotate your scene 90° around the z axis before drawing (not sure if the gfx chip handles this one automatically )

[This message has been edited by zeckensack (edited 03-06-2002).]