Implement basic operations

The procedures described in this topic enable you to:

• complete the basic server and increase performance

• customize the routines that draw a rectangle to the screen

• read an image from the screen

• set the colormap

• blank the screen

• take advantage of any accelerated routines supplied by your graphics adapter

1. Implement the driver's DrawImage(D3nfb) routines. Note that there are different functions to support depths 1, 2, 4, 8, and 16; these routines are coded in the following driver files:
   
   xxxData.c
   xxxImage.c

   On SVR5 and SCO OpenServer 5 systems, examples of these routines can be seen in the sample nte driver. See
   
   /usr/xlink/Xserver/hw/sco/ports/nte/nte8/nteData.c
   /usr/xlink/Xserver/hw/sco/ports/nte/nte8/nteImage.c

   for more information.

2. Implement the driver's ReadImage(D3nfb) routines to read an area from the screen. On SVR5 and SCO OpenServer 5 systems, examples of these routines are provided in the the following nte files.
   
   /usr/xlink/Xserver/hw/sco/ports/nte/nte8/nteData.c
   /usr/xlink/Xserver/hw/sco/ports/nte/nte8/nteImage.c

3. Implement the driver's SetColor(D3nfb) routine in the xxxCmap.c file to set the colormap. See ``Modify the colormap (SetColor)''.

4. Implement the driver's BlankScreen(D3nfb) routine. Most adapter hardware can handle this operation, but if yours cannot, the functionality can be implemented by setting all entries in the colormap to black.

5. Recompile and link the driver; see ``Compile driver template''.