Device routines

void vinit

(char *device)
Tell VOGL what the device is. This routine needs to be called if the environment variable VDEVICE isn't set, or if the value in VDEVICE is not to be used.

1. Current available devices are:

   amiga

   Amiga graphics implemented by Dr. Charles E. Campbell, Jr.

   apollo

   Apollo workstations

   cga

   IBM PC cga graphics card

   decX11

   The decstation (old) window manager. This is only included in case you need it.

   dxy

   Roland DXY plotter language

   ega

   IBM PC ega graphics card

   hercules

   IBM PC hercules graphics card

   hpgl

   HP Graphics language and compatibles

   NeXT

   NeXTStep

   postscript

   postscript devices

   ppostscript

   postscript devices (portrait mode)

   sigma

   IBM PC sigma graphics card.

   sun

   Sun workstations running sunview

   tek

   Tektronix 4010 and compatibles

   vga

   IBM PC vga graphics card

   X11

   X windows (SUN's Openwindows etc etc)

   Sun, X11, decX11, apollo, hercules, cga and ega support double buffering.

2. If device is a NULL or a null string the value of the environment variable VDEVICE is taken as the device type to be opened.

3. after init it is wise to explicitly clear the screen.

                color(BLACK);
                clear();
   

void ginit

()
Open the graphics device and do the basic initialisation. This routine is marked for obsolescence. The routine winopen (see below) should be used instead.

long winopen

(char *title)
Open the graphics device and do the basic initialisation. This routine should be used instead of ginit.

void gexit

()
Reset the window/terminal (must be the last VOGL rou tine called)

void voutput

(char *path)
Redirect output from next ginit to file given by path. This routine only applies to devices drivers that write to stdout e.g. postscript and hpgl.

void vnewdev

(char *device)
Reinitialize VOGL to use a new device without changing attributes, viewport etc. (eg. window and viewport specifications)

int getplanes

()
Returns the number of bit planes (or color planes) for a particular device. The number of colors displayable by the device is then 2^(nplanes-1)