intro(3G)

NAME
     intro - description of routines in the Graphics Library and Distributed
     Graphics Library

OVERVIEW
     This manual is the reference manual for the routines of the Graphics
     Library (GL).  For a more tutorial introduction to the GL, see the
     Graphics Library Programming Guide.

     In general, all routines in the GL can run either on a local IRIS host,
     or on a remote host connected through a network to an IRIS host, to
     perform graphics operations on an IRIS graphics display.  The
     capabilities of some routines vary between different IRIS graphics
     architectures, or between local and remote operation.  Such differences
     are noted on these routines' manual pages.

     When a manual page refers to VGX, unless it is stated otherwise, it
     applies to VGX, VGXT, and SkyWriter graphics. Similarly, a reference to
     Personal Iris applies to Personal Iris G and TG graphics, and a reference
     to Elan graphics subsystem or Elan graphics architecture applies to XS,
     XS24, XZ, Elan and Extreme.  Also, references to RealityEngine should
     also apply to VTX and RealityEngine2.

     The manual pages are available on-line.  To view them, use the IRIX
     command:

          man routine-name <Enter>


HOW THIS MANUAL IS ORGANIZED
     A manual page provides reference information for a routine of the GL.
     Because these pages are intended as on-line reference material, they tend
     to be terse.  A page is divided into a number of sections:

     NAME lists the name of the routine or routines described by the manual
          page.

     C SPECIFICATION
          lists the type declarations for the routine and its parameters.

     PARAMETERS
          describes the parameters of the routine.

     FUNCTION RETURN VALUE
          describes what the routine returns if it is a function.

     DESCRIPTION
          describes how to use the routine.

     SEE ALSO
          lists related routines or other sources of information.

     EXAMPLE
          gives an example of how the routine is used.

     NOTES
          highlights information concerning the limitations of the routine and
          differences in its behavior on the various IRIS-4D models.

     BUGS describes deviations from the specified behavior that may be fixed
          in a future release.

TYPE DECLARATIONS
     We have constructed type declarations for C wherever they add to the
     readability of the code.  Here are the type definitions as found in
     <gl/gl.h>:

          #define PATTERN_16 16
          #define PATTERN_32 32
          #define PATTERN_64 64
          #define PATTERN_16_SIZE 16
          #define PATTERN_32_SIZE 64
          #define PATTERN_64_SIZE 256

          typedef unsigned char Byte;
          typedef long Boolean;
          typedef char *String;
          typedef short Angle;
          typedef short Screencoord;
          typedef short Scoord;
          typedef long Icoord;
          typedef float Coord;
          typedef float Matrix[4][4];

          typedef unsigned short Colorindex;
          typedef unsigned char RGBvalue;

          typedef unsigned short Device;

          typedef unsigned short Linestyle;
          typedef unsigned short Cursor[16];

          typedef unsigned short Pattern16[PATTERN_16_SIZE];
          typedef unsigned short Pattern32[PATTERN_32_SIZE];
          typedef unsigned short Pattern64[PATTERN_64_SIZE];

          typedef struct {
               unsigned short offset;
               Byte w,h;
               char xoff,yoff;
               short width;
          } Fontchar;

          typedef long Object;
          typedef long Tag;
          typedef long Offset;