VORTFILE(3)            C LIBRARY FUNCTIONS            VORTFILE(3)



NAME
     VORTFILE - A Very Ordinary raster file  format  library  for
     the Very Ordinary Rendering Tool Kit.

SYNOPSIS
     #include <vort.h>


DESCRIPTION
     The VORT file format is designed to be byte independant  and
     easily  extendable.  At the moment a VORT file can be recog-
     nised by the string "VORT01" at the start of the file.

     A VORT file is made up of objects.  The  first  byte  of  an
     object  gives  its type, the second byte gives the number of
     bytes in the size of the object, the next n bytes  give  the
     object's  size,  and  the  next size bytes gives the object.
     Values are written out highbyte first. Programmes can ignore
     unknown  fields by reading the size and skipping the object.
     The first object in a VORT file should always  be  a  direc-
     tory.

     At the moment the following object types are supported:
          V_DIRECTORY     0       /* directory */
          V_IMAGE         1       /* image */
          V_TEXT          2       /* text */
          V_COLORMAP      3       /* colourmap */

  The Directory Object.
     Directories can be made up of simple objects or other direc-
     tories. The following types can be found in a directory:
          D_PARENT        0       /* address of parent directory */
          D_NULL          1       /* empty entry */
          D_OBJECT        2       /* address of object in directory */

  Image Objects.
     The following types can be found in  an  image  object.  All
     values are ints, except I_ADDR and I_COLORMAP.
          I_ADDR          0       /* address of image in file */
          I_IMWIDTH       1       /* image width in pixels */
          I_IMHEIGHT      2       /* image height in pixels */
          I_IMDEPTH       3       /* image depth in bits */
          I_RED           4       /* red channel present */
          I_GREEN         5       /* green channel present */
          I_BLUE          6       /* blue channel present */
          I_ALPHA         7       /* alpha channel present */
          I_BACKGND       8       /* background colour */
          I_DATE          9       /* creation date */
          I_COLORMAP      10      /* red, green, and blue channels
                         in colourmap */
          I_RLE_CODED     11      /* image is run length encoded */
          I_XADDR         12      /* x coord of image if fragment */



VORT 2.0          Last change: 5 Dececmber 1990                 1






VORTFILE(3)            C LIBRARY FUNCTIONS            VORTFILE(3)



          I_YADDR         13      /* y coord of image if fragment */
          I_ORIGWIDTH     14      /* width of whole image we are fragment of */
          I_ORIGHEIGHT    15      /* height of whole image we are fragment of */

  Text Objects.
     The following types can be found in a text  object.  Charac-
     ters are assumed to be 8 bits.
          T_ADDR          0       /* address of text in file */
          T_LENGTH        1       /* length of text in characters */

  Colourmap Objects.
     The following types can be found in a text object:
          C_ADDR          0       /* size of map */
          C_SIZE          1       /* size of each channel */
          C_RED           2       /* red channel present */
          C_GREEN         3       /* green channel present */
          C_BLUE          4       /* blue channel present */

  Making extensions.
     People wishing to add fields to the file format  should  get
     in touch with echidna@ecr.mu.oz.au before doing so.

SEE ALSO
     art(1),  disp(1),   movie(1),   vortinfo(1),   targ2vort(1),
     vort2ps(1),  median(1),  mulmcut(1),  greyscale(1), vort(3),
     gamma(1).





























VORT 2.0          Last change: 5 Dececmber 1990                 2