rle_hdr man page on DigitalUNIX

Man page or keyword search:  
man Server   12896 pages
apropos Keyword Search (all sections)
Output format
DigitalUNIX logo
[printable version]

RLE_HDR(3)							    RLE_HDR(3)

       rle_hdr - Structure for communication with RLE functions.

       #include <rle.h>

       rle_hdr rle_dflt_hdr;

       rle_hdr the_hdr;

       This  data  structure  provides	communication  to  and between all the
       RLE(5) file routines.  It describes the parameters of the  image	 being
       saved  or  read, and contains some variables describing file state that
       are private to the  routines.   The  public  components	are  described

	    typedef unsigned char rle_pixel;
	    typedef unsigned short rle_map;

	    rle_hdr {
		 int	 ncolors,  /* Number of colors being saved */
			 *bg_color,/* Background color array */
			 alpha,	   /* if ≠ 0, save alpha channel (color -1) */
				   /* alpha channel background is always 0 */
			 background,/* if = 0, no background processing */
				   /* if = 1 or 2, save only non-bg pixels */
				   /* If 2, set clear-to-bg flag in file */
			 xmin,	   /* Min X bound of saved raster */
			 xmax,	   /* Max X bound */
			 ymin,	   /* Min Y bound */
			 ymax,	   /* Max Y bound */
			 ncmap,	   /* number of color channels in color map */
				   /* if = 0, color map is not saved */
			 cmaplen;  /* Log2 of the number of entries in */
				   /* each channel of the color map */
		 rle_map *cmap;	   /* pointer to color map, stored as 16-bit */
				   /* words, with values left justified */
		 char	 **comments;/* Pointer to array of pointers */
				   /* to comment strings. */
		 FILE *	 rle_file; /* I/O to this file */
		  * Bit map of channels to read/save.  Indexed by (channel mod 256).
		 char	 bits[256/8];

       A global variable, rle_dflt_hdr, is available, conveniently initialized
       with default values.

	      The number of colors (exclusive of the  alpha  channel)  in  the
	      image.   This  is	 one  greater  than  the largest channel index
	      (i.e., ncolors would be 3 if channels 0, 1, and 2 were saved, or
	      if only channel 2 were saved.)

	      A	 pointer  to  an  array of ncolors integers, defines the back‐
	      ground color (if used).  The background alpha value is always 0,
	      so is not included in the bg_color array.

       alpha  If  non-zero,  an	 alpha channel is present as channel -1.  This
	      should always  be	 0  or	1.   Rle_get_setup  and	 rle_put_setup
	      enforce  this  constraint.  The alpha channel will only be actu‐
	      ally read or written if the corresponding bit in	bits  is  also

	      Controls	whether background color processing is done.  If 0, no
	      background processing is done at all (and bg_color is  ignored).
	      If 1 or 2, then runs of 3 or more pixels in the background color
	      are not saved at all.  If 2, then these runs will be restored by
	      rle_getrow;  if  1, they will not (this can lead to some strange

       xmin, xmax, ymin, ymax
	      The bounds of the image.	All pixels from xmin to	 xmax,	inclu‐
	      sive,  in	 rows  numbered	 from ymin to ymax, inclusive, will be
	      saved.  Thus the dimensions of the image are
			(xmax - xmin + 1) × (ymax - ymin + 1)

       ncmap, cmaplen
	      The size of the saved colormap (if any).	 The  color  map  will
	      have  ncmap channels, each 2^cmaplen long.  If ncmap is zero, no
	      color map is present.

       cmap   A pointer to colormap data, if present.  The data is  stored  in
	      "channel major" order, so that all the values for channel 0 pre‐
	      cede all the values for channel 1, etc.  Each  individual	 value
	      is  left-justified  in  16  bits	(i.e.,	the range of values is

	      A pointer to picture comment data, if present.   Use  the	 func‐
	      tions rle_putcom(3), rle_getcom(3), and rle_delcom(3) to manipu‐
	      late this field.

	      The standard I/O FILE  pointer  for  the	file  containing  this

       bits   A	 bitmap	 that  selects	the channels that are actually written
	      to/read from the file.  The macros below are used to modify this

       The  macro  RLE_BIT  will  retrieve the state of one of the bits in the
       bits map.  RLE_SET_BIT, and RLE_CLR_BIT set and clear bits in the  bits
       map.    The   predefined	 symbols  RLE_RED,  RLE_GREEN,	RLE_BLUE,  and
       RLE_ALPHA, or an integer value from -1 to 254  may  be  used  in	 these

       librle(3), RLE(5).

       Spencer W. Thomas, Todd Fuqua

4th Berkeley Distribution	    2/2/87			    RLE_HDR(3)

List of man pages available for DigitalUNIX

Copyright (c) for man pages and the logo by the respective OS vendor.

For those who want to learn more, the polarhome community provides shell access and support.

[legal] [privacy] [GNU] [policy] [cookies] [netiquette] [sponsors] [FAQ]
Polarhome, production since 1999.
Member of Polarhome portal.
Based on Fawad Halim's script.
Vote for polarhome
Free Shell Accounts :: the biggest list on the net