ultrix man page for xsetrgbcolormaps

XAllocStandardColormap(3X11)					     MIT X11R4					      XAllocStandardColormap(3X11)

Name
       XAllocStandardColormap, XSetRGBColormaps, XGetRGBColormaps, XStandardColormap - allocate, set, or read a standard colormap structure

Syntax
       XStandardColormap *XAllocStandardColormap()

       void XSetRGBColormaps(display, w, std_colormap, count, property)
	  Display *display;
	  Window w;
	  XStandardColormap *std_colormap;
	  int count;
	  Atom property;

       Status XGetRGBColormaps(display, w, std_colormap_return, count_return, property)
	  Display *display;
	  Window w;
	  XStandardColormap **std_colormap_return;
	  int *count_return;
	  Atom property;

Arguments
       display	 Specifies the connection to the X server.

       count	 Specifies the number of colormaps.

       count_return
		 Returns the number of colormaps.

       property  Specifies the property name.

       std_colormap
		 Specifies the structure to be used.

       std_colormap_return
		 Returns the structure.

Description
       The function allocates and returns a pointer to a structure.  Note that all fields in the structure are initially set to zero.  If insuffi-
       cient memory is available, returns NULL.  To free the memory allocated to this structure, use

       The function replaces the RGB colormap definition in the specified property on the named window.  If the property does not already exist,
       sets the RGB colormap definition in the specified property on the named window.	The property is stored with a type of RGB_COLOR_MAP and a
       format of 32.  Note that it is the caller's responsibility to honor the ICCCM restriction that only RGB_DEFAULT_MAP contain more than one
       definition.

       can generate and errors.

       The function returns the RGB colormap definitions stored in the specified property on the named window.	If the property exists, is of type
       RGB_COLOR_MAP, is of format 32, and is long enough to contain a colormap definition (if the visualid is not present, assumes the default
       visual for the screen on which the window is located; if the killid is not present, which indicates that the resources cannot be released,
       is assumed), allocates and fills in space for the returned colormaps, and returns a non-zero status.  Otherwise, none of the fields are
       set, and returns a zero status.	Note that it is the caller's responsibility to honor the ICCCM restriction that only RGB_DEFAULT_MAP con-
       tain more than one definition.

       can generate and errors.

Structures
       The structure contains:

       /* Hints */

       #define	 ReleaseByFreeingColormap    ( (XID) 1L)

       /* Values */
       typedef struct {
	    Colormap colormap;
	    unsigned long red_max;
	    unsigned long red_mult;
	    unsigned long green_max;
	    unsigned long green_mult;
	    unsigned long blue_max;
	    unsigned long blue_mult;
	    unsigned long base_pixel;
	    VisualID visualid;
	    XID killid;
       } XStandardColormap;

       The colormap member is the colormap created by the function.  The red_max, green_max, and blue_max members give the maximum red, green, and
       blue values, respectively.  Each color coefficient ranges from zero to its max, inclusive.  For example, a common colormap allocation is
       3/3/2 (3 planes for red, 3 planes for green, and 2 planes for blue).  This colormap would have red_max = 7, green_max = 7, and blue_max =
       3.  An alternate allocation that uses only 216 colors is red_max = 5, green_max = 5, and blue_max = 5.

       The red_mult, green_mult, and blue_mult members give the scale factors used to compose a full pixel value.  (See the discussion of the
       base_pixel members for further information.)  For a 3/3/2 allocation, red_mult might be 32, green_mult might be 4, and blue_mult might be
       1.  For a 6-colors-each allocation, red_mult might be 36, green_mult might be 6, and blue_mult might be 1.

       The base_pixel member gives the base pixel value used to compose a full pixel value.  Usually, the base_pixel is obtained from a call to
       the function.  Given integer red, green, and blue coefficients in their appropriate ranges, one then can compute a corresponding pixel
       value by using the following expression:

       r * red_mult + g * green_mult + b * blue_mult + base_pixel

       For colormaps, only the colormap, red_max, red_mult, and base_pixel members are defined.  The other members are ignored.

       The visualid member gives the ID number of the visual from which the colormap was created.  The killid member gives a resource ID that
       indicates whether the cells held by this standard colormap are to be released by freeing the colormap ID or by calling the function on the
       indicated resource.  (Note that this method is necessary for allocating out of an existing colormap).

       To compute a pixel value, use the following expression:

       gray * red_mult + base_pixel

       The properties containing the information have the type RGB_COLOR_MAP.

Diagnostics
       The server failed to allocate the requested resource or server memory.

       A value for an Atom argument does not name a defined Atom.

       A value for a Window argument does not name a defined Window.

See Also
       XAllocColor(3X11), XCreateColormap(3X11), XFree(3X11), XSetCloseDownMode(3X11)
       X Window System: The Complete Reference, Second Edition, Robert W. Scheifler and James Gettys

														      XAllocStandardColormap(3X11)