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XAllocColor(3)			XLIB FUNCTIONS			XAllocColor(3)

NAME
       XAllocColor,   XAllocNamedColor,	 XAllocColorCells,  XAllocColorPlanes,
       XFreeColors - allocate and free colors

SYNTAX
       Status  XAllocColor(Display   *display,	 Colormap   colormap,	XColor
	      *screen_in_out);

       Status  XAllocNamedColor(Display	 *display,  Colormap colormap, _Xconst
	      char  *color_name,  XColor   *screen_def_return,	 XColor	  *ex-
	      act_def_return);

       Status  XAllocColorCells(Display	*display, Colormap colormap, Bool con-
	      tig, unsigned long plane_masks_return[], unsigned	 int  nplanes,
	      unsigned long pixels_return[], unsigned int npixels);

       Status XAllocColorPlanes(Display	*display, Colormap colormap, Bool con-
	      tig, unsigned long pixels_return[], int ncolors, int nreds,  int
	      ngreens,	int nblues, unsigned long *rmask_return, unsigned long
	      *gmask_return, unsigned long *bmask_return);

       int XFreeColors(Display *display, Colormap colormap, unsigned long pix-
	      els[], int npixels, unsigned long	planes);

       color_name
		 Specifies  the	 color	name  string  (for example, red) whose
		 color definition structure you	want returned.

       colormap	 Specifies the colormap.

       contig	 Specifies a Boolean value that	indicates whether  the	planes
		 must be contiguous.

       display	 Specifies the connection to the X server.

       exact_def_return
		 Returns the exact RGB values.

       ncolors	 Specifies  the	number of pixel	values that are	to be returned
		 in the	pixels_return array.

       npixels	 Specifies the number of pixels.

       nplanes	 Specifies the number of plane masks that are to  be  returned
		 in the	plane masks array.

       nreds
       ngreens
       nblues
		 Specify the number of red, green, and blue planes.  The value
		 you pass must be nonnegative.

       pixels	 Specifies an array of pixel values.

       pixels_return
		 Returns an array of pixel values.

       plane_mask_return
		 Returns an array of plane masks.

       planes	 Specifies the planes you want to free.

       rmask_return
       gmask_return
       bmask_return
		 Return	bit masks for the red, green, and blue planes.

       screen_def_return
		 Returns the closest RGB values	provided by the	hardware.

       screen_in_out
		 Specifies and returns the values actually used	 in  the  col-
		 ormap.

DESCRIPTION
       The  XAllocColor	 function  allocates a read-only colormap entry	corre-
       sponding	to the closest RGB value supported by the  hardware.   XAlloc-
       Color returns the pixel value of	the color closest to the specified RGB
       elements	supported by the hardware and returns the RGB  value  actually
       used.  The corresponding	colormap cell is read-only.  In	addition, XAl-
       locColor	returns	nonzero	if it succeeded	or zero	if it failed.	Multi-
       ple  clients  that request the same effective RGB value can be assigned
       the same	read-only entry, thus allowing entries to be shared.  When the
       last  client deallocates	a shared cell, it is deallocated.  XAllocColor
       does not	use or affect the flags	in the XColor structure.

       XAllocColor can generate	a BadColor error.

       The XAllocNamedColor function looks up the named	color with respect  to
       the  screen that	is associated with the specified colormap.  It returns
       both the	exact database definition and the closest color	 supported  by
       the screen.  The	allocated color	cell is	read-only.  The	pixel value is
       returned	in screen_def_return.  If the color name is not	 in  the  Host
       Portable	 Character  Encoding,  the result is implementation-dependent.
       Use of uppercase	or lowercase does not  matter.	 If  screen_def_return
       and  exact_def_return point to the same structure, the pixel field will
       be set correctly, but the color values are undefined.  XAllocNamedColor
       returns nonzero if a cell is allocated; otherwise, it returns zero.

       XAllocNamedColor	can generate a BadColor	error.

       delim  %%  The  XAllocColorCells	 function  allocates  read/write color
       cells.  The number of colors must be positive and the number of	planes
       nonnegative,  or	 a BadValue error results.  If ncolors and nplanes are
       requested, then ncolors pixels and nplane plane masks are returned.  No
       mask  will have any bits	set to 1 in common with	any other mask or with
       any of the pixels.  By ORing together each  pixel  with	zero  or  more
       masks,  ncolors * %2 sup	nplanes% distinct pixels can be	produced.  All
       of these	are allocated writable by the request.	For GrayScale or Pseu-
       doColor,	each mask has exactly one bit set to 1.	 For DirectColor, each
       has exactly three bits set to 1.	 If contig is True and	if  all	 masks
       are  ORed  together,  a	single contiguous set of bits set to 1 will be
       formed for GrayScale or PseudoColor and three contiguous	sets  of  bits
       set  to	1  (one	 within	each pixel subfield) for DirectColor.  The RGB
       values of the allocated entries are  undefined.	 XAllocColorCells  re-
       turns nonzero if	it succeeded or	zero if	it failed.

       XAllocColorCells	can generate BadColor and BadValue errors.

       delim  %%  The  specified ncolors must be positive; and nreds, ngreens,
       and nblues must be nonnegative, or a BadValue error results.  If	 ncol-
       ors colors, nreds reds, ngreens greens, and nblues blues	are requested,
       ncolors pixels are returned; and	the masks  have	 nreds,	 ngreens,  and
       nblues  bits set	to 1, respectively.  If	contig is True,	each mask will
       have a contiguous set of	bits set to 1.	No mask	will have any bits set
       to  1 in	common with any	other mask or with any of the pixels.  For Di-
       rectColor, each mask will lie within the	corresponding pixel  subfield.
       By  ORing together subsets of masks with	each pixel value, ncolors * %2
       sup (nreds+ngreens+nblues)% distinct pixel values can be	produced.  All
       of these	are allocated by the request.  However,	in the colormap, there
       are only	ncolors	* %2 sup nreds%	independent red	entries, ncolors *  %2
       sup  ngreens%  independent  green entries, and ncolors *	%2 sup nblues%
       independent blue	entries.  This is true even for	PseudoColor.  When the
       colormap	entry of a pixel value is changed (using XStoreColors, XStore-
       Color, or XStoreNamedColor), the	pixel is decomposed according  to  the
       masks,  and the corresponding independent entries are updated.  XAlloc-
       ColorPlanes returns nonzero if it succeeded or zero if it failed.

       XAllocColorPlanes can generate BadColor and BadValue errors.

       The XFreeColors function	frees the cells	represented  by	 pixels	 whose
       values  are  in	the pixels array.  The planes argument should not have
       any bits	set to 1 in common with	any of the pixels.   The  set  of  all
       pixels  is  produced  by	 ORing together	subsets	of the planes argument
       with the	pixels.	 The request frees all of these	pixels that were allo-
       cated  by the client (using XAllocColor,	XAllocNamedColor, XAllocColor-
       Cells, and XAllocColorPlanes).  Note that freeing an  individual	 pixel
       obtained	 from XAllocColorPlanes	may not	actually allow it to be	reused
       until all of its	related	pixels are also	freed.	Similarly, a read-only
       entry is	not actually freed until it has	been freed by all clients, and
       if a client allocates the same read-only	entry multiple times, it  must
       free the	entry that many	times before the entry is actually freed.

       All  specified  pixels that are allocated by the	client in the colormap
       are freed, even if one or more pixels produce an	error.	If a specified
       pixel is	not a valid index into the colormap, a BadValue	error results.
       If a specified pixel is not allocated by	the client (that is, is	 unal-
       located	or is only allocated by	another	client)	or if the colormap was
       created with all	entries	writable (by passing AllocAll  to  XCreateCol-
       ormap), a BadAccess error results.  If more than	one pixel is in	error,
       the one that gets reported is arbitrary.

       XFreeColors can generate	BadAccess, BadColor, and BadValue errors.

DIAGNOSTICS
       BadAccess A client attempted to free a color map	entry that it did  not
		 already allocate.

       BadAccess A client attempted to store into a read-only color map	entry.

       BadColor	 A  value for a	Colormap argument does not name	a defined Col-
		 ormap.

       BadValue	 Some numeric value falls outside the range of values accepted
		 by  the request.  Unless a specific range is specified	for an
		 argument, the full range defined by the  argument's  type  is
		 accepted.   Any argument defined as a set of alternatives can
		 generate this error.

SEE ALSO
       XCreateColormap(3), XQueryColor(3), XStoreColors(3)
       Xlib - C	Language X Interface

X Version 11			 libX11	1.6.12			XAllocColor(3)

NAME | SYNTAX | DESCRIPTION | DIAGNOSTICS | SEE ALSO

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