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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, char
	      *color_name, XColor *screen_def_return, XColor *exact_def_re-
	      turn);

       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	1.6.5			XAllocColor(3)

NAME | SYNTAX | DESCRIPTION | DIAGNOSTICS | SEE ALSO

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