XCreateColormap(3X11) MIT X11R4 XCreateColormap(3X11)
Name
XCreateColormap, XCopyColormapAndFree, XFreeColormap, XSetWindowColormap, XColor - create, copy, or destroy colormaps and color structure
Syntax
Colormap XCreateColormap(display, w, visual, alloc)
Display *display;
Window w;
Visual *visual;
int alloc;
Colormap XCopyColormapAndFree(display, colormap)
Display *display;
Colormap colormap;
XFreeColormap(display, colormap)
Display *display;
Colormap colormap;
XSetWindowColormap(display, w, colormap)
Display *display;
Window w;
Colormap colormap;
Arguments
alloc Specifies the colormap entries to be allocated. You can pass or
colormap Specifies the colormap that you want to create, copy, set, or destroy.
display Specifies the connection to the X server.
visual Specifies a pointer to a visual type supported on the screen. If the visual type is not one supported by the screen, a error
results.
w Specifies the window for which you want to create or set a colormap .
Description
The function creates a colormap of the specified visual type for the screen on which the specified window resides and returns the colormap
ID associated with it. Note that the specified window is only used to determine the screen.
The initial values of the colormap entries are undefined for the visual classes and For and the entries have defined values, but those val-
ues are specific to the visual and are not defined by X. For and alloc must be or a error results. For the other visual classes, if alloc
is the colormap initially has no allocated entries, and clients can allocate them.
If alloc is the entire colormap is allocated writable. The initial values of all allocated entries are undefined. For and the effect is
as if an call returned all pixel values from zero to N - 1, where N is the colormap entries value in the specified visual. For the effect
is as if an call returned a pixel value of zero and red_mask, green_mask, and blue_mask values containing the same bits as the correspond-
ing masks in the specified visual. However, in all cases, none of these entries can be freed by using
can generate and errors.
The function creates a colormap of the same visual type and for the same screen as the specified colormap and returns the new colormap ID.
It also moves all of the client's existing allocation from the specified colormap to the new colormap with their color values intact and
their read-only or writable characteristics intact and frees those entries in the specified colormap. Color values in other entries in the
new colormap are undefined. If the specified colormap was created by the client with alloc set to the new colormap is also created with
all color values for all entries are copied from the specified colormap, and then all entries in the specified colormap are freed. If the
specified colormap was not created by the client with the allocations to be moved are all those pixels and planes that have been allocated
by the client using or and that have not been freed since they were allocated.
can generate and errors.
The function deletes the association between the colormap resource ID and the colormap and frees the colormap storage. However, this func-
tion has no effect on the default colormap for a screen. If the specified colormap is an installed map for a screen, it is uninstalled
(see If the specified colormap is defined as the colormap for a window (by or changes the colormap associated with the window to and gener-
ates a event. X does not define the colors displayed for a window with a colormap of
can generate a error.
The function sets the specified colormap of the specified window. The colormap must have the same visual type as the window, or a error
results.
can generate and errors.
Structures
The structure contains:
typedef struct {
unsigned long pixel; /* pixel value */
unsigned short red, green, blue; /* rgb values */
char flags; /* DoRed, DoGreen,
DoBlue */
char pad;
} XColor;
The red, green, and blue values are scaled between 0 and 65535. On full in a color is a value of 65535 independent of the number of bits
actually used in the display hardware. Half brightness in a color is a value of 32767, and off is 0. This representation gives uniform
results for color values across different screens. In some functions, the flags member controls which of the red, green, and blue members
is used and can be one or more of and
Diagnostics
The server failed to allocate the requested resource or server memory.
A value for a Colormap argument does not name a defined Colormap.
An window is used as a Drawable.
Some argument or pair of arguments has the correct type and range but fails
to match in some other way required by the request.
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.
A value for a Window argument does not name a defined Window.
See Also
XAllocColor(3X11), XChangeWindowAtrributes(3X11), XCreateWindow(3X11), XQueryColor(3X11), XStoreColors(3X11)
X Window System: The Complete Reference, Second Edition, Robert W. Scheifler and James Gettys
XCreateColormap(3X11)