XcmsQueryColor(3X11) XLIB FUNCTIONS XcmsQueryColor(3X11)
NAME
XcmsQueryColor, XcmsQueryColors, XcmsLookupColor - obtain
color values
SYNTAX
Status XcmsQueryColor(Display *display, Colormap colormap,
XcmsColor *color_in_out, XcmsColorFormat
result_format);
Status XcmsQueryColors(Display *display, Colormap colormap,
XcmsColor colors_in_out[], unsigned int ncolors,
XcmsColorFormat result_format);
Status XcmsLookupColor(Display *display, Colormap colormap,
char *color_string, XcmsColor *color_exact_return,
XcmsColor *color_screen_return, XcmsColorFormat
result_format);
ARGUMENTS
display Specifies the connection to the X server.
colormap Specifies the colormap.
color_exact_return
Returns the color specification parsed from the
color string or parsed from the corresponding
string found in a color-name database.
color_in_out
Specifies the pixel member that indicates the
color cell to query. The color specification
stored for the color cell is returned in this
XcmsColor structure.
color_screen_return
Returns the color that can be reproduced on the
screen.
color_string
Specifies the color string.
result_format
Specifies the color format for the returned color
specifications (color_screen_return and
color_exact_return arguments). If the format is
XcmsUndefinedFormat and the color string contains
a numerical color specification, the specification
is returned in the format used in that numerical
color specification. If the format is XcmsUnde-
finedFormat and the color string contains a color
name, the specification is returned in the format
used to store the color in the database.
XFree86 Version 4.5.0 1
XcmsQueryColor(3X11) XLIB FUNCTIONS XcmsQueryColor(3X11)
ncolors Specifies the number of XcmsColor structures in
the color-specification array.
DESCRIPTION
The XcmsQueryColor function obtains the RGB value for the
pixel value in the pixel member of the specified XcmsColor
structure and then converts the value to the target format
as specified by the result_format argument. If the pixel is
not a valid index in the specified colormap, a BadValue
error results. The XcmsQueryColors function obtains the RGB
values for pixel values in the pixel members of XcmsColor
structures and then converts the values to the target format
as specified by the result_format argument. If a pixel is
not a valid index into the specified colormap, a BadValue
error results. If more than one pixel is in error, the one
that gets reported is arbitrary.
XcmsQueryColor and XcmsQueryColors can generate BadColor and
BadValue errors.
The XcmsLookupColor function looks up the string name of a
color with respect to the screen associated with the speci-
fied colormap. It returns both the exact color values and
the closest values provided by the screen with respect to
the visual type of the specified colormap. The values are
returned in the format specified by result_format. 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. XcmsLookupColor returns XcmsSuc-
cess or XcmsSuccessWithCompression if the name is resolved;
otherwise, it returns XcmsFailure. If XcmsSuccessWith-
Compression is returned, the color specification returned in
color_screen_return is the result of gamut compression.
DIAGNOSTICS
BadColor A value for a Colormap argument does not name a
defined Colormap.
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 gen-
erate this error.
SEE ALSO
XcmsAllocColor(3X11), XcmsStoreColor(3X11),
XQueryColor(3X11)
Xlib - C Language X Interface
XFree86 Version 4.5.0 2