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
XcmsUndefinedFormat and the color string contains a color
name, the specification is returned in the format used to
store the color in the database.
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 specified 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 XcmsSuccess or
XcmsSuccessWithCompression if the name is resolved; otherwise, it
returns XcmsFailure. If XcmsSuccessWithCompression 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
generate this error.
SEE ALSO
XcmsAllocColor(3), XcmsStoreColor(3), XQueryColor(3)
Xlib - C Language X Interface