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.
