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, _Xconst 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 stringor 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 thisXcmsColorstructure.

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 colorspecifications (color_screen_return and color_exact_return arguments).If the format isXcmsUndefinedFormatand the color string contains anumerical color specification,the specification is returned in the format used in that numericalcolor specification.If the format isXcmsUndefinedFormatand the color string contains a color name,the specification is returned in the format usedto store the color in the database.

ncolors

Specifies the number ofXcmsColorstructures in the color-specification array.

DESCRIPTION¶

TheXcmsQueryColorfunction obtains the RGB valuefor the pixel value in the pixel member of the specifiedXcmsColorstructure and thenconverts the value to the target format asspecified by the result_format argument.If the pixel is not a valid index in the specified colormap, aBadValueerror results.TheXcmsQueryColorsfunction obtains the RGB valuesfor pixel values in the pixel members ofXcmsColorstructures and thenconverts the values to the target format asspecified by the result_format argument.If a pixel is not a valid index into the specified colormap, aBadValueerror results.If more than one pixel is in error,the one that gets reported is arbitrary.

XcmsQueryColorandXcmsQueryColorscan generateBadColorandBadValueerrors.

TheXcmsLookupColorfunction looks up the string name of a color with respect to the screenassociated with the specified colormap.It returns both the exact color values andthe closest values provided by the screenwith 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.XcmsLookupColorreturnsXcmsSuccessorXcmsSuccessWithCompressionif the name is resolved; otherwise, it returnsXcmsFailure.IfXcmsSuccessWithCompressionis returned, the color specification returned incolor_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 definedby the argument's type is accepted.Any argument defined as a set ofalternatives can generate this error.

SEE ALSO¶

XcmsAllocColor(3),XcmsStoreColor(3),XQueryColor(3)
Xlib - C Language X Interface