XQueryColor(3X11)             SDK X11 R4.11MU05            XQueryColor(3X11)


NAME
       XQueryColor, XQueryColors, XLookupColor, XParseColor - obtain color
       values

SYNTAX
       XQueryColor(display, colormap, definout)
             Display *display;
             Colormap colormap;
             XColor *definout;

       XQueryColors(display, colormap, defsinout, ncolors)
             Display *display;
             Colormap colormap;
             XColor defsinout[];
             int ncolors;

       Status XLookupColor(display, colormap, colorname, exactdefreturn,
       screendefreturn)
             Display *display;
             Colormap colormap;
             char *colorname;
             XColor *exactdefreturn, *screendefreturn;

       Status XParseColor(display, colormap, spec, exactdefreturn)
               Display *display;
               Colormap colormap;
               char *spec;
               XColor *exactdefreturn;

ARGUMENTS
       colormap  Specifies the colormap.

       colorname
                 Specifies the color name string (for example, red) whose
                 color definition structure you want returned.

       definout
                 Specifies and returns the RGB values for the pixel
                 specified in the structure.

       defsinout
                 Specifies and returns an array of color definition
                 structures for the pixel specified in the structure.

       display   Specifies the connection to the X server.

       exactdefreturn
                 Returns the exact RGB values.

       ncolors   Specifies the number of XColor structures in the color
                 definition array.

       screendefreturn
                 Returns the closest RGB values provided by the hardware.

       spec      Specifies the color name string; case is ignored.

       exactdefreturn
                 Returns the exact color value for later use and sets the
                 DoRed, DoGreen, and DoBlue flags.

DESCRIPTION
       The XQueryColor function returns the current RGB value for the pixel
       in the XColor structure and sets the DoRed, DoGreen, and DoBlue
       flags.  The XQueryColors function returns the RGB value for each
       pixel in each XColor structure, and sets the DoRed, DoGreen, and
       DoBlue flags in each structure.


       XQueryColor and XQueryColors can generate BadColor and BadValue
       errors.

       The XLookupColor 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.  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.  XLookupColor returns nonzero if the name
       is resolved, otherwise it returns zero.

       The XParseColor function looks up the string name of a color with
       respect to the screen associated with the specified colormap.  It
       returns the exact color value.  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.  XParseColor returns
       nonzero if the name is resolved, otherwise it returns zero.

       XLookupColor and XParseColor can generate BadColor error.

COLOR NAMES
       An RGB Device specification is identified by the prefix "rgb:" and
       conforms to the following syntax:

       rgb:<red>/<green>/<blue>

           <red>, <green>, <blue> := h | hh | hhh | hhhh
           h := single hexadecimal digits (case insignificant)

       Note that h indicates the value scaled in 4 bits, hh the value scaled
       in 8 bits, hhh the value scaled in 12 bits, and hhhh the value scaled
       in 16 bits, respectively.

       For backward compatibility, an older syntax for RGB Device is
       supported, but its continued use is not encouraged.  The syntax is an
       initial sharp sign character followed by a numeric specification, in
       one of the following formats:

       #RGB                (4 bits each)
       #RRGGBB             (8 bits each)
       #RRRGGGBBB          (12 bits each)
       #RRRRGGGGBBBB       (16 bits each)

       The R, G, and B represent single hexadecimal digits.  When fewer than
       16 bits each are specified, they represent the most-significant bits
       of the value (unlike the "rgb:" syntax, in which values are scaled).
       For example, #3a7 is the same as #3000a0007000.

       An RGB intensity specification is identified by the prefix "rgbi:"
       and conforms to the following syntax:

       rgbi:<red>/<green>/<blue>

       Note that red, green, and blue are floating point values between 0.0
       and 1.0, inclusive.  The input format for these values is an optional
       sign, a string of numbers possibly containing a decimal point, and an
       optional exponent field containing an E or e followed by a possibly
       signed integer string.

       The standard device-independent string specifications have the
       following syntax:

       CIEXYZ:<X>/<Y>/<Z>
       CIEuvY:<u>/<v>/<Y>
       CIExyY:<x>/<y>/<Y>
       CIELab:<L>/<a>/<b>
       CIELuv:<L>/<u>/<v>
       TekHVC:<H>/<V>/<C>

       All of the values (C, H, V, X, Y, Z, a, b, u, v, y, x) are floating
       point values.  The syntax for these values is an optional '+' or '-'
       sign, a string of digits possibly containing a decimal point, and an
       optional exponent field consisting of an 'E' or 'e' followed by an
       optional '+' or '-' followed by a string of digits.

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
       XAllocColor(3X11), XCreateColormap(3X11), XStoreColors(3X11)
       Xlib - C Language X Interface


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