Linux Manual Pages

Free Software * Books

Source Code

Free Media

Linux

XcmsQueryColor

HOME

XcmsQueryColor

NAME
SYNTAX
ARGUMENTS
DESCRIPTION
DIAGNOSTICS
SEE ALSO

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.

Opportunity

Personal Opportunity - Free software gives you access to billions of dollars of software at no cost. Use this software for your business, personal use or to develop a profitable skill. Access to source code provides access to a level of capabilities/information that companies protect though copyrights. Open source is a core component of the Internet and it is available to you. Leverage the billions of dollars in resources and capabilities to build a career, establish a business or change the world. The potential is endless for those who understand the opportunity.

Business Opportunity - Goldman Sachs, IBM and countless large corporations are leveraging open source to reduce costs, develop products and increase their bottom lines. Learn what these companies know about open source and how open source can give you the advantage.

Free Software

Free Software provides computer programs and capabilities at no cost but more importantly, it provides the freedom to run, edit, contribute to, and share the software. The importance of free software is a matter of access, not price. Software at no cost is a benefit but ownership rights to the software and source code is far more significant.

Free Office Software - The Libre Office suite provides top desktop productivity tools for free. This includes, a word processor, spreadsheet, presentation engine, drawing and flowcharting, database and math applications. Libre Office is available for Linux or Windows.

Free Books

The Free Books Library is a collection of thousands of the most popular public domain books in an online readable format. The collection includes great classical literature and more recent works where the U.S. copyright has expired. These books are yours to read and use without restrictions.

Source Code - Want to change a program or know how it works? Open Source provides the source code for its programs so that anyone can use, modify or learn how to write those programs themselves. Visit the GNU source code repositories to download the source.

Education

Study at Harvard, Stanford or MIT - Open edX provides free online courses from Harvard, MIT, Columbia, UC Berkeley and other top Universities. Hundreds of courses for almost all major subjects and course levels. Open edx also offers some paid courses and selected certifications.

Linux Manual Pages - A man or manual page is a form of software documentation found on Linux/Unix operating systems. Topics covered include computer programs (including library and system calls), formal standards and conventions, and even abstract concepts.