+<!--
+ ****************************************************************************
+ * Copyright (c) 1998-2016,2017 Free Software Foundation, Inc. *
+ * *
+ * Permission is hereby granted, free of charge, to any person obtaining a *
+ * copy of this software and associated documentation files (the *
+ * "Software"), to deal in the Software without restriction, including *
+ * without limitation the rights to use, copy, modify, merge, publish, *
+ * distribute, distribute with modifications, sublicense, and/or sell *
+ * copies of the Software, and to permit persons to whom the Software is *
+ * furnished to do so, subject to the following conditions: *
+ * *
+ * The above copyright notice and this permission notice shall be included *
+ * in all copies or substantial portions of the Software. *
+ * *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS *
+ * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF *
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. *
+ * IN NO EVENT SHALL THE ABOVE COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, *
+ * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR *
+ * OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR *
+ * THE USE OR OTHER DEALINGS IN THE SOFTWARE. *
+ * *
+ * Except as contained in this notice, the name(s) of the above copyright *
+ * holders shall not be used in advertising or otherwise to promote the *
+ * sale, use or other dealings in this Software without prior written *
+ * authorization. *
+ ****************************************************************************
+ * @Id: curs_color.3x,v 1.53 2017/11/20 01:03:45 tom Exp @
+-->
+<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01//EN">
<HTML>
+<HEAD>
+<meta http-equiv="Content-Type" content="text/html; charset=us-ascii">
+<meta name="generator" content="Manpage converted by man2html - see https://invisible-island.net/scripts/readme.html#others_scripts">
+<TITLE>curs_color 3x</TITLE>
+<link rev=made href="mailto:bug-ncurses@gnu.org">
+<meta http-equiv="Content-Type" content="text/html; charset=iso-8859-1">
+</HEAD>
<BODY>
+<H1 class="no-header">curs_color 3x</H1>
<PRE>
-<!-- Manpage converted by man2html 3.0.1 -->
+<STRONG><A HREF="curs_color.3x.html">curs_color(3x)</A></STRONG> <STRONG><A HREF="curs_color.3x.html">curs_color(3x)</A></STRONG>
-</PRE>
-<H2>NAME</H2><PRE>
- <B>start_color</B>, <B>init_pair</B>, <B>init_color</B>, <B>has_colors</B>,
- <B>can_change_color</B>, <B>color_content</B>, <B>pair_content</B>, <B>COLOR_PAIR</B>
- - <B>curses</B> color manipulation routines
-</PRE>
-<H2>SYNOPSIS</H2><PRE>
- <B>#</B> <B>include</B> <B><curses.h></B>
- <B>int</B> <B>start_color(void);</B>
- <B>int</B> <B>init_pair(short</B> <B>pair,</B> <B>short</B> <B>f,</B> <B>short</B> <B>b);</B>
- <B>int</B> <B>init_color(short</B> <B>color,</B> <B>short</B> <B>r,</B> <B>short</B> <B>g,</B> <B>short</B> <B>b);</B>
- <B>bool</B> <B>has_colors(void);</B>
- <B>bool</B> <B>can_change_color(void);</B>
- <B>int</B> <B>color_content(short</B> <B>color,</B> <B>short</B> <B>*r,</B> <B>short</B> <B>*g,</B> <B>short</B>
- <B>*b);</B>
- <B>int</B> <B>pair_content(short</B> <B>pair,</B> <B>short</B> <B>*f,</B> <B>short</B> <B>*b);</B>
+</PRE><H2><a name="h2-NAME">NAME</a></H2><PRE>
+ <STRONG>start_color</STRONG>, <STRONG>has_colors</STRONG>, <STRONG>can_change_color</STRONG>, <STRONG>init_pair</STRONG>, <STRONG>init_color</STRONG>,
+ <STRONG>color_content</STRONG>, <STRONG>pair_content</STRONG>, <STRONG>reset_color_pairs</STRONG>, <STRONG>COLOR_PAIR</STRONG>, <STRONG>PAIR_NUMBER</STRONG>
+ - <STRONG>curses</STRONG> color manipulation routines
-</PRE>
-<H2>DESCRIPTION</H2><PRE>
- <B>Overview</B>
- <B>curses</B> support color attributes on terminals with that
- capability. To use these routines <B>start_color</B> must be
- called, usually right after <B>initscr</B>. Colors are always
- used in pairs (referred to as color-pairs). A color-pair
- consists of a foreground color (for characters) and a
- background color (for the blank field on which the charac-
- ters are displayed). A programmer initializes a color-
- pair with the routine <B>init_pair</B>. After it has been ini-
- tialized, <B>COLOR_PAIR</B>(<I>n</I>), a macro defined in <B><curses.h></B>,
- can be used as a new video attribute.
-
- If a terminal is capable of redefining colors, the pro-
- grammer can use the routine <B>init_color</B> to change the defi-
- nition of a color. The routines <B>has_colors</B> and
- <B>can_change_color</B> return <B>TRUE</B> or <B>FALSE</B>, depending on
- whether the terminal has color capabilities and whether
- the programmer can change the colors. The routine
- <B>color_content</B> allows a programmer to extract the amounts
- of red, green, and blue components in an initialized
- color. The routine <B>pair_content</B> allows a programmer to
+
+</PRE><H2><a name="h2-SYNOPSIS">SYNOPSIS</a></H2><PRE>
+ <STRONG>#include</STRONG> <STRONG><curses.h></STRONG>
+
+ <STRONG>int</STRONG> <STRONG>start_color(void);</STRONG>
+
+ <STRONG>bool</STRONG> <STRONG>has_colors(void);</STRONG>
+ <STRONG>bool</STRONG> <STRONG>can_change_color(void);</STRONG>
+
+ <STRONG>int</STRONG> <STRONG>init_pair(short</STRONG> <STRONG>pair,</STRONG> <STRONG>short</STRONG> <STRONG>f,</STRONG> <STRONG>short</STRONG> <STRONG>b);</STRONG>
+ <STRONG>int</STRONG> <STRONG>init_color(short</STRONG> <STRONG>color,</STRONG> <STRONG>short</STRONG> <STRONG>r,</STRONG> <STRONG>short</STRONG> <STRONG>g,</STRONG> <STRONG>short</STRONG> <STRONG>b);</STRONG>
+ /* extensions */
+ <STRONG>int</STRONG> <STRONG>init_extended_pair(int</STRONG> <STRONG>pair,</STRONG> <STRONG>int</STRONG> <STRONG>f,</STRONG> <STRONG>int</STRONG> <STRONG>b);</STRONG>
+ <STRONG>int</STRONG> <STRONG>init_extended_color(int</STRONG> <STRONG>color,</STRONG> <STRONG>int</STRONG> <STRONG>r,</STRONG> <STRONG>int</STRONG> <STRONG>g,</STRONG> <STRONG>int</STRONG> <STRONG>b);</STRONG>
+
+ <STRONG>int</STRONG> <STRONG>color_content(short</STRONG> <STRONG>color,</STRONG> <STRONG>short</STRONG> <STRONG>*r,</STRONG> <STRONG>short</STRONG> <STRONG>*g,</STRONG> <STRONG>short</STRONG> <STRONG>*b);</STRONG>
+ <STRONG>int</STRONG> <STRONG>pair_content(short</STRONG> <STRONG>pair,</STRONG> <STRONG>short</STRONG> <STRONG>*f,</STRONG> <STRONG>short</STRONG> <STRONG>*b);</STRONG>
+ /* extensions */
+ <STRONG>int</STRONG> <STRONG>extended_color_content(int</STRONG> <STRONG>color,</STRONG> <STRONG>int</STRONG> <STRONG>*r,</STRONG> <STRONG>int</STRONG> <STRONG>*g,</STRONG> <STRONG>int</STRONG> <STRONG>*b);</STRONG>
+ <STRONG>int</STRONG> <STRONG>extended_pair_content(int</STRONG> <STRONG>pair,</STRONG> <STRONG>int</STRONG> <STRONG>*f,</STRONG> <STRONG>int</STRONG> <STRONG>*b);</STRONG>
+
+ /* extensions */
+ <STRONG>void</STRONG> <STRONG>reset_color_pairs(void);</STRONG>
+
+ <STRONG>int</STRONG> <STRONG>COLOR_PAIR(int</STRONG> <STRONG>n);</STRONG>
+ <STRONG>PAIR_NUMBER(</STRONG><EM>attrs</EM><STRONG>);</STRONG>
+
+
+</PRE><H2><a name="h2-DESCRIPTION">DESCRIPTION</a></H2><PRE>
+
+</PRE><H3><a name="h3-Overview">Overview</a></H3><PRE>
+ <STRONG>curses</STRONG> supports color attributes on terminals with that capability. To
+ use these routines <STRONG>start_color</STRONG> must be called, usually right after
+ <STRONG>initscr</STRONG>. Colors are always used in pairs (referred to as color-pairs).
+ A color-pair consists of a foreground color (for characters) and a
+ background color (for the blank field on which the characters are dis-
+ played). A programmer initializes a color-pair with the routine
+ <STRONG>init_pair</STRONG>. After it has been initialized, <STRONG>COLOR_PAIR</STRONG>(<EM>n</EM>) can be used to
+ convert the pair to a video attribute.
+
+ If a terminal is capable of redefining colors, the programmer can use
+ the routine <STRONG>init_color</STRONG> to change the definition of a color. The rou-
+ tines <STRONG>has_colors</STRONG> and <STRONG>can_change_color</STRONG> return <STRONG>TRUE</STRONG> or <STRONG>FALSE</STRONG>, depending
+ on whether the terminal has color capabilities and whether the program-
+ mer can change the colors. The routine <STRONG>color_content</STRONG> allows a program-
+ mer to extract the amounts of red, green, and blue components in an
+ initialized color. The routine <STRONG>pair_content</STRONG> allows a programmer to
find out how a given color-pair is currently defined.
- <B>Routine</B> <B>Descriptions</B>
- The <B>start_color</B> routine requires no arguments. It must be
- called if the programmer wants to use colors, and before
- any other color manipulation routine is called. It is
- good practice to call this routine right after <B>initscr</B>.
- <B>start_color</B> initializes eight basic colors (black, red,
- green, yellow, blue, magenta, cyan, and white), and two
- global variables, <B>COLORS</B> and <B>COLOR_PAIRS</B> (respectively
- defining the maximum number of colors and color-pairs the
- terminal can support). It also restores the colors on the
- terminal to the values they had when the terminal was just
- turned on.
-
- The <B>init_pair</B> routine changes the definition of a color-
- pair. It takes three arguments: the number of the color-
- pair to be changed, the foreground color number, and the
- background color number. For portable applications:
-
- - The value of the first argument must be between <B>1</B> and
- <B>COLOR_PAIRS-1</B>.
-
- - The value of the second and third arguments must be
- between 0 and <B>COLORS</B> (the 0 color pair is wired to
- white on black and cannot be changed).
-
- If the color-pair was previously initialized, the screen
- is refreshed and all occurrences of that color-pair is
- changed to the new definition.
-
- As an extension, ncurses allows you to set color pair 0
- via the <B>assume_default_colors</B> routine, or to specify the
- use of default colors (color number <B>-1</B>) if you first
- invoke the <B>use_default_colors</B> routine.
-
- The <B>init_color</B> routine changes the definition of a color.
- It takes four arguments: the number of the color to be
- changed followed by three RGB values (for the amounts of
- red, green, and blue components). The value of the first
- argument must be between <B>0</B> and <B>COLORS</B>. (See the section
- <B>Colors</B> for the default color index.) Each of the last
- three arguments must be a value between 0 and 1000. When
- <B>init_color</B> is used, all occurrences of that color on the
- screen immediately change to the new definition.
-
- The <B>has_colors</B> routine requires no arguments. It returns
- <B>TRUE</B> if the terminal can manipulate colors; otherwise, it
- returns <B>FALSE</B>. This routine facilitates writing terminal-
- independent programs. For example, a programmer can use
- it to decide whether to use color or some other video
- attribute.
-
- The <B>can_change_color</B> routine requires no arguments. It
- returns <B>TRUE</B> if the terminal supports colors and can
- change their definitions; other, it returns <B>FALSE</B>. This
- routine facilitates writing terminal-independent programs.
-
- The <B>color_content</B> routine gives programmers a way to find
- the intensity of the red, green, and blue (RGB) components
- in a color. It requires four arguments: the color number,
- and three addresses of <B>short</B>s for storing the information
- about the amounts of red, green, and blue components in
- the given color. The value of the first argument must be
- between 0 and <B>COLORS</B>. The values that are stored at the
- addresses pointed to by the last three arguments are
- between 0 (no component) and 1000 (maximum amount of com-
- ponent).
-
- The <B>pair_content</B> routine allows programmers to find out
- what colors a given color-pair consists of. It requires
- three arguments: the color-pair number, and two addresses
- of <B>short</B>s for storing the foreground and the background
- color numbers. The value of the first argument must be
- between 1 and <B>COLOR_PAIRS-1</B>. The values that are stored
- at the addresses pointed to by the second and third argu-
- ments are between 0 and <B>COLORS</B>.
-
- <B>Colors</B>
- In <B><curses.h></B> the following macros are defined. These are
- the default colors. <B>curses</B> also assumes that <B>COLOR_BLACK</B>
- is the default background color for all terminals.
-
- <B>COLOR_BLACK</B>
- <B>COLOR_RED</B>
- <B>COLOR_GREEN</B>
- <B>COLOR_YELLOW</B>
- <B>COLOR_BLUE</B>
- <B>COLOR_MAGENTA</B>
- <B>COLOR_CYAN</B>
- <B>COLOR_WHITE</B>
+</PRE><H3><a name="h3-Color-Rendering">Color Rendering</a></H3><PRE>
+ The <STRONG>curses</STRONG> library combines these inputs to produce the actual fore-
+ ground and background colors shown on the screen:
-</PRE>
-<H2>RETURN VALUE</H2><PRE>
- The routines <B>can_change_color()</B> and <B>has_colors()</B> return
- <B>TRUE</B> or <B>FALSE</B>.
+ <STRONG>o</STRONG> per-character video attributes (e.g., via <STRONG>waddch</STRONG>),
- All other routines return the integer <B>ERR</B> upon failure and
- an <B>OK</B> (SVr4 specifies only "an integer value other than
- <B>ERR</B>") upon successful completion.
+ <STRONG>o</STRONG> the window attribute (e.g., by <STRONG>wattrset</STRONG>), and
+ <STRONG>o</STRONG> the background character (e.g., <STRONG>wbkgdset</STRONG>).
-</PRE>
-<H2>NOTES</H2><PRE>
- In the <I>ncurses</I> implementation, there is a separate color
- activation flag, color palette, color pairs table, and
- associated COLORS and COLOR_PAIRS counts for each screen;
- the <B>start_color</B> function only affects the current screen.
- The SVr4/XSI interface is not really designed with this in
- mind, and historical implementations may use a single
- shared color palette.
+ Per-character and window attributes are usually set by a parameter con-
+ taining video attributes including a color pair value. Some functions
+ such as <STRONG>wattr_set</STRONG> use a separate parameter which is the color pair num-
+ ber.
- Note that setting an implicit background color via a color
- pair affects only character cells that a character write
- operation explicitly touches. To change the background
- color used when parts of a window are blanked by erasing
- or scrolling operations, see <B><A HREF="curs_bkgd.3x.html">curs_bkgd(3x)</A></B>.
+ The background character is a special case: it includes a character
+ value, just as if it were passed to <STRONG>waddch</STRONG>.
- Several caveats apply on 386 and 486 machines with VGA-
- compatible graphics:
+ The <STRONG>curses</STRONG> library does the actual work of combining these color pairs
+ in an internal function called from <STRONG>waddch</STRONG>:
- - COLOR_YELLOW is actually brown. To get yellow, use
- COLOR_YELLOW combined with the <B>A_BOLD</B> attribute.
+ <STRONG>o</STRONG> If the parameter passed to <STRONG>waddch</STRONG> is <EM>blank</EM>, and it uses the special
+ color pair 0,
- - The A_BLINK attribute should in theory cause the
- background to go bright. This often fails to work,
- and even some cards for which it mostly works (such
- as the Paradise and compatibles) do the wrong thing
- when you try to set a bright "yellow" background (you
- get a blinking yellow foreground instead).
+ <STRONG>o</STRONG> <STRONG>curses</STRONG> next checks the window attribute.
- - Color RGB values are not settable.
+ <STRONG>o</STRONG> If the window attribute does not use color pair 0, <STRONG>curses</STRONG> uses
+ the color pair from the window attribute.
+ <STRONG>o</STRONG> Otherwise, <STRONG>curses</STRONG> uses the background character.
-</PRE>
-<H2>PORTABILITY</H2><PRE>
- This implementation satisfies XSI Curses's minimum maxi-
- mums for <B>COLORS</B> and <B>COLOR_PAIRS</B>.
+ <STRONG>o</STRONG> If the parameter passed to <STRONG>waddch</STRONG> is <EM>not</EM> <EM>blank</EM>, or it does not use
+ the special color pair 0, <STRONG>curses</STRONG> prefers the color pair from the
+ parameter, if it is nonzero. Otherwise, it tries the window at-
+ tribute next, and finally the background character.
- The <B>init_pair</B> routine accepts negative values of fore-
- ground and background color to support the
- <B>use_default_colors</B> extension, but only if that routine has
- been first invoked.
+ Some <STRONG>curses</STRONG> functions such as <STRONG>wprintw</STRONG> call <STRONG>waddch</STRONG>. Those do not com-
+ bine its parameter with a color pair. Consequently those calls use on-
+ ly the window attribute or the background character.
- The assumption that <B>COLOR_BLACK</B> is the default background
- color for all terminals can be modified using the
- <B>assume_default_colors</B> extension,
+</PRE><H2><a name="h2-CONSTANTS">CONSTANTS</a></H2><PRE>
+ In <STRONG><curses.h></STRONG> the following macros are defined. These are the standard
+ colors (ISO-6429). <STRONG>curses</STRONG> also assumes that <STRONG>COLOR_BLACK</STRONG> is the default
+ background color for all terminals.
-</PRE>
-<H2>SEE ALSO</H2><PRE>
- <B><A HREF="ncurses.3x.html">curses(3x)</A></B>, <B><A HREF="curs_initscr.3x.html">curs_initscr(3x)</A></B>, <B><A HREF="curs_attr.3x.html">curs_attr(3x)</A></B>, <B><A HREF="dft_fgbg.3x.html">dft_fgbg(3x)</A></B>
+ <STRONG>COLOR_BLACK</STRONG>
+ <STRONG>COLOR_RED</STRONG>
+ <STRONG>COLOR_GREEN</STRONG>
+ <STRONG>COLOR_YELLOW</STRONG>
+ <STRONG>COLOR_BLUE</STRONG>
+ <STRONG>COLOR_MAGENTA</STRONG>
+ <STRONG>COLOR_CYAN</STRONG>
+ <STRONG>COLOR_WHITE</STRONG>
+
+ Some terminals support more than the eight (8) "ANSI" colors. There
+ are no standard names for those additional colors.
+
+
+</PRE><H2><a name="h2-VARIABLES">VARIABLES</a></H2><PRE>
+
+</PRE><H3><a name="h3-COLORS">COLORS</a></H3><PRE>
+ is initialized by <STRONG>start_color</STRONG> to the maximum number of colors the ter-
+ minal can support.
+
+
+</PRE><H3><a name="h3-COLOR_PAIRS">COLOR_PAIRS</a></H3><PRE>
+ is initialized by <STRONG>start_color</STRONG> to the maximum number of color pairs the
+ terminal can support.
+
+
+</PRE><H2><a name="h2-FUNCTIONS">FUNCTIONS</a></H2><PRE>
+
+</PRE><H3><a name="h3-start_color">start_color</a></H3><PRE>
+ The <STRONG>start_color</STRONG> routine requires no arguments. It must be called if
+ the programmer wants to use colors, and before any other color manipu-
+ lation routine is called. It is good practice to call this routine
+ right after <STRONG>initscr</STRONG>. <STRONG>start_color</STRONG> does this:
+
+ <STRONG>o</STRONG> It initializes two global variables, <STRONG>COLORS</STRONG> and <STRONG>COLOR_PAIRS</STRONG> (re-
+ spectively defining the maximum number of colors and color-pairs
+ the terminal can support).
+
+ <STRONG>o</STRONG> It initializes the special color pair <STRONG>0</STRONG> to the default foreground
+ and background colors. No other color pairs are initialized.
+
+ <STRONG>o</STRONG> It restores the colors on the terminal to the values they had when
+ the terminal was just turned on.
+
+ <STRONG>o</STRONG> If the terminal supports the <STRONG>initc</STRONG> (<STRONG>initialize_color</STRONG>) capability,
+ <STRONG>start_color</STRONG> initializes its internal table representing the red,
+ green and blue components of the color palette.
+
+ The components depend on whether the terminal uses CGA (aka "ANSI")
+ or HLS (i.e., the <STRONG>hls</STRONG> (<STRONG>hue_lightness_saturation</STRONG>) capability is
+ set). The table is initialized first for eight basic colors
+ (black, red, green, yellow, blue, magenta, cyan, and white), and
+ after that (if the terminal supports more than eight colors) the
+ components are initialized to <STRONG>1000</STRONG>.
+
+ <STRONG>start_color</STRONG> does not attempt to set the terminal's color palette to
+ match its built-in table. An application may use <STRONG>init_color</STRONG> to al-
+ ter the internal table along with the terminal's color.
+
+ These limits apply to color values and color pairs. Values outside
+ these limits are not legal, and may result in a runtime error:
+
+ <STRONG>o</STRONG> <STRONG>COLORS</STRONG> corresponds to the terminal database's <STRONG>max_colors</STRONG> capabili-
+ ty, (see <STRONG><A HREF="terminfo.5.html">terminfo(5)</A></STRONG>).
+
+ <STRONG>o</STRONG> color values are expected to be in the range <STRONG>0</STRONG> to <STRONG>COLORS-1</STRONG>, inclu-
+ sive (including <STRONG>0</STRONG> and <STRONG>COLORS-1</STRONG>).
+
+ <STRONG>o</STRONG> a special color value <STRONG>-1</STRONG> is used in certain extended functions to
+ denote the <EM>default</EM> <EM>color</EM> (see <STRONG>use_default_colors</STRONG>).
+
+ <STRONG>o</STRONG> <STRONG>COLOR_PAIRS</STRONG> corresponds to the terminal database's <STRONG>max_pairs</STRONG> capa-
+ bility, (see <STRONG><A HREF="terminfo.5.html">terminfo(5)</A></STRONG>).
+
+ <STRONG>o</STRONG> legal color pair values are in the range <STRONG>1</STRONG> to <STRONG>COLOR_PAIRS-1</STRONG>, inclu-
+ sive.
+
+ <STRONG>o</STRONG> color pair <STRONG>0</STRONG> is special; it denotes "no color".
+
+ Color pair <STRONG>0</STRONG> is assumed to be white on black, but is actually what-
+ ever the terminal implements before color is initialized. It can-
+ not be modified by the application.
+
+
+</PRE><H3><a name="h3-has_colors">has_colors</a></H3><PRE>
+ The <STRONG>has_colors</STRONG> routine requires no arguments. It returns <STRONG>TRUE</STRONG> if the
+ terminal can manipulate colors; otherwise, it returns <STRONG>FALSE</STRONG>. This rou-
+ tine facilitates writing terminal-independent programs. For example, a
+ programmer can use it to decide whether to use color or some other
+ video attribute.
+
+
+</PRE><H3><a name="h3-can_change_color">can_change_color</a></H3><PRE>
+ The <STRONG>can_change_color</STRONG> routine requires no arguments. It returns <STRONG>TRUE</STRONG> if
+ the terminal supports colors and can change their definitions; other,
+ it returns <STRONG>FALSE</STRONG>. This routine facilitates writing terminal-indepen-
+ dent programs.
+
+
+</PRE><H3><a name="h3-init_pair">init_pair</a></H3><PRE>
+ The <STRONG>init_pair</STRONG> routine changes the definition of a color-pair. It takes
+ three arguments: the number of the color-pair to be changed, the fore-
+ ground color number, and the background color number. For portable ap-
+ plications:
+
+ <STRONG>o</STRONG> The first argument must be a legal color pair value. If default
+ colors are used (see <STRONG>use_default_colors</STRONG>) the upper limit is adjust-
+ ed to allow for extra pairs which use a default color in foreground
+ and/or background.
+
+ <STRONG>o</STRONG> The second and third arguments must be legal color values.
+
+ If the color-pair was previously initialized, the screen is refreshed
+ and all occurrences of that color-pair are changed to the new defini-
+ tion.
+
+ As an extension, ncurses allows you to set color pair <STRONG>0</STRONG> via the <STRONG>as-</STRONG>
+ <STRONG><A HREF="assume_default_colors.3x.html">sume_default_colors(3x)</A></STRONG> routine, or to specify the use of default col-
+ ors (color number <STRONG>-1</STRONG>) if you first invoke the <STRONG><A HREF="default_colors.3x.html">use_default_colors(3x)</A></STRONG>
+ routine.
+
+ The extension <STRONG>reset_color_pairs</STRONG> tells ncurses to discard all of the
+ color-pair information which was set with <STRONG>init_pair</STRONG>. It also touches
+ the current- and standard-screens, allowing an application to switch
+ color palettes rapidly.
+
+
+</PRE><H3><a name="h3-init_color">init_color</a></H3><PRE>
+ The <STRONG>init_color</STRONG> routine changes the definition of a color. It takes
+ four arguments: the number of the color to be changed followed by three
+ RGB values (for the amounts of red, green, and blue components).
+
+ <STRONG>o</STRONG> The first argument must be a legal color value; default colors are
+ not allowed here. (See the section <STRONG>Colors</STRONG> for the default color
+ index.)
+
+ <STRONG>o</STRONG> Each of the last three arguments must be a value in the range <STRONG>0</STRONG>
+ through <STRONG>1000</STRONG>.
+
+ When <STRONG>init_color</STRONG> is used, all occurrences of that color on the screen
+ immediately change to the new definition.
+
+
+</PRE><H3><a name="h3-color_content">color_content</a></H3><PRE>
+ The <STRONG>color_content</STRONG> routine gives programmers a way to find the intensity
+ of the red, green, and blue (RGB) components in a color. It requires
+ four arguments: the color number, and three addresses of <STRONG>short</STRONG>s for
+ storing the information about the amounts of red, green, and blue com-
+ ponents in the given color.
+
+ <STRONG>o</STRONG> The first argument must be a legal color value, i.e., <STRONG>0</STRONG> through
+ <STRONG>COLORS-1</STRONG>, inclusive.
+
+ <STRONG>o</STRONG> The values that are stored at the addresses pointed to by the last
+ three arguments are in the range <STRONG>0</STRONG> (no component) through <STRONG>1000</STRONG>
+ (maximum amount of component), inclusive.
+</PRE><H3><a name="h3-pair_content">pair_content</a></H3><PRE>
+ The <STRONG>pair_content</STRONG> routine allows programmers to find out what colors a
+ given color-pair consists of. It requires three arguments: the color-
+ pair number, and two addresses of <STRONG>short</STRONG>s for storing the foreground and
+ the background color numbers.
+ <STRONG>o</STRONG> The first argument must be a legal color value, i.e., in the range
+ <STRONG>1</STRONG> through <STRONG>COLOR_PAIRS-1</STRONG>, inclusive.
+ <STRONG>o</STRONG> The values that are stored at the addresses pointed to by the sec-
+ ond and third arguments are in the range <STRONG>0</STRONG> through <STRONG>COLORS</STRONG>, inclu-
+ sive.
+</PRE><H3><a name="h3-PAIR_NUMBER">PAIR_NUMBER</a></H3><PRE>
+ <STRONG>PAIR_NUMBER(</STRONG><EM>attrs</EM>) extracts the color value from its <EM>attrs</EM> parameter
+ and returns it as a color pair number.
+</PRE><H3><a name="h3-COLOR_PAIR">COLOR_PAIR</a></H3><PRE>
+ Its inverse <STRONG>COLOR_PAIR(</STRONG><EM>n</EM><STRONG>)</STRONG> converts a color pair number to an attribute.
+ Attributes can hold color pairs in the range 0 to 255. If you need a
+ color pair larger than that, you must use functions such as <STRONG>attr_set</STRONG>
+ (which pass the color pair as a separate parameter) rather than the
+ legacy functions such as <STRONG>attrset</STRONG>.
+</PRE><H2><a name="h2-RETURN-VALUE">RETURN VALUE</a></H2><PRE>
+ The routines <STRONG>can_change_color</STRONG> and <STRONG>has_colors</STRONG> return <STRONG>TRUE</STRONG> or <STRONG>FALSE</STRONG>.
+ All other routines return the integer <STRONG>ERR</STRONG> upon failure and an <STRONG>OK</STRONG> (SVr4
+ specifies only "an integer value other than <STRONG>ERR</STRONG>") upon successful com-
+ pletion.
+ X/Open defines no error conditions. This implementation will return
+ <STRONG>ERR</STRONG> on attempts to use color values outside the range <STRONG>0</STRONG> to <STRONG>COLORS</STRONG>-1
+ (except for the default colors extension), or use color pairs outside
+ the range <STRONG>0</STRONG> to <STRONG>COLOR_PAIRS-1</STRONG>. Color values used in <STRONG>init_color</STRONG> must be
+ in the range <STRONG>0</STRONG> to <STRONG>1000</STRONG>. An error is returned from all functions if the
+ terminal has not been initialized. An error is returned from secondary
+ functions such as <STRONG>init_pair</STRONG> if <STRONG>start_color</STRONG> was not called.
+ <STRONG>init_color</STRONG>
+ returns an error if the terminal does not support this feature,
+ e.g., if the <STRONG>initialize_color</STRONG> capability is absent from the
+ terminal description.
+ <STRONG>start_color</STRONG>
+ returns an error if the color table cannot be allocated.
+</PRE><H2><a name="h2-NOTES">NOTES</a></H2><PRE>
+ In the <STRONG>ncurses</STRONG> implementation, there is a separate color activation
+ flag, color palette, color pairs table, and associated <STRONG>COLORS</STRONG> and <STRONG>COL-</STRONG>
+ <STRONG>OR_PAIRS</STRONG> counts for each screen; the <STRONG>start_color</STRONG> function only affects
+ the current screen. The SVr4/XSI interface is not really designed with
+ this in mind, and historical implementations may use a single shared
+ color palette.
+ Setting an implicit background color via a color pair affects only
+ character cells that a character write operation explicitly touches.
+ To change the background color used when parts of a window are blanked
+ by erasing or scrolling operations, see <STRONG><A HREF="curs_bkgd.3x.html">curs_bkgd(3x)</A></STRONG>.
+ Several caveats apply on older x86 machines (e.g., i386, i486) with
+ VGA-compatible graphics:
+ <STRONG>o</STRONG> COLOR_YELLOW is actually brown. To get yellow, use COLOR_YELLOW
+ combined with the <STRONG>A_BOLD</STRONG> attribute.
+ <STRONG>o</STRONG> The A_BLINK attribute should in theory cause the background to go
+ bright. This often fails to work, and even some cards for which it
+ mostly works (such as the Paradise and compatibles) do the wrong
+ thing when you try to set a bright "yellow" background (you get a
+ blinking yellow foreground instead).
+ <STRONG>o</STRONG> Color RGB values are not settable.
+</PRE><H2><a name="h2-PORTABILITY">PORTABILITY</a></H2><PRE>
+ This implementation satisfies XSI Curses's minimum maximums for <STRONG>COLORS</STRONG>
+ and <STRONG>COLOR_PAIRS</STRONG>.
+ The <STRONG>init_pair</STRONG> routine accepts negative values of foreground and back-
+ ground color to support the <STRONG><A HREF="default_colors.3x.html">use_default_colors(3x)</A></STRONG> extension, but only
+ if that routine has been first invoked.
+ The assumption that <STRONG>COLOR_BLACK</STRONG> is the default background color for all
+ terminals can be modified using the <STRONG><A HREF="default_colors.3x.html">assume_default_colors(3x)</A></STRONG> exten-
+ sion.
+ This implementation checks the pointers, e.g., for the values returned
+ by <STRONG>color_content</STRONG> and <STRONG>pair_content</STRONG>, and will treat those as optional pa-
+ rameters when null.
+ X/Open Curses does not specify a limit for the number of colors and
+ color pairs which a terminal can support. However, in its use of <STRONG>short</STRONG>
+ for the parameters, it carries over SVr4's implementation detail for
+ the compiled terminfo database, which uses signed 16-bit numbers. This
+ implementation provides extended versions of those functions which use
+ <STRONG>short</STRONG> parameters, allowing applications to use larger color- and pair-
+ numbers.
+ The <STRONG>reset_color_pairs</STRONG> function is an extension of ncurses.
+</PRE><H2><a name="h2-SEE-ALSO">SEE ALSO</a></H2><PRE>
+ <STRONG><A HREF="ncurses.3x.html">curses(3x)</A></STRONG>, <STRONG><A HREF="curs_initscr.3x.html">curs_initscr(3x)</A></STRONG>, <STRONG><A HREF="curs_attr.3x.html">curs_attr(3x)</A></STRONG>, <STRONG><A HREF="curs_variables.3x.html">curs_variables(3x)</A></STRONG>, <STRONG>de-</STRONG>
+ <STRONG><A HREF="default_colors.3x.html">fault_colors(3x)</A></STRONG>
+ <STRONG><A HREF="curs_color.3x.html">curs_color(3x)</A></STRONG>
</PRE>
-<HR>
-<ADDRESS>
-Man(1) output converted with
-<a href="http://www.oac.uci.edu/indiv/ehood/man2html.html">man2html</a>
-</ADDRESS>
+<div class="nav">
+<ul>
+<li><a href="#h2-NAME">NAME</a></li>
+<li><a href="#h2-SYNOPSIS">SYNOPSIS</a></li>
+<li><a href="#h2-DESCRIPTION">DESCRIPTION</a>
+<ul>
+<li><a href="#h3-Overview">Overview</a></li>
+<li><a href="#h3-Color-Rendering">Color Rendering</a></li>
+</ul>
+</li>
+<li><a href="#h2-CONSTANTS">CONSTANTS</a></li>
+<li><a href="#h2-VARIABLES">VARIABLES</a>
+<ul>
+<li><a href="#h3-COLORS">COLORS</a></li>
+<li><a href="#h3-COLOR_PAIRS">COLOR_PAIRS</a></li>
+</ul>
+</li>
+<li><a href="#h2-FUNCTIONS">FUNCTIONS</a>
+<ul>
+<li><a href="#h3-start_color">start_color</a></li>
+<li><a href="#h3-has_colors">has_colors</a></li>
+<li><a href="#h3-can_change_color">can_change_color</a></li>
+<li><a href="#h3-init_pair">init_pair</a></li>
+<li><a href="#h3-init_color">init_color</a></li>
+<li><a href="#h3-color_content">color_content</a></li>
+<li><a href="#h3-pair_content">pair_content</a></li>
+<li><a href="#h3-PAIR_NUMBER">PAIR_NUMBER</a></li>
+<li><a href="#h3-COLOR_PAIR">COLOR_PAIR</a></li>
+</ul>
+</li>
+<li><a href="#h2-RETURN-VALUE">RETURN VALUE</a></li>
+<li><a href="#h2-NOTES">NOTES</a></li>
+<li><a href="#h2-PORTABILITY">PORTABILITY</a></li>
+<li><a href="#h2-SEE-ALSO">SEE ALSO</a></li>
+</ul>
+</div>
</BODY>
</HTML>