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-<H1>curs_color 3x</H1>
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+<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>
+<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>
- <STRONG>start_color</STRONG>, <STRONG>init_pair</STRONG>, <STRONG>init_color</STRONG>, <STRONG>has_colors</STRONG>,
- <STRONG>can_change_color</STRONG>, <STRONG>color_content</STRONG>, <STRONG>pair_content</STRONG>, <STRONG>COLOR_PAIR</STRONG>
- - <STRONG>curses</STRONG> color manipulation routines
+</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>init_extended_pair</STRONG>, <STRONG>init_extended_color</STRONG>, <STRONG>color_content</STRONG>, <STRONG>pair_content</STRONG>,
+ <STRONG>extended_color_content</STRONG>, <STRONG>extended_pair_content</STRONG>, <STRONG>reset_color_pairs</STRONG>,
+ <STRONG>COLOR_PAIR</STRONG>, <STRONG>PAIR_NUMBER</STRONG> - <STRONG>curses</STRONG> color manipulation routines
-</PRE>
-<H2>SYNOPSIS</H2><PRE>
- <STRONG>#</STRONG> <STRONG>include</STRONG> <STRONG><curses.h></STRONG>
+</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>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>
+
<STRONG>bool</STRONG> <STRONG>has_colors(void);</STRONG>
<STRONG>bool</STRONG> <STRONG>can_change_color(void);</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>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>
-</PRE>
-<H2>DESCRIPTION</H2><PRE>
- <STRONG>Overview</STRONG>
- <STRONG>curses</STRONG> support color attributes on terminals with that ca-
- pability. 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 charac-
- ters are displayed). A programmer initializes a color-
- pair with the routine <STRONG>init_pair</STRONG>. After it has been ini-
- tialized, <STRONG>COLOR_PAIR</STRONG>(<EM>n</EM>), a macro defined in <STRONG><curses.h></STRONG>,
- can be used as a new video attribute.
-
- If a terminal is capable of redefining colors, the pro-
- grammer can use the routine <STRONG>init_color</STRONG> to change the defi-
- nition of a color. The routines <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 programmer can change the colors. The routine <STRONG>col-</STRONG>
- <STRONG>or_content</STRONG> allows a programmer 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.
-
- <STRONG>Routine</STRONG> <STRONG>Descriptions</STRONG>
- 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 manipulation routine is called. It is
- good practice to call this routine right after <STRONG>initscr</STRONG>.
- <STRONG>start_color</STRONG> initializes eight basic colors (black, red,
- green, yellow, blue, magenta, cyan, and white), and two
- global variables, <STRONG>COLORS</STRONG> and <STRONG>COLOR_PAIRS</STRONG> (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 <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 foreground color number, and the
- background color number. For portable applications:
-
- <STRONG>o</STRONG> The value of the first argument must be between <STRONG>1</STRONG> and
- <STRONG>COLOR_PAIRS-1</STRONG>, except that if default colors are used
- (see <STRONG>use_default_colors</STRONG>) the upper limit is adjusted
- to allow for extra pairs which use a default color in
- foreground and/or background.
-
- <STRONG>o</STRONG> The value of the second and third arguments must be
- between 0 and <STRONG>COLORS</STRONG>. Color pair 0 is assumed to be
- white on black, but is actually whatever the terminal
- implements before color is initialized. It cannot be
- modified by the application.
-
- If the color-pair was previously initialized, the screen
- is refreshed and all occurrences of that color-pair are
- changed to the new definition.
-
- As an extension, ncurses allows you to set color pair 0
- via the <STRONG>assume_default_colors</STRONG> routine, or to specify the
- use of default colors (color number <STRONG>-1</STRONG>) if you first in-
- voke the <STRONG>use_default_colors</STRONG> routine.
-
- 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). The value of the first
- argument must be between <STRONG>0</STRONG> and <STRONG>COLORS</STRONG>. (See the section
- <STRONG>Colors</STRONG> for the default color index.) Each of the last
- three arguments must be a value between 0 and 1000. When
- <STRONG>init_color</STRONG> is used, all occurrences of that color on the
- screen immediately change to the new definition.
-
- 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 routine facilitates writing terminal-
- independent programs. For example, a programmer can use
- it to decide whether to use color or some other video at-
- tribute.
-
- 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-independent programs.
-
- 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 components in
- the given color. The value of the first argument must be
- between 0 and <STRONG>COLORS</STRONG>. The values that are stored at the
- addresses pointed to by the last three arguments are be-
- tween 0 (no component) and 1000 (maximum amount of compo-
- nent).
-
- 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. The value of the first argument must be
- between 1 and <STRONG>COLOR_PAIRS-1</STRONG>. The values that are stored
- at the addresses pointed to by the second and third argu-
- ments are between 0 and <STRONG>COLORS</STRONG>.
-
- <STRONG>Colors</STRONG>
- In <STRONG><curses.h></STRONG> the following macros are defined. These are
- the default colors. <STRONG>curses</STRONG> also assumes that <STRONG>COLOR_BLACK</STRONG>
- is the default background color for all terminals.
+ <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.
+
+
+</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:
+
+ <STRONG>o</STRONG> per-character video attributes (e.g., via <STRONG>waddch</STRONG>),
+
+ <STRONG>o</STRONG> the window attribute (e.g., by <STRONG>wattrset</STRONG>), and
+
+ <STRONG>o</STRONG> the background character (e.g., <STRONG>wbkgdset</STRONG>).
+
+ 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.
+
+ The background character is a special case: it includes a character
+ value, just as if it were passed to <STRONG>waddch</STRONG>.
+
+ The <STRONG>curses</STRONG> library does the actual work of combining these color pairs
+ in an internal function called from <STRONG>waddch</STRONG>:
+
+ <STRONG>o</STRONG> If the parameter passed to <STRONG>waddch</STRONG> is <EM>blank</EM>, and it uses the special
+ color pair 0,
+
+ <STRONG>o</STRONG> <STRONG>curses</STRONG> next checks the window attribute.
+
+ <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.
+
+ <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.
+
+ 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.
+
+
+</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.
<STRONG>COLOR_BLACK</STRONG>
<STRONG>COLOR_RED</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), using
+ weights that depend upon the CGA/HLS choice. For "ANSI" colors the
+ weights are <STRONG>680</STRONG> or <STRONG>0</STRONG> depending on whether the corresponding red,
+ green, or blue component is used or not. That permits using <STRONG>1000</STRONG>
+ to represent bold/bright colors. After the initial eight colors
+ (if the terminal supports more than eight colors) the components
+ are initialized using the same pattern, but with weights of <STRONG>1000</STRONG>.
+ SVr4 uses a similar scheme, but uses <STRONG>1000</STRONG> for the components of the
+ initial eight colors.
+
+ <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><A HREF="default_colors.3x.html">use_default_colors(3x)</A></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>
-<H2>RETURN VALUE</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 completion.
-
- X/Open defines no error conditions. This implementation
- will return <STRONG>ERR</STRONG> on attempts to use color values outside
- the range 0 to COLORS-1 (except for the default colors ex-
- tension), or use color pairs outside the range 0 to COL-
- OR_PAIR-1. Color values used in <STRONG>init_color</STRONG> must be in the
- range 0 to 1000. An error is returned from all functions
- if the terminal has not been initialized. An error is re-
- turned from secondary functions such as <STRONG>init_pair</STRONG> if
- <STRONG>start_color</STRONG> was not called.
+
+</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><A HREF="default_colors.3x.html">use_default_colors(3x)</A></STRONG>) the upper limit is ad-
+ justed to allow for extra pairs which use a default color in fore-
+ ground 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.
+
+
+</PRE><H3><a name="h3-init_extended_pair">init_extended_pair</a></H3><PRE>
+ Because <STRONG>init_pair</STRONG> uses signed <STRONG>short</STRONG>s for its parameters, that limits
+ color-pairs and color-values to 32767 on modern hardware. The exten-
+ sion <STRONG>init_extended_pair</STRONG> uses <STRONG>int</STRONG>s for the color-pair and color-value,
+ allowing a larger number of colors to be supported.
+
+
+</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-init_extended_color">init_extended_color</a></H3><PRE>
+ Because <STRONG>init_color</STRONG> uses signed <STRONG>short</STRONG>s for its parameters, that limits
+ color-values and their red, green, and blue components to 32767 on mod-
+ ern hardware. The extension <STRONG>init_extended_color</STRONG> uses <STRONG>int</STRONG>s for the col-
+ or value and for setting the red, green, and blue components, allowing
+ a larger number of colors to be supported.
+
+
+</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-extended_color_content">extended_color_content</a></H3><PRE>
+ Because <STRONG>color_content</STRONG> uses signed <STRONG>short</STRONG>s for its parameters, that lim-
+ its color-values and their red, green, and blue components to 32767 on
+ modern hardware. The extension <STRONG>extended_color_content</STRONG> uses <STRONG>int</STRONG>s for
+ the color value and for returning the red, green, and blue components,
+ allowing a larger number of colors to be supported.
+
+
+</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-extended_pair_content">extended_pair_content</a></H3><PRE>
+ Because <STRONG>pair_content</STRONG> uses signed <STRONG>short</STRONG>s for its parameters, that limits
+ color-pair and color-values to 32767 on modern hardware. The extension
+ <STRONG>extended_pair_content</STRONG> uses <STRONG>int</STRONG>s for the color pair and for returning
+ the foreground and background colors, allowing a larger number of col-
+ ors to be supported.
+
+
+</PRE><H3><a name="h3-reset_color_pairs">reset_color_pairs</a></H3><PRE>
+ 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-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. SVr4 does document some error con-
+ ditions which apply in general:
+
+ <STRONG>o</STRONG> 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 ex-
+ tension), 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>o</STRONG> SVr4 does much the same, except that it returns <STRONG>ERR</STRONG> from <STRONG>pair_con-</STRONG>
+ <STRONG>tent</STRONG> if the pair was not initialized using <STRONG>init_pairs</STRONG> and it re-
+ turns <STRONG>ERR</STRONG> from <STRONG>color_content</STRONG> if the terminal does not support
+ changing colors.
+
+ This implementation does not return <STRONG>ERR</STRONG> for either case.
+
+ Specific functions make additional checks:
<STRONG>init_color</STRONG>
- returns an error if the terminal does not support
- this feature, e.g., if the <EM>initialize</EM><STRONG>_</STRONG><EM>color</EM> capa-
- bility is absent from the terminal description.
+ 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 al-
- located.
+ returns an error if the color table cannot be allocated.
-</PRE>
-<H2>NOTES</H2><PRE>
- In the <EM>ncurses</EM> implementation, there is a separate color
- activation flag, color palette, color pairs table, and as-
- sociated COLORS and COLOR_PAIRS 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.
-
- 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 <STRONG><A HREF="curs_bkgd.3x.html">curs_bkgd(3x)</A></STRONG>.
-
- Several caveats apply on 386 and 486 machines 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 back-
- ground 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
+</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>PORTABILITY</H2><PRE>
- This implementation satisfies XSI Curses's minimum maxi-
- mums for <STRONG>COLORS</STRONG> and <STRONG>COLOR_PAIRS</STRONG>.
+</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 fore-
- ground and background color to support the <STRONG>use_de-</STRONG>
- <STRONG>fault_colors</STRONG> extension, but only if that routine has been
- first invoked.
+ 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>as-</STRONG>
- <STRONG>sume_default_colors</STRONG> extension.
+ 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 parameters when null.
+ 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.
-</PRE>
-<H2>SEE ALSO</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>default_col-</STRONG>
- <STRONG><A HREF="default_colors.3x.html">ors(3x)</A></STRONG>
+ 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>
+
<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_extended_pair">init_extended_pair</a></li>
+<li><a href="#h3-init_color">init_color</a></li>
+<li><a href="#h3-init_extended_color">init_extended_color</a></li>
+<li><a href="#h3-color_content">color_content</a></li>
+<li><a href="#h3-extended_color_content">extended_color_content</a></li>
+<li><a href="#h3-pair_content">pair_content</a></li>
+<li><a href="#h3-extended_pair_content">extended_pair_content</a></li>
+<li><a href="#h3-reset_color_pairs">reset_color_pairs</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>
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