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diff --git a/doc/html/man/curs_color.3x.html b/doc/html/man/curs_color.3x.html index c672b72a90ef..d84a5732540a 100644 --- a/doc/html/man/curs_color.3x.html +++ b/doc/html/man/curs_color.3x.html @@ -1,6 +1,6 @@ -<!-- +<!-- **************************************************************************** - * Copyright 2018-2019,2020 Thomas E. Dickey * + * Copyright 2018-2023,2024 Thomas E. Dickey * * Copyright 1998-2016,2017 Free Software Foundation, Inc. * * * * Permission is hereby granted, free of charge, to any person obtaining a * @@ -27,35 +27,41 @@ * sale, use or other dealings in this Software without prior written * * authorization. * **************************************************************************** - * @Id: curs_color.3x,v 1.63 2020/10/24 09:35:23 tom Exp @ + * @Id: curs_color.3x,v 1.100 2024/04/20 21:24:19 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> +<TITLE>curs_color 3x 2024-04-20 ncurses 6.5 Library calls</TITLE> <link rel="author" 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> +<H1 class="no-header">curs_color 3x 2024-04-20 ncurses 6.5 Library calls</H1> <PRE> -<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> Library calls <STRONG><A HREF="curs_color.3x.html">curs_color(3x)</A></STRONG> </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 + <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>COLORS</STRONG>, <STRONG>COLOR_PAIRS</STRONG>, <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> - manipulate terminal colors with <EM>curses</EM> </PRE><H2><a name="h2-SYNOPSIS">SYNOPSIS</a></H2><PRE> <STRONG>#include</STRONG> <STRONG><curses.h></STRONG> + <EM>/*</EM> <EM>variables</EM> <EM>*/</EM> + <STRONG>int</STRONG> <STRONG>COLOR_PAIRS;</STRONG> + <STRONG>int</STRONG> <STRONG>COLORS;</STRONG> + <STRONG>int</STRONG> <STRONG>start_color(void);</STRONG> <STRONG>bool</STRONG> <STRONG>has_colors(void);</STRONG> @@ -63,89 +69,88 @@ <STRONG>int</STRONG> <STRONG>init_pair(short</STRONG> <EM>pair</EM><STRONG>,</STRONG> <STRONG>short</STRONG> <EM>f</EM><STRONG>,</STRONG> <STRONG>short</STRONG> <EM>b</EM><STRONG>);</STRONG> <STRONG>int</STRONG> <STRONG>init_color(short</STRONG> <EM>color</EM><STRONG>,</STRONG> <STRONG>short</STRONG> <EM>r</EM><STRONG>,</STRONG> <STRONG>short</STRONG> <EM>g</EM><STRONG>,</STRONG> <STRONG>short</STRONG> <EM>b</EM><STRONG>);</STRONG> - /* extensions */ + <EM>/*</EM> <EM>extensions</EM> <EM>*/</EM> <STRONG>int</STRONG> <STRONG>init_extended_pair(int</STRONG> <EM>pair</EM><STRONG>,</STRONG> <STRONG>int</STRONG> <EM>f</EM><STRONG>,</STRONG> <STRONG>int</STRONG> <EM>b</EM><STRONG>);</STRONG> <STRONG>int</STRONG> <STRONG>init_extended_color(int</STRONG> <EM>color</EM><STRONG>,</STRONG> <STRONG>int</STRONG> <EM>r</EM><STRONG>,</STRONG> <STRONG>int</STRONG> <EM>g</EM><STRONG>,</STRONG> <STRONG>int</STRONG> <EM>b</EM><STRONG>);</STRONG> <STRONG>int</STRONG> <STRONG>color_content(short</STRONG> <EM>color</EM><STRONG>,</STRONG> <STRONG>short</STRONG> <STRONG>*</STRONG><EM>r</EM><STRONG>,</STRONG> <STRONG>short</STRONG> <STRONG>*</STRONG><EM>g</EM><STRONG>,</STRONG> <STRONG>short</STRONG> <STRONG>*</STRONG><EM>b</EM><STRONG>);</STRONG> <STRONG>int</STRONG> <STRONG>pair_content(short</STRONG> <EM>pair</EM><STRONG>,</STRONG> <STRONG>short</STRONG> <STRONG>*</STRONG><EM>f</EM><STRONG>,</STRONG> <STRONG>short</STRONG> <STRONG>*</STRONG><EM>b</EM><STRONG>);</STRONG> - /* extensions */ + <EM>/*</EM> <EM>extensions</EM> <EM>*/</EM> <STRONG>int</STRONG> <STRONG>extended_color_content(int</STRONG> <EM>color</EM><STRONG>,</STRONG> <STRONG>int</STRONG> <STRONG>*</STRONG><EM>r</EM><STRONG>,</STRONG> <STRONG>int</STRONG> <STRONG>*</STRONG><EM>g</EM><STRONG>,</STRONG> <STRONG>int</STRONG> <STRONG>*</STRONG><EM>b</EM><STRONG>);</STRONG> <STRONG>int</STRONG> <STRONG>extended_pair_content(int</STRONG> <EM>pair</EM><STRONG>,</STRONG> <STRONG>int</STRONG> <STRONG>*</STRONG><EM>f</EM><STRONG>,</STRONG> <STRONG>int</STRONG> <STRONG>*</STRONG><EM>b</EM><STRONG>);</STRONG> - /* extensions */ + <EM>/*</EM> <EM>extension</EM> <EM>*/</EM> <STRONG>void</STRONG> <STRONG>reset_color_pairs(void);</STRONG> <STRONG>int</STRONG> <STRONG>COLOR_PAIR(int</STRONG> <EM>n</EM><STRONG>);</STRONG> - <STRONG>PAIR_NUMBER(</STRONG><EM>attrs</EM><STRONG>);</STRONG> + <STRONG>PAIR_NUMBER(int</STRONG> <EM>attr</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. + <EM>curses</EM> supports color attributes on terminals with that capability. + Call <STRONG>start_color</STRONG> (typically right after <STRONG><A HREF="curs_initscr.3x.html">initscr(3x)</A></STRONG>) to enable this + feature. Colors are always used in pairs. A <EM>color</EM> <EM>pair</EM> couples a + foreground color for characters with a background color for the blank + field on which characters are rendered. <STRONG>init_pair</STRONG> initializes a color + pair. The macro <STRONG>COLOR_PAIR</STRONG>(<EM>n</EM>) can then 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. + If a terminal has the relevant capability, <STRONG>init_color</STRONG> permits + (re)definition of a color. <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 capability and + whether the programmer can change the colors. <STRONG>color_content</STRONG> permits + extraction of the red, green, and blue components of an initialized + color. <STRONG>pair_content</STRONG> permits discovery of a color pair's current + definition. -</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><H3><a name="h3-Rendering">Rendering</a></H3><PRE> + <EM>curses</EM> combines the following data to render a character cell. Any of + them can include color information. - <STRONG>o</STRONG> per-character video attributes (e.g., via <STRONG>waddch</STRONG>), + <STRONG>o</STRONG> <EM>curses</EM> character attributes, as from <STRONG><A HREF="curs_addch.3x.html">waddch(3x)</A></STRONG> or <STRONG><A HREF="curs_add_wch.3x.html">wadd_wch(3x)</A></STRONG> - <STRONG>o</STRONG> the window attribute (e.g., by <STRONG>wattrset</STRONG>), and + <STRONG>o</STRONG> window attributes, as from <STRONG><A HREF="curs_attr.3x.html">wattrset(3x)</A></STRONG> or <STRONG><A HREF="curs_attr.3x.html">wattr_set(3x)</A></STRONG> - <STRONG>o</STRONG> the background character (e.g., <STRONG>wbkgdset</STRONG>). + <STRONG>o</STRONG> window background character attributes, as from <STRONG><A HREF="curs_bkgd.3x.html">wbkgdset(3x)</A></STRONG> or + <STRONG><A HREF="curs_bkgrnd.3x.html">wbkgrndset(3x)</A></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. + Per-character and window attributes are usually set through a function + parameter containing attributes including a color pair value. Some + functions, such as <STRONG>wattr_set</STRONG>, use a separate color pair number + parameter. - The background character is a special case: it includes a character - value, just as if it were passed to <STRONG>waddch</STRONG>. + The background character is a special case: it includes a character + code, just as if it were passed to <STRONG>waddch</STRONG>. - The <STRONG>curses</STRONG> library does the actual work of combining these color pairs + The <EM>curses</EM> 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> <EM>curses</EM> next checks the window attribute. - <STRONG>o</STRONG> If the window attribute does not use color pair 0, <STRONG>curses</STRONG> uses + <STRONG>o</STRONG> If the window attribute does not use color pair 0, <EM>curses</EM> uses the color pair from the window attribute. - <STRONG>o</STRONG> Otherwise, <STRONG>curses</STRONG> uses the background character. + <STRONG>o</STRONG> Otherwise, <EM>curses</EM> 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 attri- - bute next, and finally 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, <EM>curses</EM> prefers the color pair from the + parameter, if it is nonzero. Otherwise, it tries the window + attribute 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. + Some <EM>curses</EM> functions such as <STRONG>wprintw</STRONG> call <STRONG>waddch</STRONG>. Those do not + combine its parameter with a color pair. Consequently those calls use + only 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 + colors (ISO-6429). <EM>curses</EM> also assumes that <STRONG>COLOR_BLACK</STRONG> is the default background color for all terminals. <STRONG>COLOR_BLACK</STRONG> @@ -157,32 +162,39 @@ <STRONG>COLOR_CYAN</STRONG> <STRONG>COLOR_WHITE</STRONG> - Some terminals support more than the eight (8) "ANSI" colors. There + 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. + is initialized by <STRONG>start_color</STRONG> to the maximum number of colors the + terminal 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. + is initialized by <STRONG>start_color</STRONG> to the maximum number of color pairs the + terminal can support. Often, its value is the product <STRONG>COLORS</STRONG> x <STRONG>COLORS</STRONG>, + but this is not always true. + + <STRONG>o</STRONG> A few terminals use the HLS color space (see <STRONG>start_color</STRONG> below), + ignoring this rule; and + + <STRONG>o</STRONG> terminals supporting a large number of colors are limited to the + number of color pairs that a <EM>signed</EM> <EM>short</EM> value can represent. </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: + 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> 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 + <STRONG>o</STRONG> It initializes 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). <STRONG>o</STRONG> It initializes the special color pair <STRONG>0</STRONG> to the default foreground @@ -209,77 +221,77 @@ 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. + match its built-in table. An application may use <STRONG>init_color</STRONG> to + alter 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: + these limits are not valid, 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> <STRONG>COLORS</STRONG> corresponds to the terminal database's <STRONG>max_colors</STRONG> + capability, (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> color values are expected to be in the range <STRONG>0</STRONG> to <STRONG>COLORS-1</STRONG>, + inclusive (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> <STRONG>COLOR_PAIRS</STRONG> corresponds to the terminal database's <STRONG>max_pairs</STRONG> + capability, (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> valid color pair values are in the range <STRONG>1</STRONG> to <STRONG>COLOR_PAIRS-1</STRONG>, + inclusive. <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. + Color pair <STRONG>0</STRONG> 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. </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. + 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 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. + it returns <STRONG>FALSE</STRONG>. This routine facilitates writing terminal- + independent 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: + 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 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 first argument must be a valid 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 + adjusted 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. + <STRONG>o</STRONG> The second and third arguments must be valid 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. + 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 <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> + As an extension, <EM>ncurses</EM> allows you to set color pair <STRONG>0</STRONG> via the + <STRONG><A HREF="default_colors.3x.html">assume_default_colors(3x)</A></STRONG> routine, or to specify the use of default + colors (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. + color pairs and color-values to 32767 on modern hardware. The + extension <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> @@ -287,7 +299,7 @@ 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 + <STRONG>o</STRONG> The first argument must be a valid color value; default colors are not allowed here. (See the section <STRONG>Colors</STRONG> for the default color index.) @@ -300,20 +312,20 @@ </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. + color-values and their red, green, and blue components to 32767 on + modern hardware. The extension <STRONG>init_extended_color</STRONG> uses <STRONG>int</STRONG>s for the + color 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. + storing the information about the amounts of red, green, and blue + components in the given color. - <STRONG>o</STRONG> The first argument must be a legal color value, i.e., <STRONG>0</STRONG> through + <STRONG>o</STRONG> The first argument must be a valid 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 @@ -322,68 +334,70 @@ </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 + Because <STRONG>color_content</STRONG> uses signed <STRONG>short</STRONG>s for its parameters, that + limits 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- + 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>o</STRONG> The first argument must be a valid 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. + <STRONG>o</STRONG> The values that are stored at the addresses pointed to by the + second and third arguments are in the range <STRONG>0</STRONG> through <STRONG>COLORS</STRONG>, + inclusive. </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 + 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. + the foreground and background colors, allowing a larger number of + colors 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 extension <STRONG>reset_color_pairs</STRONG> tells <EM>ncurses</EM> 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> + <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><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><H3><a name="h3-PAIR_NUMBER">PAIR_NUMBER</a></H3><PRE> + <STRONG>PAIR_NUMBER(</STRONG><EM>attr</EM>) extracts the color information from its <EM>attr</EM> + parameter and returns it as a color pair number; it is the inverse + operation of <STRONG>COLOR_PAIR</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. + 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. SVr4 does document some error con- - ditions which apply in general: + X/Open defines no error conditions. SVr4 does document some error + conditions 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>. + 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>. @@ -393,9 +407,9 @@ 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 + <STRONG>o</STRONG> SVr4 does much the same, except that it returns <STRONG>ERR</STRONG> from + <STRONG>pair_content</STRONG> if the pair was not initialized using <STRONG>init_pairs</STRONG> and + it returns <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. @@ -412,12 +426,12 @@ </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. + In the <EM>ncurses</EM> implementation, there is a separate color activation + flag, color palette, color pairs table, and associated <STRONG>COLORS</STRONG> and + <STRONG>COLOR_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. @@ -439,40 +453,93 @@ <STRONG>o</STRONG> Color RGB values are not settable. +</PRE><H2><a name="h2-EXTENSIONS">EXTENSIONS</a></H2><PRE> + The functions marked as extensions were designed for <STRONG><A HREF="ncurses.3x.html">ncurses(3x)</A></STRONG>, and + are not found in SVr4 <EM>curses</EM>, 4.4BSD <EM>curses</EM>, or any other previous + curses implementation. + + </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>. + Applications employing <EM>ncurses</EM> extensions should condition their use on + the visibility of the <STRONG>NCURSES_VERSION</STRONG> preprocessor macro. + + This implementation satisfies X/Open 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 <STRONG>init_pair</STRONG> routine accepts negative values of foreground and + background 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. + terminals can be modified using the <STRONG><A HREF="default_colors.3x.html">assume_default_colors(3x)</A></STRONG> + extension. - 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. + 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. - X/Open Curses does not specify a limit for the number of colors and + 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 + 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- + 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. + The <STRONG>reset_color_pairs</STRONG> function is an extension of <EM>ncurses</EM>. + + +</PRE><H2><a name="h2-HISTORY">HISTORY</a></H2><PRE> + SVr3.2 introduced color support to curses in 1987. + + SVr4 made internal changes, e.g., moving the storage for the color + state from <STRONG>SP</STRONG> (the <EM>SCREEN</EM> structure) to <STRONG>cur_term</STRONG> (the <EM>TERMINAL</EM> + structure), but provided the same set of library functions. + + SVr4 curses limits the number of color pairs to 64, reserving color + pair zero (0) as the terminal's initial uncolored state. This limit + arises because the color pair information is a bitfield in the <STRONG>chtype</STRONG> + data type (denoted by <STRONG>A_COLOR</STRONG>). + + Other implementations of curses had different limits: + + <STRONG>o</STRONG> PCCurses (1987-1990) provided for only eight (8) colors. + + <STRONG>o</STRONG> PDCurses (1992-present) inherited the 8-color limitation from + PCCurses, but changed this to 256 in version 2.5 (2001), along with + changing <STRONG>chtype</STRONG> from 16-bits to 32-bits. + + <STRONG>o</STRONG> X/Open Curses (1992-present) added a new structure <STRONG>cchar_t</STRONG> to store + the character, attributes and color pair values, allowing increased + range of color pairs. Both color pairs and color-values used a + signed <STRONG>short</STRONG>, limiting values to 15 bits. + + <STRONG>o</STRONG> <EM>ncurses</EM> (1992-present) uses eight bits for <STRONG>A_COLOR</STRONG> in <STRONG>chtype</STRONG> + values. + + Version 5.3 provided a wide-character interface (2002), but left + color pairs as part of the attributes-field. + + Since version 6 (2015), ncurses uses a separate <STRONG>int</STRONG> for color pairs + in the <STRONG>cchar_t</STRONG> values. When those color pair values fit in 8 bits, + ncurses allows color pairs to be manipulated via the functions + using <STRONG>chtype</STRONG> values. + + <STRONG>o</STRONG> NetBSD curses used 6 bits from 2000 (when colors were first + supported) until 2004. At that point, NetBSD changed to use 10 + bits. As of 2021, that size is unchanged. Like <EM>ncurses</EM> before + version 6, the NetBSD color pair information is stored in the + attributes field of <STRONG>cchar_t</STRONG>, limiting the number of color pairs by + the size of the bitfield. </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="ncurses.3x.html">curses(3x)</A></STRONG>, <STRONG><A HREF="curs_attr.3x.html">curs_attr(3x)</A></STRONG>, <STRONG><A HREF="curs_initscr.3x.html">curs_initscr(3x)</A></STRONG>, <STRONG><A HREF="curs_variables.3x.html">curs_variables(3x)</A></STRONG>, + <STRONG><A HREF="default_colors.3x.html">default_colors(3x)</A></STRONG> - <STRONG><A HREF="curs_color.3x.html">curs_color(3x)</A></STRONG> +ncurses 6.5 2024-04-20 <STRONG><A HREF="curs_color.3x.html">curs_color(3x)</A></STRONG> </PRE> <div class="nav"> <ul> @@ -481,7 +548,7 @@ <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> +<li><a href="#h3-Rendering">Rendering</a></li> </ul> </li> <li><a href="#h2-CONSTANTS">CONSTANTS</a></li> @@ -505,13 +572,15 @@ <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> +<li><a href="#h3-PAIR_NUMBER">PAIR_NUMBER</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-EXTENSIONS">EXTENSIONS</a></li> <li><a href="#h2-PORTABILITY">PORTABILITY</a></li> +<li><a href="#h2-HISTORY">HISTORY</a></li> <li><a href="#h2-SEE-ALSO">SEE ALSO</a></li> </ul> </div> |