[PATCH] update description of init_extended_color
Andrew Burgess <[email protected]>
| Newsgroups | gmane.comp.lib.ncurses.bugs |
|---|---|
| Message-ID | <18a814c5e6ff26f10ff26e0b607642aa88efef84.1786618972.git.aburgess@redhat.com> |
While recently doing some work that involved init_extended_color I found the docs unclear and ended up having to read the ncurses source code in order to be entirely sure of the API. Specifically, I found that the man page text makes it sound like the rgb components have an extended range with init_extended_color, which isn't the case, the rgb components are still in the range 0 -> 1000. In this commit I structure the docs for init_extended_color as a copy of init_color, retaining the initial paragraph that explains the short to int change. The two bullet points make it clear what the valid values for each argument type are. While copying the init_color text I noticed that it references a non-existent section 'Colors'. I ended up referencing start_color instead as that seemed like the best choice. I also updated init_color to match. Please feel free to make any edits to this patch that are needed. This extended text, or similar, would have allowed me to use the init_extended_color API without having to check the ncurses source. Thanks, Andrew --- doc/html/man/curs_color.3x.html | 238 ++++++++++++++++---------------- man/curs_color.3x | 20 ++- 2 files changed, 137 insertions(+), 121 deletions(-) diff --git a/doc/html/man/curs_color.3x.html b/doc/html/man/curs_color.3x.html index 03d533d04..e4ff57ed3 100644 --- a/doc/html/man/curs_color.3x.html +++ b/doc/html/man/curs_color.3x.html @@ -34,14 +34,10 @@ <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 2025-08-23 ncurses 6.6 Library calls</TITLE> -<link rel="author" href="mailto:[email protected]"> - </HEAD> <BODY> -<H1 class="no-header">curs_color 3x 2025-08-23 ncurses 6.6 Library calls</H1> <PRE> -<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> +<STRONG><A HREF="">curs_color(3X)</A></STRONG> Library calls <STRONG><A HREF="">curs_color(3X)</A></STRONG> </PRE><H2><a name="h2-NAME">NAME</a></H2><PRE> @@ -54,7 +50,7 @@ </PRE><H2><a name="h2-SYNOPSIS">SYNOPSIS</a></H2><PRE> - <STRONG>#include</STRONG> <STRONG><curses.h></STRONG> + <STRONG>#include</STRONG> <STRONG><ncursesw/curses.h></STRONG> <EM>/*</EM> <EM>variables</EM> <EM>*/</EM> <STRONG>int</STRONG> <STRONG>COLOR_PAIRS;</STRONG> @@ -98,7 +94,7 @@ </PRE><H3><a name="h3-Overview">Overview</a></H3><PRE> <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 + Call <STRONG>start_color</STRONG> (typically right after <STRONG><A HREF="">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 @@ -118,12 +114,12 @@ <EM>curses</EM> combines the following data to render a character cell. Any of them can include color information. - <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> <EM>curses</EM> character attributes, as from <STRONG><A HREF="">waddch(3X)</A></STRONG> or <STRONG><A HREF="">wadd_wch(3X)</A></STRONG> - <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> window attributes, as from <STRONG><A HREF="">wattrset(3X)</A></STRONG> or <STRONG><A HREF="">wattr_set(3X)</A></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> + <STRONG>o</STRONG> window background character attributes, as from <STRONG><A HREF="">wbkgdset(3X)</A></STRONG> or + <STRONG><A HREF="">wbkgrndset(3X)</A></STRONG> Per-character and window attributes are usually set through a function parameter containing attributes including a color pair value. Some @@ -160,7 +156,7 @@ <STRONG>COLOR_GREEN</STRONG>, <STRONG>COLOR_YELLOW</STRONG>, <STRONG>COLOR_BLUE</STRONG>, <STRONG>COLOR_MAGENTA</STRONG>, <STRONG>COLOR_CYAN</STRONG>, and <STRONG>COLOR_WHITE</STRONG> accordingly. <EM>curses</EM> assumes that <STRONG>COLOR_BLACK</STRONG> is the default background color for all terminals. <EM>ncurses</EM> offers an - extension to override that assumption; see <STRONG><A HREF="default_colors.3x.html">assume_default_colors(3x)</A></STRONG>. + extension to override that assumption; see <STRONG><A HREF="">assume_default_colors(3X)</A></STRONG>. Some terminals support additional colors that lack standard names. <STRONG>A_COLOR</STRONG> is a bit mask that, when bitwise "and"-ed with a <EM>chtype</EM>, @@ -229,16 +225,16 @@ 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> - capability, (see <STRONG><A HREF="terminfo.5.html">terminfo(5)</A></STRONG>). + capability, (see <STRONG><A HREF="">terminfo(5)</A></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>). + denote the <EM>default</EM> <EM>color</EM> (see <STRONG><A HREF="">use_default_colors(3X)</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>). + capability, (see <STRONG><A HREF="">terminfo(5)</A></STRONG>). <STRONG>o</STRONG> valid color pair values are in the range <STRONG>1</STRONG> to <STRONG>COLOR_PAIRS-1</STRONG>, inclusive. @@ -252,7 +248,7 @@ </PRE><H3><a name="h3-has_colors">has_colors</a></H3><PRE> <STRONG>has_colors</STRONG> returns <STRONG>TRUE</STRONG> if the terminal supports colors and <STRONG>FALSE</STRONG> if it - does not. <STRONG><A HREF="curs_initscr.3x.html">initscr(3x)</A></STRONG> or <STRONG><A HREF="curs_initscr.3x.html">newterm(3x)</A></STRONG> must be called first, but + does not. <STRONG><A HREF="">initscr(3X)</A></STRONG> or <STRONG><A HREF="">newterm(3X)</A></STRONG> must be called first, but <STRONG>start_color</STRONG> need not be. An application might call <STRONG>has_colors</STRONG> to decide whether to use color or a video attribute like <STRONG>A_BOLD</STRONG> to render text. @@ -282,7 +278,7 @@ applications: <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 + colors are used (see <STRONG><A HREF="">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. @@ -293,8 +289,8 @@ definition. 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> + <STRONG><A HREF="">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="">use_default_colors(3X)</A></STRONG> routine. @@ -311,7 +307,7 @@ RGB values (for the amounts of red, green, and blue components). <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 + not allowed here. (See <STRONG>start_color</STRONG> above for the default color index.) <STRONG>o</STRONG> Each of the last three arguments must be a value in the range <STRONG>0</STRONG> @@ -323,157 +319,167 @@ </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 - 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. + color-values to 32767 on modern hardware. The extension + <STRONG>init_extended_color</STRONG> uses <STRONG>int</STRONG>s for the color value and for the red, + green, and blue components, allowing a larger number of color-values to + be supported. + + <STRONG>o</STRONG> The first argument must be a valid color value; default colors are + not allowed here. (See <STRONG>start_color</STRONG> above 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_extended_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 + 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. - <STRONG>o</STRONG> The first argument must be a valid 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 - three arguments are in the range <STRONG>0</STRONG> (no component) through <STRONG>1000</STRONG> + <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 - limits color-values and their red, green, and blue components to 32767 + 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, + 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 + 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 valid 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 - second and third arguments are in the range <STRONG>0</STRONG> through <STRONG>COLORS</STRONG>, + <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 - <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 + <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 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 <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 + 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-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 + 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 + <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> - <STRONG>can_change_color</STRONG> and <STRONG>has_colors</STRONG> return <STRONG>TRUE</STRONG> or <STRONG>FALSE</STRONG>. The other + <STRONG>can_change_color</STRONG> and <STRONG>has_colors</STRONG> return <STRONG>TRUE</STRONG> or <STRONG>FALSE</STRONG>. The other functions return <STRONG>OK</STRONG> on success and <STRONG>ERR</STRONG> on failure. - In <EM>ncurses</EM>, functions returning an <EM>int</EM> recognize several error + In <EM>ncurses</EM>, functions returning an <EM>int</EM> recognize several error conditions. - <STRONG>o</STRONG> All return <STRONG>ERR</STRONG> if the screen has not been initialized; see - <STRONG><A HREF="curs_initscr.3x.html">initscr(3x)</A></STRONG> or <STRONG><A HREF="curs_initscr.3x.html">newterm(3x)</A></STRONG>. + <STRONG>o</STRONG> All return <STRONG>ERR</STRONG> if the screen has not been initialized; see + <STRONG><A HREF="">initscr(3X)</A></STRONG> or <STRONG><A HREF="">newterm(3X)</A></STRONG>. - <STRONG>o</STRONG> All except <STRONG>start_color</STRONG> return <STRONG>ERR</STRONG> if <STRONG>start_color</STRONG> has not been + <STRONG>o</STRONG> All except <STRONG>start_color</STRONG> return <STRONG>ERR</STRONG> if <STRONG>start_color</STRONG> has not been called, or itself returned <STRONG>ERR</STRONG>. - <STRONG>o</STRONG> <STRONG>start_color</STRONG> returns <STRONG>ERR</STRONG> if it cannot allocate memory for its color + <STRONG>o</STRONG> <STRONG>start_color</STRONG> returns <STRONG>ERR</STRONG> if it cannot allocate memory for its color pair table. - <STRONG>o</STRONG> <STRONG>init_color</STRONG> returns <STRONG>ERR</STRONG> if the terminal type does not support - assignable color values; that is, if the <STRONG>initialize_color</STRONG> (<STRONG>initc</STRONG>) + <STRONG>o</STRONG> <STRONG>init_color</STRONG> returns <STRONG>ERR</STRONG> if the terminal type does not support + assignable color values; that is, if the <STRONG>initialize_color</STRONG> (<STRONG>initc</STRONG>) capability is absent from its description. - <STRONG>o</STRONG> <STRONG>init_color</STRONG> returns <STRONG>ERR</STRONG> if any of its <EM>r</EM>, <EM>g</EM>, <EM>b</EM> arguments is outside + <STRONG>o</STRONG> <STRONG>init_color</STRONG> returns <STRONG>ERR</STRONG> if any of its <EM>r</EM>, <EM>g</EM>, <EM>b</EM> arguments is outside the range 0-1000 inclusive. - <STRONG>o</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>, and + <STRONG>o</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>, and <STRONG>extended_pair_content</STRONG> return <STRONG>ERR</STRONG> on attempts to use - <STRONG>o</STRONG> color identifiers outside the range 0-<STRONG>COLORS</STRONG>-1 inclusive, the + <STRONG>o</STRONG> color identifiers outside the range 0-<STRONG>COLORS</STRONG>-1 inclusive, the default colors extension notwithstanding, or - <STRONG>o</STRONG> color pair identifiers outside the range 0-<STRONG>COLOR_PAIRS</STRONG>-1 + <STRONG>o</STRONG> color pair identifiers outside the range 0-<STRONG>COLOR_PAIRS</STRONG>-1 inclusive. </PRE><H2><a name="h2-NOTES">NOTES</a></H2><PRE> - In <EM>ncurses</EM>, <STRONG>init_pair</STRONG> accepts negative foreground and background color - arguments to support its <STRONG><A HREF="default_colors.3x.html">use_default_colors(3x)</A></STRONG> extension, but only + In <EM>ncurses</EM>, <STRONG>init_pair</STRONG> accepts negative foreground and background color + arguments to support its <STRONG><A HREF="">use_default_colors(3X)</A></STRONG> extension, but only after the latter function has been called. - The assumption that <STRONG>COLOR_BLACK</STRONG> is the terminal's default background - color can be overridden using <EM>ncurses</EM>'s <STRONG><A HREF="default_colors.3x.html">assume_default_colors(3x)</A></STRONG> + The assumption that <STRONG>COLOR_BLACK</STRONG> is the terminal's default background + color can be overridden using <EM>ncurses</EM>'s <STRONG><A HREF="">assume_default_colors(3X)</A></STRONG> extension. - In <EM>ncurses</EM>, each pointer passed to <STRONG>color_content</STRONG> and <STRONG>pair_content</STRONG> can + In <EM>ncurses</EM>, each pointer passed to <STRONG>color_content</STRONG> and <STRONG>pair_content</STRONG> can be null, in which case the library ignores it, permitting the application to disregard unnecessary information. - In <EM>ncurses</EM>, each screen has a color activation flag, color palette, + In <EM>ncurses</EM>, each screen has a color activation flag, color palette, color pair table, and associated <STRONG>COLORS</STRONG> and <STRONG>COLOR_PAIRS</STRONG> values; - <STRONG>start_color</STRONG> affects only the current screen. The SVr4 and X/Open - Curses interface was not really designed with this in mind; historical + <STRONG>start_color</STRONG> affects only the current screen. The SVr4 and X/Open + Curses interface was not really designed with this in mind; 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>. + 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)</A></STRONG>. - Several caveats apply to IBM PC-compatible machines of the 80486 era + Several caveats apply to IBM PC-compatible machines of the 80486 era and earlier with CGA/EGA/VGA video. - <STRONG>o</STRONG> <STRONG>COLOR_YELLOW</STRONG> was frequently converted, in the analog domain, to a - shade of brown if the intensity bit was not set. To get yellow on - such devices, one would combine <STRONG>COLOR_YELLOW</STRONG> with the <STRONG>A_BOLD</STRONG> + <STRONG>o</STRONG> <STRONG>COLOR_YELLOW</STRONG> was frequently converted, in the analog domain, to a + shade of brown if the intensity bit was not set. To get yellow on + such devices, one would combine <STRONG>COLOR_YELLOW</STRONG> with the <STRONG>A_BOLD</STRONG> attribute. - <STRONG>o</STRONG> The <STRONG>A_BLINK</STRONG> attribute should in theory make the background bright. - This often fails to work, and even VGA controllers for which it - mostly works, such as those from Paradise and compatibles, do the + <STRONG>o</STRONG> The <STRONG>A_BLINK</STRONG> attribute should in theory make the background bright. + This often fails to work, and even VGA controllers for which it + mostly works, such as those from 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 configurable on these devices (in text + <STRONG>o</STRONG> Color RGB values are not configurable on these devices (in text mode). </PRE><H2><a name="h2-EXTENSIONS">EXTENSIONS</a></H2><PRE> - The functions marked as extensions originated in <EM>ncurses</EM>, and are not - found in SVr4 <EM>curses</EM>, 4.4BSD <EM>curses</EM>, or any other previous <EM>curses</EM> + The functions marked as extensions originated in <EM>ncurses</EM>, and are not + found in SVr4 <EM>curses</EM>, 4.4BSD <EM>curses</EM>, or any other previous <EM>curses</EM> implementation. @@ -484,76 +490,76 @@ X/Open Curses Issue 4 describes these functions. It specifies no error conditions for them. - <EM>ncurses</EM> satisfies X/Open Curses's minimum maximums for <EM>COLORS</EM> and + <EM>ncurses</EM> satisfies X/Open Curses's minimum maximums for <EM>COLORS</EM> and <EM>COLOR</EM><STRONG>_</STRONG><EM>PAIRS</EM>. - 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 <EM>short</EM> - for the parameters, it carries over SVr4's implementation detail for - the compiled <EM>terminfo</EM> database, which uses signed 16-bit numbers. + for the parameters, it carries over SVr4's implementation detail for + the compiled <EM>terminfo</EM> database, which uses signed 16-bit numbers. <EM>ncurses</EM> provides extended versions of the functions using <EM>short</EM> - parameters, allowing applications to use larger color and pair + parameters, allowing applications to use larger color and pair identifiers. - SVr4 <EM>curses</EM> returns <EM>ERR</EM> from <EM>pair</EM><STRONG>_</STRONG><EM>content</EM> if its <EM>pair</EM> argument was not - initialized using <EM>init</EM><STRONG>_</STRONG><EM>pairs</EM>, and from <EM>color</EM><STRONG>_</STRONG><EM>content</EM> if the terminal + SVr4 <EM>curses</EM> returns <EM>ERR</EM> from <EM>pair</EM><STRONG>_</STRONG><EM>content</EM> if its <EM>pair</EM> argument was not + initialized using <EM>init</EM><STRONG>_</STRONG><EM>pairs</EM>, and from <EM>color</EM><STRONG>_</STRONG><EM>content</EM> if the terminal does not support changing colors. <EM>ncurses</EM> does neither. </PRE><H2><a name="h2-HISTORY">HISTORY</a></H2><PRE> - SVr3.2 (1987) introduced color support to <EM>curses</EM> with all of the - symbols in the synopsis above except those marked as extensions. It + SVr3.2 (1987) introduced color support to <EM>curses</EM> with all of the + symbols in the synopsis above except those marked as extensions. It reserved color pair 0 as the terminal's initial, "uncolored" state, and - limited the number of possible color pairs to 64, because the color + limited the number of possible color pairs to 64, because the color pair datum was encoded in six bits of a <EM>chtype</EM>. - SVr4 made only internal changes, such as moving the storage of color - state from the <EM>SCREEN</EM> structure (pointed to by <EM>SP</EM>) to the <EM>TERMINAL</EM> + SVr4 made only internal changes, such as moving the storage of color + state from the <EM>SCREEN</EM> structure (pointed to by <EM>SP</EM>) to the <EM>TERMINAL</EM> structure (pointed to by <EM>cur</EM><STRONG>_</STRONG><EM>term</EM>). - Other <EM>curses</EM> implementations impose different limits on the number of + Other <EM>curses</EM> implementations impose different limits on the number of colors and color pairs. - <STRONG>o</STRONG> <EM>PCCurses</EM> (1987-1990) provided for only 8 colors (and therefore + <STRONG>o</STRONG> <EM>PCCurses</EM> (1987-1990) provided for only 8 colors (and therefore required at most 8x8 = 64 color pairs). <STRONG>o</STRONG> <EM>PDCurses</EM> (1992-present) inherited the 8-color limitation from - <EM>PCCurses</EM>, but changed this to 256 in version 2.5 (2001), and + <EM>PCCurses</EM>, but changed this to 256 in version 2.5 (2001), and widened its <EM>chtype</EM> from 16 to 32 bits. <STRONG>o</STRONG> X/Open Curses (1992-present) specified a new structure type, - <EM>cchar</EM><STRONG>_</STRONG><EM>t</EM>, to store the character code, attribute flags, and color - pair identifier, allowing an increased range of color pairs. It - specifies a <EM>short</EM> as storing identifiers for colors and color - pairs, limiting portable values to 15 bits; negative values are + <EM>cchar</EM><STRONG>_</STRONG><EM>t</EM>, to store the character code, attribute flags, and color + pair identifier, allowing an increased range of color pairs. It + specifies a <EM>short</EM> as storing identifiers for colors and color + pairs, limiting portable values to 15 bits; negative values are invalid in System V. - <STRONG>o</STRONG> <EM>ncurses</EM> (1992-present), in its non-wide-character configuration, + <STRONG>o</STRONG> <EM>ncurses</EM> (1992-present), in its non-wide-character configuration, uses 8 bits of <EM>chtype</EM> for the color pair identifier. - Version 5.3 (2002) offered a wide-character interface, but encoded + Version 5.3 (2002) offered a wide-character interface, but encoded the color pair identifier with attributes in the character type. - Since version 6 (2015), <EM>ncurses</EM> uses a separate <EM>int</EM> for the color - pair identifier in a <EM>cchar</EM><STRONG>_</STRONG><EM>t</EM>, introducing extension functions to - manage the wider type. When a color pair value fits in 8 bits, + Since version 6 (2015), <EM>ncurses</EM> uses a separate <EM>int</EM> for the color + pair identifier in a <EM>cchar</EM><STRONG>_</STRONG><EM>t</EM>, introducing extension functions to + manage the wider type. When a color pair value fits in 8 bits, <EM>ncurses</EM> permits color pair data to be manipulated via the functions - taking <EM>chtype</EM> arguments, even when a <EM>curses</EM> window uses wide- + taking <EM>chtype</EM> arguments, even when a <EM>curses</EM> window uses wide- character cells. - <STRONG>o</STRONG> NetBSD <EM>curses</EM> used 6 bits for the color pair identifier from 2000 - (when it first added color support) until 2004. At that point, - NetBSD widened the color pair identifier to use 9 bits. As of - 2025, that size is unchanged. Like <EM>ncurses</EM> before version 6, the - NetBSD color pair datum is stored in the attributes field of + <STRONG>o</STRONG> NetBSD <EM>curses</EM> used 6 bits for the color pair identifier from 2000 + (when it first added color support) until 2004. At that point, + NetBSD widened the color pair identifier to use 9 bits. As of + 2025, that size is unchanged. Like <EM>ncurses</EM> before version 6, the + NetBSD color pair datum is stored in the attributes field of <EM>cchar</EM><STRONG>_</STRONG><EM>t</EM>, limiting the number of color pairs. </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_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="">curses(3X)</A></STRONG>, <STRONG><A HREF="">curs_attr(3X)</A></STRONG>, <STRONG><A HREF="">curs_initscr(3X)</A></STRONG>, <STRONG><A HREF="">curs_variables(3X)</A></STRONG>, + <STRONG><A HREF="">default_colors(3X)</A></STRONG> -ncurses 6.6 2025-08-23 <STRONG><A HREF="curs_color.3x.html">curs_color(3x)</A></STRONG> +ncurses 6.6 2025-08-23 <STRONG><A HREF="">curs_color(3X)</A></STRONG> </PRE> <div class="nav"> <ul> diff --git a/man/curs_color.3x b/man/curs_color.3x index 799f462bb..4667bd57a 100644 --- a/man/curs_color.3x +++ b/man/curs_color.3x @@ -399,7 +399,7 @@ the number of the color to be changed followed by three RGB values .bP The first argument must be a valid color value; default colors are not allowed here. -(See the section \fB\%Colors\fP for the default color index.) +(See \fB\%start_color\fP above for the default color index.) .bP Each of the last three arguments must be a value in the range \fB0\fP through \fB1000\fP. @@ -409,12 +409,22 @@ occurrences of that color on the screen immediately change to the new definition. .SS init_extended_color Because \fB\%init_color\fP uses signed \fBshort\fPs for its parameters, -that limits color-values and their red, green, and blue components -to 32767 on modern hardware. +that limits color-values to 32767 on modern hardware. The extension \fB\%init_extended_color\fP uses \fBint\fPs for the color value and -for setting the red, green, and blue components, -allowing a larger number of colors to be supported. +for the red, green, and blue components, +allowing a larger number of color-values to be supported. +.bP +The first argument must be a valid color value; +default colors are not allowed here. +(See \fB\%start_color\fP above for the default color index.) +.bP +Each of the last three arguments +must be a value in the range \fB0\fP through \fB1000\fP. +.PP +When \fB\%init_extended_color\fP is used, all +occurrences of that color on the screen immediately change to the new +definition. .SS color_content The \fB\%color_content\fP routine gives programmers a way to find the intensity of the red, green, and blue (RGB) components in a color. base-commit: dec1069c5d895b7e3d18abf058ac7dba6f280b3c -- 2.25.4