-</PRE><H3><a name="h3-Routine-Descriptions">Routine Descriptions</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 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>COL-</STRONG>
- <STRONG>OR_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 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_sat-</STRONG>
- <STRONG>uration</STRONG>) capability is set). The table is initialized
- first for eight basic colors (black, red, green, yel-
- low, blue, magenta, cyan, and white), and after that
- (if the terminal supports more than eight colors) the
- components are initialized to <STRONG>1000</STRONG>.
-
- <STRONG>start_color</STRONG> does not attempt to set the terminal's
- color palette to match its built-in table. An appli-
- cation 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. Val-
- ues 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_col-</STRONG>
- <STRONG>ors</STRONG> capability, which is typically a signed 16-bit in-
- teger (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>COL-</STRONG>
- <STRONG>ORS-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>use_de-</STRONG>
- <STRONG>fault_colors</STRONG>).
-
- <STRONG>o</STRONG> <STRONG>COLOR_PAIRS</STRONG> corresponds to the terminal database's
- <STRONG>max_pairs</STRONG> capability, which is typically a signed
- 16-bit integer (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>COL-</STRONG>
- <STRONG>OR_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 whatever the terminal implements before color
- is initialized. It cannot be modified by the applica-
- tion.
-
- 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>use_default_colors</STRONG>)
- the upper limit is adjusted to allow for extra pairs
- which use a default color in foreground and/or back-
- ground.
-
- <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 definition.
-
- As an extension, ncurses allows you to set color pair <STRONG>0</STRONG>
- 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 first argument must
- be a legal color value; default colors are not allowed
- here. (See the section <STRONG>Colors</STRONG> for the default color in-
- dex.) 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.
-
- 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 first argument must be a legal color
- value, i.e., <STRONG>0</STRONG> through <STRONG>COLORS-1</STRONG>, inclusive. 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.
-
- 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 first argument must be a legal color
- value, i.e., in the range <STRONG>1</STRONG> through <STRONG>COLOR_PAIRS-1</STRONG>, inclu-
- sive. 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-Colors">Colors</a></H3><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 termi-
- nals.
-
- <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>
-
+</PRE><H3><a name="h3-init_extended_pair">init_extended_pair</a></H3><PRE>
+ Because <B>init_pair</B> uses signed <B>short</B>s for its parameters, that limits
+ color-pairs and color-values to 32767 on modern hardware. The exten-
+ sion <B>init_extended_pair</B> uses <B>int</B>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 <B>init_color</B> routine changes the definition of a color. It takes
+ four arguments: the number of the color to be changed followed by three
+ RGB values (for the amounts of red, green, and blue components).
+
+ <B>o</B> The first argument must be a legal color value; default colors are
+ not allowed here. (See the section <B>Colors</B> for the default color
+ index.)
+
+ <B>o</B> Each of the last three arguments must be a value in the range <B>0</B>
+ through <B>1000</B>.
+
+ When <B>init_color</B> 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 <B>init_color</B> uses signed <B>short</B>s for its parameters, that limits
+ color-values and their red, green, and blue components to 32767 on mod-
+ ern hardware. The extension <B>init_extended_color</B> uses <B>int</B>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 <B>color_content</B> routine gives programmers a way to find the intensity
+ of the red, green, and blue (RGB) components in a color. It requires
+ four arguments: the color number, and three addresses of <B>short</B>s for
+ storing the information about the amounts of red, green, and blue com-
+ ponents in the given color.
+
+ <B>o</B> The first argument must be a legal color value, i.e., <B>0</B> through
+ <B>COLORS-1</B>, inclusive.
+
+ <B>o</B> The values that are stored at the addresses pointed to by the last
+ three arguments are in the range <B>0</B> (no component) through <B>1000</B>
+ (maximum amount of component), inclusive.
+
+
+</PRE><H3><a name="h3-extended_color_content">extended_color_content</a></H3><PRE>
+ Because <B>color_content</B> uses signed <B>short</B>s for its parameters, that lim-
+ its color-values and their red, green, and blue components to 32767 on
+ modern hardware. The extension <B>extended_color_content</B> uses <B>int</B>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 <B>pair_content</B> routine allows programmers to find out what colors a
+ given color-pair consists of. It requires three arguments: the color-
+ pair number, and two addresses of <B>short</B>s for storing the foreground and
+ the background color numbers.
+
+ <B>o</B> The first argument must be a legal color value, i.e., in the range
+ <B>1</B> through <B>COLOR_PAIRS-1</B>, inclusive.
+
+ <B>o</B> The values that are stored at the addresses pointed to by the sec-
+ ond and third arguments are in the range <B>0</B> through <B>COLORS</B>, inclu-
+ sive.
+
+
+</PRE><H3><a name="h3-extended_pair_content">extended_pair_content</a></H3><PRE>
+ Because <B>pair_content</B> uses signed <B>short</B>s for its parameters, that limits
+ color-pair and color-values to 32767 on modern hardware. The extension
+ <B>extended_pair_content</B> uses <B>int</B>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 <B>reset_color_pairs</B> tells ncurses to discard all of the
+ color-pair information which was set with <B>init_pair</B>. 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>
+ <B>PAIR_NUMBER(</B><I>attrs</I>) extracts the color value from its <I>attrs</I> parameter
+ and returns it as a color pair number.
+
+
+</PRE><H3><a name="h3-COLOR_PAIR">COLOR_PAIR</a></H3><PRE>
+ Its inverse <B>COLOR_PAIR(</B><I>n</I><B>)</B> 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 <B>attr_set</B>
+ (which pass the color pair as a separate parameter) rather than the
+ legacy functions such as <B>attrset</B>.
+