- 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.
-
- <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. Its in-
- verse <STRONG>COLOR_PAIR(</STRONG><EM>n</EM><STRONG>)</STRONG> converts a color pair number to an at-
- tribute. 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 func-
- tions such as <STRONG>attrset</STRONG>.
-
-
-</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.
+ Color pair <STRONG>0</STRONG> is assumed to be white on black, but is actually what-
+ ever the terminal implements before color is initialized. It can-
+ not be modified by the application.
+
+
+</PRE><H3><a name="h3-has_colors">has_colors</a></H3><PRE>
+ The <STRONG>has_colors</STRONG> routine requires no arguments. It returns <STRONG>TRUE</STRONG> if the
+ terminal can manipulate colors; otherwise, it returns <STRONG>FALSE</STRONG>. This rou-
+ tine facilitates writing terminal-independent programs. For example, a
+ programmer can use it to decide whether to use color or some other
+ video attribute.
+
+
+</PRE><H3><a name="h3-can_change_color">can_change_color</a></H3><PRE>
+ The <STRONG>can_change_color</STRONG> routine requires no arguments. It returns <STRONG>TRUE</STRONG> if
+ the terminal supports colors and can change their definitions; other,
+ it returns <STRONG>FALSE</STRONG>. This routine facilitates writing terminal-indepen-
+ dent programs.
+
+
+</PRE><H3><a name="h3-init_pair">init_pair</a></H3><PRE>
+ The <STRONG>init_pair</STRONG> routine changes the definition of a color-pair. It takes
+ three arguments: the number of the color-pair to be changed, the fore-
+ ground color number, and the background color number. For portable ap-
+ plications:
+
+ <STRONG>o</STRONG> The first argument must be a legal color pair value. If default
+ colors are used (see <STRONG><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.