- 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.