- The <STRONG>wnoutrefresh</STRONG> and <STRONG>doupdate</STRONG> routines allow multiple up-
- dates with more efficiency than <STRONG>wrefresh</STRONG> alone. In addi-
- tion to all the window structures, <STRONG>curses</STRONG> keeps two data
- structures representing the terminal screen: a physical
- screen, describing what is actually on the screen, and a
- virtual screen, describing what the programmer wants to
- have on the screen.
-
- The routine <STRONG>wrefresh</STRONG> works by first calling <STRONG>wnoutrefresh</STRONG>,
- which copies the named window to the virtual screen, and
- then calling <STRONG>doupdate</STRONG>, which compares the virtual screen
- to the physical screen and does the actual update. If the
- programmer wishes to output several windows at once, a se-
- ries of calls to <STRONG>wrefresh</STRONG> results in alternating calls to
- <STRONG>wnoutrefresh</STRONG> and <STRONG>doupdate</STRONG>, causing several bursts of out-
- put to the screen. By first calling <STRONG>wnoutrefresh</STRONG> for each
- window, it is then possible to call <STRONG>doupdate</STRONG> once, result-
- ing in only one burst of output, with fewer total charac-
- ters transmitted and less CPU time used. If the <EM>win</EM> argu-
- ment to <STRONG>wrefresh</STRONG> is the global variable <STRONG>curscr</STRONG>, the screen
- is immediately cleared and repainted from scratch.
-
- The phrase "copies the named window to the virtual screen"
- above is ambiguous. What actually happens is that all
- <EM>touched</EM> (changed) lines in the window are copied to the
- virtual screen. This affects programs that use overlap-
- ping windows; it means that if two windows overlap, you
- can refresh them in either order and the overlap region
- will be modified only when it is explicitly changed. (But
- see the section on <STRONG>PORTABILITY</STRONG> below for a warning about
- exploiting this behavior.)
+ The <STRONG>wnoutrefresh</STRONG> and <STRONG>doupdate</STRONG> routines allow multiple updates with more
+ efficiency than <STRONG>wrefresh</STRONG> alone. In addition to all the window struc-
+ tures, <STRONG>curses</STRONG> keeps two data structures representing the terminal
+ screen: a physical screen, describing what is actually on the screen,
+ and a virtual screen, describing what the programmer wants to have on
+ the screen.
+
+ The routine <STRONG>wrefresh</STRONG> works by first calling <STRONG>wnoutrefresh</STRONG>, which copies
+ the named window to the virtual screen, and then calling <STRONG>doupdate</STRONG>,
+ which compares the virtual screen to the physical screen and does the
+ actual update. If the programmer wishes to output several windows at
+ once, a series of calls to <STRONG>wrefresh</STRONG> results in alternating calls to
+ <STRONG>wnoutrefresh</STRONG> and <STRONG>doupdate</STRONG>, causing several bursts of output to the
+ screen. By first calling <STRONG>wnoutrefresh</STRONG> for each window, it is then pos-
+ sible to call <STRONG>doupdate</STRONG> once, resulting in only one burst of output,
+ with fewer total characters transmitted and less CPU time used. If the
+ <EM>win</EM> argument to <STRONG>wrefresh</STRONG> is the global variable <STRONG>curscr</STRONG>, the screen is
+ immediately cleared and repainted from scratch.
+
+ The phrase "copies the named window to the virtual screen" above is am-
+ biguous. What actually happens is that all <EM>touched</EM> (changed) lines in
+ the window are copied to the virtual screen. This affects programs
+ that use overlapping windows; it means that if two windows overlap, you
+ can refresh them in either order and the overlap region will be modi-
+ fied only when it is explicitly changed. (But see the section on
+ <STRONG>PORTABILITY</STRONG> below for a warning about exploiting this behavior.)