LIMIT: Difference between revisions

Revision as of 10:06, 29 April 2022

The _LIMIT statement sets the loop repeat rate of a program to so many per second, relinquishing spare CPU cycles to other applications.

_LIMIT framesPerSecond!

The framesPerSecond! SINGLE parameter value adjusts the loops per second of a program loop. Do not use negative values.
The loop code is executed before the loop is delayed. Loop cycles below once per second may delay program _EXITs.
_LIMIT measures its interval from the previous time that it was called and minor adjustments are automatically made to ensure that the number of times a loop is repeated is correct overall.
Loop cycle rates of 1000 or less can significantly reduce CPU usage in programs.
Do not use it to limit a loop to less than once every 60 seconds(.0167) or an ILLEGAL FUNCTION CALL error will occur.
Do not use _LIMIT as a timing delay outside of loops. Use _DELAY instead.
Use _LIMIT to slow down old QBasic program loops that run too fast and use too much CPU.

Example: Limits loop execution to 30 frames per second and limits the program's CPU usage.

  
PRINT "To Quit press ESC key!"
DO
   _LIMIT 30
   PRINT CHR$(26);
   IF INKEY$ = CHR$(27) THEN EXIT DO  
LOOP

To Quit press ESC key!
→→→→→→→→→→→→→→→→→→→→

Note: In the above example, _LIMIT has to be within the loop.

@@ Line 13: / Line 13: @@
 * Do not use it to limit a loop to '''less than once every 60 seconds'''(.0167) or an [[ERROR Codes|ILLEGAL FUNCTION CALL error]] will occur.
 * Do not use _LIMIT as a timing delay outside of loops. Use [[_DELAY]] instead.
-* Use _LIMIT to slow down old Qbasic program loops that run too fast and use too much CPU.
+* Use _LIMIT to slow down old QBasic program loops that run too fast and use too much CPU.