QB64-PE/internal/help/_LIMIT.txt

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


{{PageSyntax}} 
::[[_LIMIT]] ({{Parameter|LoopsPerSecond!}})


* The frames per second [[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 [[_EXIT]]s!
* _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 useage''' in programs!
* 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.


''Example:'' Limits loop execution to 30 frames per second and limits the program's CPU usage.
{{CodeStart}} '' ''
{{Cl|PRINT}} "To Quit press ESC key!"
{{Cl|DO}}
   {{Cl|_LIMIT}} 30
   {{Cl|PRINT}} {{Cl|CHR$}}(26);
   {{Cl|IF...THEN|IF}} {{Cl|INKEY$}} = {{Cl|CHR$}}(27) {{Cl|THEN}} {{Cl|EXIT DO}} '' ''
{{Cl|LOOP}} 
{{CodeEnd}}
{{OutputStart}}
To Quit press ESC key!
→→→→→→→→→→→→→→→→→→→→
{{OutputEnd}}
:''Note:'' In the above example, _LIMIT has to be within the loop.



{{PageSeeAlso}}
* [[_DELAY]]
* [[TIMER]], [[ON TIMER(n)]]
* [[SLEEP]]


{{PageNavigation}}