LIMIT: Difference between revisions
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{{DISPLAYTITLE:_LIMIT}} | {{DISPLAYTITLE:_LIMIT}} | ||
The [[_LIMIT]] statement sets the loop repeat rate of a program to so many per second, relinquishing spare CPU cycles to other applications. | The [[_LIMIT]] statement sets the loop repeat rate of a program to so many per second, relinquishing spare CPU cycles to other applications. | ||
{{PageSyntax}} | {{PageSyntax}} | ||
: [[_LIMIT]] {{Parameter|framesPerSecond!}} | : [[_LIMIT]] {{Parameter|framesPerSecond!}} | ||
Line 23: | Line 23: | ||
{{Cl|_LIMIT}} 30 | {{Cl|_LIMIT}} 30 | ||
{{Cl|PRINT}} {{Cl|CHR$}}(26); | {{Cl|PRINT}} {{Cl|CHR$}}(26); | ||
{{Cl|IF...THEN|IF}} {{Cl|INKEY$}} = {{Cl|CHR$}}(27) {{Cl|THEN}} {{Cl|EXIT DO}} | {{Cl|IF...THEN|IF}} {{Cl|INKEY$}} = {{Cl|CHR$}}(27) {{Cl|THEN}} {{Cl|EXIT DO}} | ||
{{Cl|LOOP}} | {{Cl|LOOP}} | ||
{{CodeEnd}} | {{CodeEnd}} | ||
{{OutputStart}} | {{OutputStart}} |
Revision as of 01:56, 23 January 2023
The _LIMIT statement sets the loop repeat rate of a program to so many per second, relinquishing spare CPU cycles to other applications.
Syntax
- _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.
Examples
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.
See also