How Can QueryPerformanceCounter Achieve Precise Timing in C ?

QueryPerformanceCounter: A Guide to Timing Precision

To enhance the precision of your Timer class, you've opted for QueryPerformanceCounter. However, its implementation can be elusive.

The crux of QueryPerformanceCounter lies in the LARGE_INTEGER structure, which stores a 64-bit integer representing the timestamp in counts. To determine the frequency of the counter, you employ QueryPerformanceFrequency and assign its output to PCFreq, which represents the number of ticks per second.

Next, StartCounter initializes the counter by capturing the current timestamp and assigning it to CounterStart. GetCounter retrieves the current timestamp and computes the elapsed time from CounterStart, dividing the result by PCFreq to convert it to seconds.

For microsecond precision, reduce PCFreq to its thousandth part. Alternatively, remove the division by 1000 to measure in seconds.

The provided code exemplifies the usage of QueryPerformanceCounter. Calling StartCounter commences the timer, and GetCounter returns the elapsed time since its last invocation.

This approach grants you precise timing, offering a significant improvement over millisecond intervals.

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