OpenGl Frame rate

Question

What would be the best way to measure the frame rate of my OpenGL program?

Answer 1

Measure the elapsed time and count the number of frames. Divide one by the other to give frame rate.

When the elapsed time reached one second, or more if you want to average it over a longer time period reset both counts and start again.

Answer 2

Stick a timer at the start of your main loop and test how long it takes to get back there.

Under windows you would do something like:

double oldTime  = 0.0.
while( !exit )
{
    __int64 counter;
    QueryPerformanceCounter( (LARGE_INTEGER*)&counter );

    __int64 frequency;
    QueryPerformanceFrequency( (LARGE_INTEGER*)&frequency );

    double newTime   = (double)counter / (double)frequency;
    double frameRate  = 1.0 / (newTime - oldTime);
    oldTime   = newTime;

    // Rest of your game loop goes here. 
}

Answer 3

SPF (Seconds Per Frame) is a bit more informative metric.