Getting delta time of OpenGL in Qt?

[benjysugi]

Hi,

How would I get delta time/frame time of OpenGL widget in Qt?

[Chris Kawa]

Depends on what you call a frame. Is it the time CPU spends on calculations for displaying, submitting work to the driver, the driver submitting commands to the GPU, GPU executing graphics and compute shaders, presenting a framebuffer to the output device, v-blank interval, v-sync points etc. Different apps different needs.

If all you want to know is how much time passes between calls to QOpenGLWidget::paintGL then simply create a QElapsedTimer and call its restart() method. It will give you the time elapsed since you last called it.