obs-studio/plugins/obs-transitions/easings.h

#pragma once

static inline float cubic_ease_in_out(float t)
{
	if (t < 0.5f) {
		return 4.0f * t * t * t;
	} else {
		float temp = (2.0f * t - 2.0f);
		return (t - 1.0f) * temp * temp + 1.0f;
	}
}