Source Mouse acceleration explanation

	float mouse_sensitivity = ( gHUD.GetSensitivity() != 0 ) // mouse sens != 0
		?  gHUD.GetSensitivity() : sensitivity.GetFloat(); //get mouse sens

	if ( m_customaccel.GetInt() == 1 ||  m_customaccel.GetInt() == 2 ) //if m_customaccel == 1 || == 2
	{
		float raw_mouse_movement_distance = sqrt( mx * mx + my * my ); //linear curve where sqrt(mx * mx) = mx
		float acceleration_scale = m_customaccel_scale.GetFloat(); // scale of acceleration
		float accelerated_sensitivity_max = m_customaccel_max.GetFloat(); //max sensitivity you can reach
		float accelerated_sensitivity_exponent = m_customaccel_exponent.GetFloat(); //exponent = movement raised to the power of exponent
		float accelerated_sensitivity = ( (float)pow( raw_mouse_movement_distance, accelerated_sensitivity_exponent ) * acceleration_scale + mouse_sensitivity ); //((power of float(distance of linear movement, exponent)) * scale + mouse_sensitivity)

		if ( accelerated_sensitivity_max > 0.0001f &&
			accelerated_sensitivity > accelerated_sensitivity_max ) //if accelerated max > 0.0001 and accelerated sens is over max
		{
			accelerated_sensitivity = accelerated_sensitivity_max; //set accelerated sens to max
		}

		*x *= accelerated_sensitivity; //multiply movement by accelerated sensitivity on pitch
		*y *= accelerated_sensitivity;  //multiply movement by accelerated sensitivity on yaw

		if ( m_customaccel.GetInt() == 2 || m_customaccel.GetInt() == 4 ) //if m_customaccel == 2 || == 4
		{
			*x *= m_yaw.GetFloat();  //use m_yaw value for accel
			*y *= m_pitch->GetFloat();  //use m_pitch value for accel
		}
	}
	else if ( m_customaccel.GetInt() == 3 )
	{
		float raw_mouse_movement_distance_squared = mx * mx + my * my; //hyperbola where (mx * mx) = (mx ^ 2)
		float fExp = MAX(0.0f, (m_customaccel_exponent.GetFloat() - 1.0f) / 2.0f); //returns largest of (0.0f) and (m_customaccel_exponent - 1.0f) / 2.0f) if both are the same, 0.0f is returned.
		float accelerated_sensitivity = powf( raw_mouse_movement_distance_squared, fExp ) * mouse_sensitivity; //power of float (movement distance in hyperbola, result of exponent) * mouse_sensitivity;

		*x *= accelerated_sensitivity; //multiply movement by accelerated sensitivity on pitch
		*y *= accelerated_sensitivity; //multiply movement by accelerated sensitivity on yaw
	}
	else
	{
		*x *= mouse_sensitivity; //if accel is not enabled, handle mouse sensitivity normally on pitch
		*y *= mouse_sensitivity; //if accel is not enabled, handle mouse sensitivity normally on yaw
	}
}