Function handleVisionFx

TheForceEngine/TFE_DarkForces/mission.cpp:482–503

In DOS, this was part of drawWorld() - for TFE I split it out to limit the amount of game code in the renderer.

	// In DOS, this was part of drawWorld() - 
	// for TFE I split it out to limit the amount of game code in the renderer.
	void handleVisionFx()
	{
		// Countdown to enable the night vision effect.
		if (s_visionFxCountdown != 0)
		{
			s_visionFxCountdown--;
			if (s_visionFxCountdown == 0)
			{
				setLuminanceMask(JFALSE, JTRUE, JFALSE);
			}
		}

		// Countdown to disable the night vision effect.
		if (s_visionFxEndCountdown != 0)
		{
			s_visionFxEndCountdown--;
			if (s_visionFxEndCountdown == 0)
			{
				setLuminanceMask(JFALSE, JFALSE, JFALSE);
			}
		}
	}

	void mission_exitLevel()
	{