[1.16.5] Giving potion effect based on the light level of the block player is standing on

[Sinu]

I am trying to give a blinding effect to players who are in light level of 0 but I can't seem to get it to work.

@SubscribeEvent
    public static void onPlayerTick(TickEvent.PlayerTickEvent event)
    {
		PlayerEntity player = event.player;
		World world = event.player.level;
		BlockPos blockpos = player.blockPosition();
		BlockState block = world.getBlockState(blockpos);
		
		if (block.getLightValue(world, blockpos) == 0 && block != null)
		{
			((LivingEntity)event.player).addEffect(new EffectInstance(Effects.BLINDNESS, 20, 3));
		}
    }

Am I using getLightValue correctly? Also I am correctly feeding in the correct block position?

Edited July 8, 2021 by Sinu

[Sinu]

I see. What is the second int parameter in World#getRawBrightness for? I looked at the reference and it just seems to subtract it? Not sure why..
Also I believe I tried using World#getBrightness with LightType.BLOCK but I don't think it detected the light level properly. I am trying to give the Blindness effect to players who walk into caves with light levels of 0.

[Sinu]

Sweet, that seems to have worked!
The one issue is that, I had to check if the instance was client or server because for some reason the server kept thinking the light level of the player is always 0 (is it client-side only?). So my code looks like this now:

PlayerEntity player = event.player;
		World world = event.player.level;
		BlockPos blockpos = player.blockPosition();
		BlockState block = world.getBlockState(blockpos);
		
		if (world.isClientSide)
		{
			System.out.print(world.getMaxLocalRawBrightness(blockpos) + System.lineSeparator());
			if (world.getMaxLocalRawBrightness(blockpos) == 0)
			{
				((LivingEntity)event.player).addEffect(new EffectInstance(Effects.BLINDNESS, 20, 3));	
			}
		}

But now once I walk out of the light level of 0, it still says that I have the Blindness effect even though I can see clearly. I am assuming that since I checked if the instance is client-side or not, it didn't actually give the potion effect according to the server (which makes sense) but I don't understand why Blindness goes away even after I walk into the light?

[Sinu]

Thanks for the reply. I will work around it for now!