Paper/patches/server/0813-Break-redstone-on-top-of-trap-doors-early.patch
Bjarne Koll c5a10665b8
Remove wall-time / unused skip tick protection (#11412)
Spigot still maintains some partial implementation of "tick skipping", a
practice in which the MinecraftServer.currentTick field is updated not
by an increment of one per actual tick, but instead set to
System.currentTimeMillis() / 50. This behaviour means that the tracked
tick may "skip" a tick value in case a previous tick took more than the
expected 50ms.

To compensate for this in important paths, spigot/craftbukkit
implements "wall-time". Instead of incrementing/decrementing ticks on
block entities/entities by one for each call to their tick() method,
they instead increment/decrement important values, like
an ItemEntity's age or pickupDelay, by the difference of
`currentTick - lastTick`, where `lastTick` is the value of
`currentTick` during the last tick() call.

These "fixes" however do not play nicely with minecraft's simulation
distance as entities/block entities implementing the above behaviour
would "catch up" their values when moving from a non-ticking chunk to a
ticking one as their `lastTick` value remains stuck on the last tick in
a ticking chunk and hence lead to a large "catch up" once ticked again.

Paper completely removes the "tick skipping" behaviour (See patch
"Further-improve-server-tick-loop"), making the above precautions
completely unnecessary, which also rids paper of the previous described
incompatibility with non-ticking chunks.
2024-09-19 16:36:07 +02:00

41 lines
2.6 KiB
Diff

From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: Spottedleaf <Spottedleaf@users.noreply.github.com>
Date: Mon, 1 May 2023 18:31:26 -0700
Subject: [PATCH] Break redstone on top of trap doors early
This logic hooks into the neighbour update which should be invoked
as a result of redstone powering the trap door.
diff --git a/src/main/java/net/minecraft/world/level/block/TrapDoorBlock.java b/src/main/java/net/minecraft/world/level/block/TrapDoorBlock.java
index 82e38b01446d35aa9745be6ff3c7647b46379682..336fcf4af0ffb416b5595a9e65172f36cc36aaa3 100644
--- a/src/main/java/net/minecraft/world/level/block/TrapDoorBlock.java
+++ b/src/main/java/net/minecraft/world/level/block/TrapDoorBlock.java
@@ -153,7 +153,26 @@ public class TrapDoorBlock extends HorizontalDirectionalBlock implements SimpleW
flag1 = eventRedstone.getNewCurrent() > 0;
}
// CraftBukkit end
- if ((Boolean) state.getValue(TrapDoorBlock.OPEN) != flag1) {
+ // Paper start - break redstone on trapdoors early
+ boolean open = (Boolean) state.getValue(TrapDoorBlock.OPEN) != flag1;
+ // note: this must run before any state for this block/its neighborus are written to the world
+ // we allow the redstone event to fire so that plugins can block
+ if (flag1 && open) { // if we are now powered and it caused the trap door to open
+ // in this case, first check for the redstone on top first
+ BlockPos abovePos = pos.above();
+ BlockState above = world.getBlockState(abovePos);
+ if (above.getBlock() instanceof RedStoneWireBlock) {
+ world.setBlock(abovePos, Blocks.AIR.defaultBlockState(), Block.UPDATE_CLIENTS | Block.UPDATE_NEIGHBORS);
+ Block.popResource(world, abovePos, new net.minecraft.world.item.ItemStack(net.minecraft.world.item.Items.REDSTONE));
+ // now check that this didn't change our state
+ if (world.getBlockState(pos) != state) {
+ // our state was changed, so we cannot propagate this update
+ return;
+ }
+ }
+ }
+ if (open) {
+ // Paper end - break redstone on trapdoors early
state = (BlockState) state.setValue(TrapDoorBlock.OPEN, flag1);
this.playSound((Player) null, world, pos, flag1);
}