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Bug
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Resolution: Unresolved
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None
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24w45a
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None
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Unconfirmed
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(Unassigned)
With the fix of MC-272062, the dimension_padding option in jigsaw structures behaves differently when set to 0 vs omitting the field. The 24w19a change-log specifies that dimension_padding is an optional field with a default value of 0.
How to reproduce:
- Create a new world with the attached datapack
- This datapack adds 2 structures, test:red and test:blue.
- Both structures are projected to the OCEAN_FLOOR_WG heightmap and are set to generate in all end biomes
- test:red has "dimension_padding": 0 set
- test:blue doesn't specify a dimension_padding field
- Teleport to the end: /execute in minecraft:the_end run tp @s 2000 100 0
- Look around:
- On end islands both red and blue structures generate
- In areas with no end islands, only the blue structures generate
Expected Result:
I'd expect the structures to behave identically because the only difference is adding a field and setting it to the default value.
Code analysis:
This bug happens in the check for the start piece.
net.minecraft.world.level.levelgen.structure.pools.JigsawPlacement.isStartTooCloseToWorldHeightLimits:
if (dimensionPadding == DimensionPadding.ZERO) { return false; } else { \\...
This disables dimension padding only when the pre-defined ZERO dimension padding object is used.
- When the field isn't specified the ZERO is used as the default
- When manually specifying 0 a new object with 0 padding is used, failing the check
A fix would be replacing the == with a .equals call.
Note:
In case this different behavior for omitting the field is intended, I would like to point out:
- The dimension padding is always active for all jigsaw pieces other than the start piece.
- The .optionalFieldOf CODEC method uses .equals when comparing a value with the default during encoding. This means that the data generator can never produce the dimension_padding field with the value of 0, since it would be omitted in this case. In other words: The encoding -> decoding possibly changes the behavior of the dimension padding when set to 0.