Support 1.12 and 1.13+ worlds in the same Chunky version

[leMaik]

A lot of things changed in the flattening and the new updated shiny version of Chunky doesn't support 1.12 and older worlds anymore. That leads to inconsistencies (1.12 Chunky doesn't have the new UI) and bug fixes not being applied to both versions.

By abstracting away from the world format and refactoring some things, it should be possible to open 1.12 and 1.13+ worlds in the same Chunky version one day.

[carterlasalle]

What changes so much that doesn't allow it to happen at the moment

[leMaik]

@RocketNinja15 The blocks are stored differently and instead of having block states for everything, Chunky has to implement a lot of Minecraft's block connection logic (i.e. redstone wire behavior, door rotation, …) for pre-flattening (<1.13) worlds. Also since blocks can be waterlogged as of 1.13, there are two octrees in Chunky now.

I have a proof-of-concept branch that can load 1.12 worlds and converts the blocks to Chunky 2.x blocks while loading the chunks. Doesn't support most of the blocks yet, but it's a start. The good thing is thatold Minecraft doesn't get updated, so there won't be new blocks to add to this conversion process at some point and it will be done.

[leMaik]

This is currently being worked on by @alexhliu and me. 🙃
https://github.com/leMaik/chunky/tree/legacy-block-finalization

Legacy block types that need to be finalized:

• fire
• stairs
• chest
• trapped chest
• redstone_wire
• door
• fence
• glass pane, stained glass pane
• stone wall
• iron bars
• vine
• fence_gate
• tripwire
• double plant
• chorus_plant
• large fern
• melon stem
• pumpkin stem

Blocks that were treated specially in Chunky 1.4.5 (https://github.com/chunky-dev/chunky/blob/chunky-1.x/chunky/src/java/se/llbit/chunky/renderer/scene/Scene.java#L855):

• vines
• stationary_water (mapped to water)
• water
• fire
• stationary lava (mapped to lava
• lava
• grass (might be snow covered)
• mycelium (might be snow covered)
• podzol (might be snow covered)
• doors
• bed (for pre-1.12 default color)

Some blocks used to have tile entities (we need to update the blocks in the octree):

• 1.12 bed color
• wall sign
• sign
• skull
• standing banner
• wall banner
• 1.7+ flower pots

• Chunky 1.x: https://github.com/chunky-dev/chunky/blob/chunky-1.x/chunky/src/java/se/llbit/chunky/renderer/scene/Scene.java#L989, https://github.com/chunky-dev/chunky/blob/chunky-1.x/chunky/src/java/se/llbit/chunky/renderer/scene/OctreeFinalizer.java#L88
• Chunky 2.x: https://github.com/chunky-dev/chunky/blob/master/chunky/src/java/se/llbit/chunky/renderer/scene/Scene.java#L1247

[leMaik]

We should test against the scenes from #434 later.

[ShirleyNekoDev]

Tested the PR with my old worlds and found the following problems:

• cocoa beans orientation
  
• nether portal orientation
  
• vine orientation (connect top part to open trapdoor, corner has only 1 side)
  
  
• enabling ESS reload breaks scene loading (noticed in a scene with redstone_wire which then does not get finalized anymore -> UnfinalizedLegacyBlock)

[leMaik]

• Trapdoor orientation is wrong
• Trapdoor ignores half
• Some leaves render as oak leaves
• Fences and walls should not connect to glass blocks

[leMaik]

@ShirleyNekoDev Fixed, please continue testing 😄 Can you check the vines bug again? Because I didn't even manage to get such an edge ingame (although it is possible for a vine to have up to 5 faces).

[ShirleyNekoDev]

Trapdoor vines are fixed 👍

Corner vines not - World: vines_bug.zip

[leMaik]

@ShirleyNekoDev Corner vines work fine if the block data is set correctly. In the world you sent, the block data of the vines is either 0 or 8. Even when I set that ingame in 1.12, the blocks don't show up as corner blocks. When I set corner block data, e.g. 9, it works (ingame and in Chunky). So I don't know how to fix this.

[leMaik]

This is from the world you sent. The top block is correct, the ones below it somehow are not? 🤔

Edit: looks the same ingame (1.12)