Slabbed

Hotfix for 0.5.2-beta.1, which failed to start in a real launcher.

Starts in real launchers again. Two problems that never showed in the development setup: a crosshair-targeting patch named a method that only exists on newer Minecraft versions, so the game failed while loading; and the bundled MixinExtras library was pinned to a range that could not sit next to Terrain Slabs, so Forge refused to load both mods together. Both are fixed; the mod now bundles MixinExtras 0.5.5.

A deep side placement lands on the real surface, never inside it. Clicking a lowered block's side face still lands the new slab at the height of the face you aimed at, but when the landing cell has solid ground directly under it the slab now seats on that ground, flush over a full block, exactly where a click on the ground itself would put it, instead of being recorded a full block deep inside the dirt. Side placements over open air keep following the aim all the way down.

A lowered slab that changes kind in place keeps its height. A Terrain Slabs grass slab turns into a dirt slab when you cover it, the way vanilla grass turns to dirt. On a lowered stack the converted slab popped back up to grid height and sank into the block above it, because the change of block kind was treated like the slab leaving its cell. A block that changes kind but keeps its shape is the same thing you placed, so it now keeps its height. That also covers a full block replaced in place by another full block. A change of shape, a slab becoming a carpet or a full block becoming a slab, still counts as a new block.

Item frames and paintings hang where you see the block, and remember it. A frame or painting placed on a lowered block's visible face hung at normal grid height, floating above (or beside) the surface it was aimed at. Both now hang on the drawn face, and both remember the height of the face they were hung on: it is decided once, when you hang them, saved with the world, and never re-read from the wall. Rebuilding the wall behind a frame at a different height moves the wall, not the frame. Frames and paintings from an older save take their height from their wall once, the first time they load, and remember it from then on.

Wall signs were checked too: a wall sign hangs on its wall and is never pulled down by a slab on the floor under it. An automated check for that scene now runs on every Minecraft version Slabbed supports. Thanks to ciambos on CurseForge and lochy-hash on GitHub for reporting this (GitHub issue #48).