BlockPieces

Textured geometry of a single block, for thumbnails, a block under the cursor or a template being placed. Tile rotation and the $missing blockset look the same as in the world.

import { BlockPieces, VoxelTransform } from "@jolly-pixel/voxel.renderer";

const pieces = new BlockPieces({
  shapes: view.shapes,
  atlases: view.atlases
});
const piece = pieces.resolvePiece(block, new VoxelTransform({ rotation: 1 }));

const BLOCK_PIECE_TEXTURED_GROUP = 0;
const BLOCK_PIECE_EMPTY_GROUP = 1;

type EmptyTileProbe = (
  ref: ResolvedTileRef | undefined,
  alphaCutoff: number
) => boolean;

interface BlockPiecesOptions {
  shapes: BlockShapeRegistry;
  atlases: BlocksetAtlases;
  emptyTile?: EmptyTileProbe;
}

interface BlockPiece {
  readonly geometry: THREE.BufferGeometry;
  readonly texture: THREE.Texture | null;
  readonly surface: BlockSurface;
}

class BlockPieces {
  constructor(options: BlockPiecesOptions);

  resolvePiece(
    block: ResolvedBlockDefinition,
    transform?: VoxelTransform
  ): BlockPiece | null;
  buildGeometry(
    block: ResolvedBlockDefinition,
    transform?: VoxelTransform
  ): THREE.BufferGeometry | null;
  resolveTexture(block: ResolvedBlockDefinition): THREE.Texture | null;
  findEmptySlots(block: ResolvedBlockDefinition): string[];
  clear(): void;
}

buildGeometry() returns a new geometry in block space, 0 to 1, with one group per texture slot. A slot whose tile emptyTile reports empty uses material index BLOCK_PIECE_EMPTY_GROUP, the others BLOCK_PIECE_TEXTURED_GROUP. Without a probe, only a slot with no tile is empty. It returns null for an unknown shape, and the caller owns the result.

findEmptySlots() lists the slots buildGeometry() puts in the empty group.

resolveTexture() returns the atlas texture of the blockset defaultTexture names, or the $missing texture when that blockset is not declared.

resolvePiece() caches one piece per block object and transform, and owns its geometry: do not dispose or transform it. The cache empties when the atlases change. clear() empties it and disposes the cached geometries.