world: add types to wrap common parts of section data

src/world/chunk.rs

@@ -0,0 +1,111 @@
+use std::collections::BTreeMap;
+
+use anyhow::{bail, Context, Result};
+
+use super::{
+	de,
+	section::{OldSection, PaletteSection, PaletteSectionBiomes},
+};
+use crate::types::*;
+
+pub enum Chunk<'a> {
+	V1_18 {
+		section_map: BTreeMap<SectionY, (PaletteSection<'a>, PaletteSectionBiomes<'a>)>,
+	},
+	V1_13 {
+		section_map: BTreeMap<SectionY, PaletteSection<'a>>,
+		biomes: &'a de::BiomesOld,
+	},
+	Old {
+		section_map: BTreeMap<SectionY, OldSection<'a>>,
+		biomes: &'a de::BiomesOld,
+	},
+	Empty,
+}
+
+impl<'a> Chunk<'a> {
+	pub fn new(data: &'a de::Chunk) -> Result<Self> {
+		let data_version = data.data_version.unwrap_or_default();
+
+		match &data.chunk {
+			de::ChunkVariants::V1_18 { sections } => Self::new_v1_18(data_version, sections),
+			de::ChunkVariants::Old { level } => Self::new_old(data_version, level),
+		}
+	}
+
+	fn new_v1_18(data_version: u32, sections: &'a Vec<de::SectionV1_18>) -> Result<Self> {
+		let mut section_map = BTreeMap::new();
+
+		for section in sections {
+			section_map.insert(
+				SectionY(section.y),
+				(
+					PaletteSection::new(
+						data_version,
+						section.block_states.data.as_ref(),
+						&section.block_states.palette,
+					)
+					.with_context(|| format!("Failed to load section at Y={}", section.y))?,
+					PaletteSectionBiomes::new(
+						section.biomes.data.as_ref(),
+						&section.biomes.palette,
+					)
+					.with_context(|| format!("Failed to load section biomes at Y={}", section.y))?,
+				),
+			);
+		}
+
+		Ok(Chunk::V1_18 { section_map })
+	}
+
+	fn new_old(data_version: u32, level: &'a de::LevelOld) -> Result<Self> {
+		let mut section_map_v1_13 = BTreeMap::new();
+		let mut section_map_old = BTreeMap::new();
+
+		for section in &level.sections {
+			match &section.section {
+				de::SectionOldVariants::V1_13 {
+					block_states,
+					palette,
+				} => {
+					section_map_v1_13.insert(
+						SectionY(section.y.into()),
+						PaletteSection::new(data_version, Some(block_states), palette)
+							.with_context(|| {
+								format!("Failed to load section at Y={}", section.y)
+							})?,
+					);
+				}
+				de::SectionOldVariants::Old { blocks, data } => {
+					section_map_old.insert(
+						SectionY(section.y.into()),
+						OldSection::new(blocks, data).with_context(|| {
+							format!("Failed to load section at Y={}", section.y)
+						})?,
+					);
+				}
+				de::SectionOldVariants::Empty {} => {}
+			}
+		}
+
+		// TODO Check biomes length
+		let biomes = level.biomes.as_ref().context("Invalid biome data");
+
+		Ok(
+			match (section_map_v1_13.is_empty(), section_map_old.is_empty()) {
+				(true, true) => Chunk::Empty,
+				(false, true) => Chunk::V1_13 {
+					section_map: section_map_v1_13,
+					biomes: biomes?,
+				},
+				(true, false) => Chunk::Old {
+					section_map: section_map_old,
+					biomes: biomes?,
+				},
+				(false, false) => {
+					bail!("Mixed section versions");
+				}
+			},
+		)
+	}
+}