From 5c82b80924d4c2b093ad8b71faffeb7df851c4f0 Mon Sep 17 00:00:00 2001
From: Matthias Schiffer <mschiffer@universe-factory.net>
Date: Thu, 2 Mar 2023 00:19:01 +0100
Subject: [PATCH] world/section: replace block_id_at() method with block_at()

Directly return a BlockType, preparing for early lookup of palettes.
---
 src/main.rs          |  2 +-
 src/world/layer.rs   |  8 +++-----
 src/world/section.rs | 25 +++++++++++++++----------
 3 files changed, 19 insertions(+), 16 deletions(-)

diff --git a/src/main.rs b/src/main.rs
index c351230..80f2b25 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -76,7 +76,7 @@ impl<'a> RegionProcessor<'a> {
 	/// Processes a single chunk
 	fn process_chunk(&self, data: world::de::Chunk) -> Result<Box<world::layer::BlockInfoArray>> {
 		let chunk = world::chunk::Chunk::new(&data, &self.block_types)?;
-		world::layer::top_layer(&chunk, &self.block_types)
+		world::layer::top_layer(&chunk)
 	}
 
 	fn save_region(
diff --git a/src/world/layer.rs b/src/world/layer.rs
index 0039136..a5d8383 100644
--- a/src/world/layer.rs
+++ b/src/world/layer.rs
@@ -4,7 +4,7 @@ use serde::{Deserialize, Serialize};
 
 use super::chunk::Chunk;
 use crate::{
-	resource::{BlockFlag, BlockType, BlockTypes},
+	resource::{BlockFlag, BlockType},
 	types::*,
 };
 
@@ -92,7 +92,7 @@ pub type BlockInfoArray = LayerBlockArray<Option<BlockInfo>>;
 /// determined as the block that should be visible on the rendered
 /// map. For water blocks, the height of the first non-water block
 /// is additionally filled in as the water depth.
-pub fn top_layer(chunk: &Chunk, block_types: &BlockTypes) -> Result<Box<BlockInfoArray>> {
+pub fn top_layer(chunk: &Chunk) -> Result<Box<BlockInfoArray>> {
 	use BLOCKS_PER_CHUNK as N;
 
 	let mut done = 0;
@@ -109,9 +109,7 @@ pub fn top_layer(chunk: &Chunk, block_types: &BlockTypes) -> Result<Box<BlockInf
 		}
 
 		let coords = SectionBlockCoords { xz, y };
-		let block_id = section.block_id_at(coords)?;
-		let Some(block_type) = block_types.get(block_id) else {
-			eprintln!("Unknown block type: {}", block_id);
+		let Some(block_type) = section.block_at(coords)? else {
 			continue;
 		};
 		let height = BlockHeight::new(section_y, y)?;
diff --git a/src/world/section.rs b/src/world/section.rs
index 9cf733a..471f5d0 100644
--- a/src/world/section.rs
+++ b/src/world/section.rs
@@ -3,7 +3,7 @@ use num_integer::div_rem;
 
 use super::de;
 use crate::{
-	resource::{self, BlockTypes},
+	resource::{BlockType, BlockTypes},
 	types::*,
 };
 
@@ -27,7 +27,7 @@ fn palette_bits(len: usize, min: u8, max: u8) -> Option<u8> {
 
 /// Trait for common functions of [SectionV1_13] and [SectionV0]
 pub trait Section {
-	fn block_id_at(&self, coords: SectionBlockCoords) -> Result<&str>;
+	fn block_at(&self, coords: SectionBlockCoords) -> Result<Option<BlockType>>;
 }
 
 /// Minecraft v1.18+ section biome data
@@ -68,7 +68,7 @@ impl<'a> BiomesV18<'a> {
 pub struct SectionV1_13<'a> {
 	block_states: Option<&'a fastnbt::LongArray>,
 	palette: &'a Vec<de::BlockStatePaletteEntry>,
-	_block_types: &'a BlockTypes,
+	block_types: &'a BlockTypes,
 	bits: u8,
 	aligned_blocks: bool,
 }
@@ -100,7 +100,7 @@ impl<'a> SectionV1_13<'a> {
 		Ok(Self {
 			block_states,
 			palette,
-			_block_types: block_types,
+			block_types,
 			bits,
 			aligned_blocks,
 		})
@@ -137,13 +137,18 @@ impl<'a> SectionV1_13<'a> {
 }
 
 impl<'a> Section for SectionV1_13<'a> {
-	fn block_id_at(&self, coords: SectionBlockCoords) -> Result<&str> {
+	fn block_at(&self, coords: SectionBlockCoords) -> Result<Option<BlockType>> {
 		let index = self.palette_index_at(coords);
 		let entry = self
 			.palette
 			.get(index)
 			.context("Palette index out of bounds")?;
-		Ok(&entry.name)
+
+		let block_type = self.block_types.get(&entry.name);
+		if block_type.is_none() {
+			eprintln!("Unknown block type: {}", entry.name);
+		}
+		Ok(block_type)
 	}
 }
 
@@ -152,7 +157,7 @@ impl<'a> Section for SectionV1_13<'a> {
 pub struct SectionV0<'a> {
 	blocks: &'a fastnbt::ByteArray,
 	data: &'a fastnbt::ByteArray,
-	_block_types: &'a BlockTypes,
+	block_types: &'a BlockTypes,
 }
 
 impl<'a> SectionV0<'a> {
@@ -174,13 +179,13 @@ impl<'a> SectionV0<'a> {
 		Ok(SectionV0 {
 			blocks,
 			data,
-			_block_types: block_types,
+			block_types,
 		})
 	}
 }
 
 impl<'a> Section for SectionV0<'a> {
-	fn block_id_at(&self, coords: SectionBlockCoords) -> Result<&str> {
+	fn block_at(&self, coords: SectionBlockCoords) -> Result<Option<BlockType>> {
 		let offset = coords.offset();
 		let block = self.blocks[offset] as u8;
 
@@ -192,6 +197,6 @@ impl<'a> Section for SectionV0<'a> {
 			data_byte & 0xf
 		};
 
-		Ok(resource::LEGACY_BLOCK_TYPES[block as usize][data as usize])
+		Ok(self.block_types.get_legacy(block, data))
 	}
 }