azalea-world uses azalea-block

6 files changed, 76 insertions, 6 deletions

diff --git a/Cargo.lock b/Cargo.lock
index 1ef95311..f3b5df08 100755
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -183,6 +183,7 @@ dependencies = [
 name = "azalea-world"
 version = "0.1.0"
 dependencies = [
+ "azalea-block",
  "azalea-core",
  "azalea-nbt",
  "azalea-protocol",
diff --git a/azalea-block/block-macros/src/lib.rs b/azalea-block/block-macros/src/lib.rs
index d38062d4..6206bb65 100644
--- a/azalea-block/block-macros/src/lib.rs
+++ b/azalea-block/block-macros/src/lib.rs
@@ -461,9 +461,12 @@ pub fn make_block_states(input: TokenStream) -> TokenStream {
         block_structs.extend(block_struct);
     }
 
+    let last_state_id = (state_id - 1) as u32;
     quote! {
         #property_enums
 
+        #[repr(u32)]
+        #[derive(Copy, Clone, PartialEq, Eq, Debug)]
         pub enum BlockState {
             #block_state_enum_variants
         }
@@ -479,6 +482,15 @@ pub fn make_block_states(input: TokenStream) -> TokenStream {
                 }
             }
         }
+
+        impl BlockState {
+            /// Returns the highest possible state
+            #[inline]
+            pub fn max_state() -> u32 {
+                #last_state_id
+            }
+        }
+
     }
     .into()
 }
diff --git a/azalea-block/src/lib.rs b/azalea-block/src/lib.rs
index 01c86b11..95e8ce37 100644
--- a/azalea-block/src/lib.rs
+++ b/azalea-block/src/lib.rs
@@ -4,3 +4,44 @@ mod blocks;
 pub use behavior::BlockBehavior;
 pub use blocks::*;
 
+use std::mem;
+
+impl BlockState {
+	/// Transmutes a u32 to a block state. UB if the value is not a valid block
+	/// state.
+	#[inline]
+	pub unsafe fn from_u32_unsafe(state_id: u32) -> Self {
+		mem::transmute::<u32, BlockState>(state_id)
+	}
+
+	#[inline]
+	pub fn is_valid_state(state_id: u32) -> bool {
+		state_id <= Self::max_state()
+	}
+}
+
+impl TryFrom<u32> for BlockState {
+	type Error = ();
+
+	/// Safely converts a state id to a block state.
+	fn try_from(state_id: u32) -> Result<Self, Self::Error> {
+		if Self::is_valid_state(state_id) {
+			Ok(unsafe { Self::from_u32_unsafe(state_id) })
+		} else {
+			Err(())
+		}
+	}
+}
+
+#[cfg(test)]
+mod tests {
+	use super::*;
+
+	#[test]
+	fn test_from_u32() {
+		assert_eq!(BlockState::try_from(0).unwrap(), BlockState::Air);
+
+		assert!(BlockState::try_from(BlockState::max_state()).is_ok());
+		assert!(BlockState::try_from(BlockState::max_state() + 1).is_err());
+	}
+}
diff --git a/azalea-world/Cargo.toml b/azalea-world/Cargo.toml
index e8d81ac3..79e6155d 100644
--- a/azalea-world/Cargo.toml
+++ b/azalea-world/Cargo.toml
@@ -9,3 +9,4 @@ version = "0.1.0"
 azalea-core = {path = "../azalea-core"}
 azalea-nbt = {path = "../azalea-nbt"}
 azalea-protocol = {path = "../azalea-protocol"}
+azalea-block = {path = "../azalea-block"}
diff --git a/azalea-world/src/bit_storage.rs b/azalea-world/src/bit_storage.rs
index aba52aef..c69cb216 100644
--- a/azalea-world/src/bit_storage.rs
+++ b/azalea-world/src/bit_storage.rs
@@ -188,6 +188,12 @@ impl BitStorage {
         let bit_index = (index - cell_index * self.values_per_long as usize) * self.bits;
         *cell = *cell & !(self.mask << bit_index) | (value & self.mask) << bit_index;
     }
+
+    /// The number of entries.
+    #[inline]
+    pub fn size(&self) -> usize {
+        self.size
+    }
 }
 
 #[cfg(test)]
diff --git a/azalea-world/src/lib.rs b/azalea-world/src/lib.rs
index 766c61f0..8777c0a3 100644
--- a/azalea-world/src/lib.rs
+++ b/azalea-world/src/lib.rs
@@ -8,6 +8,7 @@ use azalea_core::{BlockPos, ChunkBlockPos, ChunkPos, ChunkSectionBlockPos};
 use azalea_protocol::mc_buf::{McBufReadable, McBufWritable};
 pub use bit_storage::BitStorage;
 use palette::PalettedContainer;
+use azalea_block::BlockState;
 use std::{
     io::{Read, Write},
     ops::{Index, IndexMut},
@@ -57,7 +58,7 @@ impl World {
         self.storage.view_center = *pos;
     }
 
-    pub fn get_block_state(&self, pos: &BlockPos) -> Option<u32> {
+    pub fn get_block_state(&self, pos: &BlockPos) -> Option<BlockState> {
         self.storage.get_block_state(pos, self.min_y)
     }
 }
@@ -122,7 +123,7 @@ impl ChunkStorage {
             && (chunk_pos.z - self.view_center.z).unsigned_abs() <= self.chunk_radius
     }
 
-    pub fn get_block_state(&self, pos: &BlockPos, min_y: i32) -> Option<u32> {
+    pub fn get_block_state(&self, pos: &BlockPos, min_y: i32) -> Option<BlockState> {
         let chunk_pos = ChunkPos::from(pos);
         println!("chunk_pos {:?} block_pos {:?}", chunk_pos, pos);
         let chunk = &self[&chunk_pos];
@@ -175,7 +176,7 @@ impl Chunk {
         (y.div_floor(16) - min_section_index) as u32
     }
 
-    pub fn get(&self, pos: &ChunkBlockPos, min_y: i32) -> u32 {
+    pub fn get(&self, pos: &ChunkBlockPos, min_y: i32) -> BlockState {
         let section_index = self.section_index(pos.y, min_y);
         // TODO: make sure the section exists
         let section = &self.sections[section_index as usize];
@@ -210,6 +211,14 @@ impl McBufReadable for Section {
         //     "A section has more blocks than what should be possible. This is a bug!"
         // );
         let states = PalettedContainer::read_with_type(buf, &PalettedContainerType::BlockStates)?;
+        for i in 0..states.storage.size() {
+            if !BlockState::is_valid_state(states.storage.get(i) as u32) {
+                return Err(format!(
+                    "Invalid block state {} (index {}) found in section.",
+                    states.storage.get(i), i
+                ));
+            }
+        }
         let biomes = PalettedContainer::read_with_type(buf, &PalettedContainerType::Biomes)?;
         Ok(Section {
             block_count,
@@ -229,9 +238,9 @@ impl McBufWritable for Section {
 }
 
 impl Section {
-    // TODO: return a BlockState instead of a u32
-    fn get(&self, pos: ChunkSectionBlockPos) -> u32 {
+    fn get(&self, pos: ChunkSectionBlockPos) -> BlockState {
+        // TODO: use the unsafe method and do the check earlier
         self.states
-            .get(pos.x as usize, pos.y as usize, pos.z as usize)
+            .get(pos.x as usize, pos.y as usize, pos.z as usize).try_into().expect("Invalid block state.")
     }
 }