Merge pull request #9 from mat-1/azalea-block

azalea-block

1 files changed, 47 insertions, 0 deletions

diff --git a/azalea-block/src/lib.rs b/azalea-block/src/lib.rs
new file mode 100644
index 00000000..a6de1e92
--- /dev/null
+++ b/azalea-block/src/lib.rs
@@ -0,0 +1,47 @@
+mod behavior;
+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());
+    }
+}