world: process sign data, prepare for serialization

src/world/block_entity.rs

@@ -0,0 +1,89 @@
+//! Processing of block entity data
+
+use serde::{Deserialize, Serialize};
+
+use super::{
+	de,
+	sign::{BlockEntitySignExt, SignText},
+};
+
+/// Kind of sign block
+#[derive(Debug, Serialize, Deserialize)]
+#[serde(rename_all = "snake_case")]
+pub enum SignKind {
+	/// Standing or attached sign
+	Sign,
+	/// Hanging sign
+	HangingSign,
+}
+
+/// Processed sign data
+#[derive(Debug, Serialize, Deserialize)]
+pub struct Sign {
+	/// The kind of the sign
+	pub kind: SignKind,
+	/// The sign's front text
+	#[serde(skip_serializing_if = "SignText::is_empty", default)]
+	pub front_text: SignText,
+	/// The sign's back text
+	#[serde(skip_serializing_if = "SignText::is_empty", default)]
+	pub back_text: SignText,
+}
+
+impl Sign {
+	/// Processes a [de::BlockEntitySign] into a [Sign]
+	fn new(sign: &de::BlockEntitySign, kind: SignKind) -> Sign {
+		let (front_text, back_text) = sign.text();
+		let front_text = front_text.decode();
+		let back_text = back_text.decode();
+		Sign {
+			kind,
+			front_text,
+			back_text,
+		}
+	}
+}
+
+/// Data for different kinds of [BlockEntity]
+#[derive(Debug, Serialize, Deserialize)]
+#[serde(tag = "type", rename_all = "snake_case")]
+pub enum BlockEntityData {
+	/// A sign block
+	Sign(Sign),
+}
+
+/// A processed block entity
+#[derive(Debug, Serialize, Deserialize)]
+pub struct BlockEntity {
+	/// Global X coordinate
+	pub x: i32,
+	/// Global Y coordinate
+	pub y: i32,
+	/// Global Z coordinate
+	pub z: i32,
+	/// Entity data
+	#[serde(flatten)]
+	pub data: BlockEntityData,
+}
+
+impl BlockEntity {
+	/// Processes a [de::BlockEntity] into a [BlockEntity]
+	pub fn new(entity: &de::BlockEntity) -> Option<Self> {
+		let data = match &entity.data {
+			de::BlockEntityData::Sign(sign) => {
+				BlockEntityData::Sign(Sign::new(sign, SignKind::Sign))
+			}
+			de::BlockEntityData::HangingSign(sign) => {
+				BlockEntityData::Sign(Sign::new(sign, SignKind::HangingSign))
+			}
+			de::BlockEntityData::Other => return None,
+		};
+
+		Some(BlockEntity {
+			x: entity.x,
+			y: entity.y,
+			z: entity.z,
+			data,
+		})
+	}
+}