Move TileIdMethod from tinymvt to nusamai (#675)

nusamai/src/sink/mvt/mod.rs

@@ -2,6 +2,7 @@
 
 mod slice;
 mod tags;
+mod tileid;
 
 use std::{
     convert::Infallible,
@@ -21,7 +22,8 @@ use rayon::prelude::*;
 use serde::{Deserialize, Serialize};
 use slice::slice_cityobj_geoms;
 use tags::convert_properties;
-use tinymvt::{geometry::GeometryEncoder, tag::TagsEncoder, tileid::TileIdMethod, vector_tile};
+use tileid::TileIdMethod;
+use tinymvt::{geometry::GeometryEncoder, tag::TagsEncoder, vector_tile};
 
 use crate::{
     get_parameter_value,

nusamai/src/sink/mvt/tileid.rs

@@ -0,0 +1,34 @@
+use tinymvt::tileid::hilbert;
+
+/// Tile ID calculation method
+#[derive(Clone, Copy, Debug)]
+pub enum TileIdMethod {
+    /// Tile ID based on Hilbert curve (compliant with PMTiles)
+    Hilbert,
+}
+
+impl TileIdMethod {
+    pub fn zxy_to_id(&self, z: u8, x: u32, y: u32) -> u64 {
+        match self {
+            TileIdMethod::Hilbert => hilbert::zxy_to_id(z, x, y),
+        }
+    }
+
+    pub fn id_to_zxy(&self, tile_id: u64) -> (u8, u32, u32) {
+        match self {
+            TileIdMethod::Hilbert => hilbert::id_to_zxy(tile_id),
+        }
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn hilbert() {
+        let tile_id_method = TileIdMethod::Hilbert;
+        assert_eq!(tile_id_method.zxy_to_id(2, 1, 1), 7);
+        assert_eq!(tile_id_method.id_to_zxy(7), (2, 1, 1));
+    }
+}