fix(pg): handle SRID 4326 bbox tiles spanning over the antimeridian

martin-tile-utils/src/lib.rs

@@ -8,6 +8,9 @@ use std::fmt::{Display, Formatter, Result};
 
 /// circumference of the earth in meters
 pub const EARTH_CIRCUMFERENCE: f64 = 40_075_016.685_578_5;
+/// circumference of the earth in degrees
+pub const EARTH_CIRCUMFERENCE_DEGREES: u32 = 360;
+
 /// radius of the earth in meters
 pub const EARTH_RADIUS: f64 = EARTH_CIRCUMFERENCE / 2.0 / PI;
 

martin/src/pg/query_tables.rs

@@ -1,3 +1,4 @@
+use martin_tile_utils::EARTH_CIRCUMFERENCE_DEGREES;
 use std::collections::HashMap;
 
 use futures::pin_mut;
@@ -171,19 +172,32 @@ pub async fn table_to_query(
 
     let extent = info.extent.unwrap_or(DEFAULT_EXTENT);
     let buffer = info.buffer.unwrap_or(DEFAULT_BUFFER);
+    let margin = f64::from(buffer) / f64::from(extent);
 
+    // When calculating the bounding box to search within, a few considerations must be made when
+    // using a margin. The ST_TileEnvelope margin parameter is for use with SRID 3857.
+    // For SRID 4326, ST_Expand is used and provided with SRID 4326 specific units (degrees).
+    // If the table uses a non-standard SRID, it will fall back to existing behavior.
+    //
+    // For more context, if SRID 4326 were to be used with ST_TileEnvelope and margin
+    // parameter, the resultant bounding box for tiles on the antimeridian would be calculated
+    // incorrectly. For example, with a margin of 2 units, the antimeridian edge would transform
+    // from -180 to +178. This results in a bbox that stretches from the easternmost edge of a tile
+    // (plus margin) around the map to the westernmost edge of the tile (minus margin). The
+    // resulting bbox covers none of the original tile. In contrast, for this example, ST_Expand
+    // will result in a westernmost edge (minus margin) of -182.
     let bbox_search = if buffer == 0 {
-        "ST_TileEnvelope($1::integer, $2::integer, $3::integer)".to_string()
-    } else if pool.supports_tile_margin() {
-        let margin = f64::from(buffer) / f64::from(extent);
-        format!("ST_TileEnvelope($1::integer, $2::integer, $3::integer, margin => {margin})")
+        format!("ST_Transform(ST_TileEnvelope($1::integer, $2::integer, $3::integer), {srid})")
+    } else if pool.supports_tile_margin() && srid == 3857 {
+        format!(
+            "ST_Transform(ST_TileEnvelope($1::integer, $2::integer, $3::integer, margin => {margin}), {srid})"
+        )
+    } else if srid == 4326 {
+        format!(
+            "ST_Expand(ST_Transform(ST_TileEnvelope($1::integer, $2::integer, $3::integer), {srid}), ({margin} * {EARTH_CIRCUMFERENCE_DEGREES}) / 2^$1::integer)"
+        )
     } else {
-        // TODO: we should use ST_Expand here, but it may require a bit more math work,
-        //       so might not be worth it as it is only used for PostGIS < v3.1.
-        //       v3.1 has been out for 2+ years (december 2020)
-        // let val = EARTH_CIRCUMFERENCE * buffer as f64 / extent as f64;
-        // format!("ST_Expand(ST_TileEnvelope($1::integer, $2::integer, $3::integer), {val}/2^$1::integer)")
-        "ST_TileEnvelope($1::integer, $2::integer, $3::integer)".to_string()
+        format!("ST_Transform(ST_TileEnvelope($1::integer, $2::integer, $3::integer), {srid})")
     };
 
     let limit_clause = max_feature_count.map_or(String::new(), |v| format!("LIMIT {v}"));
@@ -204,7 +218,7 @@ FROM (
   FROM
     {schema}.{table}
   WHERE
-    {geometry_column} && ST_Transform({bbox_search}, {srid})
+    {geometry_column} && {bbox_search}
   {limit_clause}
 ) AS tile;
 "

martin/tests/pg_server_test.rs

@@ -66,6 +66,9 @@ postgres:
       MixPoints:
         content_type: application/x-protobuf
         description: a description from comment on table
+      antimeridian:
+        content_type: application/x-protobuf
+        description: public.antimeridian.geom
       auto_table:
         content_type: application/x-protobuf
         description: autodetect.auto_table.geom

martin/tests/pg_table_source_test.rs

@@ -26,6 +26,9 @@ async fn table_source() {
     MixPoints:
       content_type: application/x-protobuf
       description: a description from comment on table
+    antimeridian:
+      content_type: application/x-protobuf
+      description: public.antimeridian.geom
     auto_table:
       content_type: application/x-protobuf
       description: autodetect.auto_table.geom
@@ -124,6 +127,22 @@ async fn table_source() {
     properties:
       gid: int4
     ");
+
+    let source3 = table(&mock, "points3857");
+    assert_yaml_snapshot!(source3, @r"
+    schema: public
+    table: points3857
+    srid: 3857
+    geometry_column: geom
+    bounds:
+      - -161.40590777554058
+      - -81.50727021609012
+      - 172.51549126768532
+      - 84.2440187164111
+    geometry_type: POINT
+    properties:
+      gid: int4
+    ");
 }
 
 #[actix_rt::test]

tests/expected/auto/antimeridian_4_0_4.pbf.geojson

@@ -0,0 +1,40 @@
+{
+  "features": [
+    {
+      "geometry": {
+        "coordinates": [
+          [
+            [
+              3641,
+              2200
+            ],
+            [
+              3641,
+              1448
+            ],
+            [
+              2731,
+              1448
+            ],
+            [
+              2731,
+              2200
+            ],
+            [
+              3641,
+              2200
+            ]
+          ]
+        ],
+        "type": "Polygon"
+      },
+      "properties": {
+        "gid": 3,
+        "source_mvt_layer": "antimeridian"
+      },
+      "type": "Feature"
+    }
+  ],
+  "name": "merged",
+  "type": "FeatureCollection"
+}

tests/expected/auto/antimeridian_4_0_4.pbf.headers

@@ -0,0 +1,5 @@
+content-encoding: gzip
+content-length: 79
+content-type: application/x-protobuf
+etag: "171363189529507097744074158008402788299"
+vary: Origin, Access-Control-Request-Method, Access-Control-Request-Headers

tests/expected/auto/antimeridian_4_0_5.pbf.geojson

@@ -0,0 +1,74 @@
+{
+  "features": [
+    {
+      "geometry": {
+        "coordinates": [
+          [
+            [
+              546,
+              2636
+            ],
+            [
+              546,
+              3228
+            ],
+            [
+              1456,
+              3228
+            ],
+            [
+              1456,
+              2636
+            ],
+            [
+              546,
+              2636
+            ]
+          ]
+        ],
+        "type": "Polygon"
+      },
+      "properties": {
+        "gid": 1,
+        "source_mvt_layer": "antimeridian"
+      },
+      "type": "Feature"
+    },
+    {
+      "geometry": {
+        "coordinates": [
+          [
+            [
+              546,
+              2636
+            ],
+            [
+              546,
+              3228
+            ],
+            [
+              4096,
+              3228
+            ],
+            [
+              4096,
+              2636
+            ],
+            [
+              546,
+              2636
+            ]
+          ]
+        ],
+        "type": "Polygon"
+      },
+      "properties": {
+        "gid": 2,
+        "source_mvt_layer": "antimeridian"
+      },
+      "type": "Feature"
+    }
+  ],
+  "name": "merged",
+  "type": "FeatureCollection"
+}

tests/expected/auto/antimeridian_4_0_5.pbf.headers

@@ -0,0 +1,5 @@
+content-encoding: gzip
+content-length: 109
+content-type: application/x-protobuf
+etag: "11410412592260844908993902889337130111"
+vary: Origin, Access-Control-Request-Method, Access-Control-Request-Headers

tests/expected/auto/catalog_auto.json

@@ -48,6 +48,10 @@
       "content_type": "application/x-protobuf",
       "description": "a description from comment on table"
     },
+    "antimeridian": {
+      "content_type": "application/x-protobuf",
+      "description": "public.antimeridian.geom"
+    },
     "auto_table": {
       "content_type": "application/x-protobuf",
       "description": "autodetect.auto_table.geom"

tests/expected/auto/save_config.yaml

@@ -32,6 +32,19 @@ postgres:
       properties:
         Gid: int4
         TABLE: text
+    antimeridian:
+      schema: public
+      table: antimeridian
+      srid: 4326
+      geometry_column: geom
+      bounds:
+      - -182.0
+      - 51.0
+      - -160.0
+      - 62.0
+      geometry_type: GEOMETRY
+      properties:
+        gid: int4
     auto_table:
       schema: autodetect
       table: auto_table

tests/expected/martin-cp/flat-with-hash_save_config.yaml

@@ -31,6 +31,19 @@ postgres:
       properties:
         Gid: int4
         TABLE: text
+    antimeridian:
+      schema: public
+      table: antimeridian
+      srid: 4326
+      geometry_column: geom
+      bounds:
+      - -182.0
+      - 51.0
+      - -160.0
+      - 62.0
+      geometry_type: GEOMETRY
+      properties:
+        gid: int4
     auto_table:
       schema: autodetect
       table: auto_table

tests/expected/martin-cp/flat_save_config.yaml

@@ -31,6 +31,19 @@ postgres:
       properties:
         Gid: int4
         TABLE: text
+    antimeridian:
+      schema: public
+      table: antimeridian
+      srid: 4326
+      geometry_column: geom
+      bounds:
+      - -182.0
+      - 51.0
+      - -160.0
+      - 62.0
+      geometry_type: GEOMETRY
+      properties:
+        gid: int4
     auto_table:
       schema: autodetect
       table: auto_table

tests/expected/martin-cp/normalized_save_config.yaml

@@ -31,6 +31,19 @@ postgres:
       properties:
         Gid: int4
         TABLE: text
+    antimeridian:
+      schema: public
+      table: antimeridian
+      srid: 4326
+      geometry_column: geom
+      bounds:
+      - -182.0
+      - 51.0
+      - -160.0
+      - 62.0
+      geometry_type: GEOMETRY
+      properties:
+        gid: int4
     auto_table:
       schema: autodetect
       table: auto_table

tests/fixtures/tables/antimeridian.sql

@@ -0,0 +1,19 @@
+DROP TABLE IF EXISTS antimeridian;
+
+CREATE TABLE antimeridian
+(
+    gid serial PRIMARY KEY,
+    geom GEOMETRY (GEOMETRY, 4326)
+);
+
+INSERT INTO antimeridian (geom) VALUES (
+    GEOMFROMEWKT('SRID=4326;POLYGON((-177 51, -172 51, -172 53, -177 53, -177 51))')
+);
+INSERT INTO antimeridian (geom) VALUES (
+    GEOMFROMEWKT('SRID=4326;POLYGON((-182 51, -177 51, -177 53, -182 53, -182 51))')
+);
+INSERT INTO antimeridian (geom) VALUES (
+    GEOMFROMEWKT('SRID=4326;POLYGON ((-160 60, -165 60, -165 62, -160 62, -160 60))')
+);
+
+CREATE INDEX ON antimeridian USING gist (geom);

tests/test.sh

@@ -374,6 +374,10 @@ test_png rgba_u8_nodata_1_0_0 rgba_u8_nodata/1/0/0
 >&2 echo "***** Test server response for table source with empty SRID *****"
 test_pbf points_empty_srid_0_0_0  points_empty_srid/0/0/0
 
+>&2 echo "***** Test server response for table source with antimeridian geometries *****"
+test_pbf antimeridian_4_0_4 antimeridian/4/0/4
+test_pbf antimeridian_4_0_5 antimeridian/4/0/5
+
 >&2 echo "***** Test server response for comments *****"
 test_jsn tbl_comment              MixPoints
 test_jsn fnc_comment              function_Mixed_Name