Added PMTiles #17 (#18)

Author: m-mohr

CHANGELOG.md

@@ -8,8 +8,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ### Added
 
-- OGC WMS (Basic WMS only)
-- 3D Tiles
+- PMTiles
 
 ### Changed
 

README.md

@@ -15,6 +15,7 @@ The following services are supported:
 - [3D Tiles](#3d-tiles)
 - [OGC WMS](#ogc-wms)
 - [OGC WMTS](#ogc-wmts)
+- [PMTiles](#pmtiles)
 - [TileJSON](#tilejson)
 - [XYZ](#xyz)
 
@@ -80,6 +81,23 @@ you'd provide `https://example.com/geoserver/service/wmts` as `href`.
 
 The `href` can contain an optional server placeholder `{s}`. If `{s}` is used, the field [`href:servers`](#hrefservers) MUST be provided.
 
+### PMTiles
+
+Links to a [PMTiles](https://github.com/protomaps/PMTiles/blob/main/spec/v3/spec.md) file (versions 3.x).
+
+| Field Name      | Type                 | Description |
+| --------------- | -------------------- | ----------- |
+| rel             | string               | **REQUIRED**. Must be set to `pmtiles`. |
+| href            | string               | **REQUIRED**. Link to a PMTiles file (usually ends with `.pmtiles`). |
+| type            | string               | Recommended to be set to `application/vnd.pmtiles`. |
+| pmtiles:layers  | \[string]            | For vector tiles, the layers to show on the map by default. If not provided, it's up to the discretion of the implementation to choose a layer from the `vector_layers` in the PMTiles metadata. |
+
+The [Tile Type](https://github.com/protomaps/PMTiles/blob/main/spec/v3/spec.md#tile-type-tt) of the
+PMTiles data source can be read from the first 127 bytes of the the binary header.
+
+It is typical to assume a tile size of 256x256 pixels for raster tiles and 512x512 pixels for vector tiles,
+but they could also be inferred from the first file.
+
 ### XYZ
 
 Links to a XYZ, also known as slippy map.

examples/collection.json

@@ -86,6 +86,15 @@
       "rel": "3d-tiles",
       "title": "3D Tiles",
       "type": "application/json"
+    },
+    {
+      "href": "https://maps.example.com/item/example.pmtiles",
+      "rel": "pmtiles",
+      "title": "PMTiles",
+      "type": "application/vnd.pmtiles",
+      "pmtiles:layers": [
+        "streets"
+      ]
     }
   ]
 }

examples/item.json

@@ -83,6 +83,15 @@
       "rel": "3d-tiles",
       "title": "3D Tiles",
       "type": "application/json"
+    },
+    {
+      "href": "https://maps.example.com/item/example.pmtiles",
+      "rel": "pmtiles",
+      "title": "PMTiles",
+      "type": "application/vnd.pmtiles",
+      "pmtiles:layers": [
+        "streets"
+      ]
     }
   ],
   "assets": {}

json-schema/schema.json

@@ -38,6 +38,7 @@
               "wms",
               "wmts",
               "tilejson",
+              "pmtiles",
               "3d-tiles"
             ]
           }
@@ -140,6 +141,27 @@
                 }
               }
             }
+          },
+          {
+            "$comment": "Defines PMTiles links",
+            "if": {
+              "properties": {
+                "rel": {
+                  "const": "pmtiles"
+                }
+              }
+            },
+            "then": {
+              "properties": {
+                "pmtiles:layers": {
+                  "type": "array",
+                  "items": {
+                    "type": "string",
+                    "minLength": 1
+                  }
+                }
+              }
+            }
           }
         ]
       }