add centerAltitude to style spec

Author: NathanMOlson

CHANGELOG.md

@@ -1,6 +1,8 @@
 ## main
 
 ### ✨ Features and improvements
+
+- Added `centerAltitude` property to stylesheet ([#851](https://github.com/maplibre/maplibre-style-spec/issues/851))
 - _...Add new stuff here..._
 
 ### 🐞 Bug fixes

src/diff.test.ts

@@ -272,6 +272,25 @@ describe('diff', () => {
         ]);
     });
 
+    test('set centerAltitude to undefined', () => {
+        expect(diffStyles({
+            centerAltitude: 1
+        } as StyleSpecification, {
+        } as StyleSpecification)).toEqual([
+            {command: 'setCenterAltitude', args: [undefined]}
+        ]);
+    });
+
+    test('set centerAltitude', () => {
+        expect(diffStyles({
+            centerAltitude: 0
+        } as StyleSpecification, {
+            centerAltitude: 1
+        } as StyleSpecification)).toEqual([
+            {command: 'setCenterAltitude', args: [1]}
+        ]);
+    });
+
     test('set zoom', () => {
         expect(diffStyles({
             zoom: 12

src/diff.ts

@@ -19,6 +19,7 @@ export type DiffOperationsMap = {
     'setLayerZoomRange': [string, number, number];
     'setLayerProperty': [string, string, unknown];
     'setCenter': [number[]];
+    'setCenterAltitude': [number];
     'setZoom': [number];
     'setBearing': [number];
     'setPitch': [number];
@@ -279,6 +280,9 @@ function diffStyles(before: StyleSpecification, after: StyleSpecification): Diff
         if (!isEqual(before.center, after.center)) {
             commands.push({command: 'setCenter', args: [after.center]});
         }
+        if (!isEqual(before.centerAltitude, after.centerAltitude)) {
+            commands.push({command: 'setCenterAltitude', args: [after.centerAltitude]});
+        }
         if (!isEqual(before.zoom, after.zoom)) {
             commands.push({command: 'setZoom', args: [after.zoom]});
         }

src/reference/v8.json

@@ -34,6 +34,11 @@
         40.7736
       ]
     },
+    "centerAltitude": {
+      "type": "number",
+      "doc": "Default map center altitude in meters above sea level.  The style center altitude will be used only if the map has not been positioned by other means (e.g. map options or user interaction).",
+      "example": 123.4
+    },
     "zoom": {
       "type": "number",
       "doc": "Default zoom level.  The style zoom will be used only if the map has not been positioned by other means (e.g. map options or user interaction).",

test/integration/style-spec/tests/center-altitude.input.json

@@ -0,0 +1,6 @@
+{
+  "version": 8,
+  "centerAltitude": "123.4",
+  "sources": {},
+  "layers": []
+}

test/integration/style-spec/tests/center-altitude.output-api-supported.json

@@ -0,0 +1,6 @@
+[
+  {
+    "message": "centerAltitude: number expected, string found",
+    "line": 3
+  }
+]

test/integration/style-spec/tests/center-altitude.output.json

@@ -0,0 +1,6 @@
+[
+  {
+    "message": "centerAltitude: number expected, string found",
+    "line": 3
+  }
+]