add dds support for text-offset

src/data/bucket/symbol_bucket.js

@@ -323,7 +323,6 @@ class SymbolBucket {
         const lineHeight = layout['text-line-height'] * oneEm;
         const maxWidth = layout['symbol-placement'] !== 'line' ? layout['text-max-width'] * oneEm : 0;
         const spacing = layout['text-letter-spacing'] * oneEm;
-        const textOffset = [layout['text-offset'][0] * oneEm, layout['text-offset'][1] * oneEm];
         const fontstack = this.fontstack = layout['text-font'].join(',');
         const textAlongLine = layout['text-rotation-alignment'] === 'map' && layout['symbol-placement'] === 'line';
 
@@ -332,6 +331,7 @@ class SymbolBucket {
             let shapedTextOrientations;
             if (feature.text) {
                 const allowsVerticalWritingMode = scriptDetection.allowsVerticalWritingMode(feature.text);
+                const textOffset = this.layers[0].getLayoutValue('text-offset', {zoom: this.zoom}, feature.properties).map((t)=> t * oneEm);
 
                 shapedTextOrientations = {
                     [WritingMode.horizontal]: shapeText(feature.text, stacks[fontstack], maxWidth, lineHeight, horizontalAlign, verticalAlign, justify, spacing, textOffset, oneEm, WritingMode.horizontal),

src/style-spec/reference/v8.json

@@ -1408,6 +1408,7 @@
       "units": "ems",
       "function": "interpolated",
       "zoom-function": true,
+      "property-function": true,
       "length": 2,
       "default": [
         0,
@@ -1423,7 +1424,9 @@
           "ios": "2.0.0",
           "macos": "0.1.0"
         },
-        "data-driven styling": {}
+        "data-driven styling": {
+          "js": "0.35.0"
+        }
       }
     },
     "text-allow-overlap": {

test/integration/render-tests/text-offset/property-function/style.json

@@ -0,0 +1,68 @@
+{
+  "version": 8,
+  "metadata": {
+    "test": {
+      "height": 256
+    }
+  },
+  "center": [
+    13.418056,
+    52.499167
+  ],
+  "zoom": 14,
+  "sources": {
+    "mapbox": {
+      "type": "vector",
+      "maxzoom": 14,
+      "tiles": [
+        "local://tiles/{z}-{x}-{y}.mvt"
+      ]
+    }
+  },
+  "glyphs": "local://glyphs/{fontstack}/{range}.pbf",
+  "layers": [
+    {
+      "id": "background",
+      "type": "background",
+      "paint": {
+        "background-color": "white"
+      }
+    },
+    {
+      "id": "literal",
+      "type": "symbol",
+      "source": "mapbox",
+      "source-layer": "poi_label",
+      "layout": {
+        "symbol-placement": "point",
+        "text-allow-overlap": true,
+        "text-ignore-placement": true,
+        "text-field": "Test",
+        "text-font": [
+          "Open Sans Semibold",
+          "Arial Unicode MS Bold"
+        ],
+        "text-offset": {
+          "base": 1,
+          "stops": [
+            [
+              0,
+              [
+                0,
+                10
+              ]
+            ],
+            [
+              50,
+              [
+                20,
+                10
+              ]
+            ]
+          ],
+          "property": "localrank"
+        }
+      }
+    }
+  ]
+}