Add data-driven styling support for "icon-offset" (#3791)

* Add support for icon-offset property functions

* Moved the icon-offset determination to the symbol bucket

* Updated package.json to point to new style and test suite

* Update package.json

* Fix icon-offset zoom-and-property functions

* Update package.json

js/data/bucket/symbol_bucket.js

@@ -295,7 +295,8 @@ class SymbolBucket {
             let shapedIcon;
             if (feature.icon) {
                 const image = icons[feature.icon];
-                shapedIcon = shapeIcon(image, layout);
+                const iconOffset = this.layers[0].getLayoutValue('icon-offset', {zoom: this.zoom}, feature.properties);
+                shapedIcon = shapeIcon(image, iconOffset);
 
                 if (image) {
                     if (this.sdfIcons === undefined) {

js/symbol/shaping.js

@@ -234,11 +234,11 @@ function align(positionedGlyphs, justify, horizontalAlign, verticalAlign, maxLin
     }
 }
 
-function shapeIcon(image, layout) {
+function shapeIcon(image, iconOffset) {
     if (!image || !image.rect) return null;
 
-    const dx = layout['icon-offset'][0];
-    const dy = layout['icon-offset'][1];
+    const dx = iconOffset[0];
+    const dy = iconOffset[1];
     const x1 = dx - image.width / 2;
     const x2 = x1 + image.width;
     const y1 = dy - image.height / 2;

package.json

@@ -62,7 +62,7 @@
     "in-publish": "^2.0.0",
     "jsdom": "^9.4.2",
     "lodash.template": "^4.4.0",
-    "mapbox-gl-test-suite": "mapbox/mapbox-gl-test-suite#8a047e6226b996fa8fc4c61a30aebb55c6234896",
+    "mapbox-gl-test-suite": "mapbox/mapbox-gl-test-suite#52acb6e9e4b75b7e765ef087a0e539739e9846c1",
     "minifyify": "^7.0.1",
     "npm-run-all": "^3.0.0",
     "nyc": "^8.3.0",