mapbox coords: get canvas size from style, not attributes

The width and height attributes are expanded by devicePixelRatio,
but the style width and height are in css pixels.

Author: alexcjohnson

src/plots/mapbox/mapbox.js

@@ -727,23 +727,8 @@ proto.getView = function() {
     var center = { lon: lon, lat: lat };
 
     var canvas = map.getCanvas();
-    var width = canvas.width;
-    var height = canvas.height;
-
-    var p00, p10, p11, p01;
-
-    // attempt finding correct scale for Retina display
-    for(var scale = 2; scale > 0; scale--) {
-        var w = width / scale;
-        var h = height / scale;
-
-        p00 = map.unproject([0, 0]).toArray();
-        p10 = map.unproject([w, 0]).toArray();
-        p11 = map.unproject([w, h]).toArray();
-        p01 = map.unproject([0, h]).toArray();
-
-        if(Math.abs(lon - (p00[0] + p11[0]) / 2) < 0.0001) break;
-    }
+    var w = parseInt(canvas.style.width);
+    var h = parseInt(canvas.style.height);
 
     return {
         center: center,
@@ -752,10 +737,10 @@ proto.getView = function() {
         pitch: map.getPitch(),
         _derived: {
             coordinates: [
-                p00,
-                p10,
-                p11,
-                p01
+                map.unproject([0, 0]).toArray(),
+                map.unproject([w, 0]).toArray(),
+                map.unproject([w, h]).toArray(),
+                map.unproject([0, h]).toArray()
             ]
         }
     };