return correct latitude and longitude from mapbox p2c

 - fix choroplethmapbox hover and remove scattermapbox hack

Author: archmoj

src/plots/mapbox/mapbox.js

@@ -451,14 +451,15 @@ proto.initFx = function(calcData, fullLayout) {
     map.on('mousemove', function(evt) {
         var bb = self.div.getBoundingClientRect();
 
-        // some hackery to get Fx.hover to work
-        evt.clientX = evt.point.x + bb.left;
-        evt.clientY = evt.point.y + bb.top;
-
         evt.target.getBoundingClientRect = function() { return bb; };
 
-        self.xaxis.p2c = function() { return evt.lngLat.lng; };
-        self.yaxis.p2c = function() { return evt.lngLat.lat; };
+        var xy = [
+            evt.originalEvent.offsetX,
+            evt.originalEvent.offsetY
+        ];
+
+        self.xaxis.p2c = function() { return map.unproject(xy).lng; };
+        self.yaxis.p2c = function() { return map.unproject(xy).lat; };
 
         gd._fullLayout._rehover = function() {
             if(gd._fullLayout._hoversubplot === self.id && gd._fullLayout[self.id]) {

src/traces/scattermapbox/hover.js

@@ -22,10 +22,6 @@ module.exports = function hoverPoints(pointData, xval, yval) {
     var ya = pointData.ya;
     var subplot = pointData.subplot;
 
-    var gd = subplot.gd;
-    var scaleX = gd._fullLayout._inverseScaleX;
-    var scaleY = gd._fullLayout._inverseScaleY;
-
     // compute winding number about [-180, 180] globe
     var winding = (xval >= 0) ?
         Math.floor((xval + 180) / 360) :
@@ -42,8 +38,8 @@ module.exports = function hoverPoints(pointData, xval, yval) {
         var lon = Lib.modHalf(lonlat[0], 360);
         var lat = lonlat[1];
         var pt = subplot.project([lon, lat]);
-        var dx = pt.x - xa.c2p([xval2, lat]) * scaleX;
-        var dy = pt.y - ya.c2p([lon, yval]) * scaleY;
+        var dx = pt.x - xa.c2p([xval2, lat]);
+        var dy = pt.y - ya.c2p([lon, yval]);
         var rad = Math.max(3, d.mrc || 0);
 
         return Math.max(Math.sqrt(dx * dx + dy * dy) - rad, 1 - 3 / rad);
@@ -56,7 +52,6 @@ module.exports = function hoverPoints(pointData, xval, yval) {
 
     var di = cd[pointData.index];
     var lonlat = di.lonlat;
-
     var lonlatShifted = [Lib.modHalf(lonlat[0], 360) + lonShift, lonlat[1]];
 
     // shift labels back to original winded globe