From f6e41a1cb8c02981e8d2a3b033fc1cd269137c09 Mon Sep 17 00:00:00 2001
From: Bryan Housel <bryan@mapbox.com>
Date: Sat, 21 Jul 2018 18:52:54 -0400
Subject: [PATCH 1/2] Remove unused zoomDelta parameter

---
 modules/util/tiler.js | 9 +--------
 1 file changed, 1 insertion(+), 8 deletions(-)

diff --git a/modules/util/tiler.js b/modules/util/tiler.js
index 27bb17759..d66e29933 100644
--- a/modules/util/tiler.js
+++ b/modules/util/tiler.js
@@ -7,7 +7,6 @@ export function utilTiler() {
     var _scale = 256;
     var _scaleExtent = [0, 20];
     var _translate = [_size[0] / 2, _size[1] / 2];
-    var _zoomDelta = 0;
     var _margin = 0;
     var _skipNullIsland = false;
 
@@ -34,7 +33,7 @@ export function utilTiler() {
 
     function tiler() {
         var z = Math.max(Math.log(_scale) / Math.LN2 - 8, 0);
-        var z0 = bound(Math.round(z + _zoomDelta));
+        var z0 = bound(Math.round(z));
         var k = Math.pow(2, z - z0 + 8);
         var origin = [
             (_translate[0] - _scale / 2) / k,
@@ -139,12 +138,6 @@ export function utilTiler() {
     };
 
 
-    tiler.zoomDelta = function(val) {
-        if (!arguments.length) return _zoomDelta;
-        _zoomDelta = +val;
-        return tiler;
-    };
-
     // number to extend the rows/columns beyond those covering the viewport
     tiler.margin = function(val) {
         if (!arguments.length) return _margin;

From 292347b28ad4757af09af57fa7197cd00a3c8b2b Mon Sep 17 00:00:00 2001
From: Bryan Housel <bryan@mapbox.com>
Date: Sat, 21 Jul 2018 18:53:19 -0400
Subject: [PATCH 2/2] Use utilTiler's Null Island filter for overlay sources

---
 modules/renderer/tile_layer.js | 33 +++++++++------------------------
 1 file changed, 9 insertions(+), 24 deletions(-)

diff --git a/modules/renderer/tile_layer.js b/modules/renderer/tile_layer.js
index 36668553c..c30ee2c3e 100644
--- a/modules/renderer/tile_layer.js
+++ b/modules/renderer/tile_layer.js
@@ -8,7 +8,7 @@ import { utilPrefixCSSProperty, utilTiler } from '../util';
 export function rendererTileLayer(context) {
     var tileSize = 256;
     var transformProp = utilPrefixCSSProperty('Transform');
-    var geotile = utilTiler();
+    var tiler = utilTiler();
 
     var _projection;
     var _cache = {};
@@ -17,19 +17,6 @@ export function rendererTileLayer(context) {
     var _source;
 
 
-    // blacklist overlay tiles around Null Island..
-    function nearNullIsland(x, y, z) {
-        if (z >= 7) {
-            var center = Math.pow(2, z - 1);
-            var width = Math.pow(2, z - 6);
-            var min = center - (width / 2);
-            var max = center + (width / 2) - 1;
-            return x >= min && x <= max && y >= min && y <= max;
-        }
-        return false;
-    }
-
-
     function tileSizeAtZoom(d, z) {
         var EPSILON = 0.002;
         return ((tileSize * Math.pow(2, z - d[2])) / tileSize) + EPSILON;
@@ -94,7 +81,7 @@ export function rendererTileLayer(context) {
             _projection.translate()[1] + pixelOffset[1]
         ];
 
-        geotile
+        tiler
             .scale(_projection.scale() * 2 * Math.PI)
             .translate(translate);
 
@@ -116,7 +103,9 @@ export function rendererTileLayer(context) {
         var showDebug = context.getDebug('tile') && !_source.overlay;
 
         if (_source.validZoom(_zoom)) {
-            geotile().forEach(function(d) {
+            tiler.skipNullIsland(!!_source.overlay);
+
+            tiler().forEach(function(d) {
                 addSource(d);
                 if (d[3] === '') return;
                 if (typeof d[3] !== 'string') return; // Workaround for #2295
@@ -127,15 +116,11 @@ export function rendererTileLayer(context) {
             });
 
             requests = uniqueBy(requests, 3).filter(function(r) {
-                if (!!_source.overlay && nearNullIsland(r[0], r[1], r[2])) {
-                    return false;
-                }
                 // don't re-request tiles which have failed in the past
                 return _cache[r[3]] !== false;
             });
         }
 
-
         function load(d) {
             _cache[d[3]] = true;
             d3_select(this)
@@ -179,7 +164,7 @@ export function rendererTileLayer(context) {
 
         // Pick a representative tile near the center of the viewport
         // (This is useful for sampling the imagery vintage)
-        var dims = geotile.size();
+        var dims = tiler.size();
         var mapCenter = [dims[0] / 2, dims[1] / 2];
         var minDist = Math.max(dims[0], dims[1]);
         var nearCenter;
@@ -276,8 +261,8 @@ export function rendererTileLayer(context) {
 
 
     background.dimensions = function(_) {
-        if (!arguments.length) return geotile.size();
-        geotile.size(_);
+        if (!arguments.length) return tiler.size();
+        tiler.size(_);
         return background;
     };
 
@@ -286,7 +271,7 @@ export function rendererTileLayer(context) {
         if (!arguments.length) return _source;
         _source = _;
         _cache = {};
-        geotile.scaleExtent(_source.scaleExtent);
+        tiler.scaleExtent(_source.scaleExtent);
         return background;
     };