From 11076bf0c59c21db8d97111d2c81414629869cab Mon Sep 17 00:00:00 2001
From: Bryan Housel <bryan@mapbox.com>
Date: Wed, 25 Jul 2018 15:11:43 -0400
Subject: [PATCH] Calculate correct scale in tiler() for non-256px tile sizes

---
 modules/renderer/tile_layer.js | 5 ++---
 modules/util/tiler.js          | 3 ++-
 2 files changed, 4 insertions(+), 4 deletions(-)

diff --git a/modules/renderer/tile_layer.js b/modules/renderer/tile_layer.js
index 454e71400..3df159d3f 100644
--- a/modules/renderer/tile_layer.js
+++ b/modules/renderer/tile_layer.js
@@ -18,7 +18,7 @@ export function rendererTileLayer(context) {
 
 
     function tileSizeAtZoom(d, z) {
-        var EPSILON = 0.002;
+        var EPSILON = 0.002;    // close seams
         return ((_tileSize * Math.pow(2, z - d[2])) / _tileSize) + EPSILON;
     }
 
@@ -272,8 +272,7 @@ export function rendererTileLayer(context) {
         _source = _;
         _tileSize = _source.tileSize;
         _cache = {};
-        // tiler.tileSize(_source.tileSize).zoomExtent(_source.zoomExtent);   // not yet
-        tiler.zoomExtent(_source.zoomExtent);
+        tiler.tileSize(_source.tileSize).zoomExtent(_source.zoomExtent);
         return background;
     };
 
diff --git a/modules/util/tiler.js b/modules/util/tiler.js
index 03686c9c9..80f1989f5 100644
--- a/modules/util/tiler.js
+++ b/modules/util/tiler.js
@@ -35,7 +35,8 @@ export function utilTiler() {
     function tiler() {
         var z = geoScaleToZoom(_scale / (2 * Math.PI), _tileSize);
         var z0 = bound(Math.round(z));
-        var k = Math.pow(2, z - z0 + 8);
+        var log2ts = Math.log(_tileSize) * Math.LOG2E;
+        var k = Math.pow(2, z - z0 + log2ts);
         var origin = [
             (_translate[0] - _scale / 2) / k,
             (_translate[1] - _scale / 2) / k