From a49bbbcb06c390eead819acce941487ca7713f73 Mon Sep 17 00:00:00 2001
From: Ian Gilman <ian@iangilman.com>
Date: Fri, 8 Sep 2017 14:03:40 -0700
Subject: [PATCH] Addressing seams that appear in wrap mode on Safari and
 Firefox

---
 src/tile.js       | 15 +++++++++++++++
 src/tiledimage.js | 20 +++++++++++++++++++-
 2 files changed, 34 insertions(+), 1 deletion(-)

diff --git a/src/tile.js b/src/tile.js
index 61ba2e64..a0b29f4f 100644
--- a/src/tile.js
+++ b/src/tile.js
@@ -199,12 +199,27 @@ $.Tile = function(level, x, y, bounds, exists, url, context2D, loadWithAjax, aja
      * @memberof OpenSeadragon.Tile#
      */
     this.beingDrawn     = false;
+
     /**
      * Timestamp the tile was last touched.
      * @member {Number} lastTouchTime
      * @memberof OpenSeadragon.Tile#
      */
     this.lastTouchTime  = 0;
+
+    /**
+     * Whether this tile is in the right-most column for its level.
+     * @member {Boolean} isRightMost
+     * @memberof OpenSeadragon.Tile#
+     */
+    this.isRightMost = false;
+
+    /**
+     * Whether this tile is in the bottom-most row for its level.
+     * @member {Boolean} isBottomMost
+     * @memberof OpenSeadragon.Tile#
+     */
+    this.isBottomMost = false;
 };
 
 /** @lends OpenSeadragon.Tile.prototype */
diff --git a/src/tiledimage.js b/src/tiledimage.js
index b9c83838..a289026a 100644
--- a/src/tiledimage.js
+++ b/src/tiledimage.js
@@ -1405,7 +1405,7 @@ function getTile(
         bounds.x += ( x - xMod ) / numTiles.x;
         bounds.y += (worldHeight / worldWidth) * (( y - yMod ) / numTiles.y);
 
-        tilesMatrix[ level ][ x ][ y ] = new $.Tile(
+        tile = new $.Tile(
             level,
             x,
             y,
@@ -1416,6 +1416,16 @@ function getTile(
             tiledImage.loadTilesWithAjax,
             ajaxHeaders
         );
+
+        if (xMod === numTiles.x - 1) {
+            tile.isRightMost = true;
+        }
+
+        if (yMod === numTiles.y - 1) {
+            tile.isBottomMost = true;
+        }
+
+        tilesMatrix[ level ][ x ][ y ] = tile;
     }
 
     tile = tilesMatrix[ level ][ x ][ y ];
@@ -1602,6 +1612,14 @@ function positionTile( tile, overlap, viewport, viewportCenter, levelVisibility,
         sizeC = sizeC.plus( new $.Point( 1, 1 ) );
     }
 
+    if (tile.isRightMost && tiledImage.wrapHorizontal) {
+        sizeC.x += 0.75; // Otherwise Firefox and Safari show seams
+    }
+
+    if (tile.isBottomMost && tiledImage.wrapVertical) {
+        sizeC.y += 0.75; // Otherwise Firefox and Safari show seams
+    }
+
     tile.position   = positionC;
     tile.size       = sizeC;
     tile.squaredDistance   = tileSquaredDistance;