1 files changed, 15 insertions, 2 deletions
diff --git a/src/library_browser.js b/src/library_browser.js
index 0db2cc44..2b69e5d9 100644
--- a/src/library_browser.js
+++ b/src/library_browser.js
@@ -446,8 +446,21 @@ mergeInto(LibraryManager.library, {
         // Otherwise, calculate the movement based on the changes
         // in the coordinates.
         var rect = Module["canvas"].getBoundingClientRect();
-        var x = event.pageX - (window.scrollX + rect.left);
-        var y = event.pageY - (window.scrollY + rect.top);
+        var x, y;
+        if (event.type == 'touchstart' ||
+            event.type == 'touchend' ||
+            event.type == 'touchmove') {
+          var t = event.touches.item(0);
+          if (t) {
+            x = t.pageX - (window.scrollX + rect.left);
+            y = t.pageY - (window.scrollY + rect.top);
+          } else {
+            return;
+          }
+        } else {
+          x = event.pageX - (window.scrollX + rect.left);
+          y = event.pageY - (window.scrollY + rect.top);
+        }
 
         // the canvas might be CSS-scaled compared to its backbuffer;
         // SDL-using content will want mouse coordinates in terms