diff --git a/src/openseadragon.js b/src/openseadragon.js
index 1c413b30..262b9298 100644
--- a/src/openseadragon.js
+++ b/src/openseadragon.js
@@ -1429,22 +1429,6 @@ function OpenSeadragon( options ){
             ALWAYS:       2
         },
 
-        /**
-         * An enumeration of animation states.
-         * @static
-         * @type {Object}
-         * @property {Number} AT_REST Indicates there are no more animations running and the image is at rest.
-         * @property {Number} ANIMATION_STARTED Indicates the image is in motion and it just started.
-         * @property {Number} ANIMATING Indicates the image was in motion and is still in motion.
-         * @property {Number} ANIMATION_FINISHED Indicates the image was in motion and is not in motion anymore.
-         */
-         ANIMATION_STATES: {
-            AT_REST:            0,
-            ANIMATION_STARTED:  1,
-            ANIMATING:          2,
-            ANIMATION_FINISHED: 3
-        },
-
         /**
          * Keep track of which {@link Viewer}s have been created.
          * - Key: {@link Element} to which a Viewer is attached.
diff --git a/src/tiledimage.js b/src/tiledimage.js
index 6e426e4e..8a41f050 100644
--- a/src/tiledimage.js
+++ b/src/tiledimage.js
@@ -1960,42 +1960,6 @@ function compareTiles( previousBest, tile ) {
  */
 var DEFAULT_SUBPIXEL_ROUNDING_RULE = $.SUBPIXEL_ROUNDING_OCCURRENCES.NEVER;
 
-/**
- * @private
- * @inner
- * Determines whether the subpixel rounding enum value is {@link SUBPIXEL_ROUNDING_OCCURRENCES.ALWAYS} or not.
- *
- * @param {SUBPIXEL_ROUNDING_OCCURRENCES} value - The subpixel rounding enum value to check.
- * @returns {Boolean} True if input value is {@link SUBPIXEL_ROUNDING_OCCURRENCES.ALWAYS}, false otherwise.
- */
-function isSubPixelRoundingRuleAlways(value) {
-    return value === $.SUBPIXEL_ROUNDING_OCCURRENCES.ALWAYS;
-}
-
-/**
- * @private
- * @inner
- * Determines whether the subpixel rounding enum value is {@link SUBPIXEL_ROUNDING_OCCURRENCES.ONLY_AT_REST} or not.
- *
- * @param {SUBPIXEL_ROUNDING_OCCURRENCES} value - The subpixel rounding enum value to check.
- * @returns {Boolean} True if input value is {@link SUBPIXEL_ROUNDING_OCCURRENCES.ONLY_AT_REST}, false otherwise.
- */
- function isSubPixelRoundingRuleOnlyAtRest(value) {
-    return value === $.SUBPIXEL_ROUNDING_OCCURRENCES.ONLY_AT_REST;
-}
-
-/**
- * @private
- * @inner
- * Determines whether the subpixel rounding enum value is {@link SUBPIXEL_ROUNDING_OCCURRENCES.NEVER} or not.
- *
- * @param {SUBPIXEL_ROUNDING_OCCURRENCES} value - The subpixel rounding enum value to check.
- * @returns {Boolean} True if input value is {@link SUBPIXEL_ROUNDING_OCCURRENCES.NEVER}, false otherwise.
- */
- function isSubPixelRoundingRuleNever(value) {
-    return value === DEFAULT_SUBPIXEL_ROUNDING_RULE;
-}
-
 /**
  * @private
  * @inner
@@ -2006,9 +1970,9 @@ function isSubPixelRoundingRuleAlways(value) {
  * {@link SUBPIXEL_ROUNDING_OCCURRENCES.ALWAYS}, {@link SUBPIXEL_ROUNDING_OCCURRENCES.ONLY_AT_REST} or {@link SUBPIXEL_ROUNDING_OCCURRENCES.NEVER} value.
  */
  function isSubPixelRoundingRuleUnknown(value) {
-    return !isSubPixelRoundingRuleAlways(value) &&
-        !isSubPixelRoundingRuleOnlyAtRest(value) &&
-        !isSubPixelRoundingRuleNever(value);
+    return value !== $.SUBPIXEL_ROUNDING_OCCURRENCES.ALWAYS &&
+        value !== $.SUBPIXEL_ROUNDING_OCCURRENCES.ONLY_AT_REST &&
+        value !== $.SUBPIXEL_ROUNDING_OCCURRENCES.NEVER;
 }
 
 /**
@@ -2207,13 +2171,11 @@ function drawTiles( tiledImage, lastDrawn ) {
 
     var shouldRoundPositionAndSize = false;
 
-    if (isSubPixelRoundingRuleAlways(subPixelRoundingRule)) {
+    if (subPixelRoundingRule === $.SUBPIXEL_ROUNDING_OCCURRENCES.ALWAYS) {
         shouldRoundPositionAndSize = true;
-    } else if (isSubPixelRoundingRuleOnlyAtRest(subPixelRoundingRule)) {
-        shouldRoundPositionAndSize = tiledImage.viewer && (
-            tiledImage.viewer.getAnimationState() === $.ANIMATION_STATES.ANIMATION_FINISHED ||
-            tiledImage.viewer.getAnimationState() === $.ANIMATION_STATES.AT_REST // Testing AT_REST here is for the very first render after loading.
-        );
+    } else if (subPixelRoundingRule === $.SUBPIXEL_ROUNDING_OCCURRENCES.ONLY_AT_REST) {
+        var isAnimating = tiledImage.viewer && tiledImage.viewer.isAnimating();
+        shouldRoundPositionAndSize = !isAnimating;
     }
 
     for (var i = lastDrawn.length - 1; i >= 0; i--) {
diff --git a/src/viewer.js b/src/viewer.js
index 57b46cad..86990297 100644
--- a/src/viewer.js
+++ b/src/viewer.js
@@ -203,7 +203,6 @@ $.Viewer = function( options ) {
         fsBoundsDelta:     new $.Point( 1, 1 ),
         prevContainerSize: null,
         animating:         false,
-        animationState:    $.ANIMATION_STATES.AT_REST,
         forceRedraw:       false,
         mouseInside:       false,
         group:             null,
@@ -714,7 +713,6 @@ $.extend( $.Viewer.prototype, $.EventSource.prototype, $.ControlDock.prototype,
         }
 
         THIS[ this.hash ].animating = false;
-        THIS[ this.hash ].animationState = $.ANIMATION_STATES.AT_REST;
 
         this.world.removeAll();
         this.imageLoader.clear();
@@ -2356,10 +2354,6 @@ $.extend( $.Viewer.prototype, $.EventSource.prototype, $.ControlDock.prototype,
     isAnimating: function () {
         return THIS[ this.hash ].animating;
     },
-
-    getAnimationState: function () {
-        return THIS[ this.hash ].animationState;
-    },
 });
 
 
@@ -3509,8 +3503,6 @@ function updateOnce( viewer ) {
     var currentAnimating = THIS[ viewer.hash ].animating;
 
     if ( !currentAnimating && animated ) {
-        THIS[ viewer.hash ].animationState = $.ANIMATION_STATES.ANIMATION_STARTED;
-
         /**
          * Raised when any spring animation starts (zoom, pan, etc.).
          *
@@ -3524,18 +3516,13 @@ function updateOnce( viewer ) {
         abortControlsAutoHide( viewer );
     }
 
-    var lastAnimation = false;
+    var isAnimationFinished = currentAnimating && !animated;
 
-    if (currentAnimating) {
-        if (animated) {
-            THIS[ viewer.hash ].animationState = $.ANIMATION_STATES.ANIMATING;
-        } else {
-            THIS[ viewer.hash ].animationState = $.ANIMATION_STATES.ANIMATION_FINISHED;
-            lastAnimation = true;
-        }
+    if ( isAnimationFinished ) {
+        THIS[ viewer.hash ].animating = false;
     }
 
-    if ( animated || lastAnimation || THIS[ viewer.hash ].forceRedraw || viewer.world.needsDraw() ) {
+    if ( animated || isAnimationFinished || THIS[ viewer.hash ].forceRedraw || viewer.world.needsDraw() ) {
         drawWorld( viewer );
         viewer._drawOverlays();
         if( viewer.navigator ){
@@ -3559,9 +3546,7 @@ function updateOnce( viewer ) {
         }
     }
 
-    if ( currentAnimating && !animated ) {
-        THIS[ viewer.hash ].animationState = $.ANIMATION_STATES.AT_REST;
-
+    if ( isAnimationFinished ) {
         /**
          * Raised when any spring animation ends (zoom, pan, etc.).
          *