Add horizontal scroll support

dist/echo.js

@@ -1,4 +1,4 @@
-/*! Echo v1.4.0 | (c) 2013 @toddmotto | MIT license | github.com/toddmotto/echo */
+/*! Echo v1.4.0 | (c) 2014 @toddmotto | MIT license | github.com/toddmotto/echo */
 window.Echo = (function (window, document, undefined) {
 
   'use strict';
@@ -7,7 +7,11 @@ window.Echo = (function (window, document, undefined) {
 
   var _inView = function (el) {
     var coords = el.getBoundingClientRect();
-    return ((coords.top >= 0 && coords.left >= 0 && coords.top) <= (window.innerHeight || document.documentElement.clientHeight) + parseInt(offset));
+    return (
+      (coords.top >= 0 && coords.left >= 0) &&
+      coords.top <= (window.innerHeight || document.documentElement.clientHeight) + parseInt(offset) &&
+      coords.left <= (window.innerWidth || document.documentElement.clientWidth) + parseInt(offset)
+    );
   };
 
   var _pollImages = function () {

dist/echo.min.js

@@ -1,2 +1,2 @@
-/*! Echo v1.4.0 | (c) 2013 @toddmotto | MIT license | github.com/toddmotto/echo */
-window.Echo=function(a,b){"use strict";var c,d,e,f=[],g=function(d){var e=d.getBoundingClientRect();return(e.top>=0&&e.left>=0&&e.top)<=(a.innerHeight||b.documentElement.clientHeight)+parseInt(c)},h=function(){for(var a=f.length;a--;){var b=f[a];g(b)&&(b.src=b.getAttribute("data-echo"),f.splice(a,1))}},i=function(){clearTimeout(e),e=setTimeout(h,d)},j=function(e){var g=b.querySelectorAll("[data-echo]"),h=e||{};c=h.offset||0,d=h.throttle||250;for(var j=0;j<g.length;j++)f.push(g[j]);i(),b.addEventListener?a.addEventListener("scroll",i,!1):a.attachEvent("onscroll",i)};return{init:j,render:i}}(window,document);
+/*! Echo v1.4.0 | (c) 2014 @toddmotto | MIT license | github.com/toddmotto/echo */
+window.Echo=function(a,b){"use strict";var c,d,e,f=[],g=function(d){var e=d.getBoundingClientRect();return e.top>=0&&e.left>=0&&e.top<=(a.innerHeight||b.documentElement.clientHeight)+parseInt(c)&&e.left<=(a.innerWidth||b.documentElement.clientWidth)+parseInt(c)},h=function(){for(var a=f.length;a--;){var b=f[a];g(b)&&(b.src=b.getAttribute("data-echo"),f.splice(a,1))}},i=function(){clearTimeout(e),e=setTimeout(h,d)},j=function(e){var g=b.querySelectorAll("[data-echo]"),h=e||{};c=h.offset||0,d=h.throttle||250;for(var j=0;j<g.length;j++)f.push(g[j]);i(),b.addEventListener?a.addEventListener("scroll",i,!1):a.attachEvent("onscroll",i)};return{init:j,render:i}}(window,document);

src/echo.js

@@ -6,7 +6,11 @@ window.Echo = (function (window, document, undefined) {
 
   var _inView = function (el) {
     var coords = el.getBoundingClientRect();
-    return ((coords.top >= 0 && coords.left >= 0 && coords.top) <= (window.innerHeight || document.documentElement.clientHeight) + parseInt(offset));
+    return (
+      (coords.top >= 0 && coords.left >= 0) &&
+      coords.top <= (window.innerHeight || document.documentElement.clientHeight) + parseInt(offset) &&
+      coords.left <= (window.innerWidth || document.documentElement.clientWidth) + parseInt(offset)
+    );
   };
 
   var _pollImages = function () {