Merge branch 'zoresvit-patch-1'

1 files changed, 40 insertions, 28 deletions

diff --git a/_smooziee.js b/_smooziee.js
index ae4915c..42eb9e3 100644
--- a/_smooziee.js
+++ b/_smooziee.js
@@ -80,68 +80,80 @@ var INFO = xml`
 
 let self = liberator.plugins.smooziee = (function(){
 
-  // Mappings  {{{
   mappings.addUserMap(
     [modes.NORMAL],
     ["j"],
     "Smooth scroll down",
     function(count){
-      self.smoothScrollBy(getScrollAmount() * (count || 1));
+      self.smoothScrollBy(getScrollAmount());
     },
     {
       count: true
     }
-  );
+    );
   mappings.addUserMap(
     [modes.NORMAL],
     ["k"],
     "Smooth scroll up",
     function(count){
-      self.smoothScrollBy(getScrollAmount() * -(count || 1));
+      self.smoothScrollBy(getScrollAmount() * -1);
     },
     {
       count: true
     }
-  );
-  // }}}
-  // PUBLIC {{{
+    );
+
+  var next;
+  var win;
+  var interval;
+
   var PUBLICS = {
     smoothScrollBy: function(moment) {
       win = Buffer.findScrollableWindow();
-      interval = window.eval(liberator.globalVariables.smooziee_scroll_interval || '20');
-      destY = win.scrollY + moment;
+      interval = window.eval(liberator.globalVariables.smooth_scroll_interval || '30');
       clearTimeout(next);
       smoothScroll(moment);
     }
   }
 
-  // }}}
-  // PRIVATE {{{
-  var next;
-  var destY;
-  var win;
-  var interval;
+  function logBase(x, y) {
+    // Logarithm of arbitrary base `x`
+    return Math.log(y) / Math.log(x);
+  }
 
-  function getScrollAmount() window.eval(liberator.globalVariables.smooziee_scroll_amount || '400');
+  function getScrollAmount() {
+    // see recognition of Fibonacci Numbers (here approximation is used)
+    // http://en.wikipedia.org/wiki/Fibonacci_number#Recognizing_Fibonacci_numbers
+    phi = 1.618033;
+    sqrt5 = 2.236067;
+    fn = liberator.globalVariables.smooth_scroll_amount || '150'
+      n = Math.ceil(logBase(phi, (fn * sqrt5 + Math.sqrt(5 * Math.pow(fn, 2) + 4)) / 2))
+      return window.eval(n);
+  }
 
-  function smoothScroll(moment) {
-    if (moment > 0)
-      moment = Math.floor(moment / 2);
-    else
-      moment = Math.ceil(moment / 2);
+  function fib(n){
+    // see optimized Binet's formula for Fibonacci sequence
+    // http://en.wikipedia.org/wiki/Fibonacci_number#Closed_form_expression
+    phi = 1.618033;
+    sqrt5 = 2.236067;
+    return Math.floor((Math.pow(phi, n) / sqrt5) + 0.5)
+  }
 
-    win.scrollBy(0, moment);
+  function smoothScroll(moment) {
+    if (moment > 0) {
+      moment = moment - 1;
+      win.scrollBy(0, fib(Math.abs(moment)));
+    } else {
+      moment = moment + 1;
+      win.scrollBy(0, -fib(Math.abs(moment)));
+    }
 
-    if (Math.abs(moment) < 1) {
-      setTimeout(makeScrollTo(win.scrollX, destY), interval);
-      destY = null;
+    if (moment == 0)
       return;
-    }
+
     next = setTimeout(function() smoothScroll(moment), interval);
   }
 
-  function makeScrollTo(x, y) function() win.scrollTo(x, y);
-  // }}}
   return PUBLICS;
 })();
 // vim: sw=2 ts=2 et si fdm=marker: