Add Y axis culling for non-rotated charts

src/c3.axis.js

@@ -27,7 +27,14 @@ function c3_axis(d3, params, $$) {
         return start < stop ? [ start, stop ] : [ stop, start ];
     }
     function shouldDrawTickText(id){
-        if(!$$.config.axis_rotated) return true;
+        var heightLimits = [
+            // Left is width, right is number of tick labels to be removed
+            [-Infinity],
+            [150, 10],
+            [200, 5],
+            [270, 2],
+            [Infinity, 1]
+        ];
         var widthLimits = [
             // Left is width, right is number of tick labels to be removed
             [-Infinity],
@@ -37,9 +44,11 @@ function c3_axis(d3, params, $$) {
             [Infinity, 1]
         ];
         var divisor;
-        for(var i = widthLimits.length-1; i--; ){
-            if($$.currentWidth > widthLimits[i][0]) {
-                divisor = widthLimits[i+1][1];
+        var size = $$.config.axis_rotated ? $$.currentWidth : $$.currentHeight;
+        var sizeLimits = $$.config.axis_rotated ? widthLimits : heightLimits;
+        for(var i = sizeLimits.length-1; i--; ){
+            if(size > sizeLimits[i][0]) {
+                divisor = sizeLimits[i+1][1];
                 break;
             }
         }
@@ -181,11 +190,10 @@ function c3_axis(d3, params, $$) {
 
             text = tick.select("text");
             
-            if($$.config.axis_rotated && orient === 'bottom') {
+
             text.style('display', function(d, i){
                 return shouldDrawTickText(i) ? 'block' : 'none';
             });
-            }
             
             tspan = text.selectAll('tspan')
                 .data(function (d, i) {