Treemap: patch to fix gaps between boxes

[timbunce]

This patch isn't a complete fix, but it does greatly improve the behaviour.

The boxes get packed at integer pixel boundaries, so the random gaps are minimized and now tend to accumulate naturally at the top/right of the containing boxes.

===================================================================
--- jit.js  (revision 785)
+++ jit.js  (working copy)
@@ -8564,9 +8564,9 @@
    layoutV: function(ch, w, coord) {
        var totalArea = 0; 
        $each(ch, function(elem) { totalArea += elem._area; });
-       var width = totalArea / w, top =  0; 
+       var width = Math.round(totalArea / w), top = 0; 
        for(var i=0; i<ch.length; i++) {
-           var h = ch[i]._area / width;
+           var h = Math.round(ch[i]._area / width);
            ch[i].coord = {
                'height': h,
                'width': width,
@@ -8590,14 +8590,14 @@
    layoutH: function(ch, w, coord) {
        var totalArea = 0; 
        $each(ch, function(elem) { totalArea += elem._area; });
-       var height = totalArea / w,
+       var height = Math.round(totalArea / w),
        top = coord.height - height, 
        left = 0;

        for(var i=0; i<ch.length; i++) {
            ch[i].coord = {
                'height': height,
-               'width': ch[i]._area / height,
+               'width': Math.round(ch[i]._area / height),
                'top': top,
                'left': coord.left + left
            };

[philogb]

Applied something similar to this patch here:

http://github.com/philogb/jit/commit/48f64456508bba833a8d554fbe38862b8498f71e

Should be in 1.1.3