From 7b2aeb6baf0389ba9fb48ca90a2a5de7390b7058 Mon Sep 17 00:00:00 2001
From: Mike Bostock <mbostock@gmail.com>
Date: Mon, 28 Mar 2016 14:38:52 -0700
Subject: [PATCH] Fix #27 - save node order for resquarify.

---
 src/treemap/squarify.js | 102 +++++++++++++++++++---------------------
 1 file changed, 48 insertions(+), 54 deletions(-)

diff --git a/src/treemap/squarify.js b/src/treemap/squarify.js
index 844ab1ef..dd67d28e 100644
--- a/src/treemap/squarify.js
+++ b/src/treemap/squarify.js
@@ -1,77 +1,52 @@
+import treemapDice from "./dice";
+import treemapSlice from "./slice";
+
 export default (function custom(ratio) {
 
   function squarify(parent, x0, y0, x1, y1) {
-    var nodes = parent.children,
-        node,
+    if (parent._squarify) return resquarify(parent, x0, y0, x1, y1);
+
+    var squarified = parent._squarify = [],
+        nodes = parent.children,
+        row,
         nodeValue,
         i0 = 0,
         i1,
         n = nodes.length,
-        x2, y2,
         dx, dy,
         value = parent.value,
         sumValue,
         minValue,
         maxValue,
-        alpha,
-        beta,
         newRatio,
-        minRatio;
+        minRatio,
+        alpha,
+        beta;
 
     while (i0 < n) {
       dx = x1 - x0, dy = y1 - y0;
-      sumValue = (node = nodes[i0]).value;
+      minValue = maxValue = sumValue = nodes[i0].value;
+      alpha = Math.max(dy / dx, dx / dy) / (value * ratio);
+      beta = sumValue * sumValue * alpha;
+      minRatio = Math.max(maxValue / beta, beta / minValue);
 
-      // Are we updating a previous squarified layout?
-      if (node._squarify) {
-        for (i1 = i0 + 1; i1 < Math.abs(node._squarify); ++i1) {
-          sumValue += nodes[i1].value;
-        }
-      }
-
-      // Otherwise, we’re computing a squarified layout from scratch.
-      else {
-        minValue = maxValue = sumValue;
-        alpha = Math.max(dy / dx, dx / dy) / (value * ratio);
+      // Keep adding nodes while the aspect ratio maintains or improves.
+      for (i1 = i0 + 1; i1 < n; ++i1) {
+        sumValue += nodeValue = nodes[i1].value;
+        if (nodeValue < minValue) minValue = nodeValue;
+        if (nodeValue > maxValue) maxValue = nodeValue;
         beta = sumValue * sumValue * alpha;
-        minRatio = Math.max(maxValue / beta, beta / minValue);
-
-        // Keep adding nodes while the aspect ratio maintains or improves.
-        for (i1 = i0 + 1; i1 < n; ++i1) {
-          sumValue += nodeValue = nodes[i1].value;
-          if (nodeValue < minValue) minValue = nodeValue;
-          if (nodeValue > maxValue) maxValue = nodeValue;
-          beta = sumValue * sumValue * alpha;
-          newRatio = Math.max(maxValue / beta, beta / minValue);
-          if (newRatio > minRatio) { sumValue -= nodeValue; break; }
-          minRatio = newRatio;
-        }
-
-        node._squarify = dx < dy ? i1 : -i1;
+        newRatio = Math.max(maxValue / beta, beta / minValue);
+        if (newRatio > minRatio) { sumValue -= nodeValue; break; }
+        minRatio = newRatio;
       }
 
-      // Position the row horizontally along the top of the rect.
-      if (node._squarify > 0) {
-        for (x2 = x0, y2 = y0 + dy * sumValue / value, dx /= sumValue; i0 < i1; ++i0) {
-          node = nodes[i0], node.x0 = x2, node.y0 = y0, node.y1 = y2;
-          node.x1 = x2 += node.value * dx;
-        }
-        node.x1 = x1, y0 = y2;
-      }
-
-      // Position the row vertically along the left of the rect.
-      else {
-        for (y2 = y0, x2 = x0 + dx * sumValue / value, dy /= sumValue; i0 < i1; ++i0) {
-          node = nodes[i0], node.y0 = y2, node.x0 = x0, node.x1 = x2;
-          node.y1 = y2 += node.value * dy;
-        }
-        node.y1 = y1, x0 = x2;
-      }
-
-      value -= sumValue;
+      // Position and record the row orientation.
+      squarified.push(row = {value: sumValue, dice: dx < dy, children: nodes.slice(i0, i1)});
+      if (row.dice) treemapDice(row, x0, y0, x1, y0 += dy * sumValue / value);
+      else treemapSlice(row, x0, y0, x0 += dx * sumValue / value, y1);
+      value -= sumValue, i0 = i1;
     }
-
-    node.x1 = x1, node.y1 = y1;
   }
 
   squarify.ratio = function(x) {
@@ -79,4 +54,23 @@ export default (function custom(ratio) {
   };
 
   return squarify;
-})((1 + Math.sqrt(5)) / 2);
+})((1 + Math.sqrt(5)) / 2, false);
+
+function resquarify(parent, x0, y0, x1, y1) {
+  var squarified = parent._squarify,
+      row,
+      nodes,
+      i,
+      j = -1,
+      n,
+      m = squarified.length,
+      value = parent.value;
+
+  while (++j < m) {
+    row = squarified[j], nodes = row.children;
+    for (i = row.value = 0, n = nodes.length; i < n; ++i) row.value += nodes[i].value;
+    if (row.dice) treemapDice(row, x0, y0, x1, y0 += (y1 - y0) * row.value / value);
+    else treemapSlice(row, x0, y0, x0 += (x1 - x0) * row.value / value, y1);
+    value -= row.value;
+  }
+}