--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/toolkit/javascript/d3/src/core/interpolate.js	Thu Apr 10 14:20:23 2014 +0200
@@ -0,0 +1,183 @@
+d3.interpolate = function(a, b) {
+  var i = d3.interpolators.length, f;
+  while (--i >= 0 && !(f = d3.interpolators[i](a, b)));
+  return f;
+};
+
+d3.interpolateNumber = function(a, b) {
+  b -= a;
+  return function(t) { return a + b * t; };
+};
+
+d3.interpolateRound = function(a, b) {
+  b -= a;
+  return function(t) { return Math.round(a + b * t); };
+};
+
+d3.interpolateString = function(a, b) {
+  var m, // current match
+      i, // current index
+      j, // current index (for coallescing)
+      s0 = 0, // start index of current string prefix
+      s1 = 0, // end index of current string prefix
+      s = [], // string constants and placeholders
+      q = [], // number interpolators
+      n, // q.length
+      o;
+
+  // Reset our regular expression!
+  d3_interpolate_number.lastIndex = 0;
+
+  // Find all numbers in b.
+  for (i = 0; m = d3_interpolate_number.exec(b); ++i) {
+    if (m.index) s.push(b.substring(s0, s1 = m.index));
+    q.push({i: s.length, x: m[0]});
+    s.push(null);
+    s0 = d3_interpolate_number.lastIndex;
+  }
+  if (s0 < b.length) s.push(b.substring(s0));
+
+  // Find all numbers in a.
+  for (i = 0, n = q.length; (m = d3_interpolate_number.exec(a)) && i < n; ++i) {
+    o = q[i];
+    if (o.x == m[0]) { // The numbers match, so coallesce.
+      if (o.i) {
+        if (s[o.i + 1] == null) { // This match is followed by another number.
+          s[o.i - 1] += o.x;
+          s.splice(o.i, 1);
+          for (j = i + 1; j < n; ++j) q[j].i--;
+        } else { // This match is followed by a string, so coallesce twice.
+          s[o.i - 1] += o.x + s[o.i + 1];
+          s.splice(o.i, 2);
+          for (j = i + 1; j < n; ++j) q[j].i -= 2;
+        }
+      } else {
+          if (s[o.i + 1] == null) { // This match is followed by another number.
+          s[o.i] = o.x;
+        } else { // This match is followed by a string, so coallesce twice.
+          s[o.i] = o.x + s[o.i + 1];
+          s.splice(o.i + 1, 1);
+          for (j = i + 1; j < n; ++j) q[j].i--;
+        }
+      }
+      q.splice(i, 1);
+      n--;
+      i--;
+    } else {
+      o.x = d3.interpolateNumber(parseFloat(m[0]), parseFloat(o.x));
+    }
+  }
+
+  // Remove any numbers in b not found in a.
+  while (i < n) {
+    o = q.pop();
+    if (s[o.i + 1] == null) { // This match is followed by another number.
+      s[o.i] = o.x;
+    } else { // This match is followed by a string, so coallesce twice.
+      s[o.i] = o.x + s[o.i + 1];
+      s.splice(o.i + 1, 1);
+    }
+    n--;
+  }
+
+  // Special optimization for only a single match.
+  if (s.length === 1) {
+    return s[0] == null ? q[0].x : function() { return b; };
+  }
+
+  // Otherwise, interpolate each of the numbers and rejoin the string.
+  return function(t) {
+    for (i = 0; i < n; ++i) s[(o = q[i]).i] = o.x(t);
+    return s.join("");
+  };
+};
+
+d3.interpolateTransform = function(a, b) {
+  return d3.interpolateString(d3.transform(a) + "", d3.transform(b) + "");
+};
+
+d3.interpolateRgb = function(a, b) {
+  a = d3.rgb(a);
+  b = d3.rgb(b);
+  var ar = a.r,
+      ag = a.g,
+      ab = a.b,
+      br = b.r - ar,
+      bg = b.g - ag,
+      bb = b.b - ab;
+  return function(t) {
+    return "#"
+        + d3_rgb_hex(Math.round(ar + br * t))
+        + d3_rgb_hex(Math.round(ag + bg * t))
+        + d3_rgb_hex(Math.round(ab + bb * t));
+  };
+};
+
+// interpolates HSL space, but outputs RGB string (for compatibility)
+d3.interpolateHsl = function(a, b) {
+  a = d3.hsl(a);
+  b = d3.hsl(b);
+  var h0 = a.h,
+      s0 = a.s,
+      l0 = a.l,
+      h1 = b.h - h0,
+      s1 = b.s - s0,
+      l1 = b.l - l0;
+  return function(t) {
+    return d3_hsl_rgb(h0 + h1 * t, s0 + s1 * t, l0 + l1 * t).toString();
+  };
+};
+
+d3.interpolateArray = function(a, b) {
+  var x = [],
+      c = [],
+      na = a.length,
+      nb = b.length,
+      n0 = Math.min(a.length, b.length),
+      i;
+  for (i = 0; i < n0; ++i) x.push(d3.interpolate(a[i], b[i]));
+  for (; i < na; ++i) c[i] = a[i];
+  for (; i < nb; ++i) c[i] = b[i];
+  return function(t) {
+    for (i = 0; i < n0; ++i) c[i] = x[i](t);
+    return c;
+  };
+};
+
+d3.interpolateObject = function(a, b) {
+  var i = {},
+      c = {},
+      k;
+  for (k in a) {
+    if (k in b) {
+      i[k] = d3_interpolateByName(k)(a[k], b[k]);
+    } else {
+      c[k] = a[k];
+    }
+  }
+  for (k in b) {
+    if (!(k in a)) {
+      c[k] = b[k];
+    }
+  }
+  return function(t) {
+    for (k in i) c[k] = i[k](t);
+    return c;
+  };
+}
+
+var d3_interpolate_number = /[-+]?(?:\d*\.?\d+)(?:[eE][-+]?\d+)?/g;
+
+function d3_interpolateByName(n) {
+  return n == "transform"
+      ? d3.interpolateTransform
+      : d3.interpolate;
+}
+
+d3.interpolators = [
+  d3.interpolateObject,
+  function(a, b) { return (b instanceof Array) && d3.interpolateArray(a, b); },
+  function(a, b) { return (typeof b === "string") && d3.interpolateString(a + "", b); },
+  function(a, b) { return (typeof b === "string" ? b in d3_rgb_names || /^(#|rgb\(|hsl\()/.test(b) : b instanceof d3_Rgb || b instanceof d3_Hsl) && d3.interpolateRgb(a + "", b); },
+  function(a, b) { return (typeof b === "number") && d3.interpolateNumber(+a, b); }
+];