ui: Add the gfx::Vector3dF class.

ui/gfx/vector3d_f.cc

Index: ui/gfx/vector3d_f.cc
diff --git a/ui/gfx/vector3d_f.cc b/ui/gfx/vector3d_f.cc
new file mode 100644
index 0000000000000000000000000000000000000000..730f00b9975cf48782963c296e1e51171437f60a
--- /dev/null
+++ b/ui/gfx/vector3d_f.cc
@@ -0,0 +1,79 @@
+// Copyright (c) 2012 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "ui/gfx/vector3d_f.h"
+
+#include <cmath>
+
+#include "base/stringprintf.h"
+
+namespace gfx {
+
+Vector3dF::Vector3dF()
+    : x_(0),
+      y_(0),
+      z_(0) {
+}
+
+Vector3dF::Vector3dF(float x, float y, float z)
+    : x_(x),
+      y_(y),
+      z_(z) {
+}
+
+Vector3dF::Vector3dF(const Vector2dF& other)
+    : x_(other.x()),
+      y_(other.y()),
+      z_(0) {
+}
+
+std::string Vector3dF::ToString() const {
+  return base::StringPrintf("[%f %f %f]", x_, y_, z_);
+}
+
+bool Vector3dF::IsZero() const {
+  return x_ == 0 && y_ == 0 && z_ == 0;
+}
+
+void Vector3dF::Add(const Vector3dF& other) {
+  x_ += other.x_;
+  y_ += other.y_;
+  z_ += other.z_;
+}
+
+void Vector3dF::Subtract(const Vector3dF& other) {
+  x_ -= other.x_;
+  y_ -= other.y_;
+  z_ -= other.z_;
+}
+
+double Vector3dF::LengthSquared() const {
+  return static_cast<double>(x_) * x_ + static_cast<double>(y_) * y_ +
+      static_cast<double>(z_) * z_;
+}
+
+float Vector3dF::Length() const {
+  return static_cast<float>(std::sqrt(LengthSquared()));
+}
+
+void Vector3dF::Scale(float x_scale, float y_scale, float z_scale) {
+  x_ *= x_scale;
+  y_ *= y_scale;
+  z_ *= z_scale;
+}
+
+void Vector3dF::Cross(const Vector3dF& other) {
+  float x = y_ * other.z() - z_ * other.y();
+  float y = z_ * other.x() - x_ * other.z();
+  float z = x_ * other.y() - y_ * other.x();

[Peter Kasting, 2012/11/01 00:24:58]

Nit: You could write |z_| directly here and omit that from below, if you want. 
I don't care too much about parallel structure...

+  x_ = x;
+  y_ = y;
+  z_ = z;
+}
+
+float DotProduct(const Vector3dF& lhs, const Vector3dF& rhs) {
+  return lhs.x() * rhs.x() + lhs.y() * rhs.y() + lhs.z() * rhs.z();
+}
+
+}  // namespace gfx