ui: Add the gfx::Vector3dF class.

ui/gfx/point3_f.h

 // Copyright (c) 2011 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.
 
 #ifndef UI_GFX_POINT3_F_H_
 #define UI_GFX_POINT3_F_H_
 
+#include <string>
+
+#include "ui/base/ui_export.h"
 #include "ui/gfx/point_f.h"
+#include "ui/gfx/vector3d_f.h"
 
 namespace gfx {
 
 // A point has an x, y and z coordinate.
-class Point3F {
+class UI_EXPORT Point3F {
  public:
   Point3F() : x_(0), y_(0), z_(0) {}
 
   Point3F(float x, float y, float z) : x_(x), y_(y), z_(z) {}
 
   explicit Point3F(const PointF& point) : x_(point.x()), y_(point.y()), z_(0) {}
 
   ~Point3F() {}
 
   float x() const { return x_; }
@@ skipping 13 matching lines @@
   // Returns the squared euclidean distance between two points.
   float SquaredDistanceTo(const Point3F& other) const {
     float dx = x_ - other.x_;
     float dy = y_ - other.y_;
     float dz = z_ - other.z_;
     return dx * dx + dy * dy + dz * dz;
   }
 
   PointF AsPointF() const { return PointF(x_, y_); }
 
+  // Returns a string representation of 3d point.
+  std::string ToString() const;
+
  private:
   float x_;
   float y_;
   float z_;
 
   // copy/assign are allowed.
 };
 
+inline bool operator==(const Point3F& lhs, const Point3F& rhs) {
+  return lhs.x() == rhs.x() && lhs.y() == rhs.y() && lhs.z() == rhs.z();
+}
+
+inline bool operator!=(const Point3F& lhs, const Point3F& rhs) {
+  return !(lhs == rhs);
+}
+
+// Add a vector to a point, producing a new point offset by the vector.
+UI_EXPORT Point3F operator+(const Point3F& lhs, const Vector3dF& rhs);
+
+// Subtract a vector from a point, producing a new point offset by the vector's
+// inverse.
+UI_EXPORT Point3F operator-(const Point3F& lhs, const Vector3dF& rhs);
+
+// Subtract one point from another, producing a vector that represents the
+// distances between the two points along each axis.
+UI_EXPORT Vector3dF operator-(const Point3F& lhs, const Point3F& rhs);
+
+inline Point3F PointAtOffsetFromOrigin(const Vector3dF& offset) {
+  return Point3F(offset.x(), offset.y(), offset.z());
+}
+
 }  // namespace gfx
 
 #endif  // UI_GFX_POINT3_F_H_