vector2d_f.h

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// 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.
 
// Defines a simple float vector class.  This class is used to indicate a
// distance in two dimensions between two points. Subtracting two points should
// produce a vector, and adding a vector to a point produces the point at the
// vector's distance from the original point.
 
#ifndef UI_GFX_GEOMETRY_VECTOR2D_F_H_
#define UI_GFX_GEOMETRY_VECTOR2D_F_H_
 
#include <iosfwd>
#include <memory>
#include <string>
 
#include "gfx/gfx_export.h"
 
namespace gfx {
 
class GFX_EXPORT Vector2dF {
 public:
  constexpr Vector2dF() : x_(0), y_(0) {}
  constexpr Vector2dF(float x, float y) : x_(x), y_(y) {}
 
  constexpr float x() const { return x_; }
  void set_x(float x) { x_ = x; }
 
  constexpr float y() const { return y_; }
  void set_y(float y) { y_ = y; }
 
  // True if both components of the vector are 0.
  bool IsZero() const;
 
  // Add the components of the |other| vector to the current vector.
  void Add(const Vector2dF& other);
  // Subtract the components of the |other| vector from the current vector.
  void Subtract(const Vector2dF& other);
 
  void operator+=(const Vector2dF& other) { Add(other); }
  void operator-=(const Vector2dF& other) { Subtract(other); }
 
  void SetToMin(const Vector2dF& other) {
    x_ = x_ <= other.x_ ? x_ : other.x_;
    y_ = y_ <= other.y_ ? y_ : other.y_;
  }
 
  void SetToMax(const Vector2dF& other) {
    x_ = x_ >= other.x_ ? x_ : other.x_;
    y_ = y_ >= other.y_ ? y_ : other.y_;
  }
 
  // Gives the square of the diagonal length of the vector.
  double LengthSquared() const;
  // Gives the diagonal length of the vector.
  float Length() const;
 
  // Scale the x and y components of the vector by |scale|.
  void Scale(float scale) { Scale(scale, scale); }
  // Scale the x and y components of the vector by |x_scale| and |y_scale|
  // respectively.
  void Scale(float x_scale, float y_scale);
 
  std::string ToString() const;
 
 private:
  float x_;
  float y_;
};
 
inline constexpr bool operator==(const Vector2dF& lhs, const Vector2dF& rhs) {
  return lhs.x() == rhs.x() && lhs.y() == rhs.y();
}
 
inline constexpr bool operator!=(const Vector2dF& lhs, const Vector2dF& rhs) {
  return !(lhs == rhs);
}
 
inline constexpr Vector2dF operator-(const Vector2dF& v) {
  return Vector2dF(-v.x(), -v.y());
}
 
inline Vector2dF operator+(const Vector2dF& lhs, const Vector2dF& rhs) {
  Vector2dF result = lhs;
  result.Add(rhs);
  return result;
}
 
inline Vector2dF operator-(const Vector2dF& lhs, const Vector2dF& rhs) {
  Vector2dF result = lhs;
  result.Add(-rhs);
  return result;
}
 
// Return the cross product of two vectors.
GFX_EXPORT double CrossProduct(const Vector2dF& lhs, const Vector2dF& rhs);
 
// Return the dot product of two vectors.
GFX_EXPORT double DotProduct(const Vector2dF& lhs, const Vector2dF& rhs);
 
// Return a vector that is |v| scaled by the given scale factors along each
// axis.
GFX_EXPORT Vector2dF ScaleVector2d(const Vector2dF& v,
                                   float x_scale,
                                   float y_scale);
 
// Return a vector that is |v| scaled by the given scale factor.
inline Vector2dF ScaleVector2d(const Vector2dF& v, float scale) {
  return ScaleVector2d(v, scale, scale);
}
 
// This is declared here for use in gtest-based unit tests but is defined in
// the //ui/gfx:test_support target. Depend on that to use this in your unit
// test. This should not be used in production code - call ToString() instead.
void PrintTo(const Vector2dF& vector, ::std::ostream* os);
 
}  // namespace gfx
 
#endif  // UI_GFX_GEOMETRY_VECTOR2D_F_H_