ui/gfx/vector2d_f.h

   1 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 // Defines a simple float vector class.  This class is used to indicate a
   6 // distance in two dimensions between two points. Subtracting two points should
   7 // produce a vector, and adding a vector to a point produces the point at the
   8 // vector's distance from the original point.
   9
  10 #ifndef UI_GFX_VECTOR2D_F_H_
  11 #define UI_GFX_VECTOR2D_F_H_
  12
  13 #include <string>
  14
  15 #include "ui/base/ui_export.h"
  16
  17 namespace gfx {
  18
  19 class UI_EXPORT Vector2dF {
  20  public:
  21   Vector2dF() : x_(0), y_(0) {}
  22   Vector2dF(float x, float y) : x_(x), y_(y) {}
  23
  24   float x() const { return x_; }
  25   void set_x(float x) { x_ = x; }
  26
  27   float y() const { return y_; }
  28   void set_y(float y) { y_ = y; }
  29
  30   // True if both components of the vector are 0.
  31   bool IsZero() const;
  32
  33   // Add the components of the |other| vector to the current vector.
  34   void Add(const Vector2dF& other);
  35   // Subtract the components of the |other| vector from the current vector.
  36   void Subtract(const Vector2dF& other);
  37
  38   void operator+=(const Vector2dF& other) { Add(other); }
  39   void operator-=(const Vector2dF& other) { Subtract(other); }
  40
  41   void SetToMin(const Vector2dF& other) {
  42     x_ = x_ <= other.x_ ? x_ : other.x_;
  43     y_ = y_ <= other.y_ ? y_ : other.y_;
  44   }
  45
  46   void SetToMax(const Vector2dF& other) {
  47     x_ = x_ >= other.x_ ? x_ : other.x_;
  48     y_ = y_ >= other.y_ ? y_ : other.y_;
  49   }
  50
  51   // Gives the square of the diagonal length of the vector.
  52   double LengthSquared() const;
  53   // Gives the diagonal length of the vector.
  54   float Length() const;
  55
  56   // Scale the x and y components of the vector by |scale|.
  57   void Scale(float scale) { Scale(scale, scale); }
  58   // Scale the x and y components of the vector by |x_scale| and |y_scale|
  59   // respectively.
  60   void Scale(float x_scale, float y_scale);
  61
  62   std::string ToString() const;
  63
  64  private:
  65   float x_;
  66   float y_;
  67 };
  68
  69 inline bool operator==(const Vector2dF& lhs, const Vector2dF& rhs) {
  70   return lhs.x() == rhs.x() && lhs.y() == rhs.y();
  71 }
  72
  73 inline Vector2dF operator-(const Vector2dF& v) {
  74   return Vector2dF(-v.x(), -v.y());
  75 }
  76
  77 inline Vector2dF operator+(const Vector2dF& lhs, const Vector2dF& rhs) {
  78   Vector2dF result = lhs;
  79   result.Add(rhs);
  80   return result;
  81 }
  82
  83 inline Vector2dF operator-(const Vector2dF& lhs, const Vector2dF& rhs) {
  84   Vector2dF result = lhs;
  85   result.Add(-rhs);
  86   return result;
  87 }
  88
  89 // Return the cross product of two vectors.
  90 UI_EXPORT double CrossProduct(const Vector2dF& lhs, const Vector2dF& rhs);
  91
  92 // Return the dot product of two vectors.
  93 UI_EXPORT double DotProduct(const Vector2dF& lhs, const Vector2dF& rhs);
  94
  95 // Return a vector that is |v| scaled by the given scale factors along each
  96 // axis.
  97 UI_EXPORT Vector2dF ScaleVector2d(const Vector2dF& v,
  98                                   float x_scale,
  99                                   float y_scale);
 100
 101 // Return a vector that is |v| scaled by the given scale factor.
 102 inline Vector2dF ScaleVector2d(const Vector2dF& v, float scale) {
 103   return ScaleVector2d(v, scale, scale);
 104 }
 105
 106 }  // namespace gfx
 107
 108 #endif // UI_GFX_VECTOR2D_F_H_