ui/gfx/quad_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 #ifndef UI_GFX_QUAD_F_H_
   6 #define UI_GFX_QUAD_F_H_
   7
   8 #include <cmath>
   9 #include <string>
  10
  11 #include "ui/base/ui_export.h"
  12 #include "ui/gfx/point_f.h"
  13 #include "ui/gfx/rect_f.h"
  14
  15 namespace gfx {
  16
  17 // A Quad is defined by four corners, allowing it to have edges that are not
  18 // axis-aligned, unlike a Rect.
  19 class UI_EXPORT QuadF {
  20  public:
  21   QuadF() {}
  22   QuadF(const PointF& p1, const PointF& p2, const PointF& p3, const PointF& p4)
  23       : p1_(p1),
  24         p2_(p2),
  25         p3_(p3),
  26         p4_(p4) {}
  27
  28   explicit QuadF(const RectF& rect)
  29       : p1_(rect.x(), rect.y()),
  30         p2_(rect.right(), rect.y()),
  31         p3_(rect.right(), rect.bottom()),
  32         p4_(rect.x(), rect.bottom()) {}
  33
  34   void operator=(const RectF& rect);
  35
  36   void set_p1(const PointF& p) { p1_ = p; }
  37   void set_p2(const PointF& p) { p2_ = p; }
  38   void set_p3(const PointF& p) { p3_ = p; }
  39   void set_p4(const PointF& p) { p4_ = p; }
  40
  41   const PointF& p1() const { return p1_; }
  42   const PointF& p2() const { return p2_; }
  43   const PointF& p3() const { return p3_; }
  44   const PointF& p4() const { return p4_; }
  45
  46   // Returns true if the quad is an axis-aligned rectangle.
  47   bool IsRectilinear() const;
  48
  49   // Returns true if the points of the quad are in counter-clockwise order. This
  50   // assumes that the quad is convex, and that no three points are collinear.
  51   bool IsCounterClockwise() const;
  52
  53   // Returns true if the |point| is contained within the quad, or lies on on
  54   // edge of the quad.
  55   bool Contains(const gfx::PointF& point) const;
  56
  57   // Returns a rectangle that bounds the four points of the quad. The points of
  58   // the quad may lie on the right/bottom edge of the resulting rectangle,
  59   // rather than being strictly inside it.
  60   RectF BoundingBox() const {
  61     float rl = std::min(std::min(p1_.x(), p2_.x()), std::min(p3_.x(), p4_.x()));
  62     float rr = std::max(std::max(p1_.x(), p2_.x()), std::max(p3_.x(), p4_.x()));
  63     float rt = std::min(std::min(p1_.y(), p2_.y()), std::min(p3_.y(), p4_.y()));
  64     float rb = std::max(std::max(p1_.y(), p2_.y()), std::max(p3_.y(), p4_.y()));
  65     return RectF(rl, rt, rr - rl, rb - rt);
  66   }
  67
  68   // Add a vector to the quad, offseting each point in the quad by the vector.
  69   void operator+=(const Vector2dF& rhs);
  70   // Subtract a vector from the quad, offseting each point in the quad by the
  71   // inverse of the vector.
  72   void operator-=(const Vector2dF& rhs);
  73
  74   // Scale each point in the quad by the |scale| factor.
  75   void Scale(float scale) { Scale(scale, scale); }
  76
  77   // Scale each point in the quad by the scale factors along each axis.
  78   void Scale(float x_scale, float y_scale);
  79
  80   // Returns a string representation of quad.
  81   std::string ToString() const;
  82
  83  private:
  84   PointF p1_;
  85   PointF p2_;
  86   PointF p3_;
  87   PointF p4_;
  88 };
  89
  90 inline bool operator==(const QuadF& lhs, const QuadF& rhs) {
  91   return
  92       lhs.p1() == rhs.p1() && lhs.p2() == rhs.p2() &&
  93       lhs.p3() == rhs.p3() && lhs.p4() == rhs.p4();
  94 }
  95
  96 inline bool operator!=(const QuadF& lhs, const QuadF& rhs) {
  97   return !(lhs == rhs);
  98 }
  99
 100 // Add a vector to a quad, offseting each point in the quad by the vector.
 101 UI_EXPORT QuadF operator+(const QuadF& lhs, const Vector2dF& rhs);
 102 // Subtract a vector from a quad, offseting each point in the quad by the
 103 // inverse of the vector.
 104 UI_EXPORT QuadF operator-(const QuadF& lhs, const Vector2dF& rhs);
 105
 106 }  // namespace gfx
 107
 108 #endif  // UI_GFX_QUAD_F_H_