ui/gfx/geometry/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_GEOMETRY_QUAD_F_H_
   6 #define UI_GFX_GEOMETRY_QUAD_F_H_
   7
   8 #include <algorithm>
   9 #include <cmath>
  10 #include <iosfwd>
  11 #include <string>
  12
  13 #include "base/logging.h"
  14 #include "ui/gfx/geometry/point_f.h"
  15 #include "ui/gfx/geometry/rect_f.h"
  16 #include "ui/gfx/gfx_export.h"
  17
  18 namespace gfx {
  19
  20 // A Quad is defined by four corners, allowing it to have edges that are not
  21 // axis-aligned, unlike a Rect.
  22 class GFX_EXPORT QuadF {
  23  public:
  24   QuadF() {}
  25   QuadF(const PointF& p1, const PointF& p2, const PointF& p3, const PointF& p4)
  26       : p1_(p1),
  27         p2_(p2),
  28         p3_(p3),
  29         p4_(p4) {}
  30
  31   explicit QuadF(const RectF& rect)
  32       : p1_(rect.x(), rect.y()),
  33         p2_(rect.right(), rect.y()),
  34         p3_(rect.right(), rect.bottom()),
  35         p4_(rect.x(), rect.bottom()) {}
  36
  37   void operator=(const RectF& rect);
  38
  39   void set_p1(const PointF& p) { p1_ = p; }
  40   void set_p2(const PointF& p) { p2_ = p; }
  41   void set_p3(const PointF& p) { p3_ = p; }
  42   void set_p4(const PointF& p) { p4_ = p; }
  43
  44   const PointF& p1() const { return p1_; }
  45   const PointF& p2() const { return p2_; }
  46   const PointF& p3() const { return p3_; }
  47   const PointF& p4() const { return p4_; }
  48
  49   // Returns true if the quad is an axis-aligned rectangle.
  50   bool IsRectilinear() const;
  51
  52   // Returns true if the points of the quad are in counter-clockwise order. This
  53   // assumes that the quad is convex, and that no three points are collinear.
  54   bool IsCounterClockwise() const;
  55
  56   // Returns true if the |point| is contained within the quad, or lies on on
  57   // edge of the quad. This assumes that the quad is convex.
  58   bool Contains(const gfx::PointF& point) const;
  59
  60   // Returns a rectangle that bounds the four points of the quad. The points of
  61   // the quad may lie on the right/bottom edge of the resulting rectangle,
  62   // rather than being strictly inside it.
  63   RectF BoundingBox() const {
  64     float rl = std::min(std::min(p1_.x(), p2_.x()), std::min(p3_.x(), p4_.x()));
  65     float rr = std::max(std::max(p1_.x(), p2_.x()), std::max(p3_.x(), p4_.x()));
  66     float rt = std::min(std::min(p1_.y(), p2_.y()), std::min(p3_.y(), p4_.y()));
  67     float rb = std::max(std::max(p1_.y(), p2_.y()), std::max(p3_.y(), p4_.y()));
  68     return RectF(rl, rt, rr - rl, rb - rt);
  69   }
  70
  71   // Realigns the corners in the quad by rotating them n corners to the right.
  72   void Realign(size_t times) {
  73     DCHECK_LE(times, 4u);
  74     for (size_t i = 0; i < times; ++i) {
  75       PointF temp = p1_;
  76       p1_ = p2_;
  77       p2_ = p3_;
  78       p3_ = p4_;
  79       p4_ = temp;
  80     }
  81   }
  82
  83   // Add a vector to the quad, offseting each point in the quad by the vector.
  84   void operator+=(const Vector2dF& rhs);
  85   // Subtract a vector from the quad, offseting each point in the quad by the
  86   // inverse of the vector.
  87   void operator-=(const Vector2dF& rhs);
  88
  89   // Scale each point in the quad by the |scale| factor.
  90   void Scale(float scale) { Scale(scale, scale); }
  91
  92   // Scale each point in the quad by the scale factors along each axis.
  93   void Scale(float x_scale, float y_scale);
  94
  95   // Returns a string representation of quad.
  96   std::string ToString() const;
  97
  98  private:
  99   PointF p1_;
 100   PointF p2_;
 101   PointF p3_;
 102   PointF p4_;
 103 };
 104
 105 inline bool operator==(const QuadF& lhs, const QuadF& rhs) {
 106   return
 107       lhs.p1() == rhs.p1() && lhs.p2() == rhs.p2() &&
 108       lhs.p3() == rhs.p3() && lhs.p4() == rhs.p4();
 109 }
 110
 111 inline bool operator!=(const QuadF& lhs, const QuadF& rhs) {
 112   return !(lhs == rhs);
 113 }
 114
 115 // Add a vector to a quad, offseting each point in the quad by the vector.
 116 GFX_EXPORT QuadF operator+(const QuadF& lhs, const Vector2dF& rhs);
 117 // Subtract a vector from a quad, offseting each point in the quad by the
 118 // inverse of the vector.
 119 GFX_EXPORT QuadF operator-(const QuadF& lhs, const Vector2dF& rhs);
 120
 121 // This is declared here for use in gtest-based unit tests but is defined in
 122 // the gfx_test_support target. Depend on that to use this in your unit test.
 123 // This should not be used in production code - call ToString() instead.
 124 void PrintTo(const QuadF& quad, ::std::ostream* os);
 125
 126 }  // namespace gfx
 127
 128 #endif  // UI_GFX_GEOMETRY_QUAD_F_H_