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