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