gfx/2d/BaseSize.h

   1 /* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
   2 /* vim: set ts=8 sts=2 et sw=2 tw=80: */
   3 /* This Source Code Form is subject to the terms of the Mozilla Public
   4  * License, v. 2.0. If a copy of the MPL was not distributed with this
   5  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
   6
   7 #ifndef MOZILLA_GFX_BASESIZE_H_
   8 #define MOZILLA_GFX_BASESIZE_H_
   9
  10 #include <algorithm>
  11 #include <ostream>
  12
  13 #include "mozilla/Attributes.h"
  14
  15 namespace mozilla::gfx {
  16
  17 /**
  18  * Do not use this class directly. Subclass it, pass that subclass as the
  19  * Sub parameter, and only use that subclass. This allows methods to safely
  20  * cast 'this' to 'Sub*'.
  21  */
  22 template <class T, class Sub, class Coord = T>
  23 struct BaseSize {
  24   union {
  25     struct {
  26       T width, height;
  27     };
  28     T components[2];
  29   };
  30
  31   // Constructors
  32   constexpr BaseSize() : width(0), height(0) {}
  33   constexpr BaseSize(Coord aWidth, Coord aHeight)
  34       : width(aWidth), height(aHeight) {}
  35
  36   void SizeTo(T aWidth, T aHeight) {
  37     width = aWidth;
  38     height = aHeight;
  39   }
  40
  41   bool IsEmpty() const { return width <= 0 || height <= 0; }
  42
  43   bool IsSquare() const { return width == height; }
  44
  45   MOZ_ALWAYS_INLINE T Width() const { return width; }
  46   MOZ_ALWAYS_INLINE T Height() const { return height; }
  47
  48   // Note that '=' isn't defined so we'll get the
  49   // compiler generated default assignment operator
  50
  51   bool operator==(const Sub& aSize) const {
  52     return width == aSize.width && height == aSize.height;
  53   }
  54   bool operator!=(const Sub& aSize) const {
  55     return width != aSize.width || height != aSize.height;
  56   }
  57   bool operator<=(const Sub& aSize) const {
  58     return width <= aSize.width && height <= aSize.height;
  59   }
  60   bool operator<(const Sub& aSize) const {
  61     return *this <= aSize && *this != aSize;
  62   }
  63
  64   Sub operator+(const Sub& aSize) const {
  65     return Sub(width + aSize.width, height + aSize.height);
  66   }
  67   Sub operator-(const Sub& aSize) const {
  68     return Sub(width - aSize.width, height - aSize.height);
  69   }
  70   Sub& operator+=(const Sub& aSize) {
  71     width += aSize.width;
  72     height += aSize.height;
  73     return *static_cast<Sub*>(this);
  74   }
  75   Sub& operator-=(const Sub& aSize) {
  76     width -= aSize.width;
  77     height -= aSize.height;
  78     return *static_cast<Sub*>(this);
  79   }
  80
  81   Sub operator*(T aScale) const { return Sub(width * aScale, height * aScale); }
  82   Sub operator/(T aScale) const { return Sub(width / aScale, height / aScale); }
  83   friend Sub operator*(T aScale, const Sub& aSize) {
  84     return Sub(aScale * aSize.width, aScale * aSize.height);
  85   }
  86   void Scale(T aXScale, T aYScale) {
  87     width *= aXScale;
  88     height *= aYScale;
  89   }
  90
  91   Sub operator*(const Sub& aSize) const {
  92     return Sub(width * aSize.width, height * aSize.height);
  93   }
  94   Sub operator/(const Sub& aSize) const {
  95     return Sub(width / aSize.width, height / aSize.height);
  96   }
  97
  98   friend Sub Min(const Sub& aA, const Sub& aB) {
  99     return Sub(std::min(aA.width, aB.width), std::min(aA.height, aB.height));
 100   }
 101
 102   friend Sub Max(const Sub& aA, const Sub& aB) {
 103     return Sub(std::max(aA.width, aB.width), std::max(aA.height, aB.height));
 104   }
 105
 106   friend std::ostream& operator<<(std::ostream& aStream,
 107                                   const BaseSize<T, Sub, Coord>& aSize) {
 108     return aStream << '(' << aSize.width << " x " << aSize.height << ')';
 109   }
 110 };
 111
 112 }  // namespace mozilla::gfx
 113
 114 #endif /* MOZILLA_GFX_BASESIZE_H_ */