layout/painting/BorderCache.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_BorderCache_h_
   8 #define mozilla_BorderCache_h_
   9
  10 #include "mozilla/gfx/2D.h"
  11 #include "mozilla/HashFunctions.h"
  12 #include "PLDHashTable.h"
  13
  14 namespace mozilla {
  15 // Cache for best overlap and best dashLength.
  16
  17 struct FourFloats {
  18   typedef mozilla::gfx::Float Float;
  19
  20   Float n[4];
  21
  22   FourFloats() {
  23     n[0] = 0.0f;
  24     n[1] = 0.0f;
  25     n[2] = 0.0f;
  26     n[3] = 0.0f;
  27   }
  28
  29   FourFloats(Float a, Float b, Float c, Float d) {
  30     n[0] = a;
  31     n[1] = b;
  32     n[2] = c;
  33     n[3] = d;
  34   }
  35
  36   bool operator==(const FourFloats& aOther) const {
  37     return n[0] == aOther.n[0] && n[1] == aOther.n[1] && n[2] == aOther.n[2] &&
  38            n[3] == aOther.n[3];
  39   }
  40 };
  41
  42 class FourFloatsHashKey : public PLDHashEntryHdr {
  43  public:
  44   typedef const FourFloats& KeyType;
  45   typedef const FourFloats* KeyTypePointer;
  46
  47   explicit FourFloatsHashKey(KeyTypePointer aKey) : mValue(*aKey) {}
  48   FourFloatsHashKey(const FourFloatsHashKey& aToCopy)
  49       : mValue(aToCopy.mValue) {}
  50   ~FourFloatsHashKey() = default;
  51
  52   KeyType GetKey() const { return mValue; }
  53   bool KeyEquals(KeyTypePointer aKey) const { return *aKey == mValue; }
  54
  55   static KeyTypePointer KeyToPointer(KeyType aKey) { return &aKey; }
  56   static PLDHashNumber HashKey(KeyTypePointer aKey) {
  57     return HashBytes(aKey->n, sizeof(mozilla::gfx::Float) * 4);
  58   }
  59   enum { ALLOW_MEMMOVE = true };
  60
  61  private:
  62   const FourFloats mValue;
  63 };
  64
  65 }  // namespace mozilla
  66
  67 #endif /* mozilla_BorderCache_h_ */