add mipmaps to scaledimagecache

src/core/SkScaledImageCache.h

 /*
  * Copyright 2013 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #ifndef SkScaledImageCache_DEFINED
 #define SkScaledImageCache_DEFINED
 
 #include "SkBitmap.h"
 
+class SkMipMap;
+
 /**
  *  Cache object for bitmaps (with possible scale in X Y as part of the key).
  *
  *  Multiple caches can be instantiated, but each instance is not implicitly
  *  thread-safe, so if a given instance is to be shared across threads, the
  *  caller must manage the access itself (e.g. via a mutex).
  *
  *  As a convenience, a global instance is also defined, which can be safely
  *  access across threads via the static methods (e.g. FindAndLock, etc.).
  */
 class SkScaledImageCache {
 public:
     struct ID;
 
     /*
      *  The following static methods are thread-safe wrappers around a global
      *  instance of this cache.
      */
 
     static ID* FindAndLock(const SkBitmap& original, SkScalar scaleX,
                            SkScalar scaleY, SkBitmap* scaled);
-
+    static ID* FindAndLockMip(const SkBitmap& original, SkMipMap const**);
+    
     static ID* AddAndLock(const SkBitmap& original, SkScalar scaleX,
-                           SkScalar scaleY, const SkBitmap& scaled);
-
+                          SkScalar scaleY, const SkBitmap& scaled);
+    static ID* AddAndLockMip(const SkBitmap& original, const SkMipMap*);
+    
     static void Unlock(ID*);
 
     static size_t GetBytesUsed();
     static size_t GetByteLimit();
     static size_t SetByteLimit(size_t newLimit);
 
     ///////////////////////////////////////////////////////////////////////////
 
     SkScaledImageCache(size_t byteLimit);
     ~SkScaledImageCache();
     
     /**
      *  Search the cache for a scaled version of original. If found, return it
      *  in scaled, and return its ID pointer. Use the returned ptr to unlock
      *  the cache when you are done using scaled.
      *
      *  If a match is not found, scaled will be unmodifed, and NULL will be
      *  returned.
      */
     ID* findAndLock(const SkBitmap& original, SkScalar scaleX,
                     SkScalar scaleY, SkBitmap* scaled);
+    ID* findAndLockMip(const SkBitmap& original, SkMipMap const**);
 
     /**
      *  To add a new (scaled) bitmap to the cache, call AddAndLock. Use the
      *  returned ptr to unlock the cache when you are done using scaled.
      */
     ID* addAndLock(const SkBitmap& original, SkScalar scaleX,
                    SkScalar scaleY, const SkBitmap& scaled);
+    ID* addAndLockMip(const SkBitmap& original, const SkMipMap*);
 
     /**
      *  Given a non-null ID ptr returned by either findAndLock or addAndLock,
      *  this releases the associated resources to be available to be purged
      *  if needed. After this, the cached bitmap should no longer be
      *  referenced by the caller.
      */
     void unlock(ID*);
 
     size_t getBytesUsed() const { return fBytesUsed; }
     size_t getByteLimit() const { return fByteLimit; }
     
     /**
      *  Set the maximum number of bytes available to this cache. If the current
      *  cache exceeds this new value, it will be purged to try to fit within
      *  this new limit.
      */
     size_t setByteLimit(size_t newLimit);
 
 private:
     struct Rec;
     Rec*    fHead;
     Rec*    fTail;
 
     size_t  fBytesUsed;
     size_t  fByteLimit;
     int     fCount;
 
+    Rec* findAndLock(const SkBitmap& original, SkScalar sx, SkScalar sy);
+
     void purgeAsNeeded();
 
     // linklist management
     void moveToHead(Rec*);
     void addToHead(Rec*);
     void detach(Rec*);
 #ifdef SK_DEBUG
     void validate() const;
 #else
     void validate() const {}
 #endif
 };
 
 #endif