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      1 
      2 /*
      3  * Copyright 2006 The Android Open Source Project
      4  *
      5  * Use of this source code is governed by a BSD-style license that can be
      6  * found in the LICENSE file.
      7  */
      8 
      9 
     10 #ifndef SkGraphics_DEFINED
     11 #define SkGraphics_DEFINED
     12 
     13 #include "SkTypes.h"
     14 
     15 class SK_API SkGraphics {
     16 public:
     17     /**
     18      *  Call this at process initialization time if your environment does not
     19      *  permit static global initializers that execute code. Note that
     20      *  Init() is not thread-safe.
     21      */
     22     static void Init();
     23 
     24     /**
     25      *  Call this to release any memory held privately, such as the font cache.
     26      */
     27     static void Term();
     28 
     29     /**
     30      *  Return the version numbers for the library. If the parameter is not
     31      *  null, it is set to the version number.
     32      */
     33     static void GetVersion(int32_t* major, int32_t* minor, int32_t* patch);
     34 
     35     /**
     36      *  Return the max number of bytes that should be used by the font cache.
     37      *  If the cache needs to allocate more, it will purge previous entries.
     38      *  This max can be changed by calling SetFontCacheLimit().
     39      */
     40     static size_t GetFontCacheLimit();
     41 
     42     /**
     43      *  Specify the max number of bytes that should be used by the font cache.
     44      *  If the cache needs to allocate more, it will purge previous entries.
     45      *
     46      *  This function returns the previous setting, as if GetFontCacheLimit()
     47      *  had be called before the new limit was set.
     48      */
     49     static size_t SetFontCacheLimit(size_t bytes);
     50 
     51     /**
     52      *  Return the number of bytes currently used by the font cache.
     53      */
     54     static size_t GetFontCacheUsed();
     55 
     56     /**
     57      *  For debugging purposes, this will attempt to purge the font cache. It
     58      *  does not change the limit, but will cause subsequent font measures and
     59      *  draws to be recreated, since they will no longer be in the cache.
     60      */
     61     static void PurgeFontCache();
     62 
     63     /**
     64      *  Applications with command line options may pass optional state, such
     65      *  as cache sizes, here, for instance:
     66      *  font-cache-limit=12345678
     67      *
     68      *  The flags format is name=value[;name=value...] with no spaces.
     69      *  This format is subject to change.
     70      */
     71     static void SetFlags(const char* flags);
     72 
     73     /**
     74      *  Return the max number of bytes that should be used by the thread-local
     75      *  font cache.
     76      *  If the cache needs to allocate more, it will purge previous entries.
     77      *  This max can be changed by calling SetFontCacheLimit().
     78      *
     79      *  If this thread has never called SetTLSFontCacheLimit, or has called it
     80      *  with 0, then this thread is using the shared font cache. In that case,
     81      *  this function will always return 0, and the caller may want to call
     82      *  GetFontCacheLimit.
     83      */
     84     static size_t GetTLSFontCacheLimit();
     85 
     86     /**
     87      *  Specify the max number of bytes that should be used by the thread-local
     88      *  font cache. If this value is 0, then this thread will use the shared
     89      *  global font cache.
     90      */
     91     static void SetTLSFontCacheLimit(size_t bytes);
     92 
     93 private:
     94     /** This is automatically called by SkGraphics::Init(), and must be
     95         implemented by the host OS. This allows the host OS to register a callback
     96         with the C++ runtime to call SkGraphics::FreeCaches()
     97     */
     98     static void InstallNewHandler();
     99 };
    100 
    101 class SkAutoGraphics {
    102 public:
    103     SkAutoGraphics() {
    104         SkGraphics::Init();
    105     }
    106     ~SkAutoGraphics() {
    107         SkGraphics::Term();
    108     }
    109 };
    110 
    111 #endif
    112