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      1 
      2 /*
      3  * Copyright 2011 Google Inc.
      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 #ifndef SkImageEncoder_DEFINED
      9 #define SkImageEncoder_DEFINED
     10 
     11 #include "SkTypes.h"
     12 #include "SkTRegistry.h"
     13 
     14 class SkBitmap;
     15 class SkData;
     16 class SkWStream;
     17 
     18 class SkImageEncoder {
     19 public:
     20     enum Type {
     21         kUnknown_Type,
     22         kBMP_Type,
     23         kGIF_Type,
     24         kICO_Type,
     25         kJPEG_Type,
     26         kPNG_Type,
     27         kWBMP_Type,
     28         kWEBP_Type,
     29         kKTX_Type,
     30     };
     31     static SkImageEncoder* Create(Type);
     32 
     33     virtual ~SkImageEncoder();
     34 
     35     /*  Quality ranges from 0..100 */
     36     enum {
     37         kDefaultQuality = 80
     38     };
     39 
     40     /**
     41      *  Encode bitmap 'bm', returning the results in an SkData, at quality level
     42      *  'quality' (which can be in range 0-100). If the bitmap cannot be
     43      *  encoded, return null. On success, the caller is responsible for
     44      *  calling unref() on the data when they are finished.
     45      */
     46     SkData* encodeData(const SkBitmap&, int quality);
     47 
     48     /**
     49      * Encode bitmap 'bm' in the desired format, writing results to
     50      * file 'file', at quality level 'quality' (which can be in range
     51      * 0-100). Returns false on failure.
     52      */
     53     bool encodeFile(const char file[], const SkBitmap& bm, int quality);
     54 
     55     /**
     56      * Encode bitmap 'bm' in the desired format, writing results to
     57      * stream 'stream', at quality level 'quality' (which can be in
     58      * range 0-100). Returns false on failure.
     59      */
     60     bool encodeStream(SkWStream* stream, const SkBitmap& bm, int quality);
     61 
     62     static SkData* EncodeData(const SkBitmap&, Type, int quality);
     63     static bool EncodeFile(const char file[], const SkBitmap&, Type,
     64                            int quality);
     65     static bool EncodeStream(SkWStream*, const SkBitmap&, Type,
     66                            int quality);
     67 
     68 protected:
     69     /**
     70      * Encode bitmap 'bm' in the desired format, writing results to
     71      * stream 'stream', at quality level 'quality' (which can be in
     72      * range 0-100).
     73      *
     74      * This must be overridden by each SkImageEncoder implementation.
     75      */
     76     virtual bool onEncode(SkWStream* stream, const SkBitmap& bm, int quality) = 0;
     77 };
     78 
     79 // This macro declares a global (i.e., non-class owned) creation entry point
     80 // for each encoder (e.g., CreateJPEGImageEncoder)
     81 #define DECLARE_ENCODER_CREATOR(codec)          \
     82     SkImageEncoder *Create ## codec ();
     83 
     84 // This macro defines the global creation entry point for each encoder. Each
     85 // encoder implementation that registers with the encoder factory must call it.
     86 #define DEFINE_ENCODER_CREATOR(codec)           \
     87     SkImageEncoder *Create ## codec () {        \
     88         return SkNEW( Sk ## codec );            \
     89     }
     90 
     91 // All the encoders known by Skia. Note that, depending on the compiler settings,
     92 // not all of these will be available
     93 /** An ARGBImageEncoder will always write out
     94  *  bitmap.width() * bitmap.height() * 4
     95  *  bytes.
     96  */
     97 DECLARE_ENCODER_CREATOR(ARGBImageEncoder);
     98 DECLARE_ENCODER_CREATOR(JPEGImageEncoder);
     99 DECLARE_ENCODER_CREATOR(PNGImageEncoder);
    100 DECLARE_ENCODER_CREATOR(KTXImageEncoder);
    101 DECLARE_ENCODER_CREATOR(WEBPImageEncoder);
    102 
    103 #ifdef SK_BUILD_FOR_IOS
    104 DECLARE_ENCODER_CREATOR(PNGImageEncoder_IOS);
    105 #endif
    106 
    107 // Typedef to make registering encoder callback easier
    108 // This has to be defined outside SkImageEncoder. :(
    109 typedef SkTRegistry<SkImageEncoder*(*)(SkImageEncoder::Type)> SkImageEncoder_EncodeReg;
    110 #endif
    111