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      1 /*
      2  * Copyright 2011 Google Inc.
      3  *
      4  * Use of this source code is governed by a BSD-style license that can be
      5  * found in the LICENSE file.
      6  */
      7 
      8 #ifndef SkImageEncoder_DEFINED
      9 #define SkImageEncoder_DEFINED
     10 
     11 #include "SkImageInfo.h"
     12 #include "SkTRegistry.h"
     13 
     14 class SkBitmap;
     15 class SkPixelSerializer;
     16 class SkPixmap;
     17 class SkData;
     18 class SkWStream;
     19 
     20 class SkImageEncoder {
     21 public:
     22     // TODO (scroggo): Merge with SkEncodedFormat.
     23     enum Type {
     24         kUnknown_Type,
     25         kBMP_Type,
     26         kGIF_Type,
     27         kICO_Type,
     28         kJPEG_Type,
     29         kPNG_Type,
     30         kWBMP_Type,
     31         kWEBP_Type,
     32         kKTX_Type,
     33     };
     34     static SkImageEncoder* Create(Type);
     35 
     36     virtual ~SkImageEncoder();
     37 
     38     /*  Quality ranges from 0..100 */
     39     enum {
     40         kDefaultQuality = 80
     41     };
     42 
     43     /**
     44      *  Encode bitmap 'bm', returning the results in an SkData, at quality level
     45      *  'quality' (which can be in range 0-100). If the bitmap cannot be
     46      *  encoded, return null. On success, the caller is responsible for
     47      *  calling unref() on the data when they are finished.
     48      */
     49     SkData* encodeData(const SkBitmap&, int quality);
     50 
     51     /**
     52      * Encode bitmap 'bm' in the desired format, writing results to
     53      * file 'file', at quality level 'quality' (which can be in range
     54      * 0-100). Returns false on failure.
     55      */
     56     bool encodeFile(const char file[], const SkBitmap& bm, int quality);
     57 
     58     /**
     59      * Encode bitmap 'bm' in the desired format, writing results to
     60      * stream 'stream', at quality level 'quality' (which can be in
     61      * range 0-100). Returns false on failure.
     62      */
     63     bool encodeStream(SkWStream* stream, const SkBitmap& bm, int quality);
     64 
     65     static SkData* EncodeData(const SkImageInfo&, const void* pixels, size_t rowBytes,
     66                               Type, int quality);
     67     static SkData* EncodeData(const SkBitmap&, Type, int quality);
     68 
     69     static SkData* EncodeData(const SkPixmap&, Type, int quality);
     70 
     71     static bool EncodeFile(const char file[], const SkBitmap&, Type,
     72                            int quality);
     73     static bool EncodeStream(SkWStream*, const SkBitmap&, Type,
     74                            int quality);
     75 
     76     /** Uses SkImageEncoder to serialize images that are not already
     77         encoded as SkImageEncoder::kPNG_Type images. */
     78     static SkPixelSerializer* CreatePixelSerializer();
     79 
     80 protected:
     81     /**
     82      * Encode bitmap 'bm' in the desired format, writing results to
     83      * stream 'stream', at quality level 'quality' (which can be in
     84      * range 0-100).
     85      *
     86      * This must be overridden by each SkImageEncoder implementation.
     87      */
     88     virtual bool onEncode(SkWStream* stream, const SkBitmap& bm, int quality) = 0;
     89 };
     90 
     91 // This macro declares a global (i.e., non-class owned) creation entry point
     92 // for each encoder (e.g., CreateJPEGImageEncoder)
     93 #define DECLARE_ENCODER_CREATOR(codec)          \
     94     SkImageEncoder *Create ## codec ();
     95 
     96 // This macro defines the global creation entry point for each encoder. Each
     97 // encoder implementation that registers with the encoder factory must call it.
     98 #define DEFINE_ENCODER_CREATOR(codec) \
     99     SkImageEncoder* Create##codec() { return new Sk##codec; }
    100 
    101 // All the encoders known by Skia. Note that, depending on the compiler settings,
    102 // not all of these will be available
    103 /** An ARGBImageEncoder will always write out
    104  *  bitmap.width() * bitmap.height() * 4
    105  *  bytes.
    106  */
    107 DECLARE_ENCODER_CREATOR(ARGBImageEncoder);
    108 DECLARE_ENCODER_CREATOR(JPEGImageEncoder);
    109 DECLARE_ENCODER_CREATOR(PNGImageEncoder);
    110 DECLARE_ENCODER_CREATOR(KTXImageEncoder);
    111 DECLARE_ENCODER_CREATOR(WEBPImageEncoder);
    112 
    113 #ifdef SK_BUILD_FOR_IOS
    114 DECLARE_ENCODER_CREATOR(PNGImageEncoder_IOS);
    115 #endif
    116 
    117 // Typedef to make registering encoder callback easier
    118 // This has to be defined outside SkImageEncoder. :(
    119 typedef SkTRegistry<SkImageEncoder*(*)(SkImageEncoder::Type)> SkImageEncoder_EncodeReg;
    120 #endif
    121