Home | History | Annotate | Download | only in images 
      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 
     13 class SkBitmap;
     14 class SkWStream;
     15 
     16 class SkImageEncoder {
     17 public:
     18     enum Type {
     19         kJPEG_Type,
     20         kPNG_Type,
     21         kWEBP_Type
     22     };
     23     static SkImageEncoder* Create(Type);
     24 
     25     virtual ~SkImageEncoder();
     26 
     27     /*  Quality ranges from 0..100 */
     28     enum {
     29         kDefaultQuality = 80
     30     };
     31 
     32     /**
     33      * Encode bitmap 'bm' in the desired format, writing results to
     34      * file 'file', at quality level 'quality' (which can be in range
     35      * 0-100).
     36      *
     37      * Calls the particular implementation's onEncode() method to
     38      * actually do the encoding.
     39      */
     40     bool encodeFile(const char file[], const SkBitmap& bm, int quality);
     41 
     42     /**
     43      * Encode bitmap 'bm' in the desired format, writing results to
     44      * stream 'stream', at quality level 'quality' (which can be in
     45      * range 0-100).
     46      *
     47      * Calls the particular implementation's onEncode() method to
     48      * actually do the encoding.
     49      */
     50     bool encodeStream(SkWStream* stream, const SkBitmap& bm, int quality);
     51 
     52     static bool EncodeFile(const char file[], const SkBitmap&, Type,
     53                            int quality);
     54     static bool EncodeStream(SkWStream*, const SkBitmap&, Type,
     55                            int quality);
     56 
     57 protected:
     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).
     62      *
     63      * This must be overridden by each SkImageEncoder implementation.
     64      */
     65     virtual bool onEncode(SkWStream* stream, const SkBitmap& bm, int quality) = 0;
     66 };
     67 
     68 // This macro declares a global (i.e., non-class owned) creation entry point
     69 // for each encoder (e.g., CreateJPEGImageEncoder)
     70 #define DECLARE_ENCODER_CREATOR(codec)          \
     71     SkImageEncoder *Create ## codec ();
     72 
     73 // This macro defines the global creation entry point for each encoder. Each
     74 // encoder implementation that registers with the encoder factory must call it.
     75 #define DEFINE_ENCODER_CREATOR(codec)           \
     76     SkImageEncoder *Create ## codec () {        \
     77         return SkNEW( Sk ## codec );            \
     78     }
     79 
     80 // All the encoders known by Skia. Note that, depending on the compiler settings,
     81 // not all of these will be available
     82 DECLARE_ENCODER_CREATOR(JPEGImageEncoder);
     83 DECLARE_ENCODER_CREATOR(PNGImageEncoder);
     84 DECLARE_ENCODER_CREATOR(WEBPImageEncoder);
     85 
     86 #endif
     87