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      1 
      2 /*
      3  * Copyright 2007 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 IMAGE_CODEC_BMPDECODERHELPER_H__
     11 #define IMAGE_CODEC_BMPDECODERHELPER_H__
     12 
     13 ///////////////////////////////////////////////////////////////////////////////
     14 // this section is my current "glue" between google3 code and android.
     15 // will be fixed soon
     16 
     17 #include "SkTypes.h"
     18 #include <limits.h>
     19 #define DISALLOW_EVIL_CONSTRUCTORS(name)
     20 #define CHECK(predicate)  SkASSERT(predicate)
     21 typedef uint8_t uint8;
     22 typedef uint32_t uint32;
     23 
     24 template <typename T> class scoped_array {
     25 private:
     26   T* ptr_;
     27   scoped_array(scoped_array const&);
     28   scoped_array& operator=(const scoped_array&);
     29 
     30 public:
     31   explicit scoped_array(T* p = 0) : ptr_(p) {}
     32   ~scoped_array() {
     33     delete[] ptr_;
     34   }
     35 
     36   void reset(T* p = 0) {
     37     if (p != ptr_) {
     38       delete[] ptr_;
     39       ptr_ = p;
     40     }
     41   }
     42 
     43   T& operator[](int i) const {
     44     return ptr_[i];
     45   }
     46 };
     47 
     48 ///////////////////////////////////////////////////////////////////////////////
     49 
     50 namespace image_codec {
     51 
     52 class BmpDecoderCallback {
     53  public:
     54   BmpDecoderCallback() { }
     55   virtual ~BmpDecoderCallback() {}
     56 
     57   /**
     58    * This is called once for an image. It is passed the width and height and
     59    * should return the address of a buffer that is large enough to store
     60    * all of the resulting pixels (widht * height * 3 bytes). If it returns NULL,
     61    * then the decoder will abort, but return true, as the caller has received
     62    * valid dimensions.
     63    */
     64   virtual uint8* SetSize(int width, int height) = 0;
     65 
     66  private:
     67   DISALLOW_EVIL_CONSTRUCTORS(BmpDecoderCallback);
     68 };
     69 
     70 class BmpDecoderHelper {
     71  public:
     72   BmpDecoderHelper() { }
     73   ~BmpDecoderHelper() { }
     74   bool DecodeImage(const char* data,
     75                    size_t len,
     76                    int max_pixels,
     77                    BmpDecoderCallback* callback);
     78 
     79  private:
     80   DISALLOW_EVIL_CONSTRUCTORS(BmpDecoderHelper);
     81 
     82   void DoRLEDecode();
     83   void DoStandardDecode();
     84   void PutPixel(int x, int y, uint8 col);
     85 
     86   int GetInt();
     87   int GetShort();
     88   uint8 GetByte();
     89   int CalcShiftRight(uint32 mask);
     90   int CalcShiftLeft(uint32 mask);
     91 
     92   const uint8* data_;
     93   size_t pos_;
     94   size_t len_;
     95   int width_;
     96   int height_;
     97   int bpp_;
     98   int pixelPad_;
     99   int rowPad_;
    100   scoped_array<uint8> colTab_;
    101   uint32 redBits_;
    102   uint32 greenBits_;
    103   uint32 blueBits_;
    104   int redShiftRight_;
    105   int greenShiftRight_;
    106   int blueShiftRight_;
    107   int redShiftLeft_;
    108   int greenShiftLeft_;
    109   int blueShiftLeft_;
    110   uint8* output_;
    111   bool inverted_;
    112 };
    113 
    114 } // namespace
    115 
    116 #endif
    117