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:
ptr_(p)31   explicit scoped_array(T* p = 0) : ptr_(p) {}
~scoped_array()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:
BmpDecoderCallback()54   BmpDecoderCallback() { }
~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:
BmpDecoderHelper()72   BmpDecoderHelper() { }
~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