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1 | ///////////////////////////////////////////////////////////////////////////// | |
2 | // Name: gifdecod.h | |
3 | // Purpose: wxGIFDecoder, GIF reader for wxImage and wxAnimation | |
4 | // Author: Guillermo Rodriguez Garcia <guille@iies.es> | |
5 | // Version: 3.02 | |
6 | // CVS-ID: $Id$ | |
7 | // Copyright: (c) 1999 Guillermo Rodriguez Garcia | |
8 | // Licence: wxWindows licence | |
9 | ///////////////////////////////////////////////////////////////////////////// | |
10 | ||
11 | #ifndef _WX_GIFDECOD_H | |
12 | #define _WX_GIFDECOD_H | |
13 | ||
14 | #include "wx/defs.h" | |
15 | ||
16 | #if wxUSE_STREAMS && wxUSE_GIF | |
17 | ||
18 | #include "wx/stream.h" | |
19 | #include "wx/image.h" | |
20 | ||
21 | ||
22 | // -------------------------------------------------------------------------- | |
23 | // Constants | |
24 | // -------------------------------------------------------------------------- | |
25 | ||
26 | // Error codes: | |
27 | // Note that the error code wxGIF_TRUNCATED means that the image itself | |
28 | // is most probably OK, but the decoder didn't reach the end of the data | |
29 | // stream; this means that if it was not reading directly from file, | |
30 | // the stream will not be correctly positioned. the | |
31 | // | |
32 | enum | |
33 | { | |
34 | wxGIF_OK = 0, /* everything was OK */ | |
35 | wxGIF_INVFORMAT, /* error in gif header */ | |
36 | wxGIF_MEMERR, /* error allocating memory */ | |
37 | wxGIF_TRUNCATED /* file appears to be truncated */ | |
38 | }; | |
39 | ||
40 | // Disposal method | |
41 | // Experimental; subject to change. | |
42 | // | |
43 | enum | |
44 | { | |
45 | wxGIF_D_UNSPECIFIED = -1, /* not specified */ | |
46 | wxGIF_D_DONOTDISPOSE = 0, /* do not dispose */ | |
47 | wxGIF_D_TOBACKGROUND = 1, /* restore to background colour */ | |
48 | wxGIF_D_TOPREVIOUS = 2 /* restore to previous image */ | |
49 | }; | |
50 | ||
51 | ||
52 | #define MAX_BLOCK_SIZE 256 /* max. block size */ | |
53 | ||
54 | ||
55 | // -------------------------------------------------------------------------- | |
56 | // wxGIFDecoder class | |
57 | // -------------------------------------------------------------------------- | |
58 | ||
59 | // internal class for storing GIF image data | |
60 | class GIFImage | |
61 | { | |
62 | public: | |
63 | // def ctor | |
64 | GIFImage(); | |
65 | ||
66 | unsigned int w; /* width */ | |
67 | unsigned int h; /* height */ | |
68 | unsigned int left; /* x coord (in logical screen) */ | |
69 | unsigned int top; /* y coord (in logical screen) */ | |
70 | int transparent; /* transparent color (-1 = none) */ | |
71 | int disposal; /* disposal method (-1 = unspecified) */ | |
72 | long delay; /* delay in ms (-1 = unused) */ | |
73 | unsigned char *p; /* bitmap */ | |
74 | unsigned char *pal; /* palette */ | |
75 | GIFImage *next; /* next image */ | |
76 | GIFImage *prev; /* prev image */ | |
77 | ||
78 | DECLARE_NO_COPY_CLASS(GIFImage) | |
79 | }; | |
80 | ||
81 | ||
82 | class WXDLLEXPORT wxGIFDecoder | |
83 | { | |
84 | private: | |
85 | // logical screen | |
86 | unsigned int m_screenw; /* logical screen width */ | |
87 | unsigned int m_screenh; /* logical screen height */ | |
88 | int m_background; /* background color (-1 = none) */ | |
89 | ||
90 | // image data | |
91 | bool m_anim; /* animated GIF */ | |
92 | int m_nimages; /* number of images */ | |
93 | int m_image; /* current image */ | |
94 | GIFImage *m_pimage; /* pointer to current image */ | |
95 | GIFImage *m_pfirst; /* pointer to first image */ | |
96 | GIFImage *m_plast; /* pointer to last image */ | |
97 | ||
98 | // decoder state vars | |
99 | int m_restbits; /* remaining valid bits */ | |
100 | unsigned int m_restbyte; /* remaining bytes in this block */ | |
101 | unsigned int m_lastbyte; /* last byte read */ | |
102 | unsigned char m_buffer[MAX_BLOCK_SIZE]; /* buffer for reading */ | |
103 | unsigned char *m_bufp; /* pointer to next byte in buffer */ | |
104 | ||
105 | // input stream | |
106 | wxInputStream *m_f; /* input stream */ | |
107 | ||
108 | private: | |
109 | int getcode(int bits, int abfin); | |
110 | int dgif(GIFImage *img, int interl, int bits); | |
111 | ||
112 | public: | |
113 | // get data of current frame | |
114 | int GetFrameIndex() const; | |
115 | unsigned char* GetData() const; | |
116 | unsigned char* GetPalette() const; | |
117 | unsigned int GetWidth() const; | |
118 | unsigned int GetHeight() const; | |
119 | unsigned int GetLeft() const; | |
120 | unsigned int GetTop() const; | |
121 | int GetDisposalMethod() const; | |
122 | int GetTransparentColour() const; | |
123 | long GetDelay() const; | |
124 | ||
125 | // get global data | |
126 | unsigned int GetLogicalScreenWidth() const; | |
127 | unsigned int GetLogicalScreenHeight() const; | |
128 | int GetBackgroundColour() const; | |
129 | int GetNumberOfFrames() const; | |
130 | bool IsAnimation() const; | |
131 | ||
132 | // move through the animation | |
133 | bool GoFirstFrame(); | |
134 | bool GoLastFrame(); | |
135 | bool GoNextFrame(bool cyclic = false); | |
136 | bool GoPrevFrame(bool cyclic = false); | |
137 | bool GoFrame(int which); | |
138 | ||
139 | public: | |
140 | // constructor, destructor, etc. | |
141 | wxGIFDecoder(wxInputStream *s, bool anim = false); | |
142 | ~wxGIFDecoder(); | |
143 | bool CanRead(); | |
144 | int ReadGIF(); | |
145 | void Destroy(); | |
146 | ||
147 | // convert current frame to wxImage | |
148 | bool ConvertToImage(wxImage *image) const; | |
149 | ||
150 | DECLARE_NO_COPY_CLASS(wxGIFDecoder) | |
151 | }; | |
152 | ||
153 | ||
154 | #endif // wxUSE_STREAM && wxUSE_GIF | |
155 | #endif // _WX_GIFDECOD_H | |
156 |