Copyright ã1995 by Netsurfer, Inc., All Rights Reserved.  

SurfGIFDecoder 

Category Name:	Internal
Declared In:	SurfGIFSupport.subproj/SurfGIFDecoder.Internal

Category Description
 
Implements the custom GIF decoding engine.  Upon entry into -_decodeFromStream:, the decoder progressively decodes each part of the image stream by calling the various decoding methods implemented by this category.

The UnsupportedBlocks category defines stub methods that simply skip unsupported GIF blocks without producing an error message.

The code is heavily documented.

The following is the copyright message associated with the LWZ decoder engine that was recycled out of the netpbm package of tools.

Copyright 1990, 1991, 1993, David Koblas.  (koblas@netcom.com)

Permission to use, copy, modify, and distribute this software and its documentation for any purpose and without fee is hereby granted, provided that the above copyright notice appear in all copies and that both that copyright notice and this permission notice appear in supporting documentation.  This software is provided "as is" without express or implied warranty.

Method Types
 
- _decodeFromStream:
- _decodeLogicalScreenDescriptor:
- _decodeColorTable:entryCount:intoBuffer:
- _decodeGCT:
- _decodeGraphicControlExtension:
- _decodeImageData:
- _decompressImage32:
- _decompressImage16:
- _decodeImageDescriptor:
- _decodeData:
- _resetImageDescriptor
- _resetGraphicControlExtension
- _resetDecoder

Instance Methods
 
_decodeColorTable:entryCount:intoBuffer:
- (unsigned char *) _decodeColorTable:(NXStream *)stream entryCount:(unsigned)tableSize intoBuffer:(unsigned char *)buf

No method description. 

_decodeData:
- _decodeData:(NXStream *)stream

No method description. 

_decodeFromStream:
- _decodeFromStream:(NXStream *)stream

No method description. 

_decodeGCT:
- _decodeGCT:(NXStream *)stream

No method description. 

_decodeGraphicControlExtension:
- _decodeGraphicControlExtension:(NXStream *)stream

No method description. 

_decodeImageData:
- _decodeImageData:(NXStream *)stream

No method description. 

_decodeImageDescriptor:
- _decodeImageDescriptor:(NXStream *)stream

No method description. 

_decodeLogicalScreenDescriptor:
- _decodeLogicalScreenDescriptor:(NXStream *)stream

No method description. 

_decompressImage16:
- _decompressImage16:(NXStream *)stream

No method description. 

_decompressImage32:
- _decompressImage32:(NXStream *)stream

No method description. 

_resetDecoder
- _resetDecoder

No method description. 

_resetGraphicControlExtension
- _resetGraphicControlExtension

No method description. 

_resetImageDescriptor
- _resetImageDescriptor

No method description.