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pnmFileTypePNG.h
1 // Filename: pnmFileTypePNG.h
2 // Created by: drose (16Mar04)
3 //
4 ////////////////////////////////////////////////////////////////////
5 //
6 // PANDA 3D SOFTWARE
7 // Copyright (c) Carnegie Mellon University. All rights reserved.
8 //
9 // All use of this software is subject to the terms of the revised BSD
10 // license. You should have received a copy of this license along
11 // with this source code in a file named "LICENSE."
12 //
13 ////////////////////////////////////////////////////////////////////
14 
15 #ifndef PNMFILETYPEPNG_H
16 #define PNMFILETYPEPNG_H
17 
18 #include "pandabase.h"
19 
20 #ifdef HAVE_PNG
21 
22 // Must be first.
23 #include <png.h>
24 
25 #include "pnmFileType.h"
26 #include "pnmReader.h"
27 #include "pnmWriter.h"
28 
29 ////////////////////////////////////////////////////////////////////
30 // Class : PNMFileTypePNG
31 // Description : For reading and writing PNG files.
32 ////////////////////////////////////////////////////////////////////
33 class EXPCL_PANDA_PNMIMAGETYPES PNMFileTypePNG : public PNMFileType {
34 public:
35  PNMFileTypePNG();
36 
37  virtual string get_name() const;
38 
39  virtual int get_num_extensions() const;
40  virtual string get_extension(int n) const;
41  virtual string get_suggested_extension() const;
42 
43  virtual bool has_magic_number() const;
44  virtual bool matches_magic_number(const string &magic_number) const;
45 
46  virtual PNMReader *make_reader(istream *file, bool owns_file = true,
47  const string &magic_number = string());
48  virtual PNMWriter *make_writer(ostream *file, bool owns_file = true);
49 
50 public:
51  class Reader : public PNMReader {
52  public:
53  Reader(PNMFileType *type, istream *file, bool owns_file, string magic_number);
54  virtual ~Reader();
55 
56  virtual int read_data(xel *array, xelval *alpha_data);
57 
58  private:
59  void free_png();
60  static void png_read_data(png_structp png_ptr, png_bytep data,
61  png_size_t length);
62 
63  static void png_error(png_structp png_ptr, png_const_charp error_msg);
64  static void png_warning(png_structp png_ptr, png_const_charp warning_msg);
65 
66  png_structp _png;
67  png_infop _info;
68 
69  // We need a jmp_buf to support libpng's fatal error handling, in
70  // which the error handler must not immediately leave libpng code,
71  // but must return to the caller in Panda.
72  jmp_buf _jmpbuf;
73  };
74 
75  class Writer : public PNMWriter {
76  public:
77  Writer(PNMFileType *type, ostream *file, bool owns_file);
78  virtual ~Writer();
79 
80  virtual int write_data(xel *array, xelval *alpha);
81 
82  private:
83  void free_png();
84  static int make_png_bit_depth(int bit_depth);
85  static void png_write_data(png_structp png_ptr, png_bytep data,
86  png_size_t length);
87  static void png_flush_data(png_structp png_ptr);
88 
89  static void png_error(png_structp png_ptr, png_const_charp error_msg);
90  static void png_warning(png_structp png_ptr, png_const_charp warning_msg);
91 
92  png_structp _png;
93  png_infop _info;
94 
95  // We need a jmp_buf to support libpng's fatal error handling, in
96  // which the error handler must not immediately leave libpng code,
97  // but must return to the caller in Panda.
98  jmp_buf _jmpbuf;
99  };
100 
101  // The TypedWritable interface follows.
102 public:
103  static void register_with_read_factory();
104 
105 protected:
106  static TypedWritable *make_PNMFileTypePNG(const FactoryParams &params);
107 
108 public:
109  static TypeHandle get_class_type() {
110  return _type_handle;
111  }
112  static void init_type() {
113  PNMFileType::init_type();
114  register_type(_type_handle, "PNMFileTypePNG",
115  PNMFileType::get_class_type());
116  }
117  virtual TypeHandle get_type() const {
118  return get_class_type();
119  }
120  virtual TypeHandle force_init_type() {init_type(); return get_class_type();}
121 
122 private:
123  static TypeHandle _type_handle;
124 };
125 
126 #endif // HAVE_PNG
127 
128 #endif
virtual string get_extension(int n) const
Returns the nth possible filename extension associated with this particular file type, without a leading dot.
Definition: pnmFileType.cxx:62
virtual PNMWriter * make_writer(ostream *file, bool owns_file=true)
Allocates and returns a new PNMWriter suitable for reading from this file type, if possible...
Base class for objects that can be written to and read from Bam files.
Definition: typedWritable.h:37
This is the base class of a family of classes that represent particular image file types that PNMImag...
Definition: pnmFileType.h:35
virtual int get_num_extensions() const
Returns the number of different possible filename extensions associated with this particular file typ...
Definition: pnmFileType.cxx:50
virtual PNMReader * make_reader(istream *file, bool owns_file=true, const string &magic_number=string())
Allocates and returns a new PNMReader suitable for reading from this file type, if possible...
virtual string get_suggested_extension() const
Returns a suitable filename extension (without a leading dot) to suggest for files of this type...
Definition: pnmFileType.cxx:75
virtual bool has_magic_number() const
Returns true if this particular file type uses a magic number to identify it, false otherwise...
Definition: pnmFileType.cxx:89
An instance of this class is passed to the Factory when requesting it to do its business and construc...
Definition: factoryParams.h:40
This is an abstract base class that defines the interface for reading image files of various types...
Definition: pnmReader.h:31
This is an abstract base class that defines the interface for writing image files of various types...
Definition: pnmWriter.h:31
TypeHandle is the identifier used to differentiate C++ class types.
Definition: typeHandle.h:85
virtual bool matches_magic_number(const string &magic_number) const
Returns true if the indicated &quot;magic number&quot; byte stream (the initial few bytes read from the file) m...