Panda3D
pnmFileTypePNG.h
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1 /**
2  * PANDA 3D SOFTWARE
3  * Copyright (c) Carnegie Mellon University. All rights reserved.
4  *
5  * All use of this software is subject to the terms of the revised BSD
6  * license. You should have received a copy of this license along
7  * with this source code in a file named "LICENSE."
8  *
9  * @file pnmFileTypePNG.h
10  * @author drose
11  * @date 2004-03-16
12  */
13 
14 #ifndef PNMFILETYPEPNG_H
15 #define PNMFILETYPEPNG_H
16 
17 #include "pandabase.h"
18 
19 #ifdef HAVE_PNG
20 
21 // Must be first.
22 #include <png.h>
23 
24 #include "pnmFileType.h"
25 #include "pnmReader.h"
26 #include "pnmWriter.h"
27 
28 /**
29  * For reading and writing PNG files.
30  */
31 class EXPCL_PANDA_PNMIMAGETYPES PNMFileTypePNG : public PNMFileType {
32 public:
33  PNMFileTypePNG();
34 
35  virtual std::string get_name() const;
36 
37  virtual int get_num_extensions() const;
38  virtual std::string get_extension(int n) const;
39  virtual std::string get_suggested_extension() const;
40 
41  virtual bool has_magic_number() const;
42  virtual bool matches_magic_number(const std::string &magic_number) const;
43 
44  virtual PNMReader *make_reader(std::istream *file, bool owns_file = true,
45  const std::string &magic_number = std::string());
46  virtual PNMWriter *make_writer(std::ostream *file, bool owns_file = true);
47 
48 public:
49  class Reader : public PNMReader {
50  public:
51  Reader(PNMFileType *type, std::istream *file, bool owns_file, std::string magic_number);
52  virtual ~Reader();
53 
54  virtual int read_data(xel *array, xelval *alpha_data);
55 
56  private:
57  void free_png();
58  static void png_read_data(png_structp png_ptr, png_bytep data,
59  png_size_t length);
60 
61  static void png_error(png_structp png_ptr, png_const_charp error_msg);
62  static void png_warning(png_structp png_ptr, png_const_charp warning_msg);
63 
64  png_structp _png;
65  png_infop _info;
66 
67  // We need a jmp_buf to support libpng's fatal error handling, in which
68  // the error handler must not immediately leave libpng code, but must
69  // return to the caller in Panda.
70  jmp_buf _jmpbuf;
71  };
72 
73  class Writer : public PNMWriter {
74  public:
75  Writer(PNMFileType *type, std::ostream *file, bool owns_file);
76  virtual ~Writer();
77 
78  virtual int write_data(xel *array, xelval *alpha);
79 
80  private:
81  void free_png();
82  static int make_png_bit_depth(int bit_depth);
83  static void png_write_data(png_structp png_ptr, png_bytep data,
84  png_size_t length);
85  static void png_flush_data(png_structp png_ptr);
86 
87  static void png_error(png_structp png_ptr, png_const_charp error_msg);
88  static void png_warning(png_structp png_ptr, png_const_charp warning_msg);
89 
90  png_structp _png;
91  png_infop _info;
92 
93  // We need a jmp_buf to support libpng's fatal error handling, in which
94  // the error handler must not immediately leave libpng code, but must
95  // return to the caller in Panda.
96  jmp_buf _jmpbuf;
97  };
98 
99  // The TypedWritable interface follows.
100 public:
101  static void register_with_read_factory();
102 
103 protected:
104  static TypedWritable *make_PNMFileTypePNG(const FactoryParams &params);
105 
106 public:
107  static TypeHandle get_class_type() {
108  return _type_handle;
109  }
110  static void init_type() {
111  PNMFileType::init_type();
112  register_type(_type_handle, "PNMFileTypePNG",
113  PNMFileType::get_class_type());
114  }
115  virtual TypeHandle get_type() const {
116  return get_class_type();
117  }
118  virtual TypeHandle force_init_type() {init_type(); return get_class_type();}
119 
120 private:
121  static TypeHandle _type_handle;
122 };
123 
124 #endif // HAVE_PNG
125 
126 #endif
An instance of this class is passed to the Factory when requesting it to do its business and construc...
Definition: factoryParams.h:36
This is the base class of a family of classes that represent particular image file types that PNMImag...
Definition: pnmFileType.h:32
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:76
get_suggested_extension
Returns a suitable filename extension (without a leading dot) to suggest for files of this type,...
Definition: pnmFileType.h:49
virtual PNMReader * make_reader(std::istream *file, bool owns_file=true, const std::string &magic_number=std::string())
Allocates and returns a new PNMReader suitable for reading from this file type, if possible.
Definition: pnmFileType.cxx:96
get_num_extensions
Returns the number of different possible filename extensions associated with this particular file typ...
Definition: pnmFileType.h:44
virtual PNMWriter * make_writer(std::ostream *file, bool owns_file=true)
Allocates and returns a new PNMWriter suitable for reading from this file type, if possible.
get_extension
Returns the nth possible filename extension associated with this particular file type,...
Definition: pnmFileType.h:44
virtual bool matches_magic_number(const std::string &magic_number) const
Returns true if the indicated "magic number" byte stream (the initial few bytes read from the file) m...
Definition: pnmFileType.cxx:86
This is an abstract base class that defines the interface for reading image files of various types.
Definition: pnmReader.h:27
This is an abstract base class that defines the interface for writing image files of various types.
Definition: pnmWriter.h:27
TypeHandle is the identifier used to differentiate C++ class types.
Definition: typeHandle.h:81
Base class for objects that can be written to and read from Bam files.
Definition: typedWritable.h:35
PANDA 3D SOFTWARE Copyright (c) Carnegie Mellon University.
PANDA 3D SOFTWARE Copyright (c) Carnegie Mellon University.
PANDA 3D SOFTWARE Copyright (c) Carnegie Mellon University.
PANDA 3D SOFTWARE Copyright (c) Carnegie Mellon University.
void register_type(TypeHandle &type_handle, const std::string &name)
This inline function is just a convenient way to call TypeRegistry::register_type(),...
Definition: register_type.I:22