pngwio.c
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1 
2 /* pngwio.c - functions for data output
3  *
4  * Last changed in libpng 1.2.30 [August 15, 2008]
5  * For conditions of distribution and use, see copyright notice in png.h
6  * Copyright (c) 1998-2008 Glenn Randers-Pehrson
7  * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
8  * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
9  *
10  * This file provides a location for all output. Users who need
11  * special handling are expected to write functions that have the same
12  * arguments as these and perform similar functions, but that possibly
13  * use different output methods. Note that you shouldn't change these
14  * functions, but rather write replacement functions and then change
15  * them at run time with png_set_write_fn(...).
16  */
17 
18 #define PNG_INTERNAL
19 #include "png.h"
20 #ifdef PNG_WRITE_SUPPORTED
21 
22 /* Write the data to whatever output you are using. The default routine
23  writes to a file pointer. Note that this routine sometimes gets called
24  with very small lengths, so you should implement some kind of simple
25  buffering if you are using unbuffered writes. This should never be asked
26  to write more than 64K on a 16 bit machine. */
27 
28 void /* PRIVATE */
30 {
31  if (png_ptr->write_data_fn != NULL )
32  (*(png_ptr->write_data_fn))(png_ptr, data, length);
33  else
34  png_error(png_ptr, "Call to NULL write function");
35 }
36 
37 #if !defined(PNG_NO_STDIO)
38 /* This is the function that does the actual writing of data. If you are
39  not writing to a standard C stream, you should create a replacement
40  write_data function and use it at run time with png_set_write_fn(), rather
41  than changing the library. */
42 #ifndef USE_FAR_KEYWORD
43 void PNGAPI
45 {
46  png_uint_32 check;
47 
48  if (png_ptr == NULL) return;
49 #if defined(_WIN32_WCE)
50  if ( !WriteFile((HANDLE)(png_ptr->io_ptr), data, length, &check, NULL) )
51  check = 0;
52 #else
53  check = fwrite(data, 1, length, (png_FILE_p)(png_ptr->io_ptr));
54 #endif
55  if (check != length)
56  png_error(png_ptr, "Write Error");
57 }
58 #else
59 /* this is the model-independent version. Since the standard I/O library
60  can't handle far buffers in the medium and small models, we have to copy
61  the data.
62 */
63 
64 #define NEAR_BUF_SIZE 1024
65 #define MIN(a,b) (a <= b ? a : b)
66 
67 void PNGAPI
69 {
70  png_uint_32 check;
71  png_byte *near_data; /* Needs to be "png_byte *" instead of "png_bytep" */
73 
74  if (png_ptr == NULL) return;
75  /* Check if data really is near. If so, use usual code. */
76  near_data = (png_byte *)CVT_PTR_NOCHECK(data);
77  io_ptr = (png_FILE_p)CVT_PTR(png_ptr->io_ptr);
78  if ((png_bytep)near_data == data)
79  {
80 #if defined(_WIN32_WCE)
81  if ( !WriteFile(io_ptr, near_data, length, &check, NULL) )
82  check = 0;
83 #else
84  check = fwrite(near_data, 1, length, io_ptr);
85 #endif
86  }
87  else
88  {
89  png_byte buf[NEAR_BUF_SIZE];
90  png_size_t written, remaining, err;
91  check = 0;
92  remaining = length;
93  do
94  {
95  written = MIN(NEAR_BUF_SIZE, remaining);
96  png_memcpy(buf, data, written); /* copy far buffer to near buffer */
97 #if defined(_WIN32_WCE)
98  if ( !WriteFile(io_ptr, buf, written, &err, NULL) )
99  err = 0;
100 #else
101  err = fwrite(buf, 1, written, io_ptr);
102 #endif
103  if (err != written)
104  break;
105  else
106  check += err;
107  data += written;
108  remaining -= written;
109  }
110  while (remaining != 0);
111  }
112  if (check != length)
113  png_error(png_ptr, "Write Error");
114 }
115 
116 #endif
117 #endif
118 
119 /* This function is called to output any data pending writing (normally
120  to disk). After png_flush is called, there should be no data pending
121  writing in any buffers. */
122 #if defined(PNG_WRITE_FLUSH_SUPPORTED)
123 void /* PRIVATE */
125 {
126  if (png_ptr->output_flush_fn != NULL)
127  (*(png_ptr->output_flush_fn))(png_ptr);
128 }
129 
130 #if !defined(PNG_NO_STDIO)
131 void PNGAPI
133 {
134 #if !defined(_WIN32_WCE)
136 #endif
137  if (png_ptr == NULL) return;
138 #if !defined(_WIN32_WCE)
139  io_ptr = (png_FILE_p)CVT_PTR((png_ptr->io_ptr));
140  if (io_ptr != NULL)
141  fflush(io_ptr);
142 #endif
143 }
144 #endif
145 #endif
146 
147 /* This function allows the application to supply new output functions for
148  libpng if standard C streams aren't being used.
149 
150  This function takes as its arguments:
151  png_ptr - pointer to a png output data structure
152  io_ptr - pointer to user supplied structure containing info about
153  the output functions. May be NULL.
154  write_data_fn - pointer to a new output function that takes as its
155  arguments a pointer to a png_struct, a pointer to
156  data to be written, and a 32-bit unsigned int that is
157  the number of bytes to be written. The new write
158  function should call png_error(png_ptr, "Error msg")
159  to exit and output any fatal error messages.
160  flush_data_fn - pointer to a new flush function that takes as its
161  arguments a pointer to a png_struct. After a call to
162  the flush function, there should be no data in any buffers
163  or pending transmission. If the output method doesn't do
164  any buffering of ouput, a function prototype must still be
165  supplied although it doesn't have to do anything. If
166  PNG_WRITE_FLUSH_SUPPORTED is not defined at libpng compile
167  time, output_flush_fn will be ignored, although it must be
168  supplied for compatibility. */
169 void PNGAPI
171  png_rw_ptr write_data_fn, png_flush_ptr output_flush_fn)
172 {
173  if (png_ptr == NULL) return;
174  png_ptr->io_ptr = io_ptr;
175 
176 #if !defined(PNG_NO_STDIO)
177  if (write_data_fn != NULL)
178  png_ptr->write_data_fn = write_data_fn;
179  else
180  png_ptr->write_data_fn = png_default_write_data;
181 #else
182  png_ptr->write_data_fn = write_data_fn;
183 #endif
184 
185 #if defined(PNG_WRITE_FLUSH_SUPPORTED)
186 #if !defined(PNG_NO_STDIO)
187  if (output_flush_fn != NULL)
188  png_ptr->output_flush_fn = output_flush_fn;
189  else
190  png_ptr->output_flush_fn = png_default_flush;
191 #else
192  png_ptr->output_flush_fn = output_flush_fn;
193 #endif
194 #endif /* PNG_WRITE_FLUSH_SUPPORTED */
195 
196  /* It is an error to read while writing a png file */
197  if (png_ptr->read_data_fn != NULL)
198  {
199  png_ptr->read_data_fn = NULL;
200  png_warning(png_ptr,
201  "Attempted to set both read_data_fn and write_data_fn in");
202  png_warning(png_ptr,
203  "the same structure. Resetting read_data_fn to NULL.");
204  }
205 }
206 
207 #if defined(USE_FAR_KEYWORD)
208 #if defined(_MSC_VER)
209 void *png_far_to_near(png_structp png_ptr, png_voidp ptr, int check)
210 {
211  void *near_ptr;
212  void FAR *far_ptr;
213  FP_OFF(near_ptr) = FP_OFF(ptr);
214  far_ptr = (void FAR *)near_ptr;
215  if (check != 0)
216  if (FP_SEG(ptr) != FP_SEG(far_ptr))
217  png_error(png_ptr, "segment lost in conversion");
218  return(near_ptr);
219 }
220 # else
221 void *png_far_to_near(png_structp png_ptr, png_voidp ptr, int check)
222 {
223  void *near_ptr;
224  void FAR *far_ptr;
225  near_ptr = (void FAR *)ptr;
226  far_ptr = (void FAR *)near_ptr;
227  if (check != 0)
228  if (far_ptr != ptr)
229  png_error(png_ptr, "segment lost in conversion");
230  return(near_ptr);
231 }
232 # endif
233 # endif
234 #endif /* PNG_WRITE_SUPPORTED */
void PNGAPI png_default_write_data(png_structp png_ptr, png_bytep data, png_size_t length)
Definition: pngwio.c:44
png_voidp png_rw_ptr write_data_fn
Definition: png.h:1974
png_voidp ptr
Definition: png.h:2063
png_byte FAR * png_bytep
Definition: pngconf.h:1197
#define MIN(a, b)
Returns the min value between a and b.
Definition: IceTypes.h:146
void PNGAPI png_set_write_fn(png_structp png_ptr, png_voidp io_ptr, png_rw_ptr write_data_fn, png_flush_ptr output_flush_fn)
Definition: pngwio.c:170
void png_write_data(png_structp png_ptr, png_bytep data, png_size_t length)
Definition: pngwio.c:29
png_bytep png_bytep png_size_t length
Definition: png.h:1541
#define CVT_PTR_NOCHECK(ptr)
Definition: pngconf.h:1441
void png_flush(png_structp png_ptr)
Definition: pngwio.c:124
void PNGAPI png_default_flush(png_structp png_ptr)
Definition: pngwio.c:132
#define PNGAPI
Definition: pngconf.h:1386
png_struct FAR * png_structp
Definition: png.h:1108
void PNGAPI png_error(png_structp png_ptr, png_const_charp error_message)
Definition: pngerror.c:36
png_voidp png_rw_ptr png_flush_ptr output_flush_fn
Definition: png.h:1974
unsigned char png_byte
Definition: pngconf.h:1120
#define png_memcpy
Definition: pngconf.h:1465
void PNGAPI png_warning(png_structp png_ptr, png_const_charp warning_message)
Definition: pngerror.c:102
#define FAR
Definition: jmorecfg.h:215
png_bytep buf
Definition: png.h:2729
png_voidp io_ptr
Definition: png.h:1974
void FAR * png_voidp
Definition: pngconf.h:1196
size_t png_size_t
Definition: pngconf.h:1128
JSAMPIMAGE data
Definition: jpeglib.h:945
unsigned long png_uint_32
Definition: pngconf.h:1116
FILE * png_FILE_p
Definition: pngconf.h:1210
#define CVT_PTR(ptr)
Definition: pngconf.h:1440


openhrp3
Author(s): AIST, General Robotix Inc., Nakamura Lab of Dept. of Mechano Informatics at University of Tokyo
autogenerated on Thu Sep 8 2022 02:24:05