]> git.saurik.com Git - wxWidgets.git/blame - src/png/pngwio.c
Added formatting and symbols dialogs.
[wxWidgets.git] / src / png / pngwio.c
CommitLineData
75b6e0a0
GD
1
2/* pngwio.c - functions for data output
3 *
706b8807 4 * libpng 1.2.7 - September 12, 2004
75b6e0a0 5 * For conditions of distribution and use, see copyright notice in png.h
5b02c8a1 6 * Copyright (c) 1998-2004 Glenn Randers-Pehrson
4946a942
GD
7 * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
8 * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
75b6e0a0
GD
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"
4946a942 20#ifdef PNG_WRITE_SUPPORTED
75b6e0a0
GD
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
4946a942 28void /* PRIVATE */
75b6e0a0
GD
29png_write_data(png_structp png_ptr, png_bytep data, png_size_t length)
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
4946a942 43void PNGAPI
75b6e0a0 44png_default_write_data(png_structp png_ptr, png_bytep data, png_size_t length)
75b6e0a0
GD
45{
46 png_uint_32 check;
47
4946a942
GD
48#if defined(_WIN32_WCE)
49 if ( !WriteFile((HANDLE)(png_ptr->io_ptr), data, length, &check, NULL) )
50 check = 0;
51#else
52 check = fwrite(data, 1, length, (png_FILE_p)(png_ptr->io_ptr));
53#endif
75b6e0a0 54 if (check != length)
75b6e0a0 55 png_error(png_ptr, "Write Error");
75b6e0a0
GD
56}
57#else
58/* this is the model-independent version. Since the standard I/O library
59 can't handle far buffers in the medium and small models, we have to copy
60 the data.
61*/
62
63#define NEAR_BUF_SIZE 1024
64#define MIN(a,b) (a <= b ? a : b)
65
4946a942 66void PNGAPI
75b6e0a0 67png_default_write_data(png_structp png_ptr, png_bytep data, png_size_t length)
75b6e0a0
GD
68{
69 png_uint_32 check;
70 png_byte *near_data; /* Needs to be "png_byte *" instead of "png_bytep" */
4946a942 71 png_FILE_p io_ptr;
75b6e0a0
GD
72
73 /* Check if data really is near. If so, use usual code. */
74 near_data = (png_byte *)CVT_PTR_NOCHECK(data);
4946a942 75 io_ptr = (png_FILE_p)CVT_PTR(png_ptr->io_ptr);
75b6e0a0
GD
76 if ((png_bytep)near_data == data)
77 {
4946a942
GD
78#if defined(_WIN32_WCE)
79 if ( !WriteFile(io_ptr, near_data, length, &check, NULL) )
80 check = 0;
81#else
75b6e0a0 82 check = fwrite(near_data, 1, length, io_ptr);
4946a942 83#endif
75b6e0a0
GD
84 }
85 else
86 {
87 png_byte buf[NEAR_BUF_SIZE];
88 png_size_t written, remaining, err;
89 check = 0;
90 remaining = length;
91 do
92 {
93 written = MIN(NEAR_BUF_SIZE, remaining);
94 png_memcpy(buf, data, written); /* copy far buffer to near buffer */
4946a942
GD
95#if defined(_WIN32_WCE)
96 if ( !WriteFile(io_ptr, buf, written, &err, NULL) )
97 err = 0;
98#else
75b6e0a0 99 err = fwrite(buf, 1, written, io_ptr);
4946a942 100#endif
75b6e0a0
GD
101 if (err != written)
102 break;
103 else
104 check += err;
105 data += written;
106 remaining -= written;
107 }
108 while (remaining != 0);
109 }
110 if (check != length)
75b6e0a0 111 png_error(png_ptr, "Write Error");
75b6e0a0
GD
112}
113
114#endif
115#endif
116
117/* This function is called to output any data pending writing (normally
118 to disk). After png_flush is called, there should be no data pending
119 writing in any buffers. */
120#if defined(PNG_WRITE_FLUSH_SUPPORTED)
4946a942 121void /* PRIVATE */
75b6e0a0
GD
122png_flush(png_structp png_ptr)
123{
124 if (png_ptr->output_flush_fn != NULL)
125 (*(png_ptr->output_flush_fn))(png_ptr);
126}
127
128#if !defined(PNG_NO_STDIO)
4946a942 129void PNGAPI
75b6e0a0 130png_default_flush(png_structp png_ptr)
75b6e0a0 131{
4946a942
GD
132#if !defined(_WIN32_WCE)
133 png_FILE_p io_ptr;
134 io_ptr = (png_FILE_p)CVT_PTR((png_ptr->io_ptr));
75b6e0a0
GD
135 if (io_ptr != NULL)
136 fflush(io_ptr);
4946a942 137#endif
75b6e0a0
GD
138}
139#endif
140#endif
141
142/* This function allows the application to supply new output functions for
143 libpng if standard C streams aren't being used.
144
145 This function takes as its arguments:
146 png_ptr - pointer to a png output data structure
147 io_ptr - pointer to user supplied structure containing info about
148 the output functions. May be NULL.
149 write_data_fn - pointer to a new output function that takes as its
150 arguments a pointer to a png_struct, a pointer to
151 data to be written, and a 32-bit unsigned int that is
152 the number of bytes to be written. The new write
153 function should call png_error(png_ptr, "Error msg")
154 to exit and output any fatal error messages.
155 flush_data_fn - pointer to a new flush function that takes as its
156 arguments a pointer to a png_struct. After a call to
157 the flush function, there should be no data in any buffers
158 or pending transmission. If the output method doesn't do
159 any buffering of ouput, a function prototype must still be
160 supplied although it doesn't have to do anything. If
161 PNG_WRITE_FLUSH_SUPPORTED is not defined at libpng compile
162 time, output_flush_fn will be ignored, although it must be
163 supplied for compatibility. */
4946a942 164void PNGAPI
75b6e0a0
GD
165png_set_write_fn(png_structp png_ptr, png_voidp io_ptr,
166 png_rw_ptr write_data_fn, png_flush_ptr output_flush_fn)
167{
168 png_ptr->io_ptr = io_ptr;
169
170#if !defined(PNG_NO_STDIO)
171 if (write_data_fn != NULL)
172 png_ptr->write_data_fn = write_data_fn;
173 else
174 png_ptr->write_data_fn = png_default_write_data;
175#else
176 png_ptr->write_data_fn = write_data_fn;
177#endif
178
179#if defined(PNG_WRITE_FLUSH_SUPPORTED)
180#if !defined(PNG_NO_STDIO)
181 if (output_flush_fn != NULL)
182 png_ptr->output_flush_fn = output_flush_fn;
183 else
184 png_ptr->output_flush_fn = png_default_flush;
185#else
186 png_ptr->output_flush_fn = output_flush_fn;
187#endif
188#endif /* PNG_WRITE_FLUSH_SUPPORTED */
189
190 /* It is an error to read while writing a png file */
191 if (png_ptr->read_data_fn != NULL)
192 {
193 png_ptr->read_data_fn = NULL;
194 png_warning(png_ptr,
195 "Attempted to set both read_data_fn and write_data_fn in");
196 png_warning(png_ptr,
197 "the same structure. Resetting read_data_fn to NULL.");
198 }
199}
200
201#if defined(USE_FAR_KEYWORD)
202#if defined(_MSC_VER)
203void *png_far_to_near(png_structp png_ptr,png_voidp ptr, int check)
204{
205 void *near_ptr;
206 void FAR *far_ptr;
207 FP_OFF(near_ptr) = FP_OFF(ptr);
208 far_ptr = (void FAR *)near_ptr;
209 if(check != 0)
210 if(FP_SEG(ptr) != FP_SEG(far_ptr))
211 png_error(png_ptr,"segment lost in conversion");
212 return(near_ptr);
213}
214# else
215void *png_far_to_near(png_structp png_ptr,png_voidp ptr, int check)
216{
217 void *near_ptr;
218 void FAR *far_ptr;
219 near_ptr = (void FAR *)ptr;
220 far_ptr = (void FAR *)near_ptr;
221 if(check != 0)
222 if(far_ptr != ptr)
223 png_error(png_ptr,"segment lost in conversion");
224 return(near_ptr);
225}
226# endif
227# endif
4946a942 228#endif /* PNG_WRITE_SUPPORTED */