/[pcsx2_0.9.7]/trunk/3rdparty/wxWidgets/src/png/pngrio.c
ViewVC logotype

Annotation of /trunk/3rdparty/wxWidgets/src/png/pngrio.c

Parent Directory Parent Directory | Revision Log Revision Log


Revision 31 - (hide annotations) (download)
Tue Sep 7 03:24:11 2010 UTC (10 years, 4 months ago) by william
File MIME type: text/plain
File size: 5713 byte(s)
committing r3113 initial commit again...
1 william 31
2     /* pngrio.c - functions for data input
3     *
4     * Last changed in libpng 1.2.37 [June 4, 2009]
5     * Copyright (c) 1998-2009 Glenn Randers-Pehrson
6     * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
7     * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
8     *
9     * This code is released under the libpng license.
10     * For conditions of distribution and use, see the disclaimer
11     * and license in png.h
12     *
13     * This file provides a location for all input. Users who need
14     * special handling are expected to write a function that has the same
15     * arguments as this and performs a similar function, but that possibly
16     * has a different input method. Note that you shouldn't change this
17     * function, but rather write a replacement function and then make
18     * libpng use it at run time with png_set_read_fn(...).
19     */
20    
21     #define PNG_INTERNAL
22     #include "png.h"
23     #if defined(PNG_READ_SUPPORTED)
24    
25     /* Read the data from whatever input you are using. The default routine
26     * reads from a file pointer. Note that this routine sometimes gets called
27     * with very small lengths, so you should implement some kind of simple
28     * buffering if you are using unbuffered reads. This should never be asked
29     * to read more then 64K on a 16 bit machine.
30     */
31     void /* PRIVATE */
32     png_read_data(png_structp png_ptr, png_bytep data, png_size_t length)
33     {
34     png_debug1(4, "reading %d bytes", (int)length);
35     if (png_ptr->read_data_fn != NULL)
36     (*(png_ptr->read_data_fn))(png_ptr, data, length);
37     else
38     png_error(png_ptr, "Call to NULL read function");
39     }
40    
41     #if !defined(PNG_NO_STDIO)
42     /* This is the function that does the actual reading of data. If you are
43     * not reading from a standard C stream, you should create a replacement
44     * read_data function and use it at run time with png_set_read_fn(), rather
45     * than changing the library.
46     */
47     #ifndef USE_FAR_KEYWORD
48     void PNGAPI
49     png_default_read_data(png_structp png_ptr, png_bytep data, png_size_t length)
50     {
51     png_size_t check;
52    
53     if (png_ptr == NULL)
54     return;
55     /* fread() returns 0 on error, so it is OK to store this in a png_size_t
56     * instead of an int, which is what fread() actually returns.
57     */
58     #if defined(_WIN32_WCE)
59     if ( !ReadFile((HANDLE)(png_ptr->io_ptr), data, length, &check, NULL) )
60     check = 0;
61     #else
62     check = (png_size_t)fread(data, (png_size_t)1, length,
63     (png_FILE_p)png_ptr->io_ptr);
64     #endif
65    
66     if (check != length)
67     png_error(png_ptr, "Read Error");
68     }
69     #else
70     /* This is the model-independent version. Since the standard I/O library
71     can't handle far buffers in the medium and small models, we have to copy
72     the data.
73     */
74    
75     #define NEAR_BUF_SIZE 1024
76     #define MIN(a,b) (a <= b ? a : b)
77    
78     static void PNGAPI
79     png_default_read_data(png_structp png_ptr, png_bytep data, png_size_t length)
80     {
81     int check;
82     png_byte *n_data;
83     png_FILE_p io_ptr;
84    
85     if (png_ptr == NULL)
86     return;
87     /* Check if data really is near. If so, use usual code. */
88     n_data = (png_byte *)CVT_PTR_NOCHECK(data);
89     io_ptr = (png_FILE_p)CVT_PTR(png_ptr->io_ptr);
90     if ((png_bytep)n_data == data)
91     {
92     #if defined(_WIN32_WCE)
93     if ( !ReadFile((HANDLE)(png_ptr->io_ptr), data, length, &check, NULL) )
94     check = 0;
95     #else
96     check = fread(n_data, 1, length, io_ptr);
97     #endif
98     }
99     else
100     {
101     png_byte buf[NEAR_BUF_SIZE];
102     png_size_t read, remaining, err;
103     check = 0;
104     remaining = length;
105     do
106     {
107     read = MIN(NEAR_BUF_SIZE, remaining);
108     #if defined(_WIN32_WCE)
109     if ( !ReadFile((HANDLE)(io_ptr), buf, read, &err, NULL) )
110     err = 0;
111     #else
112     err = fread(buf, (png_size_t)1, read, io_ptr);
113     #endif
114     png_memcpy(data, buf, read); /* copy far buffer to near buffer */
115     if (err != read)
116     break;
117     else
118     check += err;
119     data += read;
120     remaining -= read;
121     }
122     while (remaining != 0);
123     }
124     if ((png_uint_32)check != (png_uint_32)length)
125     png_error(png_ptr, "read Error");
126     }
127     #endif
128     #endif
129    
130     /* This function allows the application to supply a new input function
131     * for libpng if standard C streams aren't being used.
132     *
133     * This function takes as its arguments:
134     * png_ptr - pointer to a png input data structure
135     * io_ptr - pointer to user supplied structure containing info about
136     * the input functions. May be NULL.
137     * read_data_fn - pointer to a new input function that takes as its
138     * arguments a pointer to a png_struct, a pointer to
139     * a location where input data can be stored, and a 32-bit
140     * unsigned int that is the number of bytes to be read.
141     * To exit and output any fatal error messages the new write
142     * function should call png_error(png_ptr, "Error msg").
143     * May be NULL, in which case libpng's default function will
144     * be used.
145     */
146     void PNGAPI
147     png_set_read_fn(png_structp png_ptr, png_voidp io_ptr,
148     png_rw_ptr read_data_fn)
149     {
150     if (png_ptr == NULL)
151     return;
152     png_ptr->io_ptr = io_ptr;
153    
154     #if !defined(PNG_NO_STDIO)
155     if (read_data_fn != NULL)
156     png_ptr->read_data_fn = read_data_fn;
157     else
158     png_ptr->read_data_fn = png_default_read_data;
159     #else
160     png_ptr->read_data_fn = read_data_fn;
161     #endif
162    
163     /* It is an error to write to a read device */
164     if (png_ptr->write_data_fn != NULL)
165     {
166     png_ptr->write_data_fn = NULL;
167     png_warning(png_ptr,
168     "It's an error to set both read_data_fn and write_data_fn in the ");
169     png_warning(png_ptr,
170     "same structure. Resetting write_data_fn to NULL.");
171     }
172    
173     #if defined(PNG_WRITE_FLUSH_SUPPORTED)
174     png_ptr->output_flush_fn = NULL;
175     #endif
176     }
177     #endif /* PNG_READ_SUPPORTED */

  ViewVC Help
Powered by ViewVC 1.1.22