Guy Schalnat | e5a3779 | 1996-06-05 15:50:50 -0500 | [diff] [blame] | 1 | |
| 2 | /* pngwio.c - functions for data output |
Glenn Randers-Pehrson | b6ce43d | 1998-01-01 07:13:13 -0600 | [diff] [blame] | 3 | * |
Glenn Randers-Pehrson | f5ea1b7 | 2011-01-06 06:42:51 -0600 | [diff] [blame] | 4 | * Last changed in libpng 1.5.0 [January 6, 2011] |
Glenn Randers-Pehrson | 64b863c | 2011-01-04 09:57:06 -0600 | [diff] [blame] | 5 | * Copyright (c) 1998-2011 Glenn Randers-Pehrson |
Glenn Randers-Pehrson | d436672 | 2000-06-04 14:29:29 -0500 | [diff] [blame] | 6 | * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger) |
| 7 | * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.) |
Glenn Randers-Pehrson | b6ce43d | 1998-01-01 07:13:13 -0600 | [diff] [blame] | 8 | * |
Glenn Randers-Pehrson | bfbf865 | 2009-06-26 21:46:52 -0500 | [diff] [blame] | 9 | * This code is released under the libpng license. |
Glenn Randers-Pehrson | c332bbc | 2009-06-25 13:43:50 -0500 | [diff] [blame] | 10 | * For conditions of distribution and use, see the disclaimer |
Glenn Randers-Pehrson | 037023b | 2009-06-24 10:27:36 -0500 | [diff] [blame] | 11 | * and license in png.h |
Glenn Randers-Pehrson | 3e61d79 | 2009-06-24 09:31:28 -0500 | [diff] [blame] | 12 | * |
Glenn Randers-Pehrson | 8686fff | 1998-05-21 09:27:50 -0500 | [diff] [blame] | 13 | * This file provides a location for all output. Users who need |
| 14 | * special handling are expected to write functions that have the same |
| 15 | * arguments as these and perform similar functions, but that possibly |
| 16 | * use different output methods. Note that you shouldn't change these |
Glenn Randers-Pehrson | b6ce43d | 1998-01-01 07:13:13 -0600 | [diff] [blame] | 17 | * functions, but rather write replacement functions and then change |
| 18 | * them at run time with png_set_write_fn(...). |
| 19 | */ |
Guy Schalnat | e5a3779 | 1996-06-05 15:50:50 -0500 | [diff] [blame] | 20 | |
Glenn Randers-Pehrson | beb572e | 2006-08-19 13:59:24 -0500 | [diff] [blame] | 21 | #include "pngpriv.h" |
Guy Schalnat | e5a3779 | 1996-06-05 15:50:50 -0500 | [diff] [blame] | 22 | |
Glenn Randers-Pehrson | c3cd22b | 2010-03-08 21:10:25 -0600 | [diff] [blame] | 23 | #ifdef PNG_WRITE_SUPPORTED |
| 24 | |
Guy Schalnat | e5a3779 | 1996-06-05 15:50:50 -0500 | [diff] [blame] | 25 | /* Write the data to whatever output you are using. The default routine |
Glenn Randers-Pehrson glennrp@comcast.net | b1c0d33 | 2009-05-15 20:39:34 -0500 | [diff] [blame] | 26 | * writes to 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 writes. This should never be asked |
| 29 | * to write more than 64K on a 16 bit machine. |
| 30 | */ |
Guy Schalnat | e5a3779 | 1996-06-05 15:50:50 -0500 | [diff] [blame] | 31 | |
Glenn Randers-Pehrson | 7529457 | 2000-05-06 14:09:57 -0500 | [diff] [blame] | 32 | void /* PRIVATE */ |
Glenn Randers-Pehrson | e600c51 | 2010-08-18 07:25:46 -0500 | [diff] [blame] | 33 | png_write_data(png_structp png_ptr, png_const_bytep data, png_size_t length) |
Guy Schalnat | e5a3779 | 1996-06-05 15:50:50 -0500 | [diff] [blame] | 34 | { |
Glenn Randers-Pehrson | e600c51 | 2010-08-18 07:25:46 -0500 | [diff] [blame] | 35 | /* NOTE: write_data_fn must not change the buffer! */ |
Andreas Dilger | 47a0c42 | 1997-05-16 02:46:07 -0500 | [diff] [blame] | 36 | if (png_ptr->write_data_fn != NULL ) |
Glenn Randers-Pehrson | e600c51 | 2010-08-18 07:25:46 -0500 | [diff] [blame] | 37 | (*(png_ptr->write_data_fn))(png_ptr, (png_bytep)data, length); |
Glenn Randers-Pehrson | f24daf2 | 2010-05-06 09:44:04 -0500 | [diff] [blame] | 38 | |
Guy Schalnat | e5a3779 | 1996-06-05 15:50:50 -0500 | [diff] [blame] | 39 | else |
| 40 | png_error(png_ptr, "Call to NULL write function"); |
| 41 | } |
| 42 | |
Glenn Randers-Pehrson | dbd4014 | 2009-08-31 08:42:02 -0500 | [diff] [blame] | 43 | #ifdef PNG_STDIO_SUPPORTED |
Glenn Randers-Pehrson | 8686fff | 1998-05-21 09:27:50 -0500 | [diff] [blame] | 44 | /* This is the function that does the actual writing of data. If you are |
Glenn Randers-Pehrson glennrp@comcast.net | b1c0d33 | 2009-05-15 20:39:34 -0500 | [diff] [blame] | 45 | * not writing to a standard C stream, you should create a replacement |
| 46 | * write_data function and use it at run time with png_set_write_fn(), rather |
| 47 | * than changing the library. |
| 48 | */ |
Glenn Randers-Pehrson | eae8e36 | 2010-03-12 17:36:53 -0600 | [diff] [blame] | 49 | void PNGCBAPI |
Andreas Dilger | 47a0c42 | 1997-05-16 02:46:07 -0500 | [diff] [blame] | 50 | png_default_write_data(png_structp png_ptr, png_bytep data, png_size_t length) |
Guy Schalnat | e5a3779 | 1996-06-05 15:50:50 -0500 | [diff] [blame] | 51 | { |
Glenn Randers-Pehrson | bcb3aac | 2010-09-10 22:05:27 -0500 | [diff] [blame] | 52 | png_size_t check; |
Guy Schalnat | e5a3779 | 1996-06-05 15:50:50 -0500 | [diff] [blame] | 53 | |
Glenn Randers-Pehrson | d8eb62f | 2009-05-30 20:19:20 -0500 | [diff] [blame] | 54 | if (png_ptr == NULL) |
| 55 | return; |
Glenn Randers-Pehrson | f24daf2 | 2010-05-06 09:44:04 -0500 | [diff] [blame] | 56 | |
Glenn Randers-Pehrson | 316f97a | 2000-07-08 13:19:41 -0500 | [diff] [blame] | 57 | check = fwrite(data, 1, length, (png_FILE_p)(png_ptr->io_ptr)); |
Glenn Randers-Pehrson | f24daf2 | 2010-05-06 09:44:04 -0500 | [diff] [blame] | 58 | |
Guy Schalnat | e5a3779 | 1996-06-05 15:50:50 -0500 | [diff] [blame] | 59 | if (check != length) |
Guy Schalnat | e5a3779 | 1996-06-05 15:50:50 -0500 | [diff] [blame] | 60 | png_error(png_ptr, "Write Error"); |
Guy Schalnat | e5a3779 | 1996-06-05 15:50:50 -0500 | [diff] [blame] | 61 | } |
Glenn Randers-Pehrson | 70e3f54 | 1998-01-03 22:40:55 -0600 | [diff] [blame] | 62 | #endif |
Guy Schalnat | e5a3779 | 1996-06-05 15:50:50 -0500 | [diff] [blame] | 63 | |
| 64 | /* This function is called to output any data pending writing (normally |
Glenn Randers-Pehrson glennrp@comcast.net | b1c0d33 | 2009-05-15 20:39:34 -0500 | [diff] [blame] | 65 | * to disk). After png_flush is called, there should be no data pending |
| 66 | * writing in any buffers. |
| 67 | */ |
Glenn Randers-Pehrson | dbd4014 | 2009-08-31 08:42:02 -0500 | [diff] [blame] | 68 | #ifdef PNG_WRITE_FLUSH_SUPPORTED |
Glenn Randers-Pehrson | 7529457 | 2000-05-06 14:09:57 -0500 | [diff] [blame] | 69 | void /* PRIVATE */ |
Guy Schalnat | e5a3779 | 1996-06-05 15:50:50 -0500 | [diff] [blame] | 70 | png_flush(png_structp png_ptr) |
| 71 | { |
Andreas Dilger | 47a0c42 | 1997-05-16 02:46:07 -0500 | [diff] [blame] | 72 | if (png_ptr->output_flush_fn != NULL) |
Guy Schalnat | e5a3779 | 1996-06-05 15:50:50 -0500 | [diff] [blame] | 73 | (*(png_ptr->output_flush_fn))(png_ptr); |
| 74 | } |
| 75 | |
Glenn Randers-Pehrson | 6f6a91a | 2010-03-06 13:54:59 -0600 | [diff] [blame] | 76 | # ifdef PNG_STDIO_SUPPORTED |
Glenn Randers-Pehrson | eae8e36 | 2010-03-12 17:36:53 -0600 | [diff] [blame] | 77 | void PNGCBAPI |
Guy Schalnat | e5a3779 | 1996-06-05 15:50:50 -0500 | [diff] [blame] | 78 | png_default_flush(png_structp png_ptr) |
| 79 | { |
Glenn Randers-Pehrson | 316f97a | 2000-07-08 13:19:41 -0500 | [diff] [blame] | 80 | png_FILE_p io_ptr; |
Glenn Randers-Pehrson | f24daf2 | 2010-05-06 09:44:04 -0500 | [diff] [blame] | 81 | |
Glenn Randers-Pehrson glennrp@comcast.net | b1c0d33 | 2009-05-15 20:39:34 -0500 | [diff] [blame] | 82 | if (png_ptr == NULL) |
| 83 | return; |
Glenn Randers-Pehrson | f24daf2 | 2010-05-06 09:44:04 -0500 | [diff] [blame] | 84 | |
John Bowler | baeb6d1 | 2011-11-26 18:21:02 -0600 | [diff] [blame^] | 85 | io_ptr = png_voidcast(png_FILE_p, (png_ptr->io_ptr)); |
Glenn Randers-Pehrson | 8fb550c | 2009-03-21 08:15:32 -0500 | [diff] [blame] | 86 | fflush(io_ptr); |
Guy Schalnat | e5a3779 | 1996-06-05 15:50:50 -0500 | [diff] [blame] | 87 | } |
Glenn Randers-Pehrson | 6f6a91a | 2010-03-06 13:54:59 -0600 | [diff] [blame] | 88 | # endif |
Glenn Randers-Pehrson | 70e3f54 | 1998-01-03 22:40:55 -0600 | [diff] [blame] | 89 | #endif |
Guy Schalnat | e5a3779 | 1996-06-05 15:50:50 -0500 | [diff] [blame] | 90 | |
| 91 | /* This function allows the application to supply new output functions for |
Glenn Randers-Pehrson glennrp@comcast.net | b1c0d33 | 2009-05-15 20:39:34 -0500 | [diff] [blame] | 92 | * libpng if standard C streams aren't being used. |
| 93 | * |
| 94 | * This function takes as its arguments: |
| 95 | * png_ptr - pointer to a png output data structure |
| 96 | * io_ptr - pointer to user supplied structure containing info about |
| 97 | * the output functions. May be NULL. |
| 98 | * write_data_fn - pointer to a new output function that takes as its |
| 99 | * arguments a pointer to a png_struct, a pointer to |
| 100 | * data to be written, and a 32-bit unsigned int that is |
| 101 | * the number of bytes to be written. The new write |
| 102 | * function should call png_error(png_ptr, "Error msg") |
| 103 | * to exit and output any fatal error messages. May be |
| 104 | * NULL, in which case libpng's default function will |
| 105 | * be used. |
| 106 | * flush_data_fn - pointer to a new flush function that takes as its |
| 107 | * arguments a pointer to a png_struct. After a call to |
| 108 | * the flush function, there should be no data in any buffers |
| 109 | * or pending transmission. If the output method doesn't do |
Glenn Randers-Pehrson | f24daf2 | 2010-05-06 09:44:04 -0500 | [diff] [blame] | 110 | * any buffering of output, a function prototype must still be |
Glenn Randers-Pehrson glennrp@comcast.net | b1c0d33 | 2009-05-15 20:39:34 -0500 | [diff] [blame] | 111 | * supplied although it doesn't have to do anything. If |
| 112 | * PNG_WRITE_FLUSH_SUPPORTED is not defined at libpng compile |
| 113 | * time, output_flush_fn will be ignored, although it must be |
| 114 | * supplied for compatibility. May be NULL, in which case |
| 115 | * libpng's default function will be used, if |
| 116 | * PNG_WRITE_FLUSH_SUPPORTED is defined. This is not |
| 117 | * a good idea if io_ptr does not point to a standard |
| 118 | * *FILE structure. |
| 119 | */ |
Glenn Randers-Pehrson | 7529457 | 2000-05-06 14:09:57 -0500 | [diff] [blame] | 120 | void PNGAPI |
Guy Schalnat | e5a3779 | 1996-06-05 15:50:50 -0500 | [diff] [blame] | 121 | png_set_write_fn(png_structp png_ptr, png_voidp io_ptr, |
Glenn Randers-Pehrson | 6f6a91a | 2010-03-06 13:54:59 -0600 | [diff] [blame] | 122 | png_rw_ptr write_data_fn, png_flush_ptr output_flush_fn) |
Guy Schalnat | e5a3779 | 1996-06-05 15:50:50 -0500 | [diff] [blame] | 123 | { |
Glenn Randers-Pehrson glennrp@comcast.net | b1c0d33 | 2009-05-15 20:39:34 -0500 | [diff] [blame] | 124 | if (png_ptr == NULL) |
| 125 | return; |
| 126 | |
Guy Schalnat | e5a3779 | 1996-06-05 15:50:50 -0500 | [diff] [blame] | 127 | png_ptr->io_ptr = io_ptr; |
| 128 | |
Glenn Randers-Pehrson | dbd4014 | 2009-08-31 08:42:02 -0500 | [diff] [blame] | 129 | #ifdef PNG_STDIO_SUPPORTED |
Andreas Dilger | 47a0c42 | 1997-05-16 02:46:07 -0500 | [diff] [blame] | 130 | if (write_data_fn != NULL) |
Guy Schalnat | e5a3779 | 1996-06-05 15:50:50 -0500 | [diff] [blame] | 131 | png_ptr->write_data_fn = write_data_fn; |
Glenn Randers-Pehrson glennrp@comcast.net | b1c0d33 | 2009-05-15 20:39:34 -0500 | [diff] [blame] | 132 | |
Guy Schalnat | e5a3779 | 1996-06-05 15:50:50 -0500 | [diff] [blame] | 133 | else |
Glenn Randers-Pehrson | 25d8224 | 2002-05-01 11:51:26 -0500 | [diff] [blame] | 134 | png_ptr->write_data_fn = png_default_write_data; |
Glenn Randers-Pehrson | 70e3f54 | 1998-01-03 22:40:55 -0600 | [diff] [blame] | 135 | #else |
| 136 | png_ptr->write_data_fn = write_data_fn; |
| 137 | #endif |
Guy Schalnat | e5a3779 | 1996-06-05 15:50:50 -0500 | [diff] [blame] | 138 | |
Glenn Randers-Pehrson | dbd4014 | 2009-08-31 08:42:02 -0500 | [diff] [blame] | 139 | #ifdef PNG_WRITE_FLUSH_SUPPORTED |
Glenn Randers-Pehrson | 6f6a91a | 2010-03-06 13:54:59 -0600 | [diff] [blame] | 140 | # ifdef PNG_STDIO_SUPPORTED |
Glenn Randers-Pehrson | f24daf2 | 2010-05-06 09:44:04 -0500 | [diff] [blame] | 141 | |
Andreas Dilger | 47a0c42 | 1997-05-16 02:46:07 -0500 | [diff] [blame] | 142 | if (output_flush_fn != NULL) |
Guy Schalnat | e5a3779 | 1996-06-05 15:50:50 -0500 | [diff] [blame] | 143 | png_ptr->output_flush_fn = output_flush_fn; |
Glenn Randers-Pehrson glennrp@comcast.net | b1c0d33 | 2009-05-15 20:39:34 -0500 | [diff] [blame] | 144 | |
Guy Schalnat | e5a3779 | 1996-06-05 15:50:50 -0500 | [diff] [blame] | 145 | else |
Glenn Randers-Pehrson | 25d8224 | 2002-05-01 11:51:26 -0500 | [diff] [blame] | 146 | png_ptr->output_flush_fn = png_default_flush; |
Glenn Randers-Pehrson | f24daf2 | 2010-05-06 09:44:04 -0500 | [diff] [blame] | 147 | |
Glenn Randers-Pehrson | 6f6a91a | 2010-03-06 13:54:59 -0600 | [diff] [blame] | 148 | # else |
Glenn Randers-Pehrson | 70e3f54 | 1998-01-03 22:40:55 -0600 | [diff] [blame] | 149 | png_ptr->output_flush_fn = output_flush_fn; |
Glenn Randers-Pehrson | 6f6a91a | 2010-03-06 13:54:59 -0600 | [diff] [blame] | 150 | # endif |
Guy Schalnat | e5a3779 | 1996-06-05 15:50:50 -0500 | [diff] [blame] | 151 | #endif /* PNG_WRITE_FLUSH_SUPPORTED */ |
| 152 | |
| 153 | /* It is an error to read while writing a png file */ |
Glenn Randers-Pehrson | f7d1a17 | 1998-06-06 15:31:35 -0500 | [diff] [blame] | 154 | if (png_ptr->read_data_fn != NULL) |
| 155 | { |
| 156 | png_ptr->read_data_fn = NULL; |
Glenn Randers-Pehrson | f24daf2 | 2010-05-06 09:44:04 -0500 | [diff] [blame] | 157 | |
Glenn Randers-Pehrson | f7d1a17 | 1998-06-06 15:31:35 -0500 | [diff] [blame] | 158 | png_warning(png_ptr, |
Glenn Randers-Pehrson | 92a3ef4 | 2010-03-31 21:50:21 -0500 | [diff] [blame] | 159 | "Can't set both read_data_fn and write_data_fn in the" |
| 160 | " same structure"); |
Glenn Randers-Pehrson | f7d1a17 | 1998-06-06 15:31:35 -0500 | [diff] [blame] | 161 | } |
Guy Schalnat | e5a3779 | 1996-06-05 15:50:50 -0500 | [diff] [blame] | 162 | } |
Glenn Randers-Pehrson | 3097f61 | 2001-05-07 14:52:45 -0500 | [diff] [blame] | 163 | #endif /* PNG_WRITE_SUPPORTED */ |