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 | d60b8fa | 2006-04-20 21:31:14 -0500 | [diff] [blame] | 4 | * Last changed in libpng 1.4.0 April 20, 2006 |
Glenn Randers-Pehrson | b6ce43d | 1998-01-01 07:13:13 -0600 | [diff] [blame] | 5 | * For conditions of distribution and use, see copyright notice in png.h |
Glenn Randers-Pehrson | d60b8fa | 2006-04-20 21:31:14 -0500 | [diff] [blame] | 6 | * Copyright (c) 1998-2006 Glenn Randers-Pehrson |
Glenn Randers-Pehrson | d436672 | 2000-06-04 14:29:29 -0500 | [diff] [blame] | 7 | * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger) |
| 8 | * (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] | 9 | * |
Glenn Randers-Pehrson | 8686fff | 1998-05-21 09:27:50 -0500 | [diff] [blame] | 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 |
Glenn Randers-Pehrson | b6ce43d | 1998-01-01 07:13:13 -0600 | [diff] [blame] | 14 | * functions, but rather write replacement functions and then change |
| 15 | * them at run time with png_set_write_fn(...). |
| 16 | */ |
Guy Schalnat | e5a3779 | 1996-06-05 15:50:50 -0500 | [diff] [blame] | 17 | |
Guy Schalnat | e5a3779 | 1996-06-05 15:50:50 -0500 | [diff] [blame] | 18 | #include "png.h" |
Glenn Randers-Pehrson | 3097f61 | 2001-05-07 14:52:45 -0500 | [diff] [blame] | 19 | #ifdef PNG_WRITE_SUPPORTED |
Glenn Randers-Pehrson | beb572e | 2006-08-19 13:59:24 -0500 | [diff] [blame^] | 20 | #include "pngpriv.h" |
Guy Schalnat | e5a3779 | 1996-06-05 15:50:50 -0500 | [diff] [blame] | 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 |
Glenn Randers-Pehrson | 345bc27 | 1998-06-14 14:43:31 -0500 | [diff] [blame] | 26 | to write more than 64K on a 16 bit machine. */ |
Guy Schalnat | e5a3779 | 1996-06-05 15:50:50 -0500 | [diff] [blame] | 27 | |
Glenn Randers-Pehrson | 7529457 | 2000-05-06 14:09:57 -0500 | [diff] [blame] | 28 | void /* PRIVATE */ |
Andreas Dilger | 47a0c42 | 1997-05-16 02:46:07 -0500 | [diff] [blame] | 29 | png_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] | 30 | { |
Andreas Dilger | 47a0c42 | 1997-05-16 02:46:07 -0500 | [diff] [blame] | 31 | if (png_ptr->write_data_fn != NULL ) |
Guy Schalnat | e5a3779 | 1996-06-05 15:50:50 -0500 | [diff] [blame] | 32 | (*(png_ptr->write_data_fn))(png_ptr, data, length); |
| 33 | else |
| 34 | png_error(png_ptr, "Call to NULL write function"); |
| 35 | } |
| 36 | |
Glenn Randers-Pehrson | 70e3f54 | 1998-01-03 22:40:55 -0600 | [diff] [blame] | 37 | #if !defined(PNG_NO_STDIO) |
Glenn Randers-Pehrson | 8686fff | 1998-05-21 09:27:50 -0500 | [diff] [blame] | 38 | /* This is the function that does the actual writing of data. If you are |
Guy Schalnat | e5a3779 | 1996-06-05 15:50:50 -0500 | [diff] [blame] | 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 |
Glenn Randers-Pehrson | 25d8224 | 2002-05-01 11:51:26 -0500 | [diff] [blame] | 43 | void PNGAPI |
Andreas Dilger | 47a0c42 | 1997-05-16 02:46:07 -0500 | [diff] [blame] | 44 | 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] | 45 | { |
| 46 | png_uint_32 check; |
| 47 | |
Glenn Randers-Pehrson | 316f97a | 2000-07-08 13:19:41 -0500 | [diff] [blame] | 48 | check = fwrite(data, 1, length, (png_FILE_p)(png_ptr->io_ptr)); |
Guy Schalnat | e5a3779 | 1996-06-05 15:50:50 -0500 | [diff] [blame] | 49 | if (check != length) |
Guy Schalnat | e5a3779 | 1996-06-05 15:50:50 -0500 | [diff] [blame] | 50 | png_error(png_ptr, "Write Error"); |
Guy Schalnat | e5a3779 | 1996-06-05 15:50:50 -0500 | [diff] [blame] | 51 | } |
| 52 | #else |
| 53 | /* this is the model-independent version. Since the standard I/O library |
| 54 | can't handle far buffers in the medium and small models, we have to copy |
| 55 | the data. |
| 56 | */ |
| 57 | |
| 58 | #define NEAR_BUF_SIZE 1024 |
| 59 | #define MIN(a,b) (a <= b ? a : b) |
| 60 | |
Glenn Randers-Pehrson | 25d8224 | 2002-05-01 11:51:26 -0500 | [diff] [blame] | 61 | void PNGAPI |
Andreas Dilger | 47a0c42 | 1997-05-16 02:46:07 -0500 | [diff] [blame] | 62 | 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] | 63 | { |
| 64 | png_uint_32 check; |
Andreas Dilger | 47a0c42 | 1997-05-16 02:46:07 -0500 | [diff] [blame] | 65 | png_byte *near_data; /* Needs to be "png_byte *" instead of "png_bytep" */ |
Glenn Randers-Pehrson | 316f97a | 2000-07-08 13:19:41 -0500 | [diff] [blame] | 66 | png_FILE_p io_ptr; |
Guy Schalnat | e5a3779 | 1996-06-05 15:50:50 -0500 | [diff] [blame] | 67 | |
| 68 | /* Check if data really is near. If so, use usual code. */ |
Andreas Dilger | 47a0c42 | 1997-05-16 02:46:07 -0500 | [diff] [blame] | 69 | near_data = (png_byte *)CVT_PTR_NOCHECK(data); |
Glenn Randers-Pehrson | 316f97a | 2000-07-08 13:19:41 -0500 | [diff] [blame] | 70 | io_ptr = (png_FILE_p)CVT_PTR(png_ptr->io_ptr); |
Andreas Dilger | 47a0c42 | 1997-05-16 02:46:07 -0500 | [diff] [blame] | 71 | if ((png_bytep)near_data == data) |
Guy Schalnat | e5a3779 | 1996-06-05 15:50:50 -0500 | [diff] [blame] | 72 | { |
Andreas Dilger | 47a0c42 | 1997-05-16 02:46:07 -0500 | [diff] [blame] | 73 | check = fwrite(near_data, 1, length, io_ptr); |
Guy Schalnat | e5a3779 | 1996-06-05 15:50:50 -0500 | [diff] [blame] | 74 | } |
| 75 | else |
| 76 | { |
| 77 | png_byte buf[NEAR_BUF_SIZE]; |
| 78 | png_size_t written, remaining, err; |
| 79 | check = 0; |
Andreas Dilger | 47a0c42 | 1997-05-16 02:46:07 -0500 | [diff] [blame] | 80 | remaining = length; |
Guy Schalnat | e5a3779 | 1996-06-05 15:50:50 -0500 | [diff] [blame] | 81 | do |
| 82 | { |
| 83 | written = MIN(NEAR_BUF_SIZE, remaining); |
| 84 | png_memcpy(buf, data, written); /* copy far buffer to near buffer */ |
Andreas Dilger | 02ad0ef | 1997-01-17 01:34:35 -0600 | [diff] [blame] | 85 | err = fwrite(buf, 1, written, io_ptr); |
Guy Schalnat | e5a3779 | 1996-06-05 15:50:50 -0500 | [diff] [blame] | 86 | if (err != written) |
| 87 | break; |
| 88 | else |
| 89 | check += err; |
| 90 | data += written; |
| 91 | remaining -= written; |
| 92 | } |
| 93 | while (remaining != 0); |
| 94 | } |
| 95 | if (check != length) |
Guy Schalnat | e5a3779 | 1996-06-05 15:50:50 -0500 | [diff] [blame] | 96 | png_error(png_ptr, "Write Error"); |
Guy Schalnat | e5a3779 | 1996-06-05 15:50:50 -0500 | [diff] [blame] | 97 | } |
| 98 | |
| 99 | #endif |
Glenn Randers-Pehrson | 70e3f54 | 1998-01-03 22:40:55 -0600 | [diff] [blame] | 100 | #endif |
Guy Schalnat | e5a3779 | 1996-06-05 15:50:50 -0500 | [diff] [blame] | 101 | |
| 102 | /* This function is called to output any data pending writing (normally |
| 103 | to disk). After png_flush is called, there should be no data pending |
| 104 | writing in any buffers. */ |
| 105 | #if defined(PNG_WRITE_FLUSH_SUPPORTED) |
Glenn Randers-Pehrson | 7529457 | 2000-05-06 14:09:57 -0500 | [diff] [blame] | 106 | void /* PRIVATE */ |
Guy Schalnat | e5a3779 | 1996-06-05 15:50:50 -0500 | [diff] [blame] | 107 | png_flush(png_structp png_ptr) |
| 108 | { |
Andreas Dilger | 47a0c42 | 1997-05-16 02:46:07 -0500 | [diff] [blame] | 109 | if (png_ptr->output_flush_fn != NULL) |
Guy Schalnat | e5a3779 | 1996-06-05 15:50:50 -0500 | [diff] [blame] | 110 | (*(png_ptr->output_flush_fn))(png_ptr); |
| 111 | } |
| 112 | |
Glenn Randers-Pehrson | 70e3f54 | 1998-01-03 22:40:55 -0600 | [diff] [blame] | 113 | #if !defined(PNG_NO_STDIO) |
Glenn Randers-Pehrson | 25d8224 | 2002-05-01 11:51:26 -0500 | [diff] [blame] | 114 | void PNGAPI |
Guy Schalnat | e5a3779 | 1996-06-05 15:50:50 -0500 | [diff] [blame] | 115 | png_default_flush(png_structp png_ptr) |
| 116 | { |
Glenn Randers-Pehrson | 316f97a | 2000-07-08 13:19:41 -0500 | [diff] [blame] | 117 | png_FILE_p io_ptr; |
| 118 | io_ptr = (png_FILE_p)CVT_PTR((png_ptr->io_ptr)); |
Andreas Dilger | 47a0c42 | 1997-05-16 02:46:07 -0500 | [diff] [blame] | 119 | if (io_ptr != NULL) |
Andreas Dilger | 02ad0ef | 1997-01-17 01:34:35 -0600 | [diff] [blame] | 120 | fflush(io_ptr); |
Guy Schalnat | e5a3779 | 1996-06-05 15:50:50 -0500 | [diff] [blame] | 121 | } |
| 122 | #endif |
Glenn Randers-Pehrson | 70e3f54 | 1998-01-03 22:40:55 -0600 | [diff] [blame] | 123 | #endif |
Guy Schalnat | e5a3779 | 1996-06-05 15:50:50 -0500 | [diff] [blame] | 124 | |
| 125 | /* This function allows the application to supply new output functions for |
| 126 | libpng if standard C streams aren't being used. |
| 127 | |
| 128 | This function takes as its arguments: |
| 129 | png_ptr - pointer to a png output data structure |
| 130 | io_ptr - pointer to user supplied structure containing info about |
| 131 | the output functions. May be NULL. |
Glenn Randers-Pehrson | 8686fff | 1998-05-21 09:27:50 -0500 | [diff] [blame] | 132 | write_data_fn - pointer to a new output function that takes as its |
Guy Schalnat | e5a3779 | 1996-06-05 15:50:50 -0500 | [diff] [blame] | 133 | arguments a pointer to a png_struct, a pointer to |
Glenn Randers-Pehrson | 8686fff | 1998-05-21 09:27:50 -0500 | [diff] [blame] | 134 | data to be written, and a 32-bit unsigned int that is |
Guy Schalnat | e5a3779 | 1996-06-05 15:50:50 -0500 | [diff] [blame] | 135 | the number of bytes to be written. The new write |
| 136 | function should call png_error(png_ptr, "Error msg") |
| 137 | to exit and output any fatal error messages. |
Glenn Randers-Pehrson | 8686fff | 1998-05-21 09:27:50 -0500 | [diff] [blame] | 138 | flush_data_fn - pointer to a new flush function that takes as its |
Guy Schalnat | e5a3779 | 1996-06-05 15:50:50 -0500 | [diff] [blame] | 139 | arguments a pointer to a png_struct. After a call to |
| 140 | the flush function, there should be no data in any buffers |
| 141 | or pending transmission. If the output method doesn't do |
| 142 | any buffering of ouput, a function prototype must still be |
| 143 | supplied although it doesn't have to do anything. If |
| 144 | PNG_WRITE_FLUSH_SUPPORTED is not defined at libpng compile |
| 145 | time, output_flush_fn will be ignored, although it must be |
| 146 | supplied for compatibility. */ |
Glenn Randers-Pehrson | 7529457 | 2000-05-06 14:09:57 -0500 | [diff] [blame] | 147 | void PNGAPI |
Guy Schalnat | e5a3779 | 1996-06-05 15:50:50 -0500 | [diff] [blame] | 148 | png_set_write_fn(png_structp png_ptr, png_voidp io_ptr, |
| 149 | png_rw_ptr write_data_fn, png_flush_ptr output_flush_fn) |
| 150 | { |
| 151 | png_ptr->io_ptr = io_ptr; |
| 152 | |
Glenn Randers-Pehrson | 70e3f54 | 1998-01-03 22:40:55 -0600 | [diff] [blame] | 153 | #if !defined(PNG_NO_STDIO) |
Andreas Dilger | 47a0c42 | 1997-05-16 02:46:07 -0500 | [diff] [blame] | 154 | if (write_data_fn != NULL) |
Guy Schalnat | e5a3779 | 1996-06-05 15:50:50 -0500 | [diff] [blame] | 155 | png_ptr->write_data_fn = write_data_fn; |
| 156 | else |
Glenn Randers-Pehrson | 25d8224 | 2002-05-01 11:51:26 -0500 | [diff] [blame] | 157 | png_ptr->write_data_fn = png_default_write_data; |
Glenn Randers-Pehrson | 70e3f54 | 1998-01-03 22:40:55 -0600 | [diff] [blame] | 158 | #else |
| 159 | png_ptr->write_data_fn = write_data_fn; |
| 160 | #endif |
Guy Schalnat | e5a3779 | 1996-06-05 15:50:50 -0500 | [diff] [blame] | 161 | |
| 162 | #if defined(PNG_WRITE_FLUSH_SUPPORTED) |
Glenn Randers-Pehrson | 70e3f54 | 1998-01-03 22:40:55 -0600 | [diff] [blame] | 163 | #if !defined(PNG_NO_STDIO) |
Andreas Dilger | 47a0c42 | 1997-05-16 02:46:07 -0500 | [diff] [blame] | 164 | if (output_flush_fn != NULL) |
Guy Schalnat | e5a3779 | 1996-06-05 15:50:50 -0500 | [diff] [blame] | 165 | png_ptr->output_flush_fn = output_flush_fn; |
| 166 | else |
Glenn Randers-Pehrson | 25d8224 | 2002-05-01 11:51:26 -0500 | [diff] [blame] | 167 | png_ptr->output_flush_fn = png_default_flush; |
Glenn Randers-Pehrson | 70e3f54 | 1998-01-03 22:40:55 -0600 | [diff] [blame] | 168 | #else |
| 169 | png_ptr->output_flush_fn = output_flush_fn; |
| 170 | #endif |
Guy Schalnat | e5a3779 | 1996-06-05 15:50:50 -0500 | [diff] [blame] | 171 | #endif /* PNG_WRITE_FLUSH_SUPPORTED */ |
| 172 | |
| 173 | /* It is an error to read while writing a png file */ |
Glenn Randers-Pehrson | f7d1a17 | 1998-06-06 15:31:35 -0500 | [diff] [blame] | 174 | if (png_ptr->read_data_fn != NULL) |
| 175 | { |
| 176 | png_ptr->read_data_fn = NULL; |
| 177 | png_warning(png_ptr, |
| 178 | "Attempted to set both read_data_fn and write_data_fn in"); |
| 179 | png_warning(png_ptr, |
Glenn Randers-Pehrson | beb572e | 2006-08-19 13:59:24 -0500 | [diff] [blame^] | 180 | "the same structure. Resetting read_data_fn to NULL"); |
Glenn Randers-Pehrson | f7d1a17 | 1998-06-06 15:31:35 -0500 | [diff] [blame] | 181 | } |
Guy Schalnat | e5a3779 | 1996-06-05 15:50:50 -0500 | [diff] [blame] | 182 | } |
| 183 | |
Glenn Randers-Pehrson | 5c6aeb2 | 1998-12-29 11:47:59 -0600 | [diff] [blame] | 184 | #if defined(USE_FAR_KEYWORD) |
| 185 | #if defined(_MSC_VER) |
Glenn Randers-Pehrson | a357b99 | 1998-02-08 20:56:40 -0600 | [diff] [blame] | 186 | void *png_far_to_near(png_structp png_ptr,png_voidp ptr, int check) |
Andreas Dilger | 02ad0ef | 1997-01-17 01:34:35 -0600 | [diff] [blame] | 187 | { |
Glenn Randers-Pehrson | 5c6aeb2 | 1998-12-29 11:47:59 -0600 | [diff] [blame] | 188 | void *near_ptr; |
Andreas Dilger | 02ad0ef | 1997-01-17 01:34:35 -0600 | [diff] [blame] | 189 | void FAR *far_ptr; |
| 190 | FP_OFF(near_ptr) = FP_OFF(ptr); |
| 191 | far_ptr = (void FAR *)near_ptr; |
| 192 | if(check != 0) |
| 193 | if(FP_SEG(ptr) != FP_SEG(far_ptr)) |
| 194 | png_error(png_ptr,"segment lost in conversion"); |
| 195 | return(near_ptr); |
| 196 | } |
| 197 | # else |
Glenn Randers-Pehrson | a357b99 | 1998-02-08 20:56:40 -0600 | [diff] [blame] | 198 | void *png_far_to_near(png_structp png_ptr,png_voidp ptr, int check) |
Andreas Dilger | 02ad0ef | 1997-01-17 01:34:35 -0600 | [diff] [blame] | 199 | { |
Glenn Randers-Pehrson | 5c6aeb2 | 1998-12-29 11:47:59 -0600 | [diff] [blame] | 200 | void *near_ptr; |
Andreas Dilger | 02ad0ef | 1997-01-17 01:34:35 -0600 | [diff] [blame] | 201 | void FAR *far_ptr; |
| 202 | near_ptr = (void FAR *)ptr; |
| 203 | far_ptr = (void FAR *)near_ptr; |
| 204 | if(check != 0) |
| 205 | if(far_ptr != ptr) |
| 206 | png_error(png_ptr,"segment lost in conversion"); |
| 207 | return(near_ptr); |
| 208 | } |
| 209 | # endif |
| 210 | # endif |
Glenn Randers-Pehrson | 3097f61 | 2001-05-07 14:52:45 -0500 | [diff] [blame] | 211 | #endif /* PNG_WRITE_SUPPORTED */ |