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 | 074af5e | 1999-11-28 23:32:18 -0600 | [diff] [blame^] | 4 | * libpng 1.0.5d - November 29, 1999 |
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 |
| 6 | * Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc. |
| 7 | * Copyright (c) 1996, 1997 Andreas Dilger |
Glenn Randers-Pehrson | c944229 | 1999-01-06 21:50:16 -0600 | [diff] [blame] | 8 | * Copyright (c) 1998, 1999 Glenn Randers-Pehrson |
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 | |
| 18 | #define PNG_INTERNAL |
| 19 | #include "png.h" |
| 20 | |
| 21 | /* Write the data to whatever output you are using. The default routine |
| 22 | writes to a file pointer. Note that this routine sometimes gets called |
| 23 | with very small lengths, so you should implement some kind of simple |
| 24 | 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] | 25 | to write more than 64K on a 16 bit machine. */ |
Guy Schalnat | e5a3779 | 1996-06-05 15:50:50 -0500 | [diff] [blame] | 26 | |
| 27 | void |
Andreas Dilger | 47a0c42 | 1997-05-16 02:46:07 -0500 | [diff] [blame] | 28 | 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] | 29 | { |
Andreas Dilger | 47a0c42 | 1997-05-16 02:46:07 -0500 | [diff] [blame] | 30 | if (png_ptr->write_data_fn != NULL ) |
Guy Schalnat | e5a3779 | 1996-06-05 15:50:50 -0500 | [diff] [blame] | 31 | (*(png_ptr->write_data_fn))(png_ptr, data, length); |
| 32 | else |
| 33 | png_error(png_ptr, "Call to NULL write function"); |
| 34 | } |
| 35 | |
Glenn Randers-Pehrson | 70e3f54 | 1998-01-03 22:40:55 -0600 | [diff] [blame] | 36 | #if !defined(PNG_NO_STDIO) |
Glenn Randers-Pehrson | 8686fff | 1998-05-21 09:27:50 -0500 | [diff] [blame] | 37 | /* 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] | 38 | not writing to a standard C stream, you should create a replacement |
| 39 | write_data function and use it at run time with png_set_write_fn(), rather |
| 40 | than changing the library. */ |
| 41 | #ifndef USE_FAR_KEYWORD |
| 42 | static void |
Andreas Dilger | 47a0c42 | 1997-05-16 02:46:07 -0500 | [diff] [blame] | 43 | 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] | 44 | { |
| 45 | png_uint_32 check; |
| 46 | |
Andreas Dilger | 47a0c42 | 1997-05-16 02:46:07 -0500 | [diff] [blame] | 47 | check = fwrite(data, 1, length, (FILE *)(png_ptr->io_ptr)); |
Guy Schalnat | e5a3779 | 1996-06-05 15:50:50 -0500 | [diff] [blame] | 48 | if (check != length) |
| 49 | { |
| 50 | png_error(png_ptr, "Write Error"); |
| 51 | } |
| 52 | } |
| 53 | #else |
| 54 | /* this is the model-independent version. Since the standard I/O library |
| 55 | can't handle far buffers in the medium and small models, we have to copy |
| 56 | the data. |
| 57 | */ |
| 58 | |
| 59 | #define NEAR_BUF_SIZE 1024 |
| 60 | #define MIN(a,b) (a <= b ? a : b) |
| 61 | |
Guy Schalnat | e5a3779 | 1996-06-05 15:50:50 -0500 | [diff] [blame] | 62 | static void |
Andreas Dilger | 47a0c42 | 1997-05-16 02:46:07 -0500 | [diff] [blame] | 63 | 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] | 64 | { |
| 65 | png_uint_32 check; |
Andreas Dilger | 47a0c42 | 1997-05-16 02:46:07 -0500 | [diff] [blame] | 66 | png_byte *near_data; /* Needs to be "png_byte *" instead of "png_bytep" */ |
Andreas Dilger | 02ad0ef | 1997-01-17 01:34:35 -0600 | [diff] [blame] | 67 | FILE *io_ptr; |
Guy Schalnat | e5a3779 | 1996-06-05 15:50:50 -0500 | [diff] [blame] | 68 | |
| 69 | /* Check if data really is near. If so, use usual code. */ |
Andreas Dilger | 47a0c42 | 1997-05-16 02:46:07 -0500 | [diff] [blame] | 70 | near_data = (png_byte *)CVT_PTR_NOCHECK(data); |
Andreas Dilger | 02ad0ef | 1997-01-17 01:34:35 -0600 | [diff] [blame] | 71 | io_ptr = (FILE *)CVT_PTR(png_ptr->io_ptr); |
Andreas Dilger | 47a0c42 | 1997-05-16 02:46:07 -0500 | [diff] [blame] | 72 | if ((png_bytep)near_data == data) |
Guy Schalnat | e5a3779 | 1996-06-05 15:50:50 -0500 | [diff] [blame] | 73 | { |
Andreas Dilger | 47a0c42 | 1997-05-16 02:46:07 -0500 | [diff] [blame] | 74 | check = fwrite(near_data, 1, length, io_ptr); |
Guy Schalnat | e5a3779 | 1996-06-05 15:50:50 -0500 | [diff] [blame] | 75 | } |
| 76 | else |
| 77 | { |
| 78 | png_byte buf[NEAR_BUF_SIZE]; |
| 79 | png_size_t written, remaining, err; |
| 80 | check = 0; |
Andreas Dilger | 47a0c42 | 1997-05-16 02:46:07 -0500 | [diff] [blame] | 81 | remaining = length; |
Guy Schalnat | e5a3779 | 1996-06-05 15:50:50 -0500 | [diff] [blame] | 82 | do |
| 83 | { |
| 84 | written = MIN(NEAR_BUF_SIZE, remaining); |
| 85 | png_memcpy(buf, data, written); /* copy far buffer to near buffer */ |
Andreas Dilger | 02ad0ef | 1997-01-17 01:34:35 -0600 | [diff] [blame] | 86 | err = fwrite(buf, 1, written, io_ptr); |
Guy Schalnat | e5a3779 | 1996-06-05 15:50:50 -0500 | [diff] [blame] | 87 | if (err != written) |
| 88 | break; |
| 89 | else |
| 90 | check += err; |
| 91 | data += written; |
| 92 | remaining -= written; |
| 93 | } |
| 94 | while (remaining != 0); |
| 95 | } |
| 96 | if (check != length) |
| 97 | { |
| 98 | png_error(png_ptr, "Write Error"); |
| 99 | } |
| 100 | } |
| 101 | |
| 102 | #endif |
Glenn Randers-Pehrson | 70e3f54 | 1998-01-03 22:40:55 -0600 | [diff] [blame] | 103 | #endif |
Guy Schalnat | e5a3779 | 1996-06-05 15:50:50 -0500 | [diff] [blame] | 104 | |
| 105 | /* This function is called to output any data pending writing (normally |
| 106 | to disk). After png_flush is called, there should be no data pending |
| 107 | writing in any buffers. */ |
| 108 | #if defined(PNG_WRITE_FLUSH_SUPPORTED) |
| 109 | void |
| 110 | png_flush(png_structp png_ptr) |
| 111 | { |
Andreas Dilger | 47a0c42 | 1997-05-16 02:46:07 -0500 | [diff] [blame] | 112 | if (png_ptr->output_flush_fn != NULL) |
Guy Schalnat | e5a3779 | 1996-06-05 15:50:50 -0500 | [diff] [blame] | 113 | (*(png_ptr->output_flush_fn))(png_ptr); |
| 114 | } |
| 115 | |
Glenn Randers-Pehrson | 70e3f54 | 1998-01-03 22:40:55 -0600 | [diff] [blame] | 116 | #if !defined(PNG_NO_STDIO) |
Guy Schalnat | e5a3779 | 1996-06-05 15:50:50 -0500 | [diff] [blame] | 117 | static void |
| 118 | png_default_flush(png_structp png_ptr) |
| 119 | { |
Andreas Dilger | 02ad0ef | 1997-01-17 01:34:35 -0600 | [diff] [blame] | 120 | FILE *io_ptr; |
| 121 | io_ptr = (FILE *)CVT_PTR((png_ptr->io_ptr)); |
Andreas Dilger | 47a0c42 | 1997-05-16 02:46:07 -0500 | [diff] [blame] | 122 | if (io_ptr != NULL) |
Andreas Dilger | 02ad0ef | 1997-01-17 01:34:35 -0600 | [diff] [blame] | 123 | fflush(io_ptr); |
Guy Schalnat | e5a3779 | 1996-06-05 15:50:50 -0500 | [diff] [blame] | 124 | } |
| 125 | #endif |
Glenn Randers-Pehrson | 70e3f54 | 1998-01-03 22:40:55 -0600 | [diff] [blame] | 126 | #endif |
Guy Schalnat | e5a3779 | 1996-06-05 15:50:50 -0500 | [diff] [blame] | 127 | |
| 128 | /* This function allows the application to supply new output functions for |
| 129 | libpng if standard C streams aren't being used. |
| 130 | |
| 131 | This function takes as its arguments: |
| 132 | png_ptr - pointer to a png output data structure |
| 133 | io_ptr - pointer to user supplied structure containing info about |
| 134 | the output functions. May be NULL. |
Glenn Randers-Pehrson | 8686fff | 1998-05-21 09:27:50 -0500 | [diff] [blame] | 135 | 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] | 136 | arguments a pointer to a png_struct, a pointer to |
Glenn Randers-Pehrson | 8686fff | 1998-05-21 09:27:50 -0500 | [diff] [blame] | 137 | data to be written, and a 32-bit unsigned int that is |
Guy Schalnat | e5a3779 | 1996-06-05 15:50:50 -0500 | [diff] [blame] | 138 | the number of bytes to be written. The new write |
| 139 | function should call png_error(png_ptr, "Error msg") |
| 140 | to exit and output any fatal error messages. |
Glenn Randers-Pehrson | 8686fff | 1998-05-21 09:27:50 -0500 | [diff] [blame] | 141 | 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] | 142 | arguments a pointer to a png_struct. After a call to |
| 143 | the flush function, there should be no data in any buffers |
| 144 | or pending transmission. If the output method doesn't do |
| 145 | any buffering of ouput, a function prototype must still be |
| 146 | supplied although it doesn't have to do anything. If |
| 147 | PNG_WRITE_FLUSH_SUPPORTED is not defined at libpng compile |
| 148 | time, output_flush_fn will be ignored, although it must be |
| 149 | supplied for compatibility. */ |
| 150 | void |
| 151 | png_set_write_fn(png_structp png_ptr, png_voidp io_ptr, |
| 152 | png_rw_ptr write_data_fn, png_flush_ptr output_flush_fn) |
| 153 | { |
| 154 | png_ptr->io_ptr = io_ptr; |
| 155 | |
Glenn Randers-Pehrson | 70e3f54 | 1998-01-03 22:40:55 -0600 | [diff] [blame] | 156 | #if !defined(PNG_NO_STDIO) |
Andreas Dilger | 47a0c42 | 1997-05-16 02:46:07 -0500 | [diff] [blame] | 157 | if (write_data_fn != NULL) |
Guy Schalnat | e5a3779 | 1996-06-05 15:50:50 -0500 | [diff] [blame] | 158 | png_ptr->write_data_fn = write_data_fn; |
| 159 | else |
| 160 | png_ptr->write_data_fn = png_default_write_data; |
Glenn Randers-Pehrson | 70e3f54 | 1998-01-03 22:40:55 -0600 | [diff] [blame] | 161 | #else |
| 162 | png_ptr->write_data_fn = write_data_fn; |
| 163 | #endif |
Guy Schalnat | e5a3779 | 1996-06-05 15:50:50 -0500 | [diff] [blame] | 164 | |
| 165 | #if defined(PNG_WRITE_FLUSH_SUPPORTED) |
Glenn Randers-Pehrson | 70e3f54 | 1998-01-03 22:40:55 -0600 | [diff] [blame] | 166 | #if !defined(PNG_NO_STDIO) |
Andreas Dilger | 47a0c42 | 1997-05-16 02:46:07 -0500 | [diff] [blame] | 167 | if (output_flush_fn != NULL) |
Guy Schalnat | e5a3779 | 1996-06-05 15:50:50 -0500 | [diff] [blame] | 168 | png_ptr->output_flush_fn = output_flush_fn; |
| 169 | else |
| 170 | png_ptr->output_flush_fn = png_default_flush; |
Glenn Randers-Pehrson | 70e3f54 | 1998-01-03 22:40:55 -0600 | [diff] [blame] | 171 | #else |
| 172 | png_ptr->output_flush_fn = output_flush_fn; |
| 173 | #endif |
Guy Schalnat | e5a3779 | 1996-06-05 15:50:50 -0500 | [diff] [blame] | 174 | #endif /* PNG_WRITE_FLUSH_SUPPORTED */ |
| 175 | |
| 176 | /* It is an error to read while writing a png file */ |
Glenn Randers-Pehrson | f7d1a17 | 1998-06-06 15:31:35 -0500 | [diff] [blame] | 177 | if (png_ptr->read_data_fn != NULL) |
| 178 | { |
| 179 | png_ptr->read_data_fn = NULL; |
| 180 | png_warning(png_ptr, |
| 181 | "Attempted to set both read_data_fn and write_data_fn in"); |
| 182 | png_warning(png_ptr, |
| 183 | "the same structure. Resetting read_data_fn to NULL."); |
| 184 | } |
Guy Schalnat | e5a3779 | 1996-06-05 15:50:50 -0500 | [diff] [blame] | 185 | } |
| 186 | |
Glenn Randers-Pehrson | 5c6aeb2 | 1998-12-29 11:47:59 -0600 | [diff] [blame] | 187 | #if defined(USE_FAR_KEYWORD) |
| 188 | #if defined(_MSC_VER) |
Glenn Randers-Pehrson | a357b99 | 1998-02-08 20:56:40 -0600 | [diff] [blame] | 189 | 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] | 190 | { |
Glenn Randers-Pehrson | 5c6aeb2 | 1998-12-29 11:47:59 -0600 | [diff] [blame] | 191 | void *near_ptr; |
Andreas Dilger | 02ad0ef | 1997-01-17 01:34:35 -0600 | [diff] [blame] | 192 | void FAR *far_ptr; |
| 193 | FP_OFF(near_ptr) = FP_OFF(ptr); |
| 194 | far_ptr = (void FAR *)near_ptr; |
| 195 | if(check != 0) |
| 196 | if(FP_SEG(ptr) != FP_SEG(far_ptr)) |
| 197 | png_error(png_ptr,"segment lost in conversion"); |
| 198 | return(near_ptr); |
| 199 | } |
| 200 | # else |
Glenn Randers-Pehrson | a357b99 | 1998-02-08 20:56:40 -0600 | [diff] [blame] | 201 | 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] | 202 | { |
Glenn Randers-Pehrson | 5c6aeb2 | 1998-12-29 11:47:59 -0600 | [diff] [blame] | 203 | void *near_ptr; |
Andreas Dilger | 02ad0ef | 1997-01-17 01:34:35 -0600 | [diff] [blame] | 204 | void FAR *far_ptr; |
| 205 | near_ptr = (void FAR *)ptr; |
| 206 | far_ptr = (void FAR *)near_ptr; |
| 207 | if(check != 0) |
| 208 | if(far_ptr != ptr) |
| 209 | png_error(png_ptr,"segment lost in conversion"); |
| 210 | return(near_ptr); |
| 211 | } |
| 212 | # endif |
| 213 | # endif |