3965825b97
With this change, the CMake build, which does not use DEPS to sync external projects, is able to build and use the same version of libpng that is used in other builds. This will allow all platforms (including Google3 CMake build) to test on the same version of libpng, so we do not need to make SkPngCodec support all versions of libpng. - Update CMakeLists.txt to use the checked in libpng. - Check in libpng version 1.6.22rc01 - Update README.google - Replace our old LICENSE file with the latest one from libpng GOLD_TRYBOT_URL= https://gold.skia.org/search?issue=2033063003 CQ_EXTRA_TRYBOTS=client.skia.compile:Build-Ubuntu-GCC-x86_64-Release-CMake-Trybot,Build-Mac-Clang-x86_64-Release-CMake-Trybot Review-Url: https://codereview.chromium.org/2033063003
121 lines
3.9 KiB
C
121 lines
3.9 KiB
C
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/* pngrio.c - functions for data input
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*
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* Last changed in libpng 1.6.17 [March 26, 2015]
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* Copyright (c) 1998-2002,2004,2006-2015 Glenn Randers-Pehrson
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* (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
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* (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
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*
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* This code is released under the libpng license.
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* For conditions of distribution and use, see the disclaimer
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* and license in png.h
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*
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* This file provides a location for all input. Users who need
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* special handling are expected to write a function that has the same
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* arguments as this and performs a similar function, but that possibly
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* has a different input method. Note that you shouldn't change this
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* function, but rather write a replacement function and then make
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* libpng use it at run time with png_set_read_fn(...).
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*/
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#include "pngpriv.h"
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#ifdef PNG_READ_SUPPORTED
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/* Read the data from whatever input you are using. The default routine
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* reads from a file pointer. Note that this routine sometimes gets called
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* with very small lengths, so you should implement some kind of simple
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* buffering if you are using unbuffered reads. This should never be asked
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* to read more than 64K on a 16-bit machine.
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*/
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void /* PRIVATE */
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png_read_data(png_structrp png_ptr, png_bytep data, png_size_t length)
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{
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png_debug1(4, "reading %d bytes", (int)length);
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if (png_ptr->read_data_fn != NULL)
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(*(png_ptr->read_data_fn))(png_ptr, data, length);
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else
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png_error(png_ptr, "Call to NULL read function");
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}
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#ifdef PNG_STDIO_SUPPORTED
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/* This is the function that does the actual reading of data. If you are
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* not reading from a standard C stream, you should create a replacement
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* read_data function and use it at run time with png_set_read_fn(), rather
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* than changing the library.
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*/
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void PNGCBAPI
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png_default_read_data(png_structp png_ptr, png_bytep data, png_size_t length)
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{
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png_size_t check;
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if (png_ptr == NULL)
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return;
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/* fread() returns 0 on error, so it is OK to store this in a png_size_t
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* instead of an int, which is what fread() actually returns.
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*/
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check = fread(data, 1, length, png_voidcast(png_FILE_p, png_ptr->io_ptr));
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if (check != length)
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png_error(png_ptr, "Read Error");
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}
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#endif
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/* This function allows the application to supply a new input function
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* for libpng if standard C streams aren't being used.
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*
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* This function takes as its arguments:
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*
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* png_ptr - pointer to a png input data structure
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*
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* io_ptr - pointer to user supplied structure containing info about
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* the input functions. May be NULL.
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*
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* read_data_fn - pointer to a new input function that takes as its
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* arguments a pointer to a png_struct, a pointer to
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* a location where input data can be stored, and a 32-bit
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* unsigned int that is the number of bytes to be read.
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* To exit and output any fatal error messages the new write
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* function should call png_error(png_ptr, "Error msg").
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* May be NULL, in which case libpng's default function will
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* be used.
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*/
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void PNGAPI
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png_set_read_fn(png_structrp png_ptr, png_voidp io_ptr,
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png_rw_ptr read_data_fn)
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{
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if (png_ptr == NULL)
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return;
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png_ptr->io_ptr = io_ptr;
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#ifdef PNG_STDIO_SUPPORTED
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if (read_data_fn != NULL)
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png_ptr->read_data_fn = read_data_fn;
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else
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png_ptr->read_data_fn = png_default_read_data;
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#else
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png_ptr->read_data_fn = read_data_fn;
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#endif
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#ifdef PNG_WRITE_SUPPORTED
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/* It is an error to write to a read device */
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if (png_ptr->write_data_fn != NULL)
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{
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png_ptr->write_data_fn = NULL;
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png_warning(png_ptr,
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"Can't set both read_data_fn and write_data_fn in the"
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" same structure");
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}
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#endif
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#ifdef PNG_WRITE_FLUSH_SUPPORTED
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png_ptr->output_flush_fn = NULL;
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#endif
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}
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#endif /* READ */
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