LibPNG + Boost::GIL：找不到png_infopp_NULL

Question

当尝试使用Boost :: GIL PNG IO支持编译我的文件时，我总是会遇到这个错误：

（我正在运行Mac OS X Leopard和Boost 1.42，LibPNG 1.4）

/usr/local/include/boost/gil/extension/io/png_io_private.hpp: In member function 'void boost::gil::detail::png_reader::init()':
/usr/local/include/boost/gil/extension/io/png_io_private.hpp:155: error: 'png_infopp_NULL' was not declared in this scope
/usr/local/include/boost/gil/extension/io/png_io_private.hpp:160: error: 'png_infopp_NULL' was not declared in this scope
/usr/local/include/boost/gil/extension/io/png_io_private.hpp: In destructor 'boost::gil::detail::png_reader::~png_reader()':
/usr/local/include/boost/gil/extension/io/png_io_private.hpp:174: error: 'png_infopp_NULL' was not declared in this scope
/usr/local/include/boost/gil/extension/io/png_io_private.hpp: In member function 'void boost::gil::detail::png_reader::apply(const View&)':
/usr/local/include/boost/gil/extension/io/png_io_private.hpp:186: error: 'int_p_NULL' was not declared in this scope
/usr/local/include/boost/gil/extension/io/png_io_private.hpp: In member function 'void boost::gil::detail::png_reader_color_convert<CC>::apply(const View&)':
/usr/local/include/boost/gil/extension/io/png_io_private.hpp:228: error: 'int_p_NULL' was not declared in this scope
/usr/local/include/boost/gil/extension/io/png_io_private.hpp: In member function 'void boost::gil::detail::png_writer::init()':
/usr/local/include/boost/gil/extension/io/png_io_private.hpp:317: error: 'png_infopp_NULL' was not declared in this scope

- Viet

Answer 1

libpng 1.4删除了对png_infopp_NULL和int_p_NULL的定义。所以添加

#define png_infopp_NULL (png_infopp)NULL
#define int_p_NULL (int*)NULL

在包含GIL头文件之前，在您的代码中。

- wdscxsj

---

+1 谢谢。我曾经考虑过这个问题，但为了避免其他可能出现的问题，我还是回到了1.2版本。 - Viet

Answer 2

起初我使用的是libpng 1.4版本。后来换成了1.2版本，所有问题都解决了。

- Viet