XII. Configuring for compiler xxx:
XIII. Removing unwanted object code
XIV. Changes to the build and configuration of libpng in libpng-1.5.x
- XV. Configuring libpng for multiprocessing
- XVI. Other sources of information about libpng:
+ XV. Setjmp/longjmp issues
+ XVI. Other sources of information about libpng
I. Simple installation
where you want to install the libpng "lib", "include", and "bin"
subdirectories.
+If you downloaded a GIT clone, you will need to run ./autogen.sh before
+running ./configure, to create "configure" and "Makefile.in" which are
+not included in the GIT repository.
+
+Note that "configure" is only included in the "*.tar" distributions and not
+in the "*.zip" or "*.7z" distributions. If you downloaded one of those
+distributions, see "Building with project files" or "Building with makefiles",
+below.
+
II. Rebuilding the configure scripts
If configure does not work on your system, or if you have a need to
libpng (this directory)
INSTALL (this file)
README
- *.h
- *.c
+ *.h, *.c => libpng source files
CMakeLists.txt => "cmake" script
configuration files:
configure.ac, configure, Makefile.am, Makefile.in,
libpng-config.in, aclocal.m4, config.h.in, config.sub,
depcomp, install-sh, mkinstalldirs, test-pngtest.sh
contrib
- gregbook
- libtests
- pngminim
- pngminus
- pngsuite
- visupng
+ arm-neon, conftest, examples, gregbook, libtests, pngminim,
+ pngminus, pngsuite, tools, visupng
projects
- visualc71
- vstudio
+ cbuilder5, owatcom, visualc71, vstudio, xcode
scripts
makefile.*
*.def (module definition files)
pngtest.png
etc.
zlib
- README
- *.h
- *.c
- contrib
- etc.
+ README, *.h, *.c contrib, etc.
If the line endings in the files look funny, you may wish to get the other
distribution of libpng. It is available in both tar.gz (UNIX style line
VI. Building with project files
If you are building libpng with MSVC, you can enter the
-libpng projects\visualc6 or visualc71 directory and follow the instructions
+libpng projects\visualc71 or vstudio directory and follow the instructions
in README.txt.
Otherwise enter the zlib directory and follow the instructions in zlib/README,
VIII. Configuring libpng for 16-bit platforms
You will want to look into zconf.h to tell zlib (and thus libpng) that
-it cannot allocate more then 64K at a time. Even if you can, the memory
+it cannot allocate more than 64K at a time. Even if you can, the memory
won't be accessible. So limit zlib and libpng to 64K by defining MAXSEG_64K.
IX. Configuring for DOS
after the build of pnglibconf.h and it is never included in an application
build.
-The rarely used alternative of adding a list of feature macros to the
+The formerly used alternative of adding a list of feature macros to the
CPPFLAGS setting in the build also still works; however, the macros will be
copied to pnglibconf.h and this may produce macro redefinition warnings
when the individual C files are compiled.
Configuration options are now documented in scripts/pnglibconf.dfa. This
file also includes dependency information that ensures a configuration is
-consistent; that is, if a feature is switched off dependent features are
-also removed. As a recommended alternative to using feature macros in
+consistent; that is, if a feature is switched off, dependent features are
+also switched off. As a recommended alternative to using feature macros in
pngusr.h a system builder may also define equivalent options in pngusr.dfa
(or, indeed, any file) and add that to the configuration by setting
DFA_XTRA to the file name. The makefiles in contrib/pngminim illustrate
-how to do this, and illustrate a case where pngusr.h is still required.
+how to do this, and also illustrate a case where pngusr.h is still required.
+
+After you have built libpng, the definitions that were recorded in
+pnglibconf.h are available to your application (pnglibconf.h is included
+in png.h and gets installed alongside png.h and pngconf.h in your
+$PREFIX/include directory). Do not edit pnglibconf.h after you have built
+libpng, because than the settings would not accurately reflect the settings
+that were used to build libpng.
-XV. Configuring libpng for multiprocessing
+XV. Setjmp/longjmp issues
Libpng uses setjmp()/longjmp() for error handling. Unfortunately setjmp()
is known to be not thread-safe on some platforms and we don't know of
in your pnglibconf.h or pngusr.h.
+Starting with libpng-1.6.0, the library included a "simplified API".
+This requires setjmp/longjmp, so you must either build the library
+with PNG_SETJMP_SUPPORTED defined, or with PNG_SIMPLIFIED_READ_SUPPORTED
+and PNG_SIMPLIFIED_WRITE_SUPPORTED undefined.
+
XVI. Other sources of information about libpng:
Further information can be found in the README and libpng-manual.txt
--with-pkgconfigdir=/usr/lib/pkgconfig --includedir=/usr/include
You can alternatively specify --includedir=/usr/include, /usr/local/include,
-/usr/include/libpng%NN%, or whatever.
+/usr/include/libpng16, or whatever.
If you find that the configure script is out-of-date or is not supporting
your platform properly, try running autogen.sh to regenerate "configure",
projects / platform / upstream / libpng.git / blobdiff