mirror of
https://github.com/reactos/reactos.git
synced 2024-08-20 18:35:32 +00:00
466 lines
19 KiB
Plaintext
466 lines
19 KiB
Plaintext
|
|
Installing libpng
|
|
|
|
Contents
|
|
|
|
I. Simple installation
|
|
II. Rebuilding the configure scripts
|
|
III. Using scripts/makefile*
|
|
IV. Using cmake
|
|
V. Directory structure
|
|
VI. Building with project files
|
|
VII. Building with makefiles
|
|
VIII. Configuring libpng for 16-bit platforms
|
|
IX. Configuring for DOS
|
|
X. Configuring for Medium Model
|
|
XI. Prepending a prefix to exported symbols
|
|
XII. Configuring for compiler xxx:
|
|
XIII. Removing unwanted object code
|
|
XIV. Enabling or disabling hardware optimizations
|
|
XV. Changes to the build and configuration of libpng in libpng-1.5.x
|
|
XVI. Setjmp/longjmp issues
|
|
XVII. Common linking failures
|
|
XVIII. Other sources of information about libpng
|
|
|
|
I. Simple installation
|
|
|
|
On Unix/Linux and similar systems, you can simply type
|
|
|
|
./configure [--prefix=/path]
|
|
make check
|
|
make install
|
|
|
|
and ignore the rest of this document. "/path" is the path to the directory
|
|
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
|
|
change configure.ac or Makefile.am, and you have a reasonably
|
|
up-to-date set of tools, running ./autogen.sh in a git clone before
|
|
running ./configure may fix the problem. To be really sure that you
|
|
aren't using any of the included pre-built scripts, especially if you
|
|
are building from a tar distribution instead of a git distribution,
|
|
do this:
|
|
|
|
./configure --enable-maintainer-mode
|
|
make maintainer-clean
|
|
./autogen.sh --maintainer --clean
|
|
./autogen.sh --maintainer
|
|
./configure [--prefix=/path] [other options]
|
|
make
|
|
make install
|
|
make check
|
|
|
|
III. Using scripts/makefile*
|
|
|
|
Instead, you can use one of the custom-built makefiles in the
|
|
"scripts" directory
|
|
|
|
cp scripts/pnglibconf.h.prebuilt pnglibconf.h
|
|
cp scripts/makefile.system makefile
|
|
make test
|
|
make install
|
|
|
|
The files that are presently available in the scripts directory
|
|
are listed and described in scripts/README.txt.
|
|
|
|
Or you can use one of the "projects" in the "projects" directory.
|
|
|
|
Before installing libpng, you must first install zlib, if it
|
|
is not already on your system. zlib can usually be found
|
|
wherever you got libpng; otherwise go to https://zlib.net/. You can
|
|
place zlib in the same directory as libpng or in another directory.
|
|
|
|
If your system already has a preinstalled zlib you will still need
|
|
to have access to the zlib.h and zconf.h include files that
|
|
correspond to the version of zlib that's installed.
|
|
|
|
If you wish to test with a particular zlib that is not first in the
|
|
standard library search path, put ZLIBLIB, ZLIBINC, CPPFLAGS, LDFLAGS,
|
|
and LD_LIBRARY_PATH in your environment before running "make test"
|
|
or "make distcheck":
|
|
|
|
ZLIBLIB=/path/to/lib export ZLIBLIB
|
|
ZLIBINC=/path/to/include export ZLIBINC
|
|
CPPFLAGS="-I$ZLIBINC" export CPPFLAGS
|
|
LDFLAGS="-L$ZLIBLIB" export LDFLAGS
|
|
LD_LIBRARY_PATH="$ZLIBLIB:$LD_LIBRARY_PATH" export LD_LIBRARY_PATH
|
|
|
|
If you are using one of the makefile scripts, put ZLIBLIB and ZLIBINC
|
|
in your environment and type
|
|
|
|
make ZLIBLIB=$ZLIBLIB ZLIBINC=$ZLIBINC test
|
|
|
|
IV. Using cmake
|
|
|
|
If you want to use "cmake" (see www.cmake.org), type
|
|
|
|
cmake . -DCMAKE_INSTALL_PREFIX=/path
|
|
make
|
|
make install
|
|
|
|
As when using the simple configure method described above, "/path" points to
|
|
the installation directory where you want to put the libpng "lib", "include",
|
|
and "bin" subdirectories.
|
|
|
|
V. Directory structure
|
|
|
|
You can rename the directories that you downloaded (they
|
|
might be called "libpng-x.y.z" or "libpngNN" and "zlib-1.2.8"
|
|
or "zlib128") so that you have directories called "zlib" and "libpng".
|
|
|
|
Your directory structure should look like this:
|
|
|
|
.. (the parent directory)
|
|
libpng (this directory)
|
|
INSTALL (this file)
|
|
README
|
|
*.h, *.c => libpng source files
|
|
CMakeLists.txt => "cmake" script
|
|
configuration files:
|
|
configure.ac, configure, Makefile.am, Makefile.in,
|
|
autogen.sh, config.guess, ltmain.sh, missing, libpng.pc.in,
|
|
libpng-config.in, aclocal.m4, config.h.in, config.sub,
|
|
depcomp, install-sh, mkinstalldirs, test-pngtest.sh
|
|
contrib
|
|
arm-neon, conftest, examples, gregbook, libtests, pngminim,
|
|
pngminus, pngsuite, tools, visupng
|
|
projects
|
|
cbuilder5, owatcom, visualc71, vstudio, xcode
|
|
scripts
|
|
makefile.*
|
|
*.def (module definition files)
|
|
etc.
|
|
pngtest.png
|
|
etc.
|
|
zlib
|
|
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
|
|
endings) and zip (DOS style line endings) formats.
|
|
|
|
VI. Building with project files
|
|
|
|
If you are building libpng with MSVC, you can enter the
|
|
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,
|
|
then come back here and run "configure" or choose the appropriate
|
|
makefile.sys in the scripts directory.
|
|
|
|
VII. Building with makefiles
|
|
|
|
Copy the file (or files) that you need from the
|
|
scripts directory into this directory, for example
|
|
|
|
MSDOS example:
|
|
|
|
copy scripts\makefile.msc makefile
|
|
copy scripts\pnglibconf.h.prebuilt pnglibconf.h
|
|
|
|
UNIX example:
|
|
|
|
cp scripts/makefile.std makefile
|
|
cp scripts/pnglibconf.h.prebuilt pnglibconf.h
|
|
|
|
Read the makefile to see if you need to change any source or
|
|
target directories to match your preferences.
|
|
|
|
Then read pnglibconf.dfa to see if you want to make any configuration
|
|
changes.
|
|
|
|
Then just run "make" which will create the libpng library in
|
|
this directory and "make test" which will run a quick test that reads
|
|
the "pngtest.png" file and writes a "pngout.png" file that should be
|
|
identical to it. Look for "9782 zero samples" in the output of the
|
|
test. For more confidence, you can run another test by typing
|
|
"pngtest pngnow.png" and looking for "289 zero samples" in the output.
|
|
Also, you can run "pngtest -m contrib/pngsuite/*.png" and compare
|
|
your output with the result shown in contrib/pngsuite/README.
|
|
|
|
Most of the makefiles will allow you to run "make install" to
|
|
put the library in its final resting place (if you want to
|
|
do that, run "make install" in the zlib directory first if necessary).
|
|
Some also allow you to run "make test-installed" after you have
|
|
run "make install".
|
|
|
|
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 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
|
|
|
|
For DOS users who only have access to the lower 640K, you will
|
|
have to limit zlib's memory usage via a png_set_compression_mem_level()
|
|
call. See zlib.h or zconf.h in the zlib library for more information.
|
|
|
|
X. Configuring for Medium Model
|
|
|
|
Libpng's support for medium model has been tested on most of the popular
|
|
compilers. Make sure MAXSEG_64K gets defined, USE_FAR_KEYWORD gets
|
|
defined, and FAR gets defined to far in pngconf.h, and you should be
|
|
all set. Everything in the library (except for zlib's structure) is
|
|
expecting far data. You must use the typedefs with the p or pp on
|
|
the end for pointers (or at least look at them and be careful). Make
|
|
note that the rows of data are defined as png_bytepp, which is
|
|
an "unsigned char far * far *".
|
|
|
|
XI. Prepending a prefix to exported symbols
|
|
|
|
Starting with libpng-1.6.0, you can configure libpng (when using the
|
|
"configure" script) to prefix all exported symbols by means of the
|
|
configuration option "--with-libpng-prefix=FOO_", where FOO_ can be any
|
|
string beginning with a letter and containing only uppercase
|
|
and lowercase letters, digits, and the underscore (i.e., a C language
|
|
identifier). This creates a set of macros in pnglibconf.h, so this is
|
|
transparent to applications; their function calls get transformed by
|
|
the macros to use the modified names.
|
|
|
|
XII. Configuring for compiler xxx:
|
|
|
|
All includes for libpng are in pngconf.h. If you need to add, change
|
|
or delete an include, this is the place to do it.
|
|
The includes that are not needed outside libpng are placed in pngpriv.h,
|
|
which is only used by the routines inside libpng itself.
|
|
The files in libpng proper only include pngpriv.h and png.h, which
|
|
in turn includes pngconf.h and, as of libpng-1.5.0, pnglibconf.h.
|
|
As of libpng-1.5.0, pngpriv.h also includes three other private header
|
|
files, pngstruct.h, pnginfo.h, and pngdebug.h, which contain material
|
|
that previously appeared in the public headers.
|
|
|
|
XIII. Removing unwanted object code
|
|
|
|
There are a bunch of #define's in pngconf.h that control what parts of
|
|
libpng are compiled. All the defines end in _SUPPORTED. If you are
|
|
never going to use a capability, you can change the #define to #undef
|
|
before recompiling libpng and save yourself code and data space, or
|
|
you can turn off individual capabilities with defines that begin with
|
|
"PNG_NO_".
|
|
|
|
In libpng-1.5.0 and later, the #define's are in pnglibconf.h instead.
|
|
|
|
You can also turn all of the transforms and ancillary chunk capabilities
|
|
off en masse with compiler directives that define
|
|
PNG_NO_READ[or WRITE]_TRANSFORMS, or PNG_NO_READ[or WRITE]_ANCILLARY_CHUNKS,
|
|
or all four, along with directives to turn on any of the capabilities that
|
|
you do want. The PNG_NO_READ[or WRITE]_TRANSFORMS directives disable the
|
|
extra transformations but still leave the library fully capable of reading
|
|
and writing PNG files with all known public chunks. Use of the
|
|
PNG_NO_READ[or WRITE]_ANCILLARY_CHUNKS directive produces a library
|
|
that is incapable of reading or writing ancillary chunks. If you are
|
|
not using the progressive reading capability, you can turn that off
|
|
with PNG_NO_PROGRESSIVE_READ (don't confuse this with the INTERLACING
|
|
capability, which you'll still have).
|
|
|
|
All the reading and writing specific code are in separate files, so the
|
|
linker should only grab the files it needs. However, if you want to
|
|
make sure, or if you are building a stand alone library, all the
|
|
reading files start with "pngr" and all the writing files start with "pngw".
|
|
The files that don't match either (like png.c, pngtrans.c, etc.)
|
|
are used for both reading and writing, and always need to be included.
|
|
The progressive reader is in pngpread.c
|
|
|
|
If you are creating or distributing a dynamically linked library (a .so
|
|
or DLL file), you should not remove or disable any parts of the library,
|
|
as this will cause applications linked with different versions of the
|
|
library to fail if they call functions not available in your library.
|
|
The size of the library itself should not be an issue, because only
|
|
those sections that are actually used will be loaded into memory.
|
|
|
|
XIV. Enabling or disabling hardware optimizations
|
|
|
|
Certain hardware capabilities, such as the Intel SSE instructions,
|
|
are normally detected at run time. Enable them with configure options
|
|
such as one of
|
|
|
|
--enable-arm-neon=yes
|
|
--enable-mips-msa=yes
|
|
--enable-intel-sse=yes
|
|
--enable-powerpc-vsx=yes
|
|
|
|
or enable them all at once with
|
|
|
|
--enable-hardware-optimizations=yes
|
|
|
|
or, if you are not using "configure", you can use one
|
|
or more of
|
|
|
|
CPPFLAGS += "-DPNG_ARM_NEON"
|
|
CPPFLAGS += "-DPNG_MIPS_MSA"
|
|
CPPFLAGS += "-DPNG_INTEL_SSE"
|
|
CPPFLAGS += "-DPNG_POWERPC_VSX"
|
|
|
|
See for example scripts/makefile.linux-opt
|
|
|
|
If you wish to avoid using them,
|
|
you can disable them via the configure option
|
|
|
|
--disable-hardware-optimizations
|
|
|
|
to disable them all, or
|
|
|
|
--enable-intel-sse=no
|
|
|
|
to disable a particular one,
|
|
or via compiler-command options such as
|
|
|
|
CPPFLAGS += "-DPNG_ARM_NEON_OPT=0, -DPNG_MIPS_MSA_OPT=0,
|
|
-DPNG_INTEL_SSE_OPT=0, -DPNG_POWERPC_VSX_OPT=0"
|
|
|
|
If you are using cmake, hardware optimizations are "on"
|
|
by default. To disable them, use
|
|
|
|
cmake . -DPNG_ARM_NEON=no -DPNG_INTEL_SSE=no \
|
|
-DPNG_MIPS_MSA=no -DPNG_POWERPC_VSX=no
|
|
|
|
or disable them all at once with
|
|
|
|
cmake . -DPNG_HARDWARE_OPTIMIZATIONS=no
|
|
|
|
XV. Changes to the build and configuration of libpng in libpng-1.5.x
|
|
|
|
Details of internal changes to the library code can be found in the CHANGES
|
|
file and in the GIT repository logs. These will be of no concern to the vast
|
|
majority of library users or builders; however, the few who configure libpng
|
|
to a non-default feature set may need to change how this is done.
|
|
|
|
There should be no need for library builders to alter build scripts if
|
|
these use the distributed build support - configure or the makefiles -
|
|
however, users of the makefiles may care to update their build scripts
|
|
to build pnglibconf.h where the corresponding makefile does not do so.
|
|
|
|
Building libpng with a non-default configuration has changed completely.
|
|
The old method using pngusr.h should still work correctly even though the
|
|
way pngusr.h is used in the build has been changed; however, library
|
|
builders will probably want to examine the changes to take advantage of
|
|
new capabilities and to simplify their build system.
|
|
|
|
A. Specific changes to library configuration capabilities
|
|
|
|
The exact mechanism used to control attributes of API functions has
|
|
changed. A single set of operating system independent macro definitions
|
|
is used and operating system specific directives are defined in
|
|
pnglibconf.h
|
|
|
|
As part of this the mechanism used to choose procedure call standards on
|
|
those systems that allow a choice has been changed. At present this only
|
|
affects certain Microsoft (DOS, Windows) and IBM (OS/2) operating systems
|
|
running on Intel processors. As before, PNGAPI is defined where required
|
|
to control the exported API functions; however, two new macros, PNGCBAPI
|
|
and PNGCAPI, are used instead for callback functions (PNGCBAPI) and
|
|
(PNGCAPI) for functions that must match a C library prototype (currently
|
|
only png_longjmp_ptr, which must match the C longjmp function.) The new
|
|
approach is documented in pngconf.h
|
|
|
|
Despite these changes, libpng 1.5.0 only supports the native C function
|
|
calling standard on those platforms tested so far ("__cdecl" on Microsoft
|
|
Windows). This is because the support requirements for alternative
|
|
calling conventions seem to no longer exist. Developers who find it
|
|
necessary to set PNG_API_RULE to 1 should advise the mailing list
|
|
(png-mng-implement) of this and library builders who use Openwatcom and
|
|
therefore set PNG_API_RULE to 2 should also contact the mailing list.
|
|
|
|
B. Changes to the configuration mechanism
|
|
|
|
Prior to libpng-1.5.0 library builders who needed to configure libpng
|
|
had either to modify the exported pngconf.h header file to add system
|
|
specific configuration or had to write feature selection macros into
|
|
pngusr.h and cause this to be included into pngconf.h by defining
|
|
PNG_USER_CONFIG. The latter mechanism had the disadvantage that an
|
|
application built without PNG_USER_CONFIG defined would see the
|
|
unmodified, default, libpng API and thus would probably fail to link.
|
|
|
|
These mechanisms still work in the configure build and in any makefile
|
|
build that builds pnglibconf.h, although the feature selection macros
|
|
have changed somewhat as described above. In 1.5.0, however, pngusr.h is
|
|
processed only once, at the time the exported header file pnglibconf.h is
|
|
built. pngconf.h no longer includes pngusr.h; therefore, pngusr.h is ignored
|
|
after the build of pnglibconf.h and it is never included in an application
|
|
build.
|
|
|
|
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.
|
|
|
|
All configuration now only works if pnglibconf.h is built from
|
|
scripts/pnglibconf.dfa. This requires the program awk. Brian Kernighan
|
|
(the original author of awk) maintains C source code of that awk and this
|
|
and all known later implementations (often called by subtly different
|
|
names - nawk and gawk for example) are adequate to build pnglibconf.h.
|
|
The Sun Microsystems (now Oracle) program 'awk' is an earlier version
|
|
and does not work; this may also apply to other systems that have a
|
|
functioning awk called 'nawk'.
|
|
|
|
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 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 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.
|
|
|
|
XVI. 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
|
|
any platform where it is guaranteed to be thread-safe. Therefore, if
|
|
your application is going to be using multiple threads, you should
|
|
configure libpng with PNG_NO_SETJMP in your pngusr.dfa file, with
|
|
-DPNG_NO_SETJMP on your compile line, or with
|
|
|
|
#undef PNG_SETJMP_SUPPORTED
|
|
|
|
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.
|
|
|
|
XVII. Common linking failures
|
|
|
|
If your application fails to find libpng or zlib entries while linking:
|
|
|
|
Be sure "-lz" appears after "-lpng" on your linking command.
|
|
|
|
Be sure you have built libpng, zlib, and your application for the
|
|
same platform (e.g., 32-bit or 64-bit).
|
|
|
|
If you are using the vstudio project, observe the WARNING in
|
|
project/vstudio/README.txt.
|
|
|
|
XVIII. Other sources of information about libpng:
|
|
|
|
Further information can be found in the README and libpng-manual.txt
|
|
files, in the individual makefiles, in png.h, and the manual pages
|
|
libpng.3 and png.5.
|
|
|
|
Copyright (c) 1998-2002,2006-2016 Glenn Randers-Pehrson
|
|
This document is released under the libpng license.
|
|
For conditions of distribution and use, see the disclaimer
|
|
and license in png.h.
|