CMake/Modules/FindPNG.cmake
Rolf Eike Beer 2a7975398f FindPNG: improve library detection (#14301)
-add support for upcoming version 1.7
-improve version selection, use the major and minor of the requested version
 to generate the library suffix list
-support detection of release and debug libraries
2013-07-27 22:35:11 +02:00

106 lines
4.1 KiB
CMake

# - Find the native PNG includes and library
#
# This module searches libpng, the library for working with PNG images.
#
# It defines the following variables
# PNG_INCLUDE_DIRS, where to find png.h, etc.
# PNG_LIBRARIES, the libraries to link against to use PNG.
# PNG_DEFINITIONS - You should add_definitons(${PNG_DEFINITIONS}) before compiling code that includes png library files.
# PNG_FOUND, If false, do not try to use PNG.
# PNG_VERSION_STRING - the version of the PNG library found (since CMake 2.8.8)
# Also defined, but not for general use are
# PNG_LIBRARY, where to find the PNG library.
# For backward compatiblity the variable PNG_INCLUDE_DIR is also set. It has the same value as PNG_INCLUDE_DIRS.
#
# Since PNG depends on the ZLib compression library, none of the above will be
# defined unless ZLib can be found.
#=============================================================================
# Copyright 2002-2009 Kitware, Inc.
#
# Distributed under the OSI-approved BSD License (the "License");
# see accompanying file Copyright.txt for details.
#
# This software is distributed WITHOUT ANY WARRANTY; without even the
# implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
# See the License for more information.
#=============================================================================
# (To distribute this file outside of CMake, substitute the full
# License text for the above reference.)
if(PNG_FIND_QUIETLY)
set(_FIND_ZLIB_ARG QUIET)
endif()
find_package(ZLIB ${_FIND_ZLIB_ARG})
if(ZLIB_FOUND)
find_path(PNG_PNG_INCLUDE_DIR png.h
/usr/local/include/libpng # OpenBSD
)
list(APPEND PNG_NAMES png libpng)
unset(PNG_NAMES_DEBUG)
set(_PNG_VERSION_SUFFIXES 17 16 15 14 12)
if (PNG_FIND_VERSION MATCHES "^[0-9]+\\.[0-9]+(\\..*)?$")
string(REGEX REPLACE
"^([0-9]+)\\.([0-9]+).*" "\\1\\2"
_PNG_VERSION_SUFFIX_MIN "${PNG_FIND_VERSION}")
if (PNG_FIND_VERSION_EXACT)
set(_PNG_VERSION_SUFFIXES ${_PNG_VERSION_SUFFIX_MIN})
else ()
string(REGEX REPLACE
"${_PNG_VERSION_SUFFIX_MIN}.*" "${_PNG_VERSION_SUFFIX_MIN}"
_PNG_VERSION_SUFFIXES "${_PNG_VERSION_SUFFIXES}")
endif ()
unset(_PNG_VERSION_SUFFIX_MIN)
endif ()
foreach(v IN LISTS _PNG_VERSION_SUFFIXES)
list(APPEND PNG_NAMES png${v} libpng${v})
list(APPEND PNG_NAMES_DEBUG png${v}d libpng${v}d)
endforeach()
message(STATUS "PNG r: ${PNG_NAMES} d: ${PNG_NAMES_DEBUG}")
unset(_PNG_VERSION_SUFFIXES)
find_library(PNG_LIBRARY_RELEASE NAMES ${PNG_NAMES})
find_library(PNG_LIBRARY_DEBUG NAMES ${PNG_NAMES_DEBUG})
unset(PNG_NAMES)
unset(PNG_NAMES_DEBUG)
include(${CMAKE_CURRENT_LIST_DIR}/SelectLibraryConfigurations.cmake)
select_library_configurations(PNG)
# Set by select_library_configurations(), but we want the one from
# find_package_handle_standard_args() below.
unset(PNG_FOUND)
if (PNG_LIBRARY AND PNG_PNG_INCLUDE_DIR)
# png.h includes zlib.h. Sigh.
set(PNG_INCLUDE_DIRS ${PNG_PNG_INCLUDE_DIR} ${ZLIB_INCLUDE_DIR} )
set(PNG_INCLUDE_DIR ${PNG_INCLUDE_DIRS} ) # for backward compatiblity
set(PNG_LIBRARIES ${PNG_LIBRARY} ${ZLIB_LIBRARY})
if (CYGWIN)
if(BUILD_SHARED_LIBS)
# No need to define PNG_USE_DLL here, because it's default for Cygwin.
else()
set (PNG_DEFINITIONS -DPNG_STATIC)
endif()
endif ()
endif ()
if (PNG_PNG_INCLUDE_DIR AND EXISTS "${PNG_PNG_INCLUDE_DIR}/png.h")
file(STRINGS "${PNG_PNG_INCLUDE_DIR}/png.h" png_version_str REGEX "^#define[ \t]+PNG_LIBPNG_VER_STRING[ \t]+\".+\"")
string(REGEX REPLACE "^#define[ \t]+PNG_LIBPNG_VER_STRING[ \t]+\"([^\"]+)\".*" "\\1" PNG_VERSION_STRING "${png_version_str}")
unset(png_version_str)
endif ()
endif()
# handle the QUIETLY and REQUIRED arguments and set PNG_FOUND to TRUE if
# all listed variables are TRUE
include(${CMAKE_CURRENT_LIST_DIR}/FindPackageHandleStandardArgs.cmake)
find_package_handle_standard_args(PNG
REQUIRED_VARS PNG_LIBRARY PNG_PNG_INCLUDE_DIR
VERSION_VAR PNG_VERSION_STRING)
mark_as_advanced(PNG_PNG_INCLUDE_DIR PNG_LIBRARY )