# Distributed under the OSI-approved BSD 3-Clause License. See accompanying # file Copyright.txt or https://cmake.org/licensing for details. #.rst: # FindPNG # ------- # # Find libpng, the official reference library for the PNG image format. # # Imported targets # ^^^^^^^^^^^^^^^^ # # This module defines the following :prop_tgt:`IMPORTED` target: # # ``PNG::PNG`` # The libpng library, if found. # # Result variables # ^^^^^^^^^^^^^^^^ # # This module will set the following variables in your project: # # ``PNG_INCLUDE_DIRS`` # where to find png.h, etc. # ``PNG_LIBRARIES`` # the libraries to link against to use PNG. # ``PNG_DEFINITIONS`` # You should add_definitions(${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) # # Obsolete variables # ^^^^^^^^^^^^^^^^^^ # # The following variables may also be set, for backwards compatibility: # # ``PNG_LIBRARY`` # where to find the PNG library. # ``PNG_INCLUDE_DIR`` # where to find the PNG headers (same as PNG_INCLUDE_DIRS) # # Since PNG depends on the ZLib compression library, none of the above # will be defined unless ZLib can be found. if(PNG_FIND_QUIETLY) set(_FIND_ZLIB_ARG QUIET) endif() find_package(ZLIB ${_FIND_ZLIB_ARG}) if(ZLIB_FOUND) find_path(PNG_PNG_INCLUDE_DIR png.h PATH_SUFFIXES include/libpng) list(APPEND PNG_NAMES png libpng) unset(PNG_NAMES_DEBUG) set(_PNG_VERSION_SUFFIXES 17 16 15 14 12) if (PNG_FIND_VERSION MATCHES "^([0-9]+)\\.([0-9]+)(\\..*)?$") set(_PNG_VERSION_SUFFIX_MIN "${CMAKE_MATCH_1}${CMAKE_MATCH_2}") 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() unset(_PNG_VERSION_SUFFIXES) # For compatibility with versions prior to this multi-config search, honor # any PNG_LIBRARY that is already specified and skip the search. if(NOT PNG_LIBRARY) find_library(PNG_LIBRARY_RELEASE NAMES ${PNG_NAMES}) find_library(PNG_LIBRARY_DEBUG NAMES ${PNG_NAMES_DEBUG}) include(${CMAKE_CURRENT_LIST_DIR}/SelectLibraryConfigurations.cmake) select_library_configurations(PNG) mark_as_advanced(PNG_LIBRARY_RELEASE PNG_LIBRARY_DEBUG) endif() unset(PNG_NAMES) unset(PNG_NAMES_DEBUG) # 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 compatibility set(PNG_LIBRARIES ${PNG_LIBRARY} ${ZLIB_LIBRARY}) if (CYGWIN) if(BUILD_SHARED_LIBS) # No need to define PNG_USE_DLL here, because it's default for Cygwin. else() set (PNG_DEFINITIONS -DPNG_STATIC) endif() endif () if(NOT TARGET PNG::PNG) add_library(PNG::PNG UNKNOWN IMPORTED) set_target_properties(PNG::PNG PROPERTIES INTERFACE_COMPILE_DEFINITIONS "${PNG_DEFINITIONS}" INTERFACE_INCLUDE_DIRECTORIES "${PNG_INCLUDE_DIRS}" INTERFACE_LINK_LIBRARIES ZLIB::ZLIB) if(EXISTS "${PNG_LIBRARY}") set_target_properties(PNG::PNG PROPERTIES IMPORTED_LINK_INTERFACE_LANGUAGES "C" IMPORTED_LOCATION "${PNG_LIBRARY}") endif() if(EXISTS "${PNG_LIBRARY_RELEASE}") set_property(TARGET PNG::PNG APPEND PROPERTY IMPORTED_CONFIGURATIONS RELEASE) set_target_properties(PNG::PNG PROPERTIES IMPORTED_LINK_INTERFACE_LANGUAGES_RELEASE "C" IMPORTED_LOCATION_RELEASE "${PNG_LIBRARY_RELEASE}") endif() if(EXISTS "${PNG_LIBRARY_DEBUG}") set_property(TARGET PNG::PNG APPEND PROPERTY IMPORTED_CONFIGURATIONS DEBUG) set_target_properties(PNG::PNG PROPERTIES IMPORTED_LINK_INTERFACE_LANGUAGES_DEBUG "C" IMPORTED_LOCATION_DEBUG "${PNG_LIBRARY_DEBUG}") endif() endif() endif () if (PNG_PNG_INCLUDE_DIR AND EXISTS "${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() 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 )