# Distributed under the OSI-approved BSD 3-Clause License. See accompanying # file LICENSE.rst or https://cmake.org/licensing for details. #[=======================================================================[.rst: FindPNG ------- Finds libpng, the official reference library for the PNG image format. .. note:: The PNG library depends on the ZLib compression library, which must be found for this module to succeed. Imported Targets ^^^^^^^^^^^^^^^^ .. versionadded:: 3.5 This module defines the following :ref:`Imported Targets`: ``PNG::PNG`` The libpng library, if found. Result Variables ^^^^^^^^^^^^^^^^ This module sets the following variables: ``PNG_INCLUDE_DIRS`` Directory containing the PNG headers (e.g., ``png.h``). ``PNG_LIBRARIES`` PNG libraries required for linking. ``PNG_DEFINITIONS`` Compile definitions for using PNG, if any. They can be added with :command:`target_compile_definitions` command when not using the ``PNG::PNG`` imported target. ``PNG_FOUND`` True if PNG library is found. ``PNG_VERSION_STRING`` .. versionadded:: 2.8.8 The version of the PNG library found. Obsolete Variables ^^^^^^^^^^^^^^^^^^ The following variables may also be set for backward compatibility: ``PNG_LIBRARY`` Path to the PNG library. ``PNG_INCLUDE_DIR`` Directory containing the PNG headers (same as ``PNG_INCLUDE_DIRS``). Examples ^^^^^^^^ Finding PNG library and using it in a project: .. code-block:: cmake find_package(PNG) target_link_libraries(project_target PRIVATE PNG::PNG) #]=======================================================================] cmake_policy(PUSH) cmake_policy(SET CMP0159 NEW) # file(STRINGS) with REGEX updates CMAKE_MATCH_ # Default install location on windows when installing from included cmake build # From FindZLIB.cmake set(_PNG_x86 "(x86)") set(_PNG_INCLUDE_SEARCH_NORMAL "$ENV{ProgramFiles}/libpng" "$ENV{ProgramFiles${_PNG_x86}}/libpng") set(_PNG_LIB_SEARCH_NORMAL "$ENV{ProgramFiles}/libpng/lib" "$ENV{ProgramFiles${_PNG_x86}}/libpng/lib") unset(_PNG_x86) if(PNG_FIND_QUIETLY) set(_FIND_ZLIB_ARG QUIET) endif() find_package(ZLIB ${_FIND_ZLIB_ARG}) if(ZLIB_FOUND) set(_PNG_VERSION_SUFFIXES 17 16 15 14 12) list(APPEND _PNG_INCLUDE_PATH_SUFFIXES include/libpng) foreach(v IN LISTS _PNG_VERSION_SUFFIXES) list(APPEND _PNG_INCLUDE_PATH_SUFFIXES include/libpng${v}) endforeach() find_path(PNG_PNG_INCLUDE_DIR png.h PATH_SUFFIXES ${_PNG_INCLUDE_PATH_SUFFIXES} PATHS ${_PNG_INCLUDE_SEARCH_NORMAL} ) mark_as_advanced(PNG_PNG_INCLUDE_DIR) list(APPEND PNG_NAMES png libpng) unset(PNG_NAMES_DEBUG) if (PNG_FIND_VERSION MATCHES "^([0-9]+)\\.([0-9]+)(\\..*)?$") 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} libpng${v}_static) list(APPEND PNG_NAMES_DEBUG png${v}d libpng${v}d libpng${v}_staticd) 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} NAMES_PER_DIR PATHS ${_PNG_LIB_SEARCH_NORMAL}) find_library(PNG_LIBRARY_DEBUG NAMES ${PNG_NAMES_DEBUG} NAMES_PER_DIR PATHS ${_PNG_LIB_SEARCH_NORMAL}) include(${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) unset(_PNG_INCLUDE_PATH_SUFFIXES) # 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} ${ZLIB_LIBRARY}) if((CMAKE_SYSTEM_NAME STREQUAL "Linux") AND ("${PNG_LIBRARY}" MATCHES "\\${CMAKE_STATIC_LIBRARY_SUFFIX}$")) list(APPEND PNG_LIBRARIES m) endif() if (CYGWIN) if(BUILD_SHARED_LIBS) # No need to define PNG_USE_DLL here, because it's default for Cygwin. else() set (PNG_DEFINITIONS -DPNG_STATIC) set(_PNG_COMPILE_DEFINITIONS PNG_STATIC) endif() endif () if(NOT TARGET PNG::PNG) add_library(PNG::PNG UNKNOWN IMPORTED) set_target_properties(PNG::PNG PROPERTIES INTERFACE_COMPILE_DEFINITIONS "${_PNG_COMPILE_DEFINITIONS}" INTERFACE_INCLUDE_DIRECTORIES "${PNG_INCLUDE_DIRS}" INTERFACE_LINK_LIBRARIES ZLIB::ZLIB) if((CMAKE_SYSTEM_NAME STREQUAL "Linux") AND ("${PNG_LIBRARY}" MATCHES "\\${CMAKE_STATIC_LIBRARY_SUFFIX}$")) set_property(TARGET PNG::PNG APPEND PROPERTY INTERFACE_LINK_LIBRARIES m) endif() if(EXISTS "${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 "${PNG_LIBRARY_DEBUG}") endif() endif() unset(_PNG_COMPILE_DEFINITIONS) endif () if (PNG_PNG_INCLUDE_DIR AND EXISTS "${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(FindPackageHandleStandardArgs) find_package_handle_standard_args(PNG REQUIRED_VARS PNG_LIBRARY PNG_PNG_INCLUDE_DIR VERSION_VAR PNG_VERSION_STRING) cmake_policy(POP)