| #This script just runs CMake's built in PNG finding tool. But it also checks that the | |
| #copy of libpng that cmake finds actually builds and links. | |
| cmake_minimum_required(VERSION 2.8.12) | |
| if (BUILDING_PYTHON_IN_MSVC) | |
| # Never use any system copy of libpng when building python in visual studio | |
| set(PNG_FOUND 0) | |
| return() | |
| endif() | |
| # Don't rerun this script if its already been executed. | |
| if (DEFINED PNG_FOUND) | |
| return() | |
| endif() | |
| find_package(PNG QUIET) | |
| if(PNG_FOUND) | |
| set(PNG_TEST_CMAKE_FLAGS | |
| "-DCMAKE_PREFIX_PATH=${CMAKE_PREFIX_PATH}" | |
| "-DCMAKE_INCLUDE_PATH=${CMAKE_INCLUDE_PATH}" | |
| "-DCMAKE_LIBRARY_PATH=${CMAKE_LIBRARY_PATH}") | |
| try_compile(test_for_libpng_worked | |
| ${PROJECT_BINARY_DIR}/test_for_libpng_build | |
| ${CMAKE_CURRENT_LIST_DIR}/test_for_libpng | |
| test_if_libpng_is_broken | |
| CMAKE_FLAGS "${PNG_TEST_CMAKE_FLAGS}") | |
| message (STATUS "Found system copy of libpng: ${PNG_LIBRARIES}") | |
| if(NOT test_for_libpng_worked) | |
| set(PNG_FOUND 0) | |
| message (STATUS "System copy of libpng is broken. Will build our own libpng and use that instead.") | |
| endif() | |
| endif() | |