BUILD: Refactor libpng submodule (#10238)

* relocate libpng files

* fix cmake build

* fix MSVC build

3rdparty/CMakeLists.txt

@@ -29,28 +29,7 @@ add_library(3rdparty_flatbuffers INTERFACE)
 target_include_directories(3rdparty_flatbuffers INTERFACE flatbuffers/include)
 
 # libPNG
-# Select the version of libpng to use, default is builtin
-if (NOT USE_SYSTEM_LIBPNG)
-	# We use libpng's static library and don't need to build the shared library and run the tests
-	set(PNG_SHARED OFF CACHE BOOL "Build shared lib" FORCE)
-	set(PNG_TESTS OFF CACHE BOOL "Build libpng tests" FORCE)
-	set(PNG_BUILD_ZLIB ON CACHE BOOL "ZLIB is already build or package is found" FORCE)
-	set(SKIP_INSTALL_ALL ON)
-	add_subdirectory(libpng EXCLUDE_FROM_ALL)
-
-	set(LIBPNG_TARGET png_static)
-
-	target_include_directories(png_static INTERFACE "${libpng_BINARY_DIR}" "${libpng_SOURCE_DIR}")
-else()
-	find_package(PNG REQUIRED)
-
-	add_library(3rdparty_system_libpng INTERFACE)
-	target_include_directories(3rdparty_system_libpng INTERFACE ${PNG_INCLUDE_DIR})
-	target_link_libraries(3rdparty_system_libpng INTERFACE ${PNG_LIBRARY})
-	target_compile_definitions(3rdparty_system_libpng INTERFACE ${PNG_DEFINITIONS})
-
-	set(LIBPNG_TARGET 3rdparty_system_libpng)
-endif()
+add_subdirectory(libpng EXCLUDE_FROM_ALL)
 
 
 # pugixml

3rdparty/libpng/CMakeLists.txt

@@ -0,0 +1,22 @@
+# libPNG
+# Select the version of libpng to use, default is builtin
+if (NOT USE_SYSTEM_LIBPNG)
+	# We use libpng's static library and don't need to build the shared library and run the tests
+	set(PNG_SHARED OFF CACHE BOOL "Build shared lib" FORCE)
+	set(PNG_TESTS OFF CACHE BOOL "Build libpng tests" FORCE)
+	set(PNG_BUILD_ZLIB ON CACHE BOOL "ZLIB is already build or package is found" FORCE)
+	set(SKIP_INSTALL_ALL ON)
+	add_subdirectory(libpng EXCLUDE_FROM_ALL)
+	target_include_directories(png_static INTERFACE "${libpng_BINARY_DIR}" "${libpng_SOURCE_DIR}")
+
+	set(LIBPNG_TARGET png_static PARENT_SCOPE)	
+else()
+	find_package(PNG REQUIRED)
+
+	add_library(3rdparty_system_libpng INTERFACE)
+	target_include_directories(3rdparty_system_libpng INTERFACE ${PNG_INCLUDE_DIR})
+	target_link_libraries(3rdparty_system_libpng INTERFACE ${PNG_LIBRARY})
+	target_compile_definitions(3rdparty_system_libpng INTERFACE ${PNG_DEFINITIONS})
+
+	set(LIBPNG_TARGET 3rdparty_system_libpng PARENT_SCOPE)
+endif()

3rdparty/libpng/libpng.vcxproj

@@ -114,27 +114,27 @@
     </Lib>
   </ItemDefinitionGroup>
   <ItemGroup>
-    <ClCompile Include=".\libpng\png.c">
+    <ClCompile Include="libpng\png.c">
       <PrecompiledHeader Condition="'$(Configuration)|$(Platform)'=='Debug Library|x64'">Create</PrecompiledHeader>
       <PrecompiledHeader Condition="'$(Configuration)|$(Platform)'=='Release Library|x64'">Create</PrecompiledHeader>
     </ClCompile>
-    <ClCompile Include=".\libpng\pngerror.c" />
-    <ClCompile Include=".\libpng\pngget.c" />
-    <ClCompile Include=".\libpng\pngmem.c" />
-    <ClCompile Include=".\libpng\pngpread.c" />
-    <ClCompile Include=".\libpng\pngread.c" />
-    <ClCompile Include=".\libpng\pngrio.c" />
-    <ClCompile Include=".\libpng\pngrtran.c" />
-    <ClCompile Include=".\libpng\pngrutil.c" />
-    <ClCompile Include=".\libpng\pngset.c" />
-    <ClCompile Include=".\libpng\pngtrans.c" />
-    <ClCompile Include=".\libpng\pngwio.c" />
-    <ClCompile Include=".\libpng\pngwrite.c" />
-    <ClCompile Include=".\libpng\pngwtran.c" />
-    <ClCompile Include=".\libpng\pngwutil.c" />
+    <ClCompile Include="libpng\pngerror.c" />
+    <ClCompile Include="libpng\pngget.c" />
+    <ClCompile Include="libpng\pngmem.c" />
+    <ClCompile Include="libpng\pngpread.c" />
+    <ClCompile Include="libpng\pngread.c" />
+    <ClCompile Include="libpng\pngrio.c" />
+    <ClCompile Include="libpng\pngrtran.c" />
+    <ClCompile Include="libpng\pngrutil.c" />
+    <ClCompile Include="libpng\pngset.c" />
+    <ClCompile Include="libpng\pngtrans.c" />
+    <ClCompile Include="libpng\pngwio.c" />
+    <ClCompile Include="libpng\pngwrite.c" />
+    <ClCompile Include="libpng\pngwtran.c" />
+    <ClCompile Include="libpng\pngwutil.c" />
   </ItemGroup>
   <ItemGroup>
-    <ResourceCompile Include=".\libpng\scripts\pngwin.rc">
+    <ResourceCompile Include="libpng\scripts\pngwin.rc">
       <ExcludedFromBuild Condition="'$(Configuration)|$(Platform)'=='Debug Library|x64'">true</ExcludedFromBuild>
       <ExcludedFromBuild Condition="'$(Configuration)|$(Platform)'=='Release Library|x64'">true</ExcludedFromBuild>
     </ResourceCompile>