CMake: Fix Windows Overlay PNG linking issue.

[gszadkow]

• Building libpng from patched sources.
• Linking to Overlay

[paroj]

how is this needed? The Overlay component neither directly nor indirectly links against against libpng. Only the optional freeimage plugin uses libpng via freeimage.

[gszadkow]

Steps to reproduce:

git clone https://github.com/OGRECave/ogre.git
mkdir ogre-build
cd ogre-build
mkdir RelWithDebInfo
cd RelWithDebInfo
cmake -G"Visual Studio 15 2017 Win64" -DCMAKE_BUILD_TYPE:STRING="RelWithDebInfo" ../../ogre
"C:\Program Files (x86)\Microsoft Visual Studio\2017\Community\MSBuild\15.0\Bin\MSBuild.exe"  OGRE.sln //p:Configuration=RelWithDebInfo //p:Platform=x64

or:

"C:\Program Files (x86)\Microsoft Visual Studio\2017\Community\MSBuild\15.0\Bin\MSBuild.exe" Components/Overlay/OgreOverlay.sln //p:Configuration=RelWithDebInfo //p:Platform=x6

...
Output: Link: C:\Program Files (x86)\Microsoft Visual Studio\2017\Community\VC\Tools\MSVC\14.14.26428\bin\HostX86\x64\link.exe /ERRORREPORT:QUEUE /OUT:"C:\gszadkow\repositories\ogre-build\RelWithDebInfo\bin\RelWithDebInfo\OgreOverlay.dll" /INCREMENTAL /NOLOGO ..\..\lib\RelWithDebInfo\OgreMain.lib ..\..\Dependencies\lib\freetype.lib "C:\Anaconda3-x64\Library\lib\z.lib" kernel32.lib user32.lib gdi32.lib winspool.lib shell32.lib ole32.lib oleaut32.lib uuid.lib comdlg32.lib advapi32.lib /MANIFEST /MANIFESTUAC:"level='asInvoker' uiAccess='false'" /manifest:embed /DEBUG /PDB:"C:/gszadkow/repositories/ogre-build/RelWithDebInfo/bin/RelWithDebInfo/OgreOverlay.pdb" /SUBSYSTEM:CONSOLE /TLBID:1 /DYNAMICBASE /NXCOMPAT /IMPLIB:"C:/gszadkow/repositories/ogre-build/RelWithDebInfo/lib/RelWithDebInfo/OgreOverlay.lib" /MACHINE:X64 /machine:x64 /DLL OgreOverlay.dir\RelWithDebInfo\OgreBorderPanelOverlayElement.obj OgreOverlay.dir\RelWithDebInfo\OgreFont.obj OgreOverlay.dir\RelWithDebInfo\OgreFontManager.obj OgreOverlay.dir\RelWithDebInfo\OgreOverlay.obj OgreOverlay.dir\RelWithDebInfo\OgreOverlayContainer.obj OgreOverlay.dir\RelWithDebInfo\OgreOverlayElement.obj OgreOverlay.dir\RelWithDebInfo\OgreOverlayElementCommands.obj OgreOverlay.dir\RelWithDebInfo\OgreOverlayElementFactory.obj OgreOverlay.dir\RelWithDebInfo\OgreOverlayManager.obj OgreOverlay.dir\RelWithDebInfo\OgreOverlayProfileSessionListener.obj OgreOverlay.dir\RelWithDebInfo\OgreOverlaySystem.obj OgreOverlay.dir\RelWithDebInfo\OgreOverlayTranslator.obj OgreOverlay.dir\RelWithDebInfo\OgrePanelOverlayElement.obj OgreOverlay.dir\RelWithDebInfo\OgreTextAreaOverlayElement.obj Creating library C:/gszadkow/repositories/ogre-build/RelWithDebInfo/lib/RelWithDebInfo/OgreOverlay.lib and object C:/gszadkow/repositories/ogre-build/RelWithDebInfo/lib/RelWithDebInfo/OgreOverlay.exp freetype.lib(sfnt.obj) : error LNK2019: unresolved external symbol png_create_read_struct referenced in function Load_SBit_Png [C:\gszadkow\repositories\ogre-build\RelWithDebInfo\Components\Overlay\OgreOverlay.vcxproj] freetype.lib(sfnt.obj) : error LNK2019: unresolved external symbol png_set_longjmp_fn referenced in function Load_SBit_Png [C:\gszadkow\repositories\ogre-build\RelWithDebInfo\Components\Overlay\OgreOverlay.vcxproj] freetype.lib(sfnt.obj) : error LNK2019: unresolved external symbol png_create_info_struct referenced in function Load_SBit_Png [C:\gszadkow\repositories\ogre-build\RelWithDebInfo\Components\Overlay\OgreOverlay.vcxproj] freetype.lib(sfnt.obj) : error LNK2019: unresolved external symbol png_read_info referenced in function Load_SBit_Png [C:\gszadkow\repositories\ogre-build\RelWithDebInfo\Components\Overlay\OgreOverlay.vcxproj] freetype.lib(sfnt.obj) : error LNK2019: unresolved external symbol png_set_expand_gray_1_2_4_to_8 referenced in function Load_SBit_Png [C:\gszadkow\repositories\ogre-build\RelWithDebInfo\Components\Overlay\OgreOverlay.vcxproj] freetype.lib(sfnt.obj) : error LNK2019: unresolved external symbol png_set_palette_to_rgb referenced in function Load_SBit_Png [C:\gszadkow\repositories\ogre-build\RelWithDebInfo\Components\Overlay\OgreOverlay.vcxproj] freetype.lib(sfnt.obj) : error LNK2019: unresolved external symbol png_set_tRNS_to_alpha referenced in function Load_SBit_Png [C:\gszadkow\repositories\ogre-build\RelWithDebInfo\Components\Overlay\OgreOverlay.vcxproj] freetype.lib(sfnt.obj) : error LNK2019: unresolved external symbol png_set_gray_to_rgb referenced in function Load_SBit_Png [C:\gszadkow\repositories\ogre-build\RelWithDebInfo\Components\Overlay\OgreOverlay.vcxproj] freetype.lib(sfnt.obj) : error LNK2019: unresolved external symbol png_set_filler referenced in function Load_SBit_Png [C:\gszadkow\repositories\ogre-build\RelWithDebInfo\Components\Overlay\OgreOverlay.vcxproj] freetype.lib(sfnt.obj) : error LNK2019: unresolved external symbol png_set_packing referenced in function Load_SBit_Png [C:\gszadkow\repositories\ogre-build\RelWithDebInfo\Components\Overlay\OgreOverlay.vcxproj] freetype.lib(sfnt.obj) : error LNK2019: unresolved external symbol png_set_interlace_handling referenced in function Load_SBit_Png [C:\gszadkow\repositories\ogre-build\RelWithDebInfo\Components\Overlay\OgreOverlay.vcxproj] freetype.lib(sfnt.obj) : error LNK2019: unresolved external symbol png_set_strip_16 referenced in function Load_SBit_Png [C:\gszadkow\repositories\ogre-build\RelWithDebInfo\Components\Overlay\OgreOverlay.vcxproj] freetype.lib(sfnt.obj) : error LNK2019: unresolved external symbol png_read_update_info referenced in function Load_SBit_Png [C:\gszadkow\repositories\ogre-build\RelWithDebInfo\Components\Overlay\OgreOverlay.vcxproj] freetype.lib(sfnt.obj) : error LNK2019: unresolved external symbol png_read_image referenced in function Load_SBit_Png [C:\gszadkow\repositories\ogre-build\RelWithDebInfo\Components\Overlay\OgreOverlay.vcxproj] freetype.lib(sfnt.obj) : error LNK2019: unresolved external symbol png_read_end referenced in function Load_SBit_Png [C:\gszadkow\repositories\ogre-build\RelWithDebInfo\Components\Overlay\OgreOverlay.vcxproj] freetype.lib(sfnt.obj) : error LNK2019: unresolved external symbol png_destroy_read_struct referenced in function Load_SBit_Png [C:\gszadkow\repositories\ogre-build\RelWithDebInfo\Components\Overlay\OgreOverlay.vcxproj] freetype.lib(sfnt.obj) : error LNK2019: unresolved external symbol png_get_error_ptr referenced in function error_callback [C:\gszadkow\repositories\ogre-build\RelWithDebInfo\Components\Overlay\OgreOverlay.vcxproj] freetype.lib(sfnt.obj) : error LNK2019: unresolved external symbol png_set_read_fn referenced in function Load_SBit_Png [C:\gszadkow\repositories\ogre-build\RelWithDebInfo\Components\Overlay\OgreOverlay.vcxproj] freetype.lib(sfnt.obj) : error LNK2019: unresolved external symbol png_get_io_ptr referenced in function read_data_from_FT_Stream [C:\gszadkow\repositories\ogre-build\RelWithDebInfo\Components\Overlay\OgreOverlay.vcxproj] freetype.lib(sfnt.obj) : error LNK2019: unresolved external symbol png_set_read_user_transform_fn referenced in function Load_SBit_Png [C:\gszadkow\repositories\ogre-build\RelWithDebInfo\Components\Overlay\OgreOverlay.vcxproj] freetype.lib(sfnt.obj) : error LNK2019: unresolved external symbol png_error referenced in function read_data_from_FT_Stream [C:\gszadkow\repositories\ogre-build\RelWithDebInfo\Components\Overlay\OgreOverlay.vcxproj] freetype.lib(sfnt.obj) : error LNK2019: unresolved external symbol png_get_valid referenced in function Load_SBit_Png [C:\gszadkow\repositories\ogre-build\RelWithDebInfo\Components\Overlay\OgreOverlay.vcxproj] freetype.lib(sfnt.obj) : error LNK2019: unresolved external symbol png_get_IHDR referenced in function Load_SBit_Png [C:\gszadkow\repositories\ogre-build\RelWithDebInfo\Components\Overlay\OgreOverlay.vcxproj] C:\gszadkow\repositories\ogre-build\RelWithDebInfo\bin\RelWithDebInfo\OgreOverlay.dll : fatal error LNK1120: 23 unresolved externals [C:\gszadkow\repositories\ogre-build\RelWithDebInfo\Components\Overlay\OgreOverlay.vcxproj] Done Building Project "C:\gszadkow\repositories\ogre-build\RelWithDebInfo\Components\Overlay\OgreOverlay.vcxproj" (default targets) -- FAILED. Done Building Project "C:\gszadkow\repositories\ogre-build\RelWithDebInfo\Components\Overlay\OgreOverlay.vcxproj.metaproj" (default targets) -- FAILED.

You can also reproduce this from CMake GUI and MSVC, but I find CLI more convinient to reproduce/automate build.
Also, I found Forum Topic about the same issue.

Linking PNG to Overlay target as in proposed solution solved issue for me.

[paroj]

somehow freetype picks up png on your system, which it should not. Try force disabling it by adding
-DWITH_PNG=OFF to freetype.

[gszadkow]

Now it seems to build without any problems for all configurations

mkdir Debug
cd Debug
cmake -G"Visual Studio 15 2017 Win64" -DCMAKE_BUILD_TYPE:STRING="Debug" ../../ogre
"C:\Program Files (x86)\Microsoft Visual Studio\2017\Community\MSBuild\15.0\Bin\MSBuild.exe" OGRE.sln //p:Configuration=Debug //p:Platform=x64
cd ../  

mkdir Release
cd Release
cmake -G"Visual Studio 15 2017 Win64" -DCMAKE_BUILD_TYPE:STRING="Release" ../../ogre
"C:\Program Files (x86)\Microsoft Visual Studio\2017\Community\MSBuild\15.0\Bin\MSBuild.exe" OGRE.sln //p:Configuration=Release //p:Platform=x64
cd ../  

mkdir RelWithDebInfo
cd RelWithDebInfo
cmake -G"Visual Studio 15 2017 Win64" -DCMAKE_BUILD_TYPE:STRING="RelWithDebInfo" ../../ogre
"C:\Program Files (x86)\Microsoft Visual Studio\2017\Community\MSBuild\15.0\Bin\MSBuild.exe" OGRE.sln //p:Configuration=RelWithDebInfo //p:Platform=x64
cd ../  

mkdir MinSizeRel
cd MinSizeRel
cmake -G"Visual Studio 15 2017 Win64" -DCMAKE_BUILD_TYPE:STRING="MinSizeRel" ../../ogre
"C:\Program Files (x86)\Microsoft Visual Studio\2017\Community\MSBuild\15.0\Bin\MSBuild.exe" OGRE.sln //p:Configuration=MinSizeRel //p:Platform=x64
cd ../  

[paroj]

thanks 👍