I'm fairly new to C++ / CMake, but I'd like to create a project with FLTK using CMAKE and CONAN as package manager. I'm using Windows 11, but trying to get it to run under WSL (Ubuntu 20.04). My WSL-version supports GUI applications.
When I install everything without Conan and compile the official "fltk-hello-world" from the command line using fltk-config, everything works okay. However, when I try to set it up using Conan und Cmake I get following errors:
/usr/bin/ld: /home/bfl/.conan/data/fltk/1.3.8/_/_/package/b6898709771003e31b8ea824ee836cf119580bd8/lib/libfltk.a(fl_font.cxx.o): in function `Fl_Font_Descriptor::Fl_Font_Descriptor(char const*, int, int)':
fl_font.cxx:(.text+0x232): undefined reference to `XftFontOpenXlfd'
/usr/bin/ld: fl_font.cxx:(.text+0x47e): undefined reference to `XftFontMatch'
/usr/bin/ld: fl_font.cxx:(.text+0x48f): undefined reference to `XftFontOpenPattern'
/usr/bin/ld: fl_font.cxx:(.text+0x4e1): undefined reference to `XftFontOpen'
/usr/bin/ld: /home/bfl/.conan/data/fltk/1.3.8/_/_/package/b6898709771003e31b8ea824ee836cf119580bd8/lib/libfltk.a(fl_font.cxx.o): in function `Fl_Xlib_Graphics_Driver::width(char const*, int)':
fl_font.cxx:(.text+0x954): undefined reference to `XftTextExtents32'
/usr/bin/ld: /home/bfl/.conan/data/fltk/1.3.8/_/_/package/b6898709771003e31b8ea824ee836cf119580bd8/lib/libfltk.a(fl_font.cxx.o): in function `Fl_Xlib_Graphics_Driver::width(unsigned int)':
fl_font.cxx:(.text+0xa5e): undefined reference to `XftTextExtents32'
/usr/bin/ld: /home/bfl/.conan/data/fltk/1.3.8/_/_/package/b6898709771003e31b8ea824ee836cf119580bd8/lib/libfltk.a(fl_font.cxx.o): in function `Fl_Xlib_Graphics_Driver::text_extents(char const*, int, int&, int&, int&, int&)':
fl_font.cxx:(.text+0xb07): undefined reference to `XftTextExtents32'
/usr/bin/ld: /home/bfl/.conan/data/fltk/1.3.8/_/_/package/b6898709771003e31b8ea824ee836cf119580bd8/lib/libfltk.a(fl_font.cxx.o): in function `Fl_Xlib_Graphics_Driver::draw(char const*, int, int, int)':
fl_font.cxx:(.text+0x1140): undefined reference to `XftDrawChange'
/usr/bin/ld: fl_font.cxx:(.text+0x1176): undefined reference to `XftDrawSetClip'
/usr/bin/ld: fl_font.cxx:(.text+0x1209): undefined reference to `XftDrawString32'
/usr/bin/ld: fl_font.cxx:(.text+0x12d9): undefined reference to `XftDrawCreate'
/usr/bin/ld: /home/bfl/.conan/data/fltk/1.3.8/_/_/package/b6898709771003e31b8ea824ee836cf119580bd8/lib/libfltk.a(fl_font.cxx.o): in function `Fl_Xlib_Graphics_Driver::rtl_draw(char const*, int, int, int)':
fl_font.cxx:(.text+0x149b): undefined reference to `XftTextExtents32'
/usr/bin/ld: fl_font.cxx:(.text+0x14cc): undefined reference to `XftDrawChange'
/usr/bin/ld: fl_font.cxx:(.text+0x1502): undefined reference to `XftDrawSetClip'
/usr/bin/ld: fl_font.cxx:(.text+0x1595): undefined reference to `XftDrawString32'
/usr/bin/ld: fl_font.cxx:(.text+0x15f9): undefined reference to `XftDrawCreate'
/usr/bin/ld: /home/bfl/.conan/data/fltk/1.3.8/_/_/package/b6898709771003e31b8ea824ee836cf119580bd8/lib/libfltk.a(fl_font.cxx.o): in function `fl_destroy_xft_draw(unsigned long)':
fl_font.cxx:(.text+0x10d9): undefined reference to `XftDrawChange'
collect2: error: ld returned 1 exit status
make[2]: *** [CMakeFiles/hello.dir/build.make:84: bin/hello] Error 1
make[1]: *** [CMakeFiles/Makefile2:76: CMakeFiles/hello.dir/all] Error 2
make: *** [Makefile:84: all] Error 2
So I assume that i am probably not linking XFT? But I am not sure how to do that, do I need to include the correct name in target-link-libraries? My Cmake-File looks like this:
cmake_minimum_required(VERSION 3.2.3)
project(Hello VERSION 0.1.0)
set(EXECUTABLE_NAME hello)
set(EXE_SOURCES hello.cc)
include(${CMAKE_BINARY_DIR}/conanbuildinfo.cmake)
conan_basic_setup()
add_executable(${EXECUTABLE_NAME} ${EXE_SOURCES})
target_include_directories(hello PUBLIC ${FLTK_INCLUDE_DIRS})
target_link_libraries(hello
${CONAN_LIBS})
I'm grateful for any suggestion.
Thanks,
GB
The conan recipe for fltk does not correctly deal with the cmake system of fltk.
Fltk auto-detects if the system it compiles on has Xft. If it does, then it enables the HAS_XFT variable and compiles some code into the library that uses it.
Conan does not pick up on this and doesn't add Xft to the dependent libraries.
The easiest way around this bug is to manually add the xft dependency.
If you have libXft installed on your system you can simply add an entry of Xft to the target_link_libraries of the target that uses fltk.
Like this:
target_link_libraries(hello ${CONAN_LIBS} Xft)