Cgal 5.2.1

[srsouza]

Hi! I am using Ubuntu 20.04 LTS and I am trying to get CGAL-5.2.1 running. I followed the instructions on:

https://doc.cgal.org/latest/Manual/installation.html

cd $HOME/CGAL-5.2.1
mkdir build
cd build
cmake -DCGAL_HEADER_ONLY=OFF -DCMAKE_BUILD_TYPE=Release .. # configure CGAL
make # build CGAL
make install # install CGAL
cd examples/Triangulation_2 # go to an example directory
cmake -DCGAL_DIR=$CMAKE_INSTALLED_PREFIX/lib/CGAL -DCMAKE_BUILD_TYPE=Release . # configure the examples
make # build the examples

Everything is fine but when I run draw_Triangulation_2, I get the following error message:

Impossible to draw, CGAL_USE_BASIC_VIEWER is not defined.



Then, I follow the instructions on this thread

https://stackoverflow.com/questions/53150670/impossible-to-draw-because-cgal-use-basic-viewer-is-not-defined

and put the line

#CGAL_USE_BASIC_VIEWER

at the top of the file, run the Makefile again and receive the following error messages:

[ 84%] Building CXX object CMakeFiles/draw_triangulation_2.dir/draw_triangulation_2.cpp.o
In file included from /usr/local/include/CGAL/draw_triangulation_2.h:16,
from /home/srsouza/Dropbox/Valmir/Progs/Gastrulation/CGAL-5.2.1/examples/Triangulation_2/draw_triangulation_2.cpp:5:
/usr/local/include/CGAL/Qt/Basic_viewer_qt.h:30:10: fatal error: QApplication: No such file or directory
30 | #include <QApplication>
| ^~~~~~~~~~~~~~
compilation terminated.
make[2]: *** [CMakeFiles/draw_triangulation_2.dir/build.make:63: CMakeFiles/draw_triangulation_2.dir/draw_triangulation_2.cpp.o] Error 1
make[1]: *** [CMakeFiles/Makefile2:689: CMakeFiles/draw_triangulation_2.dir/all] Error 2
make: *** [Makefile:84: all] Error 2



Could anyone help me? Thanks!

[norobro]

Try adding "-DCGAL_USE_BASIC_VIEWER" to your cmake line for the triangulation_2 example:
cmake -DCGAL_DIR=$CMAKE_INSTALLED_PREFIX/lib/CGAL -DCMAKE_BUILD_TYPE=Release -DCGAL_USE_BASIC_VIEWER .Works fine on 21.04 which has CGAL-5.2.1 in the repros. If you need 5.2.1 you might consider upgrading. https://packages.ubuntu.com/hirsute/libcgal-dev
~/Downloads/cgal/examples/Triangulation_2/build$ ldd draw_triangulation_2 | grep Qt
libQt5OpenGL.so.5 => /lib/x86_64-linux-gnu/libQt5OpenGL.so.5 (0x00007ff5fcfd3000)
libQt5Svg.so.5 => /lib/x86_64-linux-gnu/libQt5Svg.so.5 (0x00007ff5fcf76000)
libQt5Widgets.so.5 => /lib/x86_64-linux-gnu/libQt5Widgets.so.5 (0x00007ff5fc8d6000)
libQt5Gui.so.5 => /lib/x86_64-linux-gnu/libQt5Gui.so.5 (0x00007ff5fc206000)
libQt5Xml.so.5 => /lib/x86_64-linux-gnu/libQt5Xml.so.5 (0x00007ff5fc1c1000)
libQt5Core.so.5 => /lib/x86_64-linux-gnu/libQt5Core.so.5 (0x00007ff5fbc67000)

[srsouza]

Thanks for the reply with the detailed instructions. However, it did not work for me. I still have the same error message and when I run ldd I get:


linux-vdso.so.1 (0x00007ffd73bb9000)
libCGAL.so.13 => /usr/local/lib/libCGAL.so.13 (0x00007f8db0f84000)
libgmp.so.10 => /lib/x86_64-linux-gnu/libgmp.so.10 (0x00007f8db0eed000)
libstdc++.so.6 => /lib/x86_64-linux-gnu/libstdc++.so.6 (0x00007f8db0d0c000)
libgcc_s.so.1 => /lib/x86_64-linux-gnu/libgcc_s.so.1 (0x00007f8db0cf1000)
libc.so.6 => /lib/x86_64-linux-gnu/libc.so.6 (0x00007f8db0aff000)
/lib64/ld-linux-x86-64.so.2 (0x00007f8db0fac000)
libm.so.6 => /lib/x86_64-linux-gnu/libm.so.6 (0x00007f8db09b0000)


It seems that Qt5 is not installed, but I checked that they are indeed. Any further suggestions?

[norobro]

/usr/local/include/CGAL/Qt/Basic_viewer_qt.h:30:10: fatal error: QApplication: No such file or directory
30 | #include <QApplication>
| ^~~~~~~~~~~~~~
compilation terminated.
The above indicates that the compiler can't locate the Qt5 header files.

Do you have qtbase5-dev installed? https://packages.ubuntu.com/focal/qtbase5-dev

[monkeybrain20122]

cgal has a lot of options, instead using cmake to confiigure, use the cmake gui, inside the build directory


ccmake ..


then you can see all the options and toggle to activate them. This way you get more legible feedback.

[srsouza]

Thanks for the reply. I finally got it working, although through a noncanonical path...

I installed:

1) debian10.9,
2) anaconda3 (open source)
https://www.anaconda.com
3) The libraries: libqt5opengl5-dev libgmp-dev libmpfr-dev libboost-dev libeigen3-dev libqt5opengl5-dev

and it finally worked!

Thank you all for the help.