CGAL users discussion list

[Amal Dev P <>]

Hai,

While trying to integrate OpenGL and GLUT with "terrain.cpp" of examples folder in CGAL 4.6 using Mac (Yosemite) and Xcode 6.3, I am getting the following errors initially:

​-------------------------------------------------------​

​​

Linking CXX executable terrain

Undefined symbols for architecture x86_64:

  "_glBegin", referenced from:

      drawFilledCircle(float, float, float) in terrain.cpp.o

      pointset() in terrain.cpp.o

  "_glClear", referenced from:

      display() in terrain.cpp.o

  "_glClearColor", referenced from:

      _main in terrain.cpp.o

  "_glColor3f", referenced from:

      pointset() in terrain.cpp.o

      _main in terrain.cpp.o

  "_glEnd", referenced from:

      drawFilledCircle(float, float, float) in terrain.cpp.o

      pointset() in terrain.cpp.o

  "_glFlush", referenced from:

      display() in terrain.cpp.o

  "_glLineWidth", referenced from:

      pointset() in terrain.cpp.o

      _main in terrain.cpp.o

  "_glLoadIdentity", referenced from:

      reshape(int, int) in terrain.cpp.o

  "_glMatrixMode", referenced from:

      reshape(int, int) in terrain.cpp.o

  "_glOrtho", referenced from:

      reshape(int, int) in terrain.cpp.o

  "_glPointSize", referenced from:

      pointset() in terrain.cpp.o

  "_glVertex2f", referenced from:

      drawFilledCircle(float, float, float) in terrain.cpp.o

      pointset() in terrain.cpp.o

  "_glViewport", referenced from:

      reshape(int, int) in terrain.cpp.o

  "_glutCreateWindow", referenced from:

      _main in terrain.cpp.o

  "_glutDestroyWindow", referenced from:

      kbd(unsigned char, int, int) in terrain.cpp.o

  "_glutDisplayFunc", referenced from:

      _main in terrain.cpp.o

  "_glutInit", referenced from:

      _main in terrain.cpp.o

  "_glutInitDisplayMode", referenced from:

      _main in terrain.cpp.o

  "_glutInitWindowSize", referenced from:

      _main in terrain.cpp.o

  "_glutKeyboardFunc", referenced from:

      _main in terrain.cpp.o

  "_glutMainLoop", referenced from:

      _main in terrain.cpp.o

  "_glutReshapeFunc", referenced from:

      _main in terrain.cpp.o

ld: symbol(s) not found for architecture x86_64

clang: error: linker command failed with exit code 1 (use -v to see invocation)

make[2]: *** [terrain] Error 1

make[1]: *** [CMakeFiles/terrain.dir/all] Error 2

make: *** [all] Error 2

​----------------------------------------------------------

Later I found out we have to link OpenGL as well as GLUT with the program​. For that I added the following lines in CMakeLists.txt:

-----------------------------------------------------------

find_package(OpenGL REQUIRED)

include_directories(${OPENGL_INCLUDE_DIR})

add_executable(Triangulation_2_example terrain.cpp)

target_link_libraries(Triangulation_2_example ${

​OPENGL

_LIBRARY}) 

​-------------------------------------------------------------

Which reduced the errors as follows: 

-----------------------------------------------------------

Linking CXX executable Triangulation_2_example

Undefined symbols for architecture x86_64:

  "_glutCreateWindow", referenced from:

      _main in terrain.cpp.o

  "_glutDestroyWindow", referenced from:

      kbd(unsigned char, int, int) in terrain.cpp.o

  "_glutDisplayFunc", referenced from:

      _main in terrain.cpp.o

  "_glutInit", referenced from:

      _main in terrain.cpp.o

  "_glutInitDisplayMode", referenced from:

      _main in terrain.cpp.o

  "_glutInitWindowSize", referenced from:

      _main in terrain.cpp.o

  "_glutKeyboardFunc", referenced from:

      _main in terrain.cpp.o

  "_glutMainLoop", referenced from:

      _main in terrain.cpp.o

  "_glutReshapeFunc", referenced from:

      _main in terrain.cpp.o

ld: symbol(s) not found for architecture x86_64

clang: error: linker command failed with exit code 1 (use -v to see invocation)

make[2]: *** [Triangulation_2_example] Error 1

make[1]: *** [CMakeFiles/Triangulation_2_example.dir/all] Error 2

make: *** [all] Error 2

-----------------------------------------------------------

​Whereas adding only the following lines in CMakeLists.txt:

-----------------------------------------------------------

find_package(GLUT REQUIRED)

include_directories(${GLUT_INCLUDE_DIR})

add_executable(Triangulation_2_example terrain.cpp)

target_link_libraries(Triangulation_2_example ${GLUT_LIBRARY}) 

-----------------------------------------------------------

results in the errors as follows:

-----------------------------------------------------------

Linking CXX executable Triangulation_2_example

Undefined symbols for architecture x86_64:

  "_glBegin", referenced from:

      drawFilledCircle(float, float, float) in terrain.cpp.o

      pointset() in terrain.cpp.o

  "_glClear", referenced from:

      display() in terrain.cpp.o

  "_glClearColor", referenced from:

      _main in terrain.cpp.o

  "_glColor3f", referenced from:

      pointset() in terrain.cpp.o

      _main in terrain.cpp.o

  "_glEnd", referenced from:

      drawFilledCircle(float, float, float) in terrain.cpp.o

      pointset() in terrain.cpp.o

  "_glFlush", referenced from:

      display() in terrain.cpp.o

  "_glLineWidth", referenced from:

      pointset() in terrain.cpp.o

      _main in terrain.cpp.o

  "_glLoadIdentity", referenced from:

      reshape(int, int) in terrain.cpp.o

  "_glMatrixMode", referenced from:

      reshape(int, int) in terrain.cpp.o

  "_glOrtho", referenced from:

      reshape(int, int) in terrain.cpp.o

  "_glPointSize", referenced from:

      pointset() in terrain.cpp.o

  "_glVertex2f", referenced from:

      drawFilledCircle(float, float, float) in terrain.cpp.o

      pointset() in terrain.cpp.o

  "_glViewport", referenced from:

      reshape(int, int) in terrain.cpp.o

ld: symbol(s) not found for architecture x86_64

clang: error: linker command failed with exit code 1 (use -v to see invocation)

make[2]: *** [Triangulation_2_example] Error 1

make[1]: *** [CMakeFiles/Triangulation_2_example.dir/all] Error 2

make: *** [all] Error 2

-----------------------------------------------------------

So I understood that we have to link both OpenGL as well as GLUT and I added the following commands in CMakeLists.txt:

-----------------------------------------------------------

find_package(OpenGL REQUIRED)

include_directories(${OPENGL_INCLUDE_DIR})

find_package(GLUT REQUIRED)

include_directories(${GLUT_INCLUDE_DIR})

set(CMAKE_CXX_FLAGS "-g -Wall")

add_executable(Triangulation_2_example terrain.cpp)

target_link_libraries(Triangulation_2_example ${GLUT_LIBRARY} ${OPENGL_LIBRARY})

-----------------------------------------------------------

And this is giving me the initial error again (the one without linking OpenGL as well as GLUT).

Any help is appreciated.

Thanks in advance

--

Warm Regards

       Amal Dev P.,

       PhD Scholar,

       Advanced Geometric Computing Lab,

       Department of Engineering Design,

       IIT Madras, India - 600 036