2

So, I am using freeglut to try to do some openGL stuff, but I keep getting errors saying that references are undefined:

"C:\Program Files (x86)\JetBrains\CLion 2016.2.1\bin\cmake\bin\cmake.exe" --build C:\Users\Nick\.CLion2016.2\system\cmake\generated\cs455opengl-9b23e7f0\9b23e7f0\Debug --target all -- -j 4
Scanning dependencies of target cs455openGL
[ 50%] Building CXX object CMakeFiles/cs455openGL.dir/main.cpp.obj
[100%] Linking CXX executable cs455openGL.exe
CMakeFiles\cs455openGL.dir/objects.a(main.cpp.obj): In function `Z4initv':
C:/Users/Nick/ClionProjects/cs455opengl/main.cpp:12: undefined reference to `glClearColor@16'
C:/Users/Nick/ClionProjects/cs455opengl/main.cpp:13: undefined reference to `glMatrixMode@4'
C:/Users/Nick/ClionProjects/cs455opengl/main.cpp:14: undefined reference to `glLoadIdentity@0'
C:/Users/Nick/ClionProjects/cs455opengl/main.cpp:15: undefined reference to `glOrtho@48'
CMakeFiles\cs455openGL.dir/objects.a(main.cpp.obj): In function `Z7displayv':
C:/Users/Nick/ClionProjects/cs455opengl/main.cpp:20: undefined reference to `glClear@4'
C:/Users/Nick/ClionProjects/cs455opengl/main.cpp:21: undefined reference to `glColor3f@12'
C:/Users/Nick/ClionProjects/cs455opengl/main.cpp:22: undefined reference to `glVertex3f@12'
C:/Users/Nick/ClionProjects/cs455opengl/main.cpp:23: undefined reference to `glVertex3f@12'
C:/Users/Nick/ClionProjects/cs455opengl/main.cpp:24: undefined reference to `glVertex3f@12'
C:/Users/Nick/ClionProjects/cs455opengl/main.cpp:25: undefined reference to `glVertex3f@12'
C:/Users/Nick/ClionProjects/cs455opengl/main.cpp:26: undefined reference to `glEnd@0'
C:/Users/Nick/ClionProjects/cs455opengl/main.cpp:27: undefined reference to `glFlush@0'
collect2.exe: error: ld returned 1 exit status
CMakeFiles\cs455openGL.dir\build.make:95: recipe for target 'cs455openGL.exe' failed
CMakeFiles\Makefile2:66: recipe for target 'CMakeFiles/cs455openGL.dir/all' failed
mingw32-make.exe[2]: *** [cs455openGL.exe] Error 1
mingw32-make.exe[1]: *** [CMakeFiles/cs455openGL.dir/all] Error 2
mingw32-make.exe: *** [all] Error 2
Makefile:82: recipe for target 'all' failed

I am using MinGW with CLion to do this project. I thought that I got everything correctly. I moved the appropriate files into the include folder in MinGW, as well as the bin folder, and also the lib folder. Then, I have this in my CMakeLists.txt:

cmake_minimum_required(VERSION 3.3)
project(cs455openGL)
find_package(OpenGL REQUIRED)
find_package(GLUT REQUIRED)

set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -std=gnu++11")

set(SOURCE_FILES main.cpp)
add_executable(cs455openGL ${SOURCE_FILES})
link_directories(${OPENGL_gl_LIBRARY})
target_link_libraries(cs455openGL libfreeglut.a libfreeglut_static.a)

The libraries I linked were the only library files that freeglut came with. I've been scouring the internet for answers and no one seems to have run into this.

So, what am I missing? CLion doesn't show any errors before it is compiled. I can even go into the functions in the header files provided by freeglut. Why then, are these functions not defined in my program?

0

1 Answer 1

5

This is a linking error, and tells you that the linker does not find the functions defined by the OpenGL library.

You have to add ${OPENGL_LIBRARIES} to target_link_libraries.

And for glut - and any other library - you should not use the library name (libfreeglut.a) directly, but always use the variables populated by the find_package:

target_link_libraries(cs455openGL ${OPENGL_LIBRARIES} ${GLUT_LIBRARY})
Sign up to request clarification or add additional context in comments.

Comments

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Start asking to get answers

Find the answer to your question by asking.

Ask question

Explore related questions

See similar questions with these tags.