c++ undefined reference errors when trying to compile opengl project

Question

I tried to compile my c++/opengl-project with the g++ command. (I need this since I want to recompile it on every target system with a second self-written program.)

But when I execute:

g++ -Iinclude -Isrc $(pkg-config --cflags freetype2) -L/usr/X11R6/lib -L/usr/lib $(pkg-config --libs glew) -lglut $(pkg-config --libs glu) $(pkg-config --libs freetype2) main.cpp  (some more source files) src/Vec4.cpp

I get lots of 'undefined references' for gl/glu/glut/glew-functions, so I guess something fails with the libs:

/tmp/ccUm2dEl.o: In function `Box::render()':
Box.cpp:(.text+0x6e8): undefined reference to `glEnable'
Box.cpp:(.text+0x72c): undefined reference to `glBindTexture'
Box.cpp:(.text+0x736): undefined reference to `glBegin'
...
TextureManager.cpp:(.text+0x23b): undefined reference to `glTexParameteri'
TextureManager.cpp:(.text+0x295): undefined reference to `glTexImage2D'
collect2: ld gab 1 als Ende-Status zurück

I did some research, but according to what I found out the above command should be correct. I checked the pkg-config-calls as well and they seem to work. Before I tried the g++ command I used the Codeblocks IDE to compile it and it worked. Here are my settings:

In Compiler settings|Other options:

`pkg-config --cflags freetype2`

In Linker settings|Link libraries:

glut

In Linker settings|Other linker options:

`pkg-config --libs glu`
`pkg-config --libs glew`
`pkg-config --libs freetype2`

In Search directories|Compiler:

include
src

My system (Ubuntu Precise):

$ uname -a
Linux andromeda 3.2.0-32-generic #51-Ubuntu SMP Wed Sep 26 21:33:09 UTC 2012 x86_64 x86_64 x86_64 GNU/Linux

$ g++ -dumpversion
4.6

glxinfo
GLX version: 1.4
OpenGL version string: 4.2.0 NVIDIA 304.43

Codeblocks-version: 10.04

Thanks in advice

Put your files (.cpp and .o) before the libraries you link to on the command line. — Mat
– Mat, Commented Nov 3, 2012 at 15:35
I don't see libGL being added. Try adding -lGL after the X11 libraries. — datenwolf
– datenwolf, Commented Nov 3, 2012 at 17:38

Some programmer dude · Accepted Answer · 2012-11-03 15:36:22Z

1

The problem is most likely that you link in the wrong order. The GNU linker wants its libraries in kind of reverse order, so if you place the linker libraries last on the command line it should go better.

answered Nov 3, 2012 at 15:36

Some programmer dude

411k36 gold badges420 silver badges655 bronze badges

Sign up to request clarification or add additional context in comments.

2 Comments

Kos Over a year ago

+1 If object or library A requires B, then A needs to before B in the command line. This holds for .o files and libs linked with -l.

freecraft Over a year ago

library A requires B I already paid attention to that, but thanks. I put the libs to the end and it worked! Thanks, you saved my day. I never got an answer that fast on any other forum before, seems like stackoverflow is much more useful than I thought.

Collectives™ on Stack Overflow

c++ undefined reference errors when trying to compile opengl project

1 Answer 1

2 Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

2 Comments

Your Answer

Sign up or log in

Post as a guest

Related