[Updatetd 8/March/2019] - Fixing #include’s to maintain existing compatibility when extending compatibility to GNU/Linux.

As one of my final year modules I picked G53GRA - Graphics. This module aims to teach the fundamental of 3D computer graphics with strong emphasis on practical work which is to be done using FreeGLUT implementation of OpenGL API. Upon getting ready to set up my working environment for the upcoming coursework, I noticed that all of the set up instructions were outlined for Windows/Visual Studio and MacOS/XCode, which weren’t particularly useful to someone running Linux/CLion combination and when attempting to open & run the solution I encountered numerous errors.

Below I outlined the solution that got this working on my machine, however couple things worth noting:

  • This is a very case-specific solution
  • I’m inexperienced with CMake, so this might not be the best solution

Solution

Step 1 - Install FreeGLUT

Ensure you have the necessary freeglut library installed on your machine. For debian based distributions, use:

sudo apt-get install freeglut3-dev

Step 2 - Import the project

Use CLion’s “Import Project from Sources” option to import the project and to auto-generate the CMake file for you.

Step 3 - Update #include’s

In Engine.h & Camera.h add

#elif __linux__
#include <GL/glut.h>

And in Texture.cpp, within #else add:

#ifdef __linux__

#include <GL/gl.h>

#include <GL/glut.h>

#else

#include <OpenGL/OpenGL.h>

#include <GLUT/glut.h>

#endif
  • In Engine.h, Camera.h & Texture.cpp change #include <GLUT/glut.h> to #include <GL/glut.h>
  • In Texture.cpp change #include <OpenGL/OpenGL.h> to #include <GL/gl.h>

Step 4 - Update CMakeLists.txt

Now, at this point I had numerous “‘undefined reference to ‘gl____’” errors, which are caused by the linker, to fix these you simply need to provide correct file paths and here is where CMake file mentioned in an earlier step comes in.

At the top of the CMake, after CMake version and project name are set add the following commands:

find_package(OpenGL REQUIRED)
find_package(GLUT REQUIRED)

These (find_package()) commands will locate and load into memory the locations of the necessary libraries. Lastly, at the very end of the CMake add the following command, don’t forget to replace <project_name> with the name of your project:

target_link_libraries(<project_name> ${OPENGL_LIBRARIES} ${GLUT_LIBRARY})