As the titles says I can\'t seem to build the project with OpenGL and Glut.
I get Undefined reference errors for OpenGL functions.
I tried doing :
In recent versions of CMake (3.10+) there is a new way to use OpenGL using a so-called IMPORTED target:
cmake_minimum_required(VERSION 3.10)
project(testas)
add_executable(testas main.cpp)
find_package(OpenGL REQUIRED COMPONENTS OpenGL)
find_package(GLUT REQUIRED)
add_dependencies(testas OpenGL::OpenGL)
include_directories(${GLUT_INCLUDE_DIRS} )
target_link_libraries(testas OpenGL::OpenGL ${GLUT_LIBRARY} )
At the moment the only practical difference seems to be on Linux (where GLVND is used if available), but presumably this solution should be more future-proof, as CMake has more information about your intentions and other tools parsing your CMakeFiles will better understand the dependency tree.
I use these two cmake files to build my OpenGL projects, and they all work well.
First, the main CMakeLists.txt
cmake_minimum_required(VERSION 3.1.0)
project(project_name)
set(CMAKE_MODULE_PATH ${CMAKE_MODULE_PATH} "${CMAKE_CURRENT_SOURCE_DIR}/CMakeModules/")
find_package(OpenGL REQUIRED)
find_package(FREEGLUT REQUIRED)
find_package(GLEW REQUIRED)
if(NOT ${OPENGL_FOUND})
message("OPENGL not found")
endif()
include_directories(
${PROJECT_SOURCE_DIR}
${FREEGLUT_INCLUDE_DIR}
${GLEW_INCLUDE_DIR}
${OPENGL_INCLUDE_DIR}
)
message(${OPENGL_INCLUDE_DIR})
add_executable(${PROJECT_NAME} ${PROJECT_SOURCE_DIR}/filename.cpp)
target_link_libraries(${PROJECT_NAME}
${OPENGL_LIBRARY}
${FREEGLUT_LIBRARY}
${GLEW_LIBRARY}
)
Second, the find GLUT cmake file under CMakeModules directory
# Try to find the FREEGLUT library
#
# FREEGLUT_INCLUDE_DIR
# FREEGLUT_LIBRARY
# FREEGLUT_FOUND
FIND_PATH(
FREEGLUT_INCLUDE_DIR GL/freeglut.h GL/gl.h GL/glu.h GL/glew.h
${CMAKE_INCLUDE_PATH}
$ENV{include}
${OPENGL_INCLUDE_DIR}
/usr/include
/usr/local/include
)
SET(STORE_CMAKE_FIND_FRAMEWORK ${CMAKE_FIND_FRAMEWORK})
SET(CMAKE_FIND_FRAMEWORK NEVER)
FIND_LIBRARY(
FREEGLUT_LIBRARY
NAMES freeglut_static freeglut glut GL
PATH
/opt/local/lib
${CMAKE_LIBRARY_PATH}
$ENV{lib}
/usr/lib
/usr/local/lib
)
SET(CMAKE_FIND_FRAMEWORK ${STORE_CMAKE_FIND_FRAMEWORK})
IF (FREEGLUT_INCLUDE_DIR AND FREEGLUT_LIBRARY)
SET(FREEGLUT_FOUND TRUE)
ENDIF (FREEGLUT_INCLUDE_DIR AND FREEGLUT_LIBRARY)
IF (FREEGLUT_FOUND)
IF (NOT FREEGLUT_FIND_QUIETLY)
MESSAGE(STATUS "Found FREEGLUT: ${FREEGLUT_LIBRARY}")
ENDIF (NOT FREEGLUT_FIND_QUIETLY)
ELSE (FREEGLUT_FOUND)
IF (FREEGLUT_FIND_REQUIRED)
MESSAGE(FATAL_ERROR "Could not find FREEGLUT")
ENDIF (FREEGLUT_FIND_REQUIRED)
ENDIF (FREEGLUT_FOUND)
find_package(OpenGL)
will find the package for you, but it doesn't link the package to the target.
To link to a library, you can use target_link_libraries(<target> <item>)
. In addition, you also need to set the include directory
, so that the linker knows where to look for things. This is done with the include_directories
.
An example CMakeLists.txt
which would do this looks something like this:
cmake_minimum_required(VERSION 2.8)
project(testas)
add_executable(testas main.cpp)
find_package(OpenGL REQUIRED)
find_package(GLUT REQUIRED)
include_directories( ${OPENGL_INCLUDE_DIRS} ${GLUT_INCLUDE_DIRS} )
target_link_libraries(testas ${OPENGL_LIBRARIES} ${GLUT_LIBRARY} )
If OpenGL
is a necessity for your project, you might consider either testing OpenGL_FOUND
after the find_package(OpenGL)
or using REQUIRED
, which will stop cmake
if OpenGL
is not found.
For more information and better examples:
In particular, the CMake wiki
and cmake and opengl
links should give you enough to get things working.