Issue
My project structure looks like this:
Two CMakeLists.txt files that deserve attention:
CMakeLists.txt
cmake_minimum_required(VERSION 3.9)
project(noam_engine)
find_package(glfw3 REQUIRED)
find_package(OpenGL REQUIRED)
find_package(GLEW REQUIRED)
set(CMAKE_CXX_STANDARD 11)
set(NE_LIBRARIES common math graphics)
FOREACH(lib ${NE_LIBRARIES})
add_subdirectory(src/${lib})
ENDFOREACH(lib)
add_executable(noam_engine src/main.cpp)
if(OPENGL_FOUND AND GLEW_FOUND)
target_include_directories(noam_engine PUBLIC include ${OPENGL_INCLUDE_DIR} ${GLEW_INCLUDE_DIRS})
target_link_libraries(noam_engine ${NE_LIBRARIES})
endif()
src/graphics/CMakeLists.txt
cmake_minimum_required(VERSION 3.9)
find_package(glfw3 REQUIRED)
find_package(OpenGL REQUIRED)
find_package(GLEW REQUIRED)
file(GLOB SRC "*.cpp")
add_library(graphics ${SRC})
if(OPENGL_FOUND AND GLEW_FOUND)
target_include_directories(graphics PUBLIC ${PROJECT_SOURCE_DIR}/include ${OPENGL_INCLUDE_DIR} ${GLEW_INCLUDE_DIRS})
target_link_libraries(graphics ${OPENGL_gl_LIBRARY} ${GLFW3_LIBRARY} ${GLEW_LIBRARIES})
message(STATUS "GLFW and GLEW successfully linked")
message(STATUS ${OPENGL_gl_LIBRARY})
message(STATUS ${GLFW3_LIBRARY})
message(STATUS ${GLEW_LIBRARIES})
else()
message(STATUS "Cannot find GL libraries")
endif()
In a few words I want to create a bunch of static libraries of the engine, in particular, link graphics
library with GL's, and finally link all of them with the executable in a root CMakeLists.txt.
But I noticed that ${GLFW3_LIBRARY} is empty and I got a linker error, for example, when I call glfwInit(). I followed the guide during building and installation of GLFW
cmake .
make
make install
I believe headers and libraries are in /usr/local/*, but apparently CMake cannot find them or maybe I did something wrong.
The only hypothesis I have is that find_package doesn't know about glfw3Config.cmake which is in deps/glfw/*
Solution
I took the script from https://github.com/JoeyDeVries/LearnOpenGL/blob/master/cmake/modules/FindGLFW3.cmake and put it into cmake folder. Then in CMakeLists.txt I added
list(APPEND CMAKE_MODULE_PATH "${PROJECT_SOURCE_DIR}/cmake")
Now everything works properly
Thanks @Tsyvarev
Answered By - Kirill Korolev Answer Checked By - Dawn Plyler (WPSolving Volunteer)