How to improve my script and copy program resources on build? - c++

Question

So I got into a problem where I needed to use linux for a while instead of windows, and figured linux doesn't have Visual Studio. I then also realized that I made my project Visual Studio only, which I don't want.
So I looked up some CMake tutorials and try'ed creating some examples that could be loaded in both Visual Studio and CodeBlocks. When I got that to work, I went and code a CMake script for my actual program by piecing together what I learned and what I found in tutorials.
See here:
cmake_minimum_required(VERSION 2.8.9)
add_subdirectory(libraries/glfw)
project (OpenGLEngine3D)
include_directories(libraries/glfw/include)
include_directories(libraries/glm)
include_directories(libraries/glad/include)
include_directories(libraries/whereami/src)
include_directories(libraries/stb)
file(GLOB SOURCES "src/*.cpp" "src/*.h" "libraries/whereami/src/whereami.c" "libraries/glad/src/glad.c")
add_executable(OpenGLEngine3D ${SOURCES})
target_link_libraries(OpenGLEngine3D glfw)
Its dirty(I think) but it works.
So now my first question is, how to improve my CMake script? What is redundant or done in a poor way?
Now my program also requires some resources(like shaders, textures) which I have stored in a directory along with my CMake script, libraries and c++ files.
So my second question is, how would I tell CMake to the ide/compiler to copy the files in a certain directory to the program build directory(where the compiled binaries are) after compiling?(And have it only do it when the files aren't there ofc.)
Thanks!

Answer 1

I recently came across this article, which might be help you with CMake.
Here are a couple suggestions from me:
You're safe to use newer version of CMake. Currently, it's 3.11. There's no point in sticking to old versions.
Consider listing all your sources in a variable (using set command) instead of using file(GLOB). file(GLOB) will be evaluated only once, when generating build files. If you add new sources, you'll have to re-generate it manually, so it doesn't help too much, and is harder to debug (and really, debugging more complex CMake projects can be painful).
Avoid using include_directories (and link_libraries). Prefer using target_include_directories which works per-target. It allows to express dependencies between targets (when you have more than one - which might happen as your project grows)
You might consider using find_package(GLFW), instead of including GLFW in your project. Edit: actually, CMake doesn't came with find module for GLFW, but you can use an external module for this (e. g. this one) as described here.
Edit:
Example below illustrates the idea behind point 2), assuming that sources are placed in "src/" directory on the same level as CMakeLists.txt file:
set(engine_sources
"src/header_1.hpp"
"src/source_1.cpp"
# and so on for reset of files...
)
add_executable(OpenGLEngine3D ${engine_sources})
As for the second question: that's what file(COPY) command is for. Alternatively, you could just leave assets in source directory, and set working directory in IDE.
Side note: if you choose the second options, there appears to be a way to set this from CMake for Visual Studio, by setting VS_DEBUGGER_WORKING_DIRECTORY property:
set_target_properties(OpenGLEngine3D PROPERTIES VS_DEBUGGER_WORKING_DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR})
(I haven't checked if this works as expected, as I rarely use VS. I remember looking for something like that in the past, and just recently came across it.)