Managing dependencies

CMake has the ability to search our dependencies and external libraries, giving us the ability to build complex projects, depending on the external components in our projects, and add some requirements.

In this book, the most important dependency is, of course, OpenCV, and we will add it to all of our projects:

    cmake_minimum_required (VERSION 3.0) 
    PROJECT(Chapter2) 
# Requires OpenCV 
    FIND_PACKAGE( OpenCV 4.0.0 REQUIRED ) 
# Show a message with the opencv version detected 
    MESSAGE("OpenCV version : ${OpenCV_VERSION}") 
# Add the paths to the include directories/to the header files
    include_directories(${OpenCV_INCLUDE_DIRS}) 
# Add the paths to the compiled libraries/objects
    link_directories(${OpenCV_LIB_DIR}) 
# Create a variable called SRC 
    SET(SRC main.cpp) 
# Create our executable 
    ADD_EXECUTABLE(${PROJECT_NAME} ${SRC}) 
# Link our library 
    TARGET_LINK_LIBRARIES(${PROJECT_NAME} ${OpenCV_LIBS})

 

Now, let's understand the working of...