CMake入門之建立一個基於PCL的最小工程

     最近在學習PCL，藉助Cmake可省去繁瑣的添加包含目錄和依賴庫操做。

     一個典型的CMakeLists.txt內容一般爲：

1 cmake_minimum_required(VERSION 2.6 FATAL_ERROR)
2 project(MY_GRAND_PROJECT)
3 find_package(PCL 1.3 REQUIRED COMPONENTS common io)
4 include_directories(${PCL_INCLUDE_DIRS})
5 link_directories(${PCL_LIBRARY_DIRS})
6 add_definitions(${PCL_DEFINITIONS})
7 add_executable(pcd_write_test pcd_write.cpp)
8 target_link_libraries(pcd_write_test ${PCL_COMMON_LIBRARIES} ${PCL_IO_LIBRARIES})

CMake文件第一行：

cmake_minimum_required(VERSION 2.6 FATAL_ERROR)

這一句對Cmake來講是必需的，須要在這句添加知足你對Cmake特徵需求的最小版本號。

接下來一句:

project(MY_GRAND_PROJECT)

創建一個工程，括號內MY_GRAND_PROJECT爲本身工程的名字。

find_package(PCL 1.3 REQUIRED COMPONENTS common io)

因爲咱們是創建一個PCL項目，所以須要找到對應的PCL package，若是找不到則項目建立失敗。除此以外，咱們還能夠使用一下方式：

1）若是是須要某一個PCL的某一個組件： find_package(PCL 1.3 REQUIRED COMPONENTS io)

2）若是是幾個組件：find_package(PCL 1.3 REQUIRED COMPONENTS io common)

3）若是須要整個安裝包：find_package(PCL 1.3 REQUIRED)

include_directories(${PCL_INCLUDE_DIRS})
link_directories(${PCL_LIBRARY_DIRS})
add_definitions(${PCL_DEFINITIONS})

當PCL安裝包找到以後，就須要添加對應的包含目錄和依賴庫了。咱們須要設置幾個相關的變量：

• PCL_FOUND: set to 1 if PCL is found, otherwise unset
• PCL_INCLUDE_DIRS: set to the paths to PCL installed headers and the dependency headers
• PCL_LIBRARIES: set to the file names of the built and installed PCL libraries
• PCL_LIBRARY_DIRS: set to the paths to where PCL libraries and 3rd party dependencies reside
• PCL_VERSION: the version of the found PCL
• PCL_COMPONENTS: lists all available components
• PCL_DEFINITIONS: lists the needed preprocessor definitions and compiler flags

add_executable(pcd_write_test pcd_write.cpp)

接下來這須要從pcd_write.cpp文件生成一個名爲pcd_write_test的可執行文件。

在生成對應的exe文件以後，須要調用PCL相關函數，所以須要添加相應連接庫：

target_link_libraries(pcd_write_test ${PCL_COMMON_LIBRARIES} ${PCL_IO_LIBRARIES})

至此，就能夠使用CMake生成本身的工程了。