opencv：同时装多版本opencv的选用/OPENGL

参考：opencv CmakeLists.txt 小示例

用这个the book "Mastering OpenCV with Practical Computer Vision Projects"工程代码：https://github.com/MasteringOpenCV/code/tree/master/Chapter3_MarkerlessAR

这是cmakelists文件

cmake_minimum_required(VERSION 2.6)
project(EXAMPLE_MARKERLESS_AR)

find_package(OpenCV REQUIRED )
find_package(OpenGL REQUIRED )

include_directories(${OpenCV_INCLUDE_DIR})
include_directories(${OpenGL_INCLUDE_DIR})

link_directories(${OpenCV_LIBRARY_DIR})
link_directories(${OpenGL_LIBRARY_DIR})

include_directories(${EXAMPLE_MARKERLESS_AR_SOURCE_DIR}/src)
add_subdirectory(src)

由于最近遇到这样的问题：

OpenCV Error: No OpenGL support (Library was built without OpenGL support) in cvNamedWindow, file /tmp/buildd/ros-hydro-opencv2-2.4.9-2precise-20141231-1923/modules/highgui/src/window_gtk.cpp, line 845

检查我CMAKE安装的bash文件  和配置结果输出显示

cmake -D CMAKE_BUILD_TYPE=RELEASE -D CMAKE_INSTALL_PREFIX=/usr/local -D WITH_TBB=ON -D BUILD_NEW_PYTHON_SUPPORT=ON -D WITH_V4L=ON -D INSTALL_C_EXAMPLES=ON -D INSTALL_PYTHON_EXAMPLES=ON -D BUILD_EXAMPLES=ON -D WITH_QT=ON -D WITH_OPENGL=ON ..

此opencv支持openGL, 。怀疑是    find_package(OpenCV REQUIRED )   找到的是安装时ROS时安装的opencv  ，它不支持opengl。

所以下面必须设置选用的opencv的路径.  或  用IDE QT在系统变量中设置   OpenCV_DIR。。

ps:

在OpenCV_DIR下存在配置文件 OpenCVConfig.cmake.     ( 缺省安装中只有OpenCVConfig.cmake.in文件, 当使用cmake编译OpenCV后,

会根据上述的.cmake.in文件产生对应的 OpenCVConfig.cmake文件.)

检查 OpenCVConfig.cmake 中的路径变量是否正确, 并做修改后保存.

与INCLUDE路径相关的变量:  OpenCV_INCLUDE_DIRS

与LIB路径相关的变量:  OpenCV_LIB_DIR

<pre name="code" class="html">cmake_minimum_required(VERSION 2.6)
project(EXAMPLE_MARKERLESS_AR)
 set(OpenCV_DIR /home/agv/OpenCV/opencv-2.4.9/build)  ###############
 find_package(OpenCV REQUIRED )
find_package(OpenGL REQUIRED )

include_directories(${OpenCV_INCLUDE_DIR})
include_directories(${OpenGL_INCLUDE_DIR})

link_directories(${OpenCV_LIBRARY_DIR})
link_directories(${OpenGL_LIBRARY_DIR})

include_directories(${EXAMPLE_MARKERLESS_AR_SOURCE_DIR}/src)
add_subdirectory(src)

参考：

http://www.cmake.org/cmake/help/v3.0/command/find_package.html

http://www.cnblogs.com/coderfenghc/archive/2012/07/15/2592758.html

http://www.yeolar.com/note/2014/12/16/cmake-how-to-find-libraries/