ubuntuopenglcmakemesa

How to use CMake to find and link OpenGL(mesa) package in Ubuntu

I am totally new in CMake and OpenGL. I now need to use OpenGL as a library in my project on my Ubuntu 15.04 64bit PC, which is built by CMake 3.0.2.

I have been working on this several days, nearly frustrated. I get confused with a bunch of problems.

mesa and OpenGL

First of all, I installed the mesa package with command sudo apt-get install mesa-common-dev, which get me mesa 10.5.2.

Then I browse the package files with dpkg -L mesa-common-dev:

/.
/usr
/usr/share
/usr/share/bug
...
/usr/share/bug/mesa-common-dev/control

/usr/share/doc
...
/usr/share/doc/mesa-common-dev/faq.html

/usr/lib
/usr/lib/x86_64-linux-gnu
/usr/lib/x86_64-linux-gnu/pkgconfig
/usr/lib/x86_64-linux-gnu/pkgconfig/dri.pc

/usr/include
/usr/include/GL
/usr/include/GL/gl.h
...
/usr/include/GL/glx_mangle.h

QUESTION 1: Where are the shared libraries (.so) and static libraries (.a)?

CMake

I now have a CMakeLists.txt, with the OpenGL module named OPENGL

...
find_package(OPENGL REQUIRED)  # here is CMakeLists.txt:45
...
include_directories(${OPENGL_INCLUDE_DIRS})
link_directories(${OPENGL_LIBRARY_DIRS})
target_link_libraries(MyProj ... ${OPENGL_LIBRARIES})
...

So I definitely need to have a cmake file, say FindOPENGL.cmake, like this (took GLEW's cmake file as a template):

# OPENGL_FOUND             If OPENGL is found
# OPENGL_LIBRARIES         OPENGL libraries
# OPENGL_INCLUDE_DIRS      OPENGL include directories
# OPENGL_LIBRARY_DIRS      OPENGL library directories

if(UNIX)
  set(OPENGL_INC_NAMES gl.h)
  set(OPENGL_LIB_NAMES libGL.so.1.2.0)
endif(UNIX)

# OPENGL static library     # line 17
find_library(OPENGL_LIBRARIES
    NAMES ${OPENGL_LIB_NAMES}
    PATHS /usr/x86_64-linux-gnu/mesa
    DOC "OPENGL library")

# OPENGL library dir        # line 23
find_path(OPENGL_LIBRARY_DIRS
    NAMES ${OPENGL_LIB_NAMES}
    PATHS /usr/x86_64-linux-gnu/mesa
    DOC "OPENGL include directories")

# OPENGL include dir        # line 29
find_path(OPENGL_INCLUDE_DIRS
    NAMES ${OPENGL_INC_NAMES}
    PATHS /usr/include/GL
    DOC "OPENGL include directories")

# Version
set(OPENGL_VERSION 1.13.0)

# Set package standard args
include(FindPackageHandleStandardArgs)
FIND_PACKAGE_HANDLE_STANDARD_ARGS(OPENGL       # here is FindOPENGL.cmake:40
    REQUIRED_VARS OPENGL_LIBRARIES OPENGL_INCLUDE_DIRS OPENGL_LIBRARY_DIRS
    VERSION_VAR OPENGL_VERSION)

QUESTION 2: How to link static libraries and shared libraries in cmake file, and what is the difference between line 17/23/29?

I then run cmake and get following errors:

CMake Error at /usr/share/cmake-3.0/Modules/FindPackageHandleStandardArgs.cmake:136 (message):
  Cound NOT find OPENGL (missing: OPENGL_LIBRARIES OPENGL_LIBRARY_DIRS)
  (found version "1.13.0")
Call Stack (most recent call first):
  /usr/share/cmake-3.0/Modules/FindPackageHandleStandardArgs.cmake:343 (_FPHSA_FAILURE_MESSAGE)
  cmake/modules/FindOPENGL.cmake:40 (FIND_PACKAGE_HANDLE_STANDARD_ARGS)
  CMakeLists.txt:45 (find_package)

QUESTION 3: How come I get this error and how can I fix it? Did I do something wrong through the whole procedure?

Update

Thanks for @usr1234567 's answer, I then delete my FindOPENGL.cmake and try to make use of /usr/share/cmake-3.0/Modules/FindOpenGL.cmake. I still get the error missing: OPENGL_gl_LIBRARY. I look into this cmake file for the definition of OPENGL_gl_LIBRARY, and manually check the lib paths in it, unfortunately none of the paths listed exists.

Did I install mesa properly?

Solution