使用fcl库做碰撞检测

fcl库是真难用，导入自己的项目的时候遇到各种坑。

第一个坑就是git clone并build fcl库后生成的fcl-config.cmake里面有问题，需要在这里进行相应修改

set_and_check(FCL_INCLUDE_DIRS "/home/xxxx/fcl/build/include")
set(FCL_LIBRARIES fcl)
set_and_check(FCL_LIBRARY_DIRS "/home/xxxx/fcl/build/lib")

第二个坑就是当你想在自己的项目中也跑通官方的test的时候，需要googletest库，把test文件夹中的一些文件也要copy进自己的项目，以及在自己的项目中也要引用ccd库，还有一个Threads库，改写自己项目的CMakeLists.txt贼麻烦。

cmake_minimum_required(VERSION 2.8)
 
project(test_fcl)
 
set( CMAKE_BUILD_TYPE "Debug" )

find_package(Eigen3 REQUIRED)

set(CMAKE_PREFIX_PATH /home/robotics/fcl/build)
find_package(fcl REQUIRED)

find_package(ccd QUIET)

set(CMAKE_PREFIX_PATH /home/robotics/googletest/build/googletest/generated)
find_package(GTest REQUIRED)

find_package(Threads REQUIRED)

# If ccd-config.cmake is not found, use pkg-config and/or find_path() and
# find_library()
if(NOT ccd_FOUND)
  if(PKG_CONFIG_FOUND)
    pkg_search_module(PC_CCD ccd libccd)
  endif()

  # The include directory returned by pkg_config is very unreliable:
  #  1. PC_CCD_INCLUDE_DIRS cannot locate ccd.h definitively, it could be:
  #     a) PC_CCD_INCLUDE_DIRS/ccd/ccd.h
  #     b) PC_CCD_INCLUDE_DIRS/ccd.h
  #  2. It may be empty due to pkg-config's de-duplication, if the path is
  #     provided by:
  #     a) $PKG_CONFIG_SYSTEM_INCLUDE_PATH
  #     b) $C_INCLUDE_PATH
  #     c) $CPLUS_INCLUDE_PATH
  find_path(CCD_INCLUDE_DIR ccd/ccd.h
    HINTS "${PC_CCD_INCLUDE_DIRS}"
          "${PC_CCD_INCLUDE_DIRS}/.."
          ENV PKG_CONFIG_SYSTEM_INCLUDE_PATH
          ENV C_INCLUDE_PATH
          ENV CPLUS_INCLUDE_PATH)

  # Using find_library() even if pkg-config is available ensures that the full
  # path to the ccd library is available in CCD_LIBRARIES
  find_library(CCD_LIBRARY ccd
    HINTS "${PC_CCD_LIBRARY_DIRS}")

  # libccd links to LibM on UNIX.
  if(CYGWIN OR NOT WIN32)
    find_library(M_LIBRARY m)
  endif()

  if(CCD_INCLUDE_DIR AND CCD_LIBRARY)
    set(CCD_INCLUDE_DIRS "${CCD_INCLUDE_DIR}")
    set(CCD_LIBRARIES "${CCD_LIBRARY}" "${M_LIBRARY}")
    set(ccd_FOUND ON)

    mark_as_advanced(CCD_INCLUDE_DIR CCD_LIBRARY)
  endif()
endif()

if(NOT ccd_FOUND)
  message(FATAL_ERROR "CCD is required by FCL")
endif()

set(PKG_EXTERNAL_DEPS "ccd eigen3")
 
include_directories(
${EIGEN3_INCLUDE_DIRS}
${CMAKE_CURRENT_SOURCE_DIR}/include
${CMAKE_CURRENT_SOURCE_DIR}/test
${ccd_INCLUDE_DIRS}
${GTEST_INCLUDE_DIRS}
/home/robotics/fcl/build/include
/home/robotics/fcl/include
)

set(SRC_LIST 
./test/test_fcl_utility.cpp
./src/main.cpp)
 
add_executable(main ${SRC_LIST})

target_link_libraries(main 
ccd
fcl
gtest
Threads::Threads
)