panda3d/cmake/modules/FindOpenCV.cmake

# Filename: FindOpenCV.cmake
# Authors: CFSworks (3 Nov, 2018)
#
# Usage:
#   find_package(OpenCV [REQUIRED] [QUIET])
#
# This supports the following components:
#   calib3d
#   contrib
#   core
#   features2d
#   flann
#   gpu
#   highgui
#   imgproc
#   legacy
#   ml
#   nonfree
#   objdetect
#   photo
#   stitching
#   superres
#   video
#   videoio
#   videostab
#
# Once done this will define:
#   OPENCV_FOUND        - system has OpenCV
#   OpenCV_INCLUDE_DIRS - the include dir(s) containing OpenCV header files
#   OpenCV_comp_LIBRARY - the path to the OpenCV library for the particular
#                         component
#   OpenCV_LIBS         - the paths to the OpenCV libraries for the requested
#                         component(s)
#   OpenCV_VERSION_MAJOR- a "best guess" of the major version (X.x)
#   OpenCV_VERSION_MINOR- a "best guess" of the minor version (x.X)
#

set(OpenCV_INCLUDE_DIRS)

find_path(OpenCV_V1_INCLUDE_DIR
  NAMES "cv.h"
  PATH_SUFFIXES "opencv")
mark_as_advanced(OpenCV_V1_INCLUDE_DIR)
if(OpenCV_V1_INCLUDE_DIR)
  list(APPEND OpenCV_INCLUDE_DIRS "${OpenCV_V1_INCLUDE_DIR}")

  # This is a wild guess:
  set(OpenCV_VERSION_MAJOR 1)
  set(OpenCV_VERSION_MINOR 0)
endif()

find_path(OpenCV_V2_INCLUDE_DIR "opencv2/core/version.hpp")
mark_as_advanced(OpenCV_V2_INCLUDE_DIR)
if(OpenCV_V2_INCLUDE_DIR)
  list(APPEND OpenCV_INCLUDE_DIRS "${OpenCV_V2_INCLUDE_DIR}")

  file(STRINGS "${OpenCV_V2_INCLUDE_DIR}/opencv2/core/version.hpp"
    _version_major REGEX "#define CV_VERSION_EPOCH")
  file(STRINGS "${OpenCV_V2_INCLUDE_DIR}/opencv2/core/version.hpp"
    _version_minor REGEX "#define CV_VERSION_MAJOR")

  string(REGEX REPLACE "[^0-9]" "" OpenCV_VERSION_MAJOR "${_version_major}")
  string(REGEX REPLACE "[^0-9]" "" OpenCV_VERSION_MINOR "${_version_minor}")
  unset(_version_major)
  unset(_version_minor)
endif()

set(OpenCV_LIBS)
foreach(_component calib3d contrib core features2d flann gpu highgui imgproc
                  legacy ml nonfree objdetect photo stitching superres video
                  videoio videostab)

  list(FIND OpenCV_FIND_COMPONENTS "${_component}" _index)
  if(_index GREATER -1 OR _component STREQUAL "core")
    if(NOT OpenCV_${_component}_LIBRARY)
      find_library(OpenCV_${_component}_LIBRARY
        NAMES "opencv_${_component}")
    endif()

    if(OpenCV_${_component}_LIBRARY)
      list(APPEND OpenCV_LIBS "${OpenCV_${_component}_LIBRARY}")
      set(OpenCV_${_component}_FOUND ON)
    endif()
  endif()
  unset(_index)
endforeach(_component)
unset(_component)

include(FindPackageHandleStandardArgs)
find_package_handle_standard_args(OpenCV HANDLE_COMPONENTS
  REQUIRED_VARS OpenCV_INCLUDE_DIRS OpenCV_LIBS
  OpenCV_VERSION_MAJOR OpenCV_VERSION_MINOR)