From 654abdc5eb438e83e23bac86384dbe364060c630 Mon Sep 17 00:00:00 2001
From: Sam Edwards <CFSworks@gmail.com>
Date: Sat, 5 Jan 2019 13:53:55 -0700
Subject: [PATCH] CMake: Detect when to set OPENCV_VER_23/OPENCV_VER_3

---
 cmake/modules/FindOpenCV.cmake  | 39 ++++++++++++++++++++++-----------
 dtool/Package.cmake             |  9 +++++++-
 dtool/dtool_config.h.in         |  1 -
 panda/src/vision/CMakeLists.txt |  6 +++++
 4 files changed, 40 insertions(+), 15 deletions(-)

diff --git a/cmake/modules/FindOpenCV.cmake b/cmake/modules/FindOpenCV.cmake
index fcb6e1b49b..77d49edfbe 100644
--- a/cmake/modules/FindOpenCV.cmake
+++ b/cmake/modules/FindOpenCV.cmake
@@ -21,6 +21,7 @@
 #   stitching
 #   superres
 #   video
+#   videoio
 #   videostab
 #
 # Once done this will define:
@@ -30,33 +31,44 @@
 #                         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)
-if(NOT OpenCV_V1_INCLUDE_DIR)
-  find_path(OpenCV_V1_INCLUDE_DIR
-    NAMES "cv.h"
-    PATH_SUFFIXES "opencv")
 
-  mark_as_advanced(OpenCV_V1_INCLUDE_DIR)
-endif()
+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()
 
-if(NOT OpenCV_V2_INCLUDE_DIR)
-  find_path(OpenCV_V2_INCLUDE_DIR "opencv2/core/core.hpp")
-
-  mark_as_advanced(OpenCV_V2_INCLUDE_DIR)
-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
-                  videostab)
+                  videoio videostab)
 
   list(FIND OpenCV_FIND_COMPONENTS "${_component}" _index)
   if(_index GREATER -1 OR _component STREQUAL "core")
@@ -76,4 +88,5 @@ unset(_component)
 
 include(FindPackageHandleStandardArgs)
 find_package_handle_standard_args(OpenCV HANDLE_COMPONENTS
-  REQUIRED_VARS OpenCV_INCLUDE_DIRS OpenCV_LIBS)
+  REQUIRED_VARS OpenCV_INCLUDE_DIRS OpenCV_LIBS
+  OpenCV_VERSION_MAJOR OpenCV_VERSION_MINOR)
diff --git a/dtool/Package.cmake b/dtool/Package.cmake
index c30402aa6b..39a80cb080 100644
--- a/dtool/Package.cmake
+++ b/dtool/Package.cmake
@@ -474,7 +474,7 @@ package_status(EGL "EGL")
 #
 
 # OpenCV
-find_package(OpenCV QUIET COMPONENTS core highgui)
+find_package(OpenCV QUIET COMPONENTS core highgui OPTIONAL_COMPONENTS videoio)
 
 package_option(OPENCV
   "Enable support for OpenCV.  This will be built into the 'vision' package."
@@ -482,6 +482,13 @@ package_option(OPENCV
 
 package_status(OPENCV "OpenCV")
 
+if(OpenCV_VERSION_MAJOR GREATER_EQUAL 3)
+  set(OPENCV_VER_3 ON)
+elseif(OpenCV_VERSION_MAJOR GREATER_EQUAL 2 AND
+       OpenCV_VERSION_MINOR GREATER_EQUAL 3)
+  set(OPENCV_VER_23 ON)
+endif()
+
 # ARToolKit
 find_package(ARToolKit QUIET)
 
diff --git a/dtool/dtool_config.h.in b/dtool/dtool_config.h.in
index 5a20f9666c..59950c5480 100644
--- a/dtool/dtool_config.h.in
+++ b/dtool/dtool_config.h.in
@@ -108,7 +108,6 @@
 
 /* Define if we have OpenCV installed and want to build for OpenCV.  */
 #cmakedefine HAVE_OPENCV
-#cmakedefine OPENCV_VER_23
 
 /* Define if we have FFMPEG installed and want to build for FFMPEG.  */
 #cmakedefine HAVE_FFMPEG
diff --git a/panda/src/vision/CMakeLists.txt b/panda/src/vision/CMakeLists.txt
index a581ef3076..f1497fcf6e 100644
--- a/panda/src/vision/CMakeLists.txt
+++ b/panda/src/vision/CMakeLists.txt
@@ -33,6 +33,12 @@ target_link_libraries(p3vision panda
 set_target_properties(p3vision PROPERTIES CXX_EXCEPTIONS ON)
 target_interrogate(p3vision ALL)
 
+if(OPENCV_VER_3)
+  set_target_properties(p3vision PROPERTIES COMPILE_DEFINITIONS "OPENCV_VER_3")
+elseif(OPENCV_VER_23)
+  set_target_properties(p3vision PROPERTIES COMPILE_DEFINITIONS "OPENCV_VER_23")
+endif()
+
 install(TARGETS p3vision
   EXPORT Vision COMPONENT Vision
   DESTINATION lib