[cmake] Change FindSdl.cmake to support SDL1 on OSX

project/cmake/modules/FindSdl.cmake

@@ -1,21 +1,46 @@
-# - Try to find SDL2
-# Once done this will define
+#.rst:
+# FindSDL
+# -------
+# Finds the SDL library
 #
-# SDL_FOUND - system has libSDL
-# SDL_INCLUDE_DIRS - the libSDL include directory
-# SDL_LIBRARIES - The libSDL libraries
+# This will will define the following variables::
+#
+# SDL_FOUND - system has SDL
+# SDL_INCLUDE_DIRS - the SDL include directory
+# SDL_LIBRARIES - the SDL libraries
+# SDL_DEFINITIONS - the SDL compile definitions
 
 if(PKG_CONFIG_FOUND)
-  pkg_check_modules (SDL sdl2)
-else()
-  find_package(SDL)
-  list(APPEND SDL_INCLUDE_DIRS ${SDL_INCLUDE_DIR})
-  list(APPEND SDL_LIBRARIES ${SDL_LIBRARIES})
+  pkg_check_modules(PC_SDL2 sdl2 QUIET)
+  if(PC_SDL2_FOUND)
+    set(SDL_VERSION ${PC_SDL2_VERSION})
+  else()
+    pkg_check_modules(PC_SDL1 sdl QUIET)
+    if(PC_SDL1_FOUND)
+      set(SDL_VERSION ${PC_SDL1_VERSION})
+    endif()
+  endif()
 endif()
 
+find_path(SDL_INCLUDE_DIR SDL/SDL.h
+                          PATHS ${PC_SDL2_INCLUDE_DIR} ${PC_SDL1_INCLUDE_DIR})
+find_library(SDL_LIBRARY NAMES SDL2 SDL
+                         PATHS ${PC_SDL2_LIBDIR} ${PC_SDL1_LIBDIR})
+
 include(FindPackageHandleStandardArgs)
-find_package_handle_standard_args(Sdl DEFAULT_MSG SDL_INCLUDE_DIRS SDL_LIBRARIES)
+find_package_handle_standard_args(Sdl REQUIRED_VARS SDL_LIBRARY SDL_INCLUDE_DIR
+                                      VERSION_VAR SDL_VERSION)
 
-list(APPEND SDL_DEFINITIONS -DHAVE_SDL=1)
+if(SDL_FOUND)
+  set(SDL_LIBRARIES ${SDL_LIBRARY})
+  set(SDL_INCLUDE_DIRS ${SDL_INCLUDE_DIR})
+  set(SDL_DEFINITIONS -DHAVE_SDL=1)
+
+  if(SDL_VERSION VERSION_GREATER 2)
+    list(APPEND SDL_DEFINITIONS -DHAVE_SDL_VERSION=2)
+  elseif(SDL_VERSION VERSION_GREATER 1)
+    list(APPEND SDL_DEFINITIONS -DHAVE_SDL_VERSION=1)
+  endif()
+endif()
 
-mark_as_advanced(SDL_INCLUDE_DIRS SDL_LIBRARIES SDL_DEFINITIONS)
+mark_as_advanced(SDL_LIBRARY SDL_INCLUDE_DIR)