From: Sven Eckelmann <sven@narfation.org>
Date: Sun, 23 Feb 2020 09:26:22 +0100
Subject: cmake: Switch to external SDL2 configuration file

The Debian bullseye libsdl2-dev package moved its header files to a
non-common path. Instead the sdl2-config.cmake is shipped with the package.
This file is automatically used when the it finds no FindSDL2.cmake in our
cmake modules directory.

Signed-off-by: Sven Eckelmann <sven@narfation.org>
Origin: upstream, https://sourceforge.net/p/s3d/code/ci/5703fce4af70b7d7d499ea2b64840be78aabd06b/
Bug-Debian: https://bugs.debian.org/951929
---
 ConfigureChecks.cmake        |   2 +-
 cmake/modules/FindSDL2.cmake | 181 -------------------------------------------
 server/CMakeLists.txt        |   2 +-
 3 files changed, 2 insertions(+), 183 deletions(-)
 delete mode 100644 cmake/modules/FindSDL2.cmake

diff --git a/ConfigureChecks.cmake b/ConfigureChecks.cmake
index 6a1dd44..62d2dea 100644
--- a/ConfigureChecks.cmake
+++ b/ConfigureChecks.cmake
@@ -68,7 +68,7 @@ endif (TARGET OpenGL::OpenGL)
 # try to find lib and add include dir for SDL
 find_package(SDL2)
 if (SDL2_FOUND)
-	include_directories(${SDL2_INCLUDE_DIR})
+	include_directories(${SDL2_INCLUDE_DIRS})
 	set(G_SDL SDL2_FOUND)
 else (SDL2_FOUND)
 	find_package(SDL)
diff --git a/cmake/modules/FindSDL2.cmake b/cmake/modules/FindSDL2.cmake
deleted file mode 100644
index fcb97ab..0000000
--- a/cmake/modules/FindSDL2.cmake
+++ /dev/null
@@ -1,181 +0,0 @@
-# Locate SDL2 library
-# This module defines
-# SDL2_LIBRARY, the name of the library to link against
-# SDL2_FOUND, if false, do not try to link to SDL2
-# SDL2_INCLUDE_DIR, where to find SDL.h
-#
-# This module responds to the the flag:
-# SDL2_BUILDING_LIBRARY
-# If this is defined, then no SDL2_main will be linked in because
-# only applications need main().
-# Otherwise, it is assumed you are building an application and this
-# module will attempt to locate and set the the proper link flags
-# as part of the returned SDL2_LIBRARY variable.
-#
-# Don't forget to include SDL2main.h and SDL2main.m your project for the
-# OS X framework based version. (Other versions link to -lSDL2main which
-# this module will try to find on your behalf.) Also for OS X, this
-# module will automatically add the -framework Cocoa on your behalf.
-#
-#
-# Additional Note: If you see an empty SDL2_LIBRARY_TEMP in your configuration
-# and no SDL2_LIBRARY, it means CMake did not find your SDL2 library
-# (SDL2.dll, libsdl2.so, SDL2.framework, etc).
-# Set SDL2_LIBRARY_TEMP to point to your SDL2 library, and configure again.
-# Similarly, if you see an empty SDL2MAIN_LIBRARY, you should set this value
-# as appropriate. These values are used to generate the final SDL2_LIBRARY
-# variable, but when these values are unset, SDL2_LIBRARY does not get created.
-#
-#
-# $SDL2DIR is an environment variable that would
-# correspond to the ./configure --prefix=$SDL2DIR
-# used in building SDL2.
-# l.e.galup  9-20-02
-#
-# Modified by Eric Wing.
-# Added code to assist with automated building by using environmental variables
-# and providing a more controlled/consistent search behavior.
-# Added new modifications to recognize OS X frameworks and
-# additional Unix paths (FreeBSD, etc).
-# Also corrected the header search path to follow "proper" SDL2 guidelines.
-# Added a search for SDL2main which is needed by some platforms.
-# Added a search for threads which is needed by some platforms.
-# Added needed compile switches for MinGW.
-#
-# On OSX, this will prefer the Framework version (if found) over others.
-# People will have to manually change the cache values of
-# SDL2_LIBRARY to override this selection or set the CMake environment
-# CMAKE_INCLUDE_PATH to modify the search paths.
-#
-# Note that the header path has changed from SDL2/SDL.h to just SDL.h
-# This needed to change because "proper" SDL2 convention
-# is #include "SDL.h", not <SDL2/SDL.h>. This is done for portability
-# reasons because not all systems place things in SDL2/ (see FreeBSD).
-#
-# Ported by Johnny Patterson. This is a literal port for SDL2 of the FindSDL.cmake
-# module with the minor edit of changing "SDL" to "SDL2" where necessary. This
-# was not created for redistribution, and exists temporarily pending official
-# SDL2 CMake modules.
-
-#=============================================================================
-# SPDX-FileCopyrightText: 2003-2009 Kitware, Inc.
-# SPDX-License-Identifier: BSD-3-Clause
-#
-# Distributed under the OSI-approved BSD License (the "License");
-# see accompanying file Copyright.txt for details.
-#
-# This software is distributed WITHOUT ANY WARRANTY; without even the
-# implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
-# See the License for more information.
-#=============================================================================
-# (To distribute this file outside of CMake, substitute the full
-#  License text for the above reference.)
-
-FIND_PATH(SDL2_INCLUDE_DIR SDL.h
-  HINTS
-  $ENV{SDL2DIR}
-  PATH_SUFFIXES include/SDL2 include
-  PATHS
-  ~/Library/Frameworks
-  /Library/Frameworks
-  /usr/local/include/SDL2
-  /usr/include/SDL2
-  /sw # Fink
-  /opt/local # DarwinPorts
-  /opt/csw # Blastwave
-  /opt
-)
-#MESSAGE("SDL2_INCLUDE_DIR is ${SDL2_INCLUDE_DIR}")
-
-FIND_LIBRARY(SDL2_LIBRARY_TEMP
-  NAMES SDL2
-  HINTS
-  $ENV{SDL2DIR}
-  PATH_SUFFIXES lib64 lib
-  PATHS
-  /sw
-  /opt/local
-  /opt/csw
-  /opt
-)
-
-#MESSAGE("SDL2_LIBRARY_TEMP is ${SDL2_LIBRARY_TEMP}")
-
-IF(NOT SDL2_BUILDING_LIBRARY)
-  IF(NOT ${SDL2_INCLUDE_DIR} MATCHES ".framework")
-    # Non-OS X framework versions expect you to also dynamically link to
-    # SDL2main. This is mainly for Windows and OS X. Other (Unix) platforms
-    # seem to provide SDL2main for compatibility even though they don't
-    # necessarily need it.
-    FIND_LIBRARY(SDL2MAIN_LIBRARY
-      NAMES SDL2main
-      HINTS
-      $ENV{SDL2DIR}
-      PATH_SUFFIXES lib64 lib
-      PATHS
-      /sw
-      /opt/local
-      /opt/csw
-      /opt
-    )
-  ENDIF(NOT ${SDL2_INCLUDE_DIR} MATCHES ".framework")
-ENDIF(NOT SDL2_BUILDING_LIBRARY)
-
-# SDL2 may require threads on your system.
-# The Apple build may not need an explicit flag because one of the
-# frameworks may already provide it.
-# But for non-OSX systems, I will use the CMake Threads package.
-IF(NOT APPLE)
-  FIND_PACKAGE(Threads)
-ENDIF(NOT APPLE)
-
-# MinGW needs an additional library, mwindows
-# It's total link flags should look like -lmingw32 -lSDL2main -lSDL2 -lmwindows
-# (Actually on second look, I think it only needs one of the m* libraries.)
-IF(MINGW)
-  SET(MINGW32_LIBRARY mingw32 CACHE STRING "mwindows for MinGW")
-ENDIF(MINGW)
-
-SET(SDL2_FOUND "NO")
-IF(SDL2_LIBRARY_TEMP)
-  # For SDL2main
-  IF(NOT SDL2_BUILDING_LIBRARY)
-    IF(SDL2MAIN_LIBRARY)
-      SET(SDL2_LIBRARY_TEMP ${SDL2MAIN_LIBRARY} ${SDL2_LIBRARY_TEMP})
-    ENDIF(SDL2MAIN_LIBRARY)
-  ENDIF(NOT SDL2_BUILDING_LIBRARY)
-
-  # For OS X, SDL2 uses Cocoa as a backend so it must link to Cocoa.
-  # CMake doesn't display the -framework Cocoa string in the UI even
-  # though it actually is there if I modify a pre-used variable.
-  # I think it has something to do with the CACHE STRING.
-  # So I use a temporary variable until the end so I can set the
-  # "real" variable in one-shot.
-  IF(APPLE)
-    SET(SDL2_LIBRARY_TEMP ${SDL2_LIBRARY_TEMP} "-framework Cocoa")
-  ENDIF(APPLE)
-
-  # For threads, as mentioned Apple doesn't need this.
-  # In fact, there seems to be a problem if I used the Threads package
-  # and try using this line, so I'm just skipping it entirely for OS X.
-  IF(NOT APPLE)
-    SET(SDL2_LIBRARY_TEMP ${SDL2_LIBRARY_TEMP} ${CMAKE_THREAD_LIBS_INIT})
-  ENDIF(NOT APPLE)
-
-  # For MinGW library
-  IF(MINGW)
-    SET(SDL2_LIBRARY_TEMP ${MINGW32_LIBRARY} ${SDL2_LIBRARY_TEMP})
-  ENDIF(MINGW)
-
-  # Set the final string here so the GUI reflects the final state.
-  SET(SDL2_LIBRARY ${SDL2_LIBRARY_TEMP} CACHE STRING "Where the SDL2 Library can be found")
-  # Set the temp variable to INTERNAL so it is not seen in the CMake GUI
-  SET(SDL2_LIBRARY_TEMP "${SDL2_LIBRARY_TEMP}" CACHE INTERNAL "")
-
-  SET(SDL2_FOUND "YES")
-ENDIF(SDL2_LIBRARY_TEMP)
-
-INCLUDE(FindPackageHandleStandardArgs)
-
-FIND_PACKAGE_HANDLE_STANDARD_ARGS(SDL2
-                                  REQUIRED_VARS SDL2_LIBRARY SDL2_INCLUDE_DIR)
diff --git a/server/CMakeLists.txt b/server/CMakeLists.txt
index b08238c..cfada6b 100644
--- a/server/CMakeLists.txt
+++ b/server/CMakeLists.txt
@@ -14,7 +14,7 @@ set(server_sdl_src graphics_sdl.c user_sdl.c)
 # add sdl files and libs
 if (SDL2_FOUND)
 	list(APPEND server_src ${server_sdl_src})
-	list(APPEND server_libs ${SDL2_LIBRARY})
+	list(APPEND server_libs ${SDL2_LIBRARIES})
 endif (SDL2_FOUND)
 
 if (SDL_FOUND)