From 348bcc999707c120a026f373bd3770b9d5e52935 Mon Sep 17 00:00:00 2001
From: oxmox <oxmox@noreply.localhost>
Date: Wed, 22 Feb 2023 20:29:22 +0100
Subject: [PATCH] use the included SDL if not appropriate system-wide SDL was
 found

---
 CMakeLists.txt             |  7 ++++++-
 external/CMakeLists.txt    |  9 +++++++--
 src/CMakeLists.txt         |  1 -
 src/doompanning.cc         |  2 +-
 src/dp_doom/CMakeLists.txt | 36 +++---------------------------------
 5 files changed, 17 insertions(+), 38 deletions(-)

diff --git a/CMakeLists.txt b/CMakeLists.txt
index 0d7d5bb..56457f5 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -1,4 +1,4 @@
-cmake_minimum_required(VERSION 3.12)
+cmake_minimum_required(VERSION 3.14)
 
 project(doompanning)
 
@@ -8,5 +8,10 @@ set(CMAKE_EXPORT_COMPILE_COMMANDS ON)
 set(CMAKE_RUNTIME_OUTPUT_DIRECTORY ${CMAKE_BINARY_DIR})
 set(CMAKE_VERBOSE_MAKEFILE ON CACHE BOOL "ON")
 
+# The SDL renderer backend in the version of ImGui included in this repo
+# requires at least SDL-2.0.17. This is enforced in
+# external/imgui/backends/imgui_impl_sdlrenderer.cpp .
+find_package(SDL2 2.0.17)
+
 add_subdirectory(external)
 add_subdirectory(src)
diff --git a/external/CMakeLists.txt b/external/CMakeLists.txt
index f042a51..9f975cc 100644
--- a/external/CMakeLists.txt
+++ b/external/CMakeLists.txt
@@ -2,7 +2,12 @@ option(NNG_SETSTACKSIZE "Use rlimit for thread stack size" ON)
 set(NNG_TESTS OFF)
 set(NNG_ENABLE_NNGCAT OFF)
 add_subdirectory(nng)
-find_package(SDL2 REQUIRED)
+
+if (NOT SDL2_FOUND)
+    add_subdirectory(SDL)
+else()
+    message("-- Using system-installed SDL version ${SDL2_VERSION}")
+endif()
 
 add_library(imgui OBJECT
     ${CMAKE_CURRENT_SOURCE_DIR}/imgui/imgui.cpp
@@ -15,4 +20,4 @@ add_library(imgui OBJECT
 )
 
 target_include_directories(imgui PUBLIC ${CMAKE_CURRENT_SOURCE_DIR}/imgui)
-target_link_libraries(imgui PUBLIC SDL2::SDL2-static)
\ No newline at end of file
+target_link_libraries(imgui PUBLIC SDL2::SDL2-static)
diff --git a/src/CMakeLists.txt b/src/CMakeLists.txt
index 9d289ca..61eac65 100644
--- a/src/CMakeLists.txt
+++ b/src/CMakeLists.txt
@@ -42,7 +42,6 @@ target_link_libraries(dp_imgui_demo
 )
 
 if (WIN32)
-    find_package(SDL2)
     target_link_libraries(doompanning PRIVATE SDL2::SDL2main)
     target_link_libraries(dp_imgui_demo PRIVATE SDL2::SDL2main)
 endif()
diff --git a/src/doompanning.cc b/src/doompanning.cc
index c033c8d..070c286 100644
--- a/src/doompanning.cc
+++ b/src/doompanning.cc
@@ -3,7 +3,7 @@
 #include <imgui.h>
 #include <backends/imgui_impl_sdl.h>
 #include <backends/imgui_impl_sdlrenderer.h>
-#include <SDL2/SDL.h>
+#include <SDL.h>
 
 #include <algorithm>
 #include <array>
diff --git a/src/dp_doom/CMakeLists.txt b/src/dp_doom/CMakeLists.txt
index 1b69ace..e6d45bd 100644
--- a/src/dp_doom/CMakeLists.txt
+++ b/src/dp_doom/CMakeLists.txt
@@ -3,8 +3,8 @@ cmake_minimum_required(VERSION 3.19)
 project(dp_doom LANGUAGES C)
 
 set(CMAKE_EXPORT_COMPILE_COMMANDS ON)
-set(BACKEND "nng" CACHE STRING "Which backend to use: Xlib, SDL1, SDL2 or nng")
-option(WILDMIDI "Render MIDI using the WildMIDI library" OFF)
+set(BACKEND "nng" CACHE STRING "Which backend to use: Xlib, SDL2 or nng")
+option(WILDMIDI "Render MIDI using the WildMIDI library" ON)
 
 add_executable(dp_doom WIN32
 	"linuxdoom-1.10/am_map.c"
@@ -174,22 +174,6 @@ if(BACKEND STREQUAL "Xlib")
 
 	# These are for miniaudio.
 	target_link_libraries(dp_doom PRIVATE m ${CMAKE_DL_LIBS} pthread)
-elseif(BACKEND STREQUAL "SDL1")
-	target_sources(dp_doom PRIVATE
-		"linuxdoom-1.10/ib_sound/ib_sound_sdl.c"
-		"linuxdoom-1.10/ib_system/ib_system_sdl.c"
-		"linuxdoom-1.10/ib_video/ib_video_sdl.c"
-	)
-
-	find_package(SDL REQUIRED)
-
-	# TODO - Add support for in-tree builds (I don't think it's
-	# actually possible with SDL1 since it lacks a CMake build system)
-	#if(NOT SDL-FOUND)
-	#  add_subdirectory("external/sdl1" EXCLUDE_FROM_ALL)
-	#endif()
-
-	target_link_libraries(dp_doom PRIVATE SDL::SDL)
 elseif(BACKEND STREQUAL "SDL2")
 	target_sources(dp_doom PRIVATE
 		"linuxdoom-1.10/ib_sound/ib_sound_sdl.c"
@@ -197,20 +181,7 @@ elseif(BACKEND STREQUAL "SDL2")
 		"linuxdoom-1.10/ib_video/ib_video_sdl.c"
 	)
 
-	find_package(SDL2)
-
-	if(NOT SDL2_FOUND)
-		add_subdirectory("external/SDL" EXCLUDE_FROM_ALL)
-		if(SDL_STATIC)
-			target_link_libraries(dp_doom PRIVATE SDL2::SDL2main SDL2::SDL2-static)
-		else()
-			target_link_libraries(dp_doom PRIVATE SDL2::SDL2main SDL2::SDL2)
-		endif()
-	else()
-		target_link_libraries(dp_doom PRIVATE SDL2::SDL2main SDL2::SDL2)
-	endif()
-
-	target_compile_definitions(dp_doom PRIVATE INCLUDE_SDL2_MAIN)
+	target_link_libraries(dp_doom PRIVATE SDL2::SDL2main SDL2::SDL2-static)
 elseif(BACKEND STREQUAL "nng")
 	target_sources(dp_doom PRIVATE
 		"linuxdoom-1.10/ib_sound/ib_sound_nng.c"
@@ -218,7 +189,6 @@ elseif(BACKEND STREQUAL "nng")
 		"linuxdoom-1.10/ib_video/ib_video_nng.c"
 	)
 
-	find_package(SDL2 REQUIRED)
 	target_link_libraries(dp_doom
 		PRIVATE SDL2::SDL2
 		PRIVATE m