From 10312f699833c73e9b343184c20fd82b65267d81 Mon Sep 17 00:00:00 2001
From: Daniel Gibson <metalcaedes@gmail.com>
Date: Sun, 2 Jun 2024 14:07:29 +0200
Subject: [PATCH] Allow disabling Dear ImGui integration in CMake

and do it automatically when using SDL1.2, as it requires SDL2
(or SDL3 once we support it)
---
 neo/CMakeLists.txt                   | 23 +++++++++++++++++++----
 neo/framework/Dhewm3SettingsMenu.cpp |  9 +++++++--
 2 files changed, 26 insertions(+), 6 deletions(-)

diff --git a/neo/CMakeLists.txt b/neo/CMakeLists.txt
index bec62303..fc8c3c98 100644
--- a/neo/CMakeLists.txt
+++ b/neo/CMakeLists.txt
@@ -56,6 +56,7 @@ endif()
 option(DEDICATED	"Build the dedicated server" OFF)
 option(ONATIVE		"Optimize for the host CPU" OFF)
 option(SDL2			"Use SDL2 instead of SDL1.2" ON)
+option(IMGUI		"Build with Dear ImGui integration - requires SDL2 and C++11" ON)
 option(REPRODUCIBLE_BUILD "Replace __DATE__ and __TIME__ by hardcoded values for reproducible builds" OFF)
 
 option(HARDLINK_GAME "Compile gamecode into executable (no game DLLs)" OFF)
@@ -71,10 +72,6 @@ if(NOT MSVC) # GCC/clang or compatible, hopefully
 	endif()
 endif()
 
-# we need C++11 for ImGui
-# TODO: if we allow disabling ImGui, we could disable setting the c++ standard - or maybe just embrace C++11?
-set (CMAKE_CXX_STANDARD 11)
-
 if(NOT CMAKE_SYSTEM_PROCESSOR)
 	message(FATAL_ERROR "No target CPU architecture set")
 endif()
@@ -222,6 +219,20 @@ if(REPRODUCIBLE_BUILD)
 	add_definitions(-DID_REPRODUCIBLE_BUILD)
 endif()
 
+if(IMGUI)
+	if(SDL2)
+		# we need C++11 for ImGui
+		set (CMAKE_CXX_STANDARD 11)
+		message(STATUS "Dear ImGui integration enabled")
+	else()
+		message(WARNING "Disabling IMGUI because SDL1.2 is used - it needs SDL2!")
+		set(IMGUI OFF)
+		add_definitions(-DIMGUI_DISABLE)
+	endif()
+else()
+	message(STATUS "Dear ImGui integration disabled")
+	add_definitions(-DIMGUI_DISABLE)
+endif()
 
 find_package(CURL QUIET)
 if(CURL_FOUND)
@@ -757,6 +768,7 @@ set(src_idlib
 
 add_globbed_headers(src_idlib "idlib")
 
+if(IMGUI)
 set(src_imgui
 	libs/imgui/backends/imgui_impl_sdl2.cpp
 	libs/imgui/backends/imgui_impl_opengl2.cpp
@@ -773,6 +785,9 @@ set(src_imgui
 	sys/sys_imgui.cpp
 	sys/imgui_savestyle.cpp
 )
+else()
+set(src_imgui sys/sys_imgui.h)
+endif()
 
 
 set(src_game
diff --git a/neo/framework/Dhewm3SettingsMenu.cpp b/neo/framework/Dhewm3SettingsMenu.cpp
index 5c1df4f3..1d746f6e 100644
--- a/neo/framework/Dhewm3SettingsMenu.cpp
+++ b/neo/framework/Dhewm3SettingsMenu.cpp
@@ -1,9 +1,9 @@
+#ifndef IMGUI_DISABLE
 
 #define IMGUI_DEFINE_MATH_OPERATORS
 
 #include "Common.h"
 
-#ifndef IMGUI_DISABLE
 
 #include "idlib/LangDict.h"
 
@@ -2386,6 +2386,11 @@ void Com_Dhewm3Settings_f( const idCmdArgs &args )
 
 #else // IMGUI_DISABLE - just a stub function
 
-void Com_Dhewm3Settings_f( const idCmdArgs &args ) {}
+#include "Common.h"
+
+void Com_Dhewm3Settings_f( const idCmdArgs &args )
+{
+	common->Warning( "Dear ImGui is disabled in this build, so the dhewm3 settings menu is not available!" );
+}
 
 #endif