Add portable engine mode

Default on every homebrew platform and Windows
Needed to ignore installation paths and not writing configuration in
$HOME on e.g. Linux or *BSD platforms

BUILDING.md

@@ -35,6 +35,8 @@ http://www.alister.eu/jazz/oj/build.php
 
 - `DATAPATH` - add a fixed path for game data files
 - `SCALE` - enable scaling of the video output (i.e. Scale2X...)
+- `PORTABLE` - Do not use external directories for configuration saving, etc.
+  (This only affects Unix platforms, Windows version is always portable)
 
 Some ports have their own options, see (Platforms)[PLATFORMS.md] for details.
 

CMakeLists.txt

@@ -1,4 +1,4 @@
-cmake_minimum_required(VERSION 3.13...3.24)
+cmake_minimum_required(VERSION 3.16...3.27)
 
 project(OpenJazz
 	VERSION 20220827
@@ -17,6 +17,7 @@ set(CMAKE_CXX_STANDARD_REQUIRED OFF)
 
 # platform
 
+include(CMakeDependentOption)
 include(Platform-Helpers)
 
 # Endianess check
@@ -124,16 +125,30 @@ target_include_directories(OpenJazz PUBLIC src)
 
 # Default Options
 
+set(SCALE_STATUS "Disabled")
 option(SCALE "Allow scaling" ${OJ_SCALE})
 if(SCALE)
+	set(SCALE_STATUS "Enabled, scale2x")
 	target_compile_definitions(OpenJazz PRIVATE SCALE)
 	set(OJ_LIBS_SCALE scale2x)
 endif()
 
+cmake_dependent_option(PORTABLE "Do not write to external directories, etc." OFF
+	"NOT OJ_DEFAULT_PORTABLE" ON)
+if(PORTABLE)
+	set(PORTABLE_STATUS "Enabled")
+	target_compile_definitions(OpenJazz PRIVATE PORTABLE)
+else()
+	set(PORTABLE_STATUS "Disabled")
+endif()
+if((PORTABLE AND OJ_DEFAULT_PORTABLE) OR (NOT PORTABLE AND NOT OJ_DEFAULT_PORTABLE))
+	set(PORTABLE_STATUS "${PORTABLE_STATUS} (Default)")
+endif()
+
 # path to game data
 
 set(DATAPATH "" CACHE PATH "Fixed path where game data is available")
-if(${DATAPATH})
+if(DATAPATH)
 	target_compile_definitions(OpenJazz PRIVATE DATAPATH="${DATAPATH}")
 endif()
 
@@ -349,7 +364,12 @@ if(ROMFS)
 	message(STATUS "RomFS: Embedding directory \"${ROMFS_PATH}\"")
 endif()
 message(STATUS "Network: ${NETWORK_STATUS}")
+message(STATUS "Scaling: ${SCALE_STATUS}")
+if(DATAPATH)
+	message(STATUS "Additional/System Game Data Path: \"${DATAPATH}\"")
+endif()
 message(STATUS "Manual page: ${MANUAL_STATUS}")
+message(STATUS "Portable Engine: ${PORTABLE_STATUS}")
 message(STATUS "")
 message(STATUS "In case something goes wrong, report bugs to https://github.com/AlisterT/openjazz/issues")
 message(STATUS "")

Makefile

@@ -4,7 +4,8 @@ include openjazz.mk
 # Sane defaults
 CXX ?= g++
 CXXFLAGS ?= -g -Wall -O2
-CPPFLAGS = -Isrc -DSCALE -Iext/scale2x -Iext/psmplug -Iext/miniz -Iext/argparse
+DEFINES = -DSCALE -DPORTABLE
+CPPFLAGS = $(DEFINES) -Isrc -Iext/scale2x -Iext/psmplug -Iext/miniz -Iext/argparse
 
 # Network support
 CXXFLAGS += -DUSE_SOCKETS

builds/cmake/Platform-Helpers.cmake

@@ -4,6 +4,7 @@ set(PLATFORM_LIST "")
 set(OJ_SCALE ON)
 set(OJ_LIBS_NET)
 set(OJ_LIBS_HOST)
+set(OJ_DEFAULT_PORTABLE ON)
 
 option(PANDORA "Build for Pandora" OFF)     # arm-none-linux-gnueabi
 option(CAANOO "Build for GP2X Canoo" OFF)   # arm-gph-linux-gnueabi
@@ -113,8 +114,12 @@ endif()
 if(${OJ_HOST} STREQUAL "Unknown")
 	set(OJ_HOST ${CMAKE_SYSTEM_NAME})
 	set(OJ_ALLOW_NEW_SDL TRUE)
+
+	if(UNIX)
+		# usually we do a system-wide installation
+		set(OJ_DEFAULT_PORTABLE OFF)
+	endif()
 endif()
 
 # choose SDL library for Linux/Windows/Mac/etc., but not homebrew platforms
-include(CMakeDependentOption)
 cmake_dependent_option(LEGACY_SDL "Build for SDL 1.2" OFF "OJ_ALLOW_NEW_SDL" ON)

src/main.cpp

@@ -158,20 +158,12 @@ void startUp (const char *argv0, int pathCount, char *paths[]) {
 
 	// Determine paths
 
-	// Use hard-coded data paths, if available
-#ifdef DATAPATH
-	gamePaths.add(createString(DATAPATH), PATH_TYPE_SYSTEM|PATH_TYPE_GAME);
-#endif
-
 	PLATFORM_AddGamePaths();
 
 	// Use any provided paths
-	for (int i = 0; i < pathCount; i++) {
-
+	for (int i = 0; i < pathCount; i++)
 		gamePaths.add(createString(paths[i]), PATH_TYPE_GAME);
 
-	}
-
 
 	// Use the path of the program, but check before, since it is not always available
 	// At least crashes in Dolphin emulator (Wii) and 3DS (.cia build)
@@ -193,9 +185,13 @@ void startUp (const char *argv0, int pathCount, char *paths[]) {
 
 	}
 
-	// Last Resort: Use the current working directory
+	// Use the current working directory
 	gamePaths.add(createString(""), PATH_TYPE_GAME|PATH_TYPE_CONFIG|PATH_TYPE_TEMP);
 
+	// Use hard-coded data paths, if available
+#ifdef DATAPATH
+	gamePaths.add(createString(DATAPATH), PATH_TYPE_SYSTEM|PATH_TYPE_GAME);
+#endif
 
 	// Default settings
 

src/platforms/platforms.h

@@ -80,7 +80,10 @@ inline void PLATFORM_AddGamePaths() {
 
 // using __unix__ might add too much
 #if (__linux__ && !__ANDROID__) || __FreeBSD__ || __OpenBSD__
+	#ifndef PORTABLE
+	// Only use XDG dirs for installed package
 	XDG_AddGamePaths();
+	#endif
 #endif
 }