meson: fixed some install_relative issues

meson.build

@@ -122,9 +122,16 @@ else
     endif
 endif
 
+if get_option('install_freedesktop') == 'auto'
+    install_xdg = not config.get('TAISEI_BUILDCONF_RELATIVE_DATA_PATH')
+else
+    install_xdg = get_option('install_freedesktop') == 'true'
+endif
+
 if config.get('TAISEI_BUILDCONF_RELATIVE_DATA_PATH')
     data_path = 'data'
-    doc_path = '.'
+    doc_path = ''
+    xdg_path = 'freedesktop.org'
 
     if macos_app_bundle
         # This is relative to SDL_GetBasePath(), which will return '/path/to/Taisei.app/Contents/Resources' for a macOS bundle.
@@ -132,6 +139,9 @@ if config.get('TAISEI_BUILDCONF_RELATIVE_DATA_PATH')
 
         # Actual installation path
         data_path = join_paths(datadir, data_path)
+
+        # I don't know why would you do that, but more power to you
+        xdg_path = join_paths(datadir, xdg_path)
     else
         # HACK
         rel_dpath = []
@@ -142,12 +152,13 @@ if config.get('TAISEI_BUILDCONF_RELATIVE_DATA_PATH')
         endforeach
         rel_dpath += data_path
 
-        config.set_quoted('TAISEI_BUILDCONF_DATA_PATH', format(join_paths(rel_dpath)))
+        config.set_quoted('TAISEI_BUILDCONF_DATA_PATH', join_paths(rel_dpath))
     endif
 else
     data_path = join_paths(datadir, 'taisei')
     config.set_quoted('TAISEI_BUILDCONF_DATA_PATH', join_paths(get_option('prefix'), data_path))
     doc_path = join_paths(datadir, 'doc', 'taisei')
+    xdg_path = data_path
 endif
 
 if get_option('buildtype').startswith('debug')
@@ -195,9 +206,12 @@ Summary:
         taisei_deps.contains(dep_zip),
         config.get('TAISEI_BUILDCONF_RELATIVE_DATA_PATH'),
         get_option('prefix'),
-        bindir,
-        data_path,
-        doc_path,
+
+        # the $ is intentional
+        join_paths('$prefix', bindir),
+        join_paths('$prefix', data_path),
+        join_paths('$prefix', doc_path),
+
         get_option('buildtype'),
         taisei_version_string
     )

meson_options.txt

@@ -2,10 +2,10 @@ option('version_fallback', type : 'string', description : 'Overrides the version
 option('enable_audio', type : 'combo', choices : ['auto', 'true', 'false'], description : 'Enable audio support (needs SDL2_mixer)')
 option('package_data', type : 'combo', choices : ['auto', 'true', 'false'], description : 'Package the game’s assets into a compressed archive instead of bundling plain files (needs libzip)')
 option('install_relative', type : 'combo', choices : ['auto', 'true', 'false'], description : 'Use only relative paths to the executable and install everything in the same directory. Always enabled for macOS bundles')
+option('install_freedesktop', type : 'combo', choices : ['auto', 'true', 'false'], description : 'Install freedesktop.org integration files (launchers, icons, replay file associations, etc.). Mostly relevant for Linux/BSD/etc. desktop systems')
 option('win_console', type : 'boolean', value : false, description : 'Use the console subsystem on Windows')
 option('static', type : 'boolean', value : false, description : 'Build statically linked executable')
 option('intel_intrin', type : 'boolean', value : true, description : 'Use some x86-specific intrinsics for optimizations where appropriate (if possible). Note that this is not equivalent to e.g. supplying -march in CFLAGS')
-
 option('macos_bundle', type : 'boolean', value : true, description : 'Make a macOS application bundle on install (ignored on other platforms)')
 option('macos_lib_path', type : 'string', description : 'List of paths (separated like the PATH environment variable) from where required runtime libraries will be copied into the bundle (useful for cross-compiling)')
 option('macos_tool_path', type : 'string', description : 'List of paths (separated like the PATH environment variable) from where macOS-specific utilities (such as otool and install_name_tool) can be found. This is prepended to PATH (useful for cross-compiling)')

xdg/meson.build

@@ -1,10 +1,10 @@
-if host_machine.system() != 'windows' and host_machine.system() != 'darwin'
+if install_xdg
     install_data('taisei-replay-viewer.desktop', 'taisei.desktop',
-                 install_dir : join_paths(get_option('datadir'), 'applications'))
+                 install_dir : join_paths(xdg_path, 'applications'))
     install_data('taisei.png',
-                 install_dir : join_paths(get_option('datadir'), 'icons/hicolor/128x128/apps'))
+                 install_dir : join_paths(xdg_path, 'icons/hicolor/128x128/apps'))
     install_data('taisei-replay.png',
-                 install_dir : join_paths(get_option('datadir'), 'icons/hicolor/256x256/mimetypes'))
+                 install_dir : join_paths(xdg_path, 'icons/hicolor/256x256/mimetypes'))
     install_data('taisei.xml',
-                 install_dir : join_paths(get_option('datadir'), 'mime/packages'))
+                 install_dir : join_paths(xdg_path, 'mime/packages'))
 endif