SCI: Add engine option for LSL7's "brutally difficult" mode

This was originally triggered by adding a file named GET_HARD to the
installation directory. But that's not very discoverable.

engines/sci/detection.h

@@ -43,6 +43,7 @@ namespace Sci {
 #define GAMEOPTION_PALETTE_MODS             GUIO_GAMEOPTIONS15
 #define GAMEOPTION_SQ1_BEARDED_MUSICIANS    GUIO_GAMEOPTIONS16
 #define GAMEOPTION_TTS                      GUIO_GAMEOPTIONS17
+#define GAMEOPTION_HARD_MODE                GUIO_GAMEOPTIONS18
 
 enum SciGameId {
 	GID_ALL,

engines/sci/detection_options.h

@@ -230,6 +230,18 @@ const ADExtraGuiOptionsMap optionsList[] = {
  	},
 #endif
 
+	{
+		GAMEOPTION_HARD_MODE,
+		{
+			_s("Enable hard mode"),
+			_s("Make the game \"brutally difficult\". This was originally triggered by the presence of a file named GET_HARD."),
+			"hard_mode",
+			false,
+			0,
+			0
+		}
+	},
+
 	AD_EXTRA_GUI_OPTIONS_TERMINATOR
 };
 

engines/sci/detection_tables.h

@@ -3666,12 +3666,13 @@ static const struct ADGameDescription SciGameDescriptions[] = {
 							 GUIO_NOMIDI, \
 							 GUIO_NOLAUNCHLOAD, \
 							 GAMEOPTION_LARRYSCALE)
-#define GUIO_LSL7      GUIO6(GUIO_NOASPECT, \
+#define GUIO_LSL7      GUIO7(GUIO_NOASPECT, \
 							 GUIO_NOMIDI, \
 							 GAMEOPTION_ENABLE_BLACK_LINED_VIDEO, \
 							 GAMEOPTION_ORIGINAL_SAVELOAD, \
 							 GAMEOPTION_HQ_VIDEO, \
-							 GAMEOPTION_LARRYSCALE)
+							 GAMEOPTION_LARRYSCALE, \
+							 GAMEOPTION_HARD_MODE)
 
 	// Larry 7 - English DOS Demo (provided by richiefs in bug report #4214)
 	// SCI interpreter version 2.100.002

engines/sci/engine/kfile.cpp

@@ -835,10 +835,19 @@ reg_t kFileIOExists(EngineState *s, int argc, reg_t *argv) {
 		}
 
 		int findSaveNo = -1;
-		if (g_sci->getGameId() == GID_LSL7 && name == "autosvsg.000") {
-			// LSL7 checks to see if the autosave save exists when deciding whether
-			// to go to the main menu or not on startup
-			findSaveNo = kAutoSaveId;
+		if (g_sci->getGameId() == GID_LSL7) {
+			if (name == "autosvsg.000") {
+				// LSL7 checks to see if the autosave save exists when deciding
+				// whether to go to the main menu or not on startup
+				findSaveNo = kAutoSaveId;
+			} else if (name == "get_hard") {
+				// As mentioned in the Spring 1997 issue of Interaction
+				// Magazine, page 58, placing a file named GET_HARD in your
+				// game directory will make the game "brutally difficult" in
+				// ways never really explained. But that's not really
+				// discoverable, so we make it an option instead.
+				return ConfMan.getBool("hard_mode") ? TRUE_REG : NULL_REG;
+			}
 		} else if (g_sci->getGameId() == GID_RAMA) {
 			// RAMA checks to see if save game files exist before showing them in
 			// the native save/load dialogue