Allow setting game directory from CLI; add -v flag

- Use the directory the binary is in as the default path, so you can use
  "./games/fallout/fallout-ce" without having to cd to that directory.

- Also allow setting the game directory from argv.

- Add -v option for verbose information; this was protected by a _DEBUG
  preprocessor flag, and not having to recompile is helpful.

- Output GNWSystemError() to stderr as well. For whatever reason I don't
  get any popup window (not sure why), so the game would simply exit
  without any information. It doesn't hurt to print it anyway.

- Add -h flag to document all of this.

Note: I only tested this on my Linux system, as that's the only machine
I have access to. In particular, I'm not entirely sure if my usage of
PathRemoveFileSpecA() is correct, but I have no way to test it.

Also clarify which values are read from f1_res.ini, as per my reading of
src/plib/gnw/svga.cc (Fixes #84).

CMakeLists.txt

@@ -281,6 +281,7 @@ endif()
 if(WIN32)
     target_link_libraries(${EXECUTABLE_NAME}
         winmm
+        Shlwapi
     )
 endif()
 

README.md

@@ -16,6 +16,8 @@ Download and copy `fallout-ce.exe` to your `Fallout` folder. It serves as a drop
 
 - Use Windows installation as a base - it contains data assets needed to play. Copy `Fallout` folder somewhere, for example `/home/john/Desktop/Fallout`.
 
+- Make sure the `DATA` directory is in lower-case.
+
 - Download and copy `fallout-ce` to this folder.
 
 - Install [SDL2](https://libsdl.org/download-2.0.php):
@@ -77,15 +79,26 @@ The second configuration file is `f1_res.ini`. Use it to change game window size
 SCR_WIDTH=1280
 SCR_HEIGHT=720
 WINDOWED=1
+SCALE_2X=1
 ```
 
+It only reads these values from `f1_res.ini`; all other values are ignored.
+
 Recommendations:
 - **Desktops**: Use any size you see fit.
 - **Tablets**: Set these values to logical resolution of your device, for example iPad Pro 11 is 1668x2388 (pixels), but it's logical resolution is 834x1194 (points).
 - **Mobile phones**: Set height to 480, calculate width according to your device screen (aspect) ratio, for example Samsung S21 is 20:9 device, so the width should be 480 * 20 / 9 = 1067.
 
 In time this stuff will receive in-game interface, right now you have to do it manually.
 
+You can use `[section]name=value` from the commandline to override values from the configuration file. For example:
+
+    % ./fallout1-ce ~/games/fallout '[preferences]brightness=2'
+
+Note that the CLI values will be written to `fallout.cfg`! Overriding values from `f1_res.ini` is not supported.
+
+Add `-v` to show more debug information.
+
 ## Contributing
 
 Here is a couple of current goals. Open up an issue if you have suggestion or feature request.

src/game/game.cc

@@ -1211,7 +1211,7 @@ static int game_init_databases()
 
     master_db_handle = db_init(main_file_name, NULL, patch_file_name, 1);
     if (master_db_handle == INVALID_DATABASE_HANDLE) {
-        GNWSystemError("Could not find the master datafile. Please make sure the FALLOUT CD is in the drive and that you are running FALLOUT from the directory you installed it to.");
+        GNWSystemError("Could not find MASTER.DAT. Please make sure that you are running FALLOUT from the directory you installed it to.");
         return -1;
     }
 
@@ -1228,7 +1228,7 @@ static int game_init_databases()
     critter_db_handle = db_init(main_file_name, NULL, patch_file_name, 1);
     if (critter_db_handle == INVALID_DATABASE_HANDLE) {
         db_select(master_db_handle);
-        GNWSystemError("Could not find the critter datafile. Please make sure the FALLOUT CD is in the drive and that you are running FALLOUT from the directory you installed it to.");
+        GNWSystemError("Could not find CRITTER.DAT. Please make sure that you are running FALLOUT from the directory you installed it to.");
         return -1;
     }
 

src/game/gconfig.cc

@@ -1,9 +1,19 @@
 #include "game/gconfig.h"
 
 #include <stdio.h>
+#include <stdlib.h>
 #include <string.h>
 
+#ifdef _WIN32
+#include <direct.h>
+#include <shlwapi.h>
+#else
+#include <libgen.h>
+#include <unistd.h>
+#endif
+
 #include "platform_compat.h"
+#include "plib/gnw/debug.h"
 
 namespace fallout {
 
@@ -119,6 +129,52 @@ bool gconfig_init(bool isMapper, int argc, char** argv)
         config_set_value(&game_config, GAME_CONFIG_MAPPER_KEY, GAME_CONFIG_DEFAULT_F8_AS_GAME_KEY, 1);
     }
 
+    char* gamedir = NULL;
+    for (int i = 1; i < argc; i++) {
+        if (strlen(argv[i]) < 2 || argv[i][0] != '-') {
+            if (gamedir == NULL && strchr(argv[i], '[') == NULL && strchr(argv[i], ']') == NULL)
+                gamedir = argv[i];
+            continue;
+        }
+
+        switch (argv[i][1]) {
+        case 'v':
+            do_debug = true;
+            break;
+        case 'h':
+            printf("usage: %s [-v] [game_dir] [option...]\n"
+                   "\n"
+                   "Flags:\n"
+                   "  -v           Print more information.\n\n"
+                   "  game_dir     Fallout installation directory; defaults to directory binary\n"
+                   "               is in.\n\n"
+                   "  option       Any list of option to override from fallout.cfg\n"
+                   "               as \"[section]key=value\" Note that new value will be written\n"
+                   "               to fallout.cfg! Overriding values from f1_res.ini is not\n"
+                   "               supported.\n\n",
+                argv[0]);
+            exit(0);
+        }
+    }
+    if (gamedir == NULL) {
+#if _WIN32
+        gamedir = (char*)calloc(strlen(argv[0]), sizeof(char));
+        strcpy(gamedir, argv[0]);
+        PathRemoveFileSpecA(gamedir);
+#else
+        gamedir = dirname(argv[0]);
+#endif
+        if (gamedir == NULL) {
+            perror("resolving argv[0]");
+            exit(1);
+        }
+    }
+    debug_printf("game directory: %s\n", gamedir);
+    if (chdir(gamedir) == -1) {
+        perror("changing to game directory");
+        exit(1);
+    }
+
     // Make `fallout.cfg` file path.
     sep = strrchr(argv[0], '\\');
     if (sep != NULL) {

src/plib/gnw/debug.cc

@@ -13,6 +13,8 @@
 
 namespace fallout {
 
+bool do_debug = false;
+
 static int debug_mono(char* string);
 static int debug_log(char* string);
 static int debug_screen(char* string);
@@ -143,9 +145,8 @@ int debug_printf(const char* format, ...)
 
         rc = debug_func(string);
     } else {
-#ifdef _DEBUG
-        SDL_LogMessageV(SDL_LOG_CATEGORY_APPLICATION, SDL_LOG_PRIORITY_INFO, format, args);
-#endif
+        if (do_debug)
+            SDL_LogMessageV(SDL_LOG_CATEGORY_APPLICATION, SDL_LOG_PRIORITY_INFO, format, args);
         rc = -1;
     }
 

src/plib/gnw/debug.h

@@ -5,6 +5,8 @@ namespace fallout {
 
 typedef int(DebugFunc)(char* string);
 
+extern bool do_debug;
+
 void GNW_debug_init();
 void debug_register_mono();
 void debug_register_log(const char* fileName, const char* mode);

src/plib/gnw/gnw.cc

@@ -1351,6 +1351,8 @@ static int colorClose(void* handle)
 // 0x4C42B8
 bool GNWSystemError(const char* text)
 {
+    fprintf(stderr, "%s\n", text);
+
     SDL_Cursor* prev = SDL_GetCursor();
     SDL_Cursor* cursor = SDL_CreateSystemCursor(SDL_SYSTEM_CURSOR_ARROW);
     SDL_SetCursor(cursor);