Implement gamedata loading from binary path

even if $PWD is not the same path as the executable is in, the game
will look for game data in directories next to the executable.

Makefile

@@ -574,6 +574,7 @@ GAME_OBJS_ = \
 
 # Used by the client
 CLIENT_OBJS_ := \
+	src/backends/generic/misc.o \
 	src/backends/generic/qal.o \
 	src/backends/generic/vid.o \
  	src/backends/generic/qgl.o \
@@ -698,7 +699,8 @@ SERVER_OBJS_ := \
 	src/server/sv_save.o \
 	src/server/sv_send.o \
 	src/server/sv_user.o \
-	src/server/sv_world.o
+	src/server/sv_world.o \
+	src/backends/generic/misc.o
 
 ifeq ($(OSTYPE), Windows)
 SERVER_OBJS_ += \

src/backends/generic/misc.c

@@ -0,0 +1,141 @@
+/*
+ * Copyright (C) 1997-2001 Id Software, Inc.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or (at
+ * your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
+ *
+ * See the GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
+ * 02111-1307, USA.
+ *
+ * =======================================================================
+ *
+ * This file implements some generic funktions
+ *
+ * =======================================================================
+ */
+
+#include <stdio.h>
+#include <string.h>
+
+#if defined(__linux) || defined(__FreeBSD__) || defined(__NetBSD__) || defined(__OpenBSD__)
+#include <unistd.h> // readlink(), amongst others
+#endif
+
+#ifdef __FreeBSD__
+#include <sys/sysctl.h> // for sysctl() to get path to executable
+#endif
+
+#ifdef _WIN32
+#include <windows.h> // GetModuleFileNameA()
+#endif
+
+#ifdef __APPLE__
+#include <mach-o/dyld.h> // _NSGetExecutablePath
+#endif
+
+#ifndef PATH_MAX
+// this is mostly for windows. windows has a MAX_PATH = 260 #define, but allows
+// longer paths anyway.. this might not be the maximum allowed length, but is
+// hopefully good enough for realistic usecases
+#define PATH_MAX 4096
+#define _DG__DEFINED_PATH_MAX
+#endif
+
+static void SetExecutablePath(char* exePath)
+{
+	// !!! this assumes that exePath can hold PATH_MAX chars !!!
+
+#ifdef _WIN32
+
+	DWORD len = GetModuleFileNameA(NULL, exePath, PATH_MAX);
+	if(len <= 0 || len == PATH_MAX)
+	{
+		// an error occured, clear exe path
+		exePath[0] = '\0';
+	}
+
+#elif defined(__linux) || defined(__NetBSD__) || defined(__OpenBSD__)
+
+	// all the platforms that have /proc/$pid/exe or similar that symlink the
+	// real executable - basiscally Linux and the BSDs except for FreeBSD which
+	// doesn't enable proc by default and has a sysctl() for this
+	char buf[PATH_MAX] = {0};
+#ifdef __linux
+	snprintf(buf, sizeof(buf), "/proc/%d/exe", getpid());
+#else // the BSDs
+	snprintf(buf, sizeof(buf), "/proc/%d/file", getpid());
+#endif
+	// readlink() doesn't null-terminate!
+	int len = readlink(buf, exePath, PATH_MAX-1);
+	if (len <= 0)
+	{
+		// an error occured, clear exe path
+		exePath[0] = '\0';
+	}
+	else
+	{
+		exePath[len] = '\0';
+	}
+
+#elif defined(__FreeBSD__)
+
+	// the sysctl should also work when /proc/ is not mounted (which seems to
+	// be common on FreeBSD), so use it..
+	int name[4] = {CTL_KERN, KERN_PROC, KERN_PROC_PATHNAME, -1};
+	size_t len = PATH_MAX-1;
+	int ret = sysctl(name, sizeof(name)/sizeof(name[0]), exePath, &len, NULL, 0);
+	if(ret != 0)
+	{
+		// an error occured, clear exe path
+		exePath[0] = '\0';
+	}
+
+#elif defined(__APPLE__)
+
+	uint32_t bufSize = PATH_MAX;
+	if(_NSGetExecutablePath(exePath, &bufSize) != 0)
+	{
+		// WTF, PATH_MAX is not enough to hold the path?
+		// an error occured, clear exe path
+		exePath[0] = '\0';
+	}
+
+	// TODO: realpath() ?
+	// TODO: no idea what this is if the executable is in an app bundle
+
+#else
+
+#error "Unsupported Platform!" // feel free to add implementation for your platform and send me a patch
+
+#endif
+}
+
+const char *Sys_GetBinaryDir(void)
+{
+	static char exeDir[PATH_MAX] = {0};
+
+	if(exeDir[0] != '\0') return exeDir;
+
+	SetExecutablePath(exeDir);
+
+	// cut off executable name
+	char* lastSlash = strrchr(exeDir, '/');
+#ifdef _WIN32
+	char* lastBackSlash = strrchr(exeDir, '\\');
+	if(lastSlash == NULL || lastBackSlash > lastSlash) lastSlash = lastBackSlash;
+#endif // _WIN32
+
+	if(lastSlash != NULL) lastSlash[1] = '\0'; // cut off after last (back)slash
+
+	return exeDir;
+}

src/common/filesystem.c

@@ -1368,7 +1368,7 @@ FS_AddHomeAsGameDirectory(char *dir)
 		return;
 	}
 
-    len = snprintf(gdir, sizeof(gdir), "%s%s/", home, dir);
+	len = snprintf(gdir, sizeof(gdir), "%s%s/", home, dir);
 	FS_CreatePath(gdir);
 
 	if ((len > 0) && (len < sizeof(gdir)) && (gdir[len - 1] == '/'))
@@ -1400,6 +1400,26 @@ FS_AddSystemwideGameDirectory(char *dir)
 }
 #endif
 
+void FS_AddBinaryDirAsGameDirectory(const char* dir)
+{
+	char gdir[MAX_OSPATH];
+	const char *datadir = Sys_GetBinaryDir();
+	if(datadir[0] == '\0')
+	{
+		return;
+	}
+	int len = snprintf(gdir, sizeof(gdir), "%s%s/", datadir, dir);
+
+	printf("Using binary dir %s to fetch paks\n", gdir);
+
+	if ((len > 0) && (len < sizeof(gdir)) && (gdir[len - 1] == '/'))
+	{
+		gdir[len - 1] = 0;
+	}
+
+	FS_AddGameDirectory(gdir);
+}
+
 /*
  * Allows enumerating all of the directories in the search path.
  */
@@ -1675,6 +1695,7 @@ FS_SetGamedir(char *dir)
 #endif
 
 		FS_AddGameDirectory(va("%s/%s", fs_basedir->string, dir));
+		FS_AddBinaryDirAsGameDirectory(dir);
 		FS_AddHomeAsGameDirectory(dir);
 	}
 }
@@ -2086,6 +2107,7 @@ FS_InitFilesystem(void)
 
 	/* Add baseq2 to search path. */
 	FS_AddGameDirectory(va("%s/" BASEDIRNAME, fs_basedir->string));
+	FS_AddBinaryDirAsGameDirectory(BASEDIRNAME);
 	FS_AddHomeAsGameDirectory(BASEDIRNAME);
 
 	/* Any set gamedirs will be freed up to here. */

src/common/header/common.h

@@ -793,6 +793,7 @@ void Sys_SendKeyEvents(void);
 void Sys_Error(char *error, ...);
 void Sys_Quit(void);
 char *Sys_GetHomeDir(void);
+const char *Sys_GetBinaryDir(void);
 
 void Sys_FreeLibrary(void *handle);
 void *Sys_LoadLibrary(const char *path, const char *sym, void **handle);