remove the assumption that game is ran from cwd at root

CMakeLists.txt

@@ -173,14 +173,14 @@ function(give_options_without_warnings target)
                                          ${BUILD_FLAGS}
                                          $<$<CONFIG:Release>:${BUILD_FLAGS_RELEASE}>
                                          $<$<CONFIG:Debug>:${BUILD_FLAGS_DEBUG}>
-                                         $<$<BOOL:${LINUX}>:-Wl,-rpath,./>)
+                                         $<$<BOOL:${LINUX}>:-Wl,-rpath,$ORIGIN/>)
 
         target_link_options(${target} PUBLIC
                                       ${BUILD_FLAGS}
                                       # -Wl,--no-undefined # TODO: use later for implementing no-libc
                                       $<$<CONFIG:Release>:${BUILD_FLAGS_RELEASE}>
                                       $<$<CONFIG:Debug>:${BUILD_FLAGS_DEBUG}>
-                                      $<$<BOOL:${LINUX}>:-Wl,-rpath,./>)
+                                      $<$<BOOL:${LINUX}>:-Wl,-rpath,$ORIGIN/>)
 
         target_compile_definitions(${target} PUBLIC
                                              ORGANIZATION_NAME="${ORGANIZATION_NAME}"

src/game_object/twn_linux_game_object.c

@@ -7,7 +7,7 @@
 #include <dlfcn.h>
 
 
-#define GAME_OBJECT_PATH "./libgame.so"
+#define GAME_OBJECT_NAME "libgame.so"
 #define MODIFIED_TICKS_MERGED 10
 
 
@@ -21,6 +21,7 @@ static uint64_t last_tick_modified;
 static bool loaded_after_modification = true;
 static SDL_mutex *lock;
 
+static char *game_object_path;
 
 static void load_game_object(void) {
     /* needs to be closed otherwise symbols aren't resolved again */
@@ -31,7 +32,7 @@ static void load_game_object(void) {
         game_end_callback = NULL;
     }
 
-    void *new_handle = dlopen(GAME_OBJECT_PATH, RTLD_LAZY);
+    void *new_handle = dlopen(game_object_path, RTLD_LAZY);
     if (!new_handle) {
         log_critical("Hot Reload Error: Cannot open game code shared object (%s)", dlerror());
         goto ERR_OPENING_SO;
@@ -95,10 +96,12 @@ static void watcher_callback(XWATCHER_FILE_EVENT event,
 
 
 void game_object_load(void) {
+    SDL_asprintf(&game_object_path, "%s%s", ctx.base_dir, GAME_OBJECT_NAME);
+
     watcher = xWatcher_create();
 
     xWatcher_reference dir;
-    dir.path = GAME_OBJECT_PATH;
+    dir.path = game_object_path;
     dir.callback_func = watcher_callback;
 
     xWatcher_appendFile(watcher, &dir);

src/system/linux/twn_elf.c

@@ -1,5 +1,6 @@
 #include "twn_elf.h"
 #include "twn_game_object_c.h"
+#include "twn_engine_context_c.h"
 
 #include <fcntl.h>
 #include <unistd.h>
@@ -9,6 +10,8 @@
 #define __USE_GNU
 #include <dlfcn.h>
 
+#include <SDL2/SDL.h>
+
 #include <stdbool.h>
 #include <stdio.h>
 #include <stdlib.h>
@@ -33,7 +36,8 @@ bool infer_elf_section_bounds(const char *const restrict name,
     } else {
         /* dynamically linked */
         from_shared_object = true;
-        memcpy(buf, "libgame.so", sizeof "libgame.so");
+        if (SDL_snprintf(buf, sizeof buf, "%s%s", ctx.base_dir, "libgame.so") < 0)
+            goto ERR_CANT_APPEND_BASE_PATH;
     }
 
     int elf = open(buf, O_RDONLY);
@@ -84,6 +88,7 @@ ERR_NOT_ELF:
     close(elf);
 
 ERR_CANT_OPEN_SELF:
+ERR_CANT_APPEND_BASE_PATH:
 ERR_CANT_READLINK:
     return result;
 }

src/twn_engine_context_c.h

@@ -21,6 +21,8 @@ typedef struct EngineContext {
     /* the program's actual argc and argv */
     int argc;
     char **argv;
+    /* where the app was run from, used as the root for packs */
+    char *base_dir;
 
     /* configuration */
     toml_table_t *config_table;

src/twn_loop.c

@@ -232,7 +232,7 @@ static void resolve_pack_dependencies(const char *pack_name) {
         }
 
         char *dep_pack_name;
-        if (SDL_asprintf(&dep_pack_name, "%s.btw", dep_name.u.s) == -1) {
+        if (SDL_asprintf(&dep_pack_name, "%s%s.btw", ctx.base_dir, dep_name.u.s) == -1) {
             CRY("resolve_pack_dependencies()", "Allocation error");
             SDL_free(dep_name.u.s);
             goto ERR_DEP_PATH_ALLOC_FAIL;
@@ -249,12 +249,21 @@ static void resolve_pack_dependencies(const char *pack_name) {
                 continue;
             }
 
-            if (!PHYSFS_mount(dep_source.u.s, "/", true))
+            char *dep_source_path;
+            if (SDL_asprintf(&dep_source_path, "%s%s", ctx.base_dir, dep_source.u.s) == -1) {
+                CRY("resolve_pack_dependencies()", "Allocation error");
+                SDL_free(dep_name.u.s);
+                SDL_free(dep_pack_name);
+                goto ERR_DEP_PATH_ALLOC_FAIL;
+            }
+
+            if (!PHYSFS_mount(dep_source_path, "/", true))
                 CRY("Cannot load pack", "Nothing is given to work with");
 
             log_info("Pack loaded: %s\n", dep_source.u.s);
 
             SDL_free(dep_source.u.s);
+            SDL_free(dep_source_path);
         } else
             log_info("Pack loaded: %s\n", dep_pack_name);
 
@@ -638,6 +647,7 @@ static void clean_up(void) {
     toml_free(ctx.config_table);
     PHYSFS_deinit();
 
+    SDL_free(ctx.base_dir);
     SDL_GL_DeleteContext(ctx.gl_context);
     SDL_Quit();
 }
@@ -652,6 +662,7 @@ static void reset_state(void) {
 int enter_loop(int argc, char **argv) {
     ctx.argc = argc;
     ctx.argv = argv;
+    ctx.base_dir = SDL_GetBasePath();
 
     /* needs to be done before anything else so config can be loaded */
     /* TODO: ANDROID: see the warning in physicsfs PHYSFS_init docs/header */
@@ -699,11 +710,17 @@ int enter_loop(int argc, char **argv) {
     /* data path not explicitly specified, look into convention defined places */
     if (!data_dir_mounted) {
         /* try mouning data folder first, relative to executable root */
-        if (!PHYSFS_mount("data", NULL, true)) {
+        char *full_path;
-            if (!PHYSFS_mount("data.btw", NULL, true))
+        SDL_asprintf(&full_path, "%sdata", ctx.base_dir);
+        if (!PHYSFS_mount(full_path, NULL, true)) {
+            SDL_free(full_path);
+            SDL_asprintf(&full_path, "%sdata.btw", ctx.base_dir);
+            if (!PHYSFS_mount(full_path, NULL, true))
+                SDL_free(full_path);
                 CRY_PHYSFS("Cannot find data.btw or data directory in root. Please create them or specify with --data-dir parameter.");
                 return EXIT_FAILURE;
         }
+        SDL_free(full_path);
     }
 
     if (!initialize())