core: mod: create a mod interface

Create a skeleton mod interface so that the engine can load shared
libraries or DLLs as in-game mods. The API should be compiler agnostic
as much as possible.

Signed-off-by: Danny Holman <dholman@gymli.org>

1 files changed, 69 insertions, 0 deletions

diff --git a/core/mod.c b/core/mod.c
new file mode 100644
index 0000000..4a4eac8
--- /dev/null
+++ b/core/mod.c
@@ -0,0 +1,69 @@
+#include <rune/core/mod.h>
+#include <rune/core/logging.h>
+#include <rune/core/alloc.h>
+#include <stdio.h>
+#include <string.h>
+#include <dirent.h>
+#include <dlfcn.h>
+
+struct list_head *mods = NULL;
+
+void _load_mod(const char *filename) {
+        char mod_path[4096];
+        sprintf(mod_path, "mods/%s", filename);
+        void *handle = dlopen(mod_path, RTLD_LAZY);
+        if (handle == NULL)
+                log_output(LOG_ERROR, "Error loading mod %s: %s", filename, dlerror());
+}
+
+void rune_load_mods(void) {
+        DIR *dir = opendir("mods");
+        if (dir == NULL) {
+                log_output(LOG_INFO, "No mods folder found, skipping mod loading");
+                return;
+        }
+
+        struct dirent *mods_de;
+        while ((mods_de = readdir(dir)) != NULL) {
+                if (strstr(mods_de->d_name, ".so"))
+                        _load_mod(mods_de->d_name);
+        }
+}
+
+void rune_init_mods(void) {
+        struct list_head *temp = mods;
+        struct mod *mod;
+        while (temp != NULL) {
+                mod = (struct mod*)((void*)temp - offsetof(struct mod, list));
+                (*mod->init_func)();
+                temp = temp->next;
+        }
+}
+
+void rune_close_mods(void) {
+        if (mods == NULL)
+                return;
+
+        struct list_head *temp = mods;
+        struct mod *mod;
+        while (temp != NULL) {
+                mod = (struct mod*)((void*)temp - offsetof(struct mod, list));
+                (*mod->exit_func)();
+                temp = temp->next;
+                rune_free(mod);
+        }
+}
+
+void rune_register_mod(const char *name, mod_func init_func, mod_func exit_func, mod_func update_func) {
+        struct mod *new = rune_alloc(sizeof(struct mod));
+        new->name = name;
+        new->init_func = init_func;
+        new->exit_func = exit_func;
+        new->update_func = update_func;
+        new->list.next = NULL;
+        new->list.prev = NULL;
+        if (mods == NULL)
+                mods = &new->list;
+        else
+                list_add(&new->list, mods);
+}