Refactor idlist, move all global vars to local scope

- Replace list_foreach with LIST_FOREACH macro.
- Remove `game` global variable and make it local everywhere.
- Move global vars `fld`, `nxt` and `texts` into `game` struct.
- Add `static` qualifier to engine.c's specific global vars.
- Move `sfRenderWindow window` global var to local scope

3 files changed, 13 insertions, 3 deletions

diff --git a/include/common.h b/include/common.h
index 2273e4d..140044d 100644
--- a/include/common.h
+++ b/include/common.h
@@ -1,3 +1,5 @@
+struct field;
+
 struct game {
     size_t      level;
     int         started;
@@ -14,4 +16,8 @@ struct game {
     sfClock    *repPushDown;  // repeat latency when hold Down arrow
     sfClock    *repKeyLeft;   // repeat latency when hold Left arrow
     sfClock    *repKeyRight;  // repeat latency when hold Right arrow
+
+    struct field *fld;
+    struct field *nxt;
+    struct idlist *texts;
 };
diff --git a/include/engine.h b/include/engine.h
index 4e0ee33..48342e9 100644
--- a/include/engine.h
+++ b/include/engine.h
@@ -1,2 +1,4 @@
-void transition_init(void);
-void main_loop(void);
+struct game;
+
+void transition_init(struct game *game);
+void main_loop(struct game *);
diff --git a/include/idlist.h b/include/idlist.h
index c006a32..6d09e16 100644
--- a/include/idlist.h
+++ b/include/idlist.h
@@ -18,5 +18,7 @@ struct idlist  *list_new();
 struct idlist  *list_append(struct idlist *list);
 struct idlist  *list_get(const struct idlist *list, size_t id);
 void            list_rm_node(struct idlist *node);
-void            list_foreach(struct idlist *list, void (*job)(void *));
 void            list_destroy(struct idlist *list);
+
+#define LIST_FOREACH(head, e) \
+    for (struct idlist *e = head; e; e = e->next)