Refactor/RNG system (#476)

* Extract rng manipulation to its own file

* clang format

* Get CPU cycles since game start to use for RNG

* change a few things

* clang format

* Implement suggestions from @ricfehr3

* clang format

* Fix rebase issue

* clang format

* Create RngInfo struct to hold seed and step

* clang format

* Make a note about rng_restore system not having been tested properly yet

* Apply suggestions from @ricfehr3

Co-authored-by: Rickey <ric@rf3.xyz>

* clang format

---------

Co-authored-by: MathisMartin31 <mathis.martin31@gmail.com>
Co-authored-by: Rickey <ric@rf3.xyz>

source/game/game_over.c

@@ -7,6 +7,7 @@
 #include "game/main_menu.h"
 #include "graphic_utils.h"
 #include "layout.h"
+#include "random.h"
 #include "soundbank.h"
 #include "timer.h"
 #include "util.h"
@@ -128,4 +129,5 @@ void game_over_on_exit(void)
 {
     condition = END_CONDITION_NONE;
     game_reset();
+    rng_shuffle_seed();
 }

source/game/main_menu.c

@@ -127,14 +127,6 @@ void game_main_menu_on_update(void)
     main_menu_ace->sprite_object->trotation = lu_sin((g_game_vars.timer << 8) / 2) / 3;
     card_object_update(main_menu_ace);
 
-    // Seed randomization
-    g_game_vars.rng_seed++;
-    // If the keys have changed, make it more pseudo-random
-    if (key_curr_state() != key_prev_state())
-    {
-        g_game_vars.rng_seed *= 2;
-    }
-
     selection_grid_process_input(&main_menu_selection_grid);
 }
 

source/game/shop.c

@@ -17,6 +17,7 @@
 #include "joker.h"
 #include "layout.h"
 #include "list.h"
+#include "random.h"
 #include "save.h"
 #include "soundbank.h"
 #include "timer.h"
@@ -196,7 +197,7 @@ static inline int game_shop_get_rand_available_joker_id(void)
         return UNDEFINED;
 
     int matching_joker_ids[jokers_avail_size];
-    int fallback_random_idx = get_rand() % jokers_avail_size;
+    int fallback_random_idx = rng_get_u32() % jokers_avail_size;
     int fallback_random_joker_id = UNDEFINED;
     int match_count = 0;
 
@@ -215,8 +216,8 @@ static inline int game_shop_get_rand_available_joker_id(void)
         }
     }
 
-    int selected_joker_id =
-        (match_count > 0) ? matching_joker_ids[get_rand() % match_count] : fallback_random_joker_id;
+    int selected_joker_id = (match_count > 0) ? matching_joker_ids[rng_get_u32() % match_count]
+                                              : fallback_random_joker_id;
 
     return selected_joker_id;
 }