map: implement seeded generation; allow passing custom seed

Signed-off-by: NotAShelf <raf@notashelf.dev>
Change-Id: I742b7e59c7ca872539d4ebfe3a03b44f6a6a6964

src/common.h

@@ -173,6 +173,8 @@ typedef struct {
   int potions_used;
   int floors_reached;
   int final_score;
+  // Seed for this run
+  unsigned int run_seed;
 } GameState;
 
 

src/main.c

@@ -12,7 +12,9 @@
 #include "settings.h"
 #include <stddef.h>
 #include <stdio.h>
+#include <stdlib.h>
 #include <string.h>
+#include <time.h>
 
 // Add message to action log
 static void add_log(GameState *gs, const char *msg) {
@@ -102,11 +104,14 @@ static void update_effects(GameState *gs) {
 
 // Initialize a new floor
 static void init_floor(GameState *gs, int floor_num) {
+  // Seed RNG with run seed combined with floor number for deterministic generation
+  rng_seed(gs->run_seed + floor_num * 54321);
+
   // Generate dungeon
   dungeon_generate(&gs->dungeon, &gs->map, floor_num);
 
   // Seed rng for this floor's content
-  rng_seed(floor_num * 54321);
+  rng_seed(gs->run_seed + floor_num * 98765);
 
   // Find spawn position
   int start_x, start_y;
@@ -477,7 +482,9 @@ static int handle_input(GameState *gs) {
 
   // Check for restart (works during game over)
   if (IsKeyPressed(KEY_R) && gs->game_over) {
+    unsigned int saved_seed = gs->run_seed;
     memset(gs, 0, sizeof(GameState));
+    gs->run_seed = saved_seed;
     init_floor(gs, 1);
     return 0;
   }
@@ -508,12 +515,12 @@ void load_audio_assets(GameState *gs) {
 }
 
 // Main game loop
-static void game_loop(void) {
+static void game_loop(unsigned int run_seed) {
   GameState gs;
   memset(&gs, 0, sizeof(GameState));
+  gs.run_seed = run_seed;
   load_audio_assets(&gs);
   // Initialize first floor
-  rng_seed(12345);
   init_floor(&gs, 1);
 
   // Disable esc to exit
@@ -532,7 +539,9 @@ static void game_loop(void) {
       if (IsKeyPressed(KEY_Q))
         break;
       if (IsKeyPressed(KEY_R)) {
+        unsigned int saved_seed = gs.run_seed;
         memset(&gs, 0, sizeof(GameState));
+        gs.run_seed = saved_seed;
         gs.game_over = 0;
         gs.game_won = 0;
         load_audio_assets(&gs);
@@ -599,7 +608,23 @@ static void game_loop(void) {
   }
 }
 
-int main(void) {
+int main(int argc, char **argv) {
+  // Parse command-line arguments
+  unsigned int run_seed = 0;
+  for (int i = 1; i < argc; i++) {
+    if (strcmp(argv[i], "--seed") == 0 && i + 1 < argc) {
+      run_seed = (unsigned int)atoi(argv[i + 1]);
+      i++;  // Skip the value
+    }
+  }
+
+  // If no seed provided, generate random seed from time
+  if (run_seed == 0) {
+    run_seed = (unsigned int)time(NULL);
+  }
+
+  printf("Starting game with seed: %u\n", run_seed);
+
   // Initialize audio
   audio_init();
   // Initialize random number generator
@@ -609,7 +634,7 @@ int main(void) {
   SetTargetFPS(60);
 
   // Run game
-  game_loop();
+  game_loop(run_seed);
 
   // Cleanup
   CloseWindow();

src/map.c

@@ -170,9 +170,6 @@ void get_random_floor_tile(Map *map, int *x, int *y, int attempts) {
 }
 
 void dungeon_generate(Dungeon *d, Map *map, int floor_num) {
-  // Seed RNG with floor number for deterministic generation
-  rng_seed(floor_num * 12345);
-
   // Initialize map to all walls
   map_init(map);