Try to get a good position to spawn at. Also gets a good initial move-direction based on where you spawn.

src/game/session/game_session.c

@@ -42,8 +42,8 @@ void game_session_init_default_settings(bool online, Game_Session_Settings *out_
     out_settings->seed         = 1337; // TODO: SS - Randomize.
     out_settings->online       = online;
     out_settings->tickrate     = 10.0;
-    out_settings->level_width  = 128;
-    out_settings->level_height = 64;
+    out_settings->level_width  = 32;
+    out_settings->level_height = 32;
     out_settings->max_players  = online ? 8 : 2;
 }
 

src/game/shared/game_world.c

@@ -31,11 +31,15 @@ Game_World *game_world_create(uint32_t seed, uint16_t level_width, uint16_t leve
     { // TEMP: SS - Testing ..
         for(uint16_t i = 0; i < 8; i++) {
             Entity_ID entity_food;
+
+            uint16_t x = 0;
+            uint16_t y = 0;
+            assert(game_world_find_position_to_spawn(w, &x, &y));
+            
             assert(game_world_create_entity(
                 w,
                 Entity_Type_Food,
-                (uint16_t)random_u32_range(&w->random_generator, 0, level_width),
-                (uint16_t)random_u32_range(&w->random_generator, 0, level_height),
+                x, y,
                 &entity_food
             ));
         }
@@ -128,3 +132,62 @@ Entity *game_world_try_get_entity_by_id(Game_World *world, Entity_ID id) {
 
     return &world->entities[id];
 }
+
+bool game_world_find_position_to_spawn(Game_World *world, uint16_t *out_x, uint16_t *out_y) {
+    assert(world != NULL);
+    assert(out_x != NULL);
+    assert(out_y != NULL);
+    
+    uint8_t attempts = MAX_ATTEMPTS_AT_FINDING_POSITION_TO_SPAWN;
+    while(attempts > 0) {
+        uint16_t potential_x = random_u32_range(&world->random_generator, 0, (uint32_t) world->grid.width);
+        uint16_t potential_y = random_u32_range(&world->random_generator, 0, (uint32_t) world->grid.height);
+
+        Grid_Cell *cell = grid_get_cell(&world->grid, potential_x, potential_y);
+        assert(cell != NULL);
+
+        // Check if cell is free.
+        if(cell->entity == NULL) {
+            *out_x = potential_x;
+            *out_y = potential_y;
+            return true;
+        }
+
+        if(attempts > 0) {
+            attempts -= 1;
+        }
+        else {
+            break;
+        }
+    }
+    
+    *out_x = 0;
+    *out_y = 0;
+    return false;
+}
+
+Entity_Movement_Direction game_world_choose_initial_move_direction_based_on_coords(Game_World *world, uint16_t x, uint16_t y) {
+    assert(world != NULL);
+
+    Grid *grid = &world->grid;
+    
+    // TODO: SS - Consider potential obstacles in the grid (lava, walls etc) if we ever have them.
+
+    if (x == 0) {
+        return Entity_Movement_Direction_Right;
+    }
+
+    if (x == grid->width - 1) {
+        return Entity_Movement_Direction_Left;
+    }
+
+    if (y == 0) {
+        return Entity_Movement_Direction_Down;
+    }
+
+    if (y == grid->height - 1) {
+        return Entity_Movement_Direction_Up;
+    }
+
+    return Entity_Movement_Direction_Up;
+}

src/game/shared/game_world.h

@@ -29,4 +29,9 @@ void game_world_destroy_entity(Game_World *world, Entity_ID entity_id, bool dest
 
 Entity *game_world_try_get_entity_by_id(Game_World *world, Entity_ID id);
 
+#define MAX_ATTEMPTS_AT_FINDING_POSITION_TO_SPAWN 8
+
+bool game_world_find_position_to_spawn(Game_World *world, uint16_t *out_x, uint16_t *out_y);
+Entity_Movement_Direction game_world_choose_initial_move_direction_based_on_coords(Game_World *world, uint16_t x, uint16_t y);
+
 #endif

src/game/simulation/simulation_world.c

@@ -62,18 +62,27 @@ void simulation_world_tick(Simulation_World *simulation_world) {
                 assert(!player->active);
                 player->active = true;
 
+                Game_World *gw = simulation_world->game_world;
+                assert(gw != NULL);
+                
+                uint16_t spawn_x = 0;
+                uint16_t spawn_y = 0;
+                assert(game_world_find_position_to_spawn(gw, &spawn_x, &spawn_y));
+                
                 assert(game_world_create_entity(
-                    simulation_world->game_world,
+                    gw,
                     Entity_Type_Snake_Head,
-                    i+6, 15, // NOTE: SS - Hardcoded spawn-position.
+                    spawn_x, spawn_y,
                     &player->entity_id
                 ));
 
-                Entity *player_entity = game_world_try_get_entity_by_id(simulation_world->game_world, player->entity_id);
+                Entity *player_entity = game_world_try_get_entity_by_id(gw, player->entity_id);
 
                 // Set initial move-direction for player-entities.
-                // The initial direction should probably take the spawn-position in to account.
-                player_entity->move_direction = Entity_Movement_Direction_Up;
+                player_entity->move_direction = game_world_choose_initial_move_direction_based_on_coords(
+                    gw,
+                    spawn_x, spawn_y
+                );
 
                 break;
             }

src/todo.md

@@ -1,10 +1,16 @@
 # TODO
+- [x] find_good_position_to_spawn()
+    - A lot of gameplay-functionality depends on this.
+- [x] Set initial move-direction based on where you spawn.
+    - Can be improved and take more things in to account.
+    - Right now it's only considering the size of of the grid, but what if we want to have obstacles in the grid?
+    - We also don't take if two players spawn one cell from each other in to consideration.
 - Add player-death.
     - [ ] Went out of bounds.
     - [ ] Hit other snake's head.
     - [ ] Hit yours/other snake's body.
 - Spawn players at a random position.
-    - [ ] When initially joining.
+    - [x] When initially joining.
     - [ ] When dead and should respawn.
 - Spawn food every N tick(?)
     - [ ] Spawn food at a random position every N tick.
@@ -13,6 +19,11 @@
         - This can easily be implemented later.
         - If we have that much food on the board, don't spawn new food.
         - Otherwise, spawn new food at a random position.
-- [ ] When a player disconnects, all children should recursively be destroyed too. Not just the head.
+- [x] When a player disconnects, all children should recursively be destroyed too. Not just the head.
+- [ ] Change player-movement?
+    - Only inputs needed are RIGHT and LEFT. Turn relative to your head.
+        - Right now we're moving relative to world-up.
+        - This would fix issues with invalid inputs, for example when the player inputs RIGHT when going LEFT.
+    - Make this an option later?
 - [ ] Sound effects + music.
 - [ ] Customize the session.