implementation of map change during gameplay by crossing map borders

src/main.c

@@ -32,11 +32,11 @@ extern Map *worldRPG[];
 /* Game data (defined in "game.h")*/
 Game game = {
     NULL,
-    {10*PXSIZE, 48*PXSIZE, 0, 0, 0, 0, 100, SPEED},
+    {10*PXSIZE, 48*PXSIZE, 0, 0, 10*PXSIZE, 48*PXSIZE, 100, SPEED},
     false, false, false, 0
 
     /* debug variables*/
-    , false, false
+    , false, true
 }; 
 
 /* screen capture management code */
@@ -93,7 +93,7 @@ int main(void) {
     }
     timer_start(timer);
 
-    game.map_level = worldRPG[2];
+    game.map_level = worldRPG[0];
 
 
     #if USB_FEATURE

src/map.c

@@ -199,7 +199,7 @@ short int get_tile(Game *game, int x, int y, int l) {
     
     /* Get the tile at (x, y) on layer l. Returns the tile ID or MAP_OUTSIDE if
      * she's not found. */
-    return x>=0 && x < map_level->w && y>=0 && y < map_level->h ?
+    return (x>=0 && x < map_level->w && y>=0 && y < map_level->h) ?
         map_level->layers[l][y * map_level->w + x] : MAP_OUTSIDE;
 }
 
@@ -208,7 +208,7 @@ short int get_walkable(Game *game, int x, int y) {
     Map *map_level = game->map_level;
     /* Get the tile at (x, y). Returns the tile ID or MAP_OUTSIDE if she's not
      * found. */
-    return x>=0 && x < map_level->w && y>=0 && y < map_level->h ?
+    return (x>=0 && x < map_level->w && y>=0 && y < map_level->h) ?
         map_level->walkable[y * map_level->w + x] : MAP_OUTSIDE;
 }
 
@@ -231,7 +231,7 @@ Map *get_map_for_coordinates( Game *game, int x, int y )
         i++;
         current = worldRPG[i];
     }
-    while (current!=NULL)
+    while (current!=NULL);
     
     /* else we return NULL cause the point is a not within a map */
     return NULL;

src/player.c

@@ -41,6 +41,7 @@ void player_move(Game *game, Direction direction) {
     
     /* If the player will collide with a hard tile or if the will go outside of
      * the map. */
+  
     if(player_collision(game, direction, P_CENTER)){
         
         /* If the will collide with the center of the player. */
@@ -102,7 +103,32 @@ bool player_collision(Game *game, Direction direction,
     int player_tile_x = player->x+dx;
     int player_tile_y = player->y+dy;
     
-    /* Handle a negative position diffrently than a positive one. */
+    /* check where the player is expected to go on the next move */
+    /* if outside the map, we check if there is a map on the other */
+    /* side of the current map*/
+    if (get_walkable(game, player_tile_x, player_tile_y) == MAP_OUTSIDE)
+    {
+        // we compute the expected world coordinates accordingly
+        // while taking care of the scaling between fx and cg models (PXSIZE)
+        int worldX = (player->wx+dx) / PXSIZE;
+        int worldY = (player->wy+dy) / PXSIZE;
+        Map *map = get_map_for_coordinates(game, worldX, worldY );
+        if (map!=NULL && map!=game->map_level)
+        {
+            game->map_level = map;
+
+            player->wx = worldX * PXSIZE;
+            player->wy = worldY * PXSIZE;
+
+            player->x = (worldX - map->xmin ) * PXSIZE;
+            player->y = (worldY - map->ymin ) * PXSIZE;
+
+            return false;
+        }
+    }
+
+
+    /* Handle a negative position differently than a positive one. */
     if(player_tile_x < 0) player_tile_x = player_tile_x/T_WIDTH-1;
     else player_tile_x = player_tile_x/T_WIDTH;
     
@@ -111,7 +137,7 @@ bool player_collision(Game *game, Direction direction,
     
     int on_walkable = get_walkable(game, player_tile_x, player_tile_y);
     
-    int speed = on_walkable >= 0 && on_walkable < WALKABLE_TILE_MAX ?
+    int speed = (on_walkable >= 0 && on_walkable < WALKABLE_TILE_MAX) ?
                           walkable_speed[on_walkable] : 0;
     
     /* if he's on a hard tile */