modify world generation rule

module/block.py

@@ -12,6 +12,7 @@ class Block:
     flowable = False # 可流动
     fallible = False # 可下坠
     collision = True # 可以碰撞
+    destroyable = True # 可被破坏
 
     def __init__(self, x: int, y: int):
         self.x = x
@@ -42,7 +43,7 @@ class Block:
         # 判碰撞：
         return left < player.x < right and top < player.y < bottom
 
-    def get_collision_surface(self) -> tuple[int]:
+    def get_collision_surface(self) -> tuple[int, int, int, int]:
         # 获得方块表面界限（碰撞面）
         # 上、右、下、左
         real_x = self.x * BLOCK_SIZE + BLOCK_SIZE / 2
@@ -107,4 +108,9 @@ class WaterBlock(Block):
     collision = False
 
     def __init__(self, x: int, y: int):
-        super().__init__(x, y)
+        super().__init__(x, y)
+
+class BedrockBlock(Block):
+    id = 'bedrock'
+    color = COLORS.get(id)
+    destroyable = False