From 40fa44f9368254d45bee66b145ab7b89d106df42 Mon Sep 17 00:00:00 2001
From: Jeffrey Hsu <xfj12@outlook.com>
Date: Sat, 1 Feb 2025 11:21:20 +0800
Subject: [PATCH] fix gravity simulation bug

---
 main.py          |  5 -----
 module/player.py | 28 ++++++++++++++++++++--------
 2 files changed, 20 insertions(+), 13 deletions(-)

diff --git a/main.py b/main.py
index e31cdef..9f4413c 100644
--- a/main.py
+++ b/main.py
@@ -31,7 +31,6 @@ while running:
                     player.put_block(bx, by)
             elif event.button == 3:  # 右键拆除方块
                 player.put_block(bx, by, 'delete')
-                player.on_ground = False  # 不完美解决方法，挖方块时更新状态
         elif event.type == pygame.KEYDOWN:
             if event.key == pygame.K_1:
                 player.select_block(GrassBlock)
@@ -61,12 +60,8 @@ while running:
         player.move(0, player.velocity)
 
     # 绘制世界
-    screen.fill(COLORS["air"])
     for row in world:
         for block in row:
-            if block.id == "air":
-                continue
-
             rect = pygame.Rect(block.x * BLOCK_SIZE, block.y * BLOCK_SIZE, BLOCK_SIZE, BLOCK_SIZE)
             pygame.draw.rect(screen, block.color, rect)
 
diff --git a/module/player.py b/module/player.py
index c0d9c79..98e25e0 100644
--- a/module/player.py
+++ b/module/player.py
@@ -18,8 +18,7 @@ class Player:
 
     def move(self, dx: float, dy: float):
         # 仅需检测玩家当前区块的上下左右的方块是否有碰撞体积
-        block_x_idx = int(self.x) // BLOCK_SIZE
-        block_y_idx = int(self.y) // BLOCK_SIZE
+        block_x_idx, block_y_idx = self.get_pixel_idx()
 
         top_block = self.world[block_x_idx][block_y_idx - 1] if block_y_idx > 0 else None
         bottom_block = self.world[block_x_idx][block_y_idx + 1] if block_y_idx < HEIGHT // 20 - 1 else None
@@ -31,7 +30,6 @@ class Player:
         if dy > 0 and bottom_block is not None and bottom_block.collision:
             if bottom_block.check_collision(self):
                 new_y = bottom_block.get_collision_surface()[0] - 10
-                self.on_ground = True
             else:
                 new_y = self.y + dy
         # 向上移动时且上面方块有碰撞体积，与下表面碰撞
@@ -79,12 +77,26 @@ class Player:
             pass
 
     def draw(self, screen: pygame.Surface):
-        pygame.draw.circle(screen, COLORS["player"], (self.x, self.y), PLAYER_SIZE // 2)
         self.move(0, 0)
-        # 绘制玩家所在区块颜色
-        if OPTIONS['debug']:
-            block_x = int(self.x) // BLOCK_SIZE * BLOCK_SIZE
-            block_y = int(self.y) // BLOCK_SIZE * BLOCK_SIZE
 
+        # 重力检测
+        block_x_idx, block_y_idx = self.get_pixel_idx()
+
+        bottom_block = self.world[block_x_idx][block_y_idx + 1] if block_y_idx < HEIGHT // 20 - 1 else None
+        if bottom_block and bottom_block.collision and bottom_block.check_collision(self):
+            self.on_ground = True
+        else:
+            self.on_ground = False
+
+        pygame.draw.circle(screen, COLORS["player"], (self.x, self.y), PLAYER_SIZE // 2)
+
+        if OPTIONS['debug']:
+            block_x = block_x_idx * BLOCK_SIZE
+            block_y = block_y_idx * BLOCK_SIZE
+
+            # 绘制玩家所在区块颜色
             rect = pygame.Rect(block_x, block_y, BLOCK_SIZE, BLOCK_SIZE)
             pygame.draw.rect(screen, '#ffd5004d', rect)
+
+    def get_pixel_idx(self) -> tuple[int, int]:
+        return int(self.x) // BLOCK_SIZE, int(self.y) // BLOCK_SIZE
\ No newline at end of file