How do I create a "rpg door" effect in pygame, and what's wrong with my method?

Question

I'm creating a game where going near a door(defined using Rect function) calls a function which loads a new game screen which gives the effect of going through to that door inside the house. I tried to do the same thing with the coming out mechanism where I tried to define an area with a Rect object and made it so that when the player comes near it the main game loop is called and it would give the effect of coming out the door but doing so makes it so that the player is stuck in an infinite loop of the screen fading away. the part of the code is attached below and the full code is here

this is the door collision detection

    out = pygame.Rect(360, 580, 80, 10)
    player_rect = playerImgXL.get_rect(topleft=(playerXxl, playerYxl))

    if player_rect.colliderect(out):
        game()  # coming out of the house

this is the game loop function

def game():
  global present_dialogue
  global current_dialogue
  global playerX
  global playerY
  clock.tick(12)
  mixer.music.pause()
  mixer.music.load('pallet_music.mp3')
  # mixer.music.play(100)
  playerX_change = 0
  playerY_change = 0
  running = True
  while running:
      present_dialogue = None
      current_dialogue = None
      for event in pygame.event.get():
          if event.type == pygame.QUIT:
              pygame.quit()
              sys.exit()
      redrawgamewindow()
      pygame.display.update()

this isn't the entire game loop there's just the event detection and collision detection between the sys.exit statement and the display update statement

this is the redrawgamewindow function that I call at the end of the game loop

def redrawgamewindow():
  global walkcount
  scr.fill((0, 0, 0))
  scr.blit(pallet, (60, 0))
  if current_dialogue:
      scr.blit(*current_dialogue)
      npc_one_dialogue()
  if walkcount + 1 >= 29:
      walkcount = 0
  if up:
      scr.blit(WalkFront[walkcount // 7], (playerX, playerY))
      walkcount += 1
  elif down:
      scr.blit(WalkBack[walkcount // 7], (playerX, playerY))
      walkcount += 1
  elif left:
      scr.blit(WalkLeft[walkcount // 7], (playerX, playerY))
      walkcount += 1
  elif right:
      scr.blit(WalkRight[walkcount // 7], (playerX, playerY))
      walkcount += 1
  else:
      player(playerX, playerY)
  if present_dialogue:
      scr.blit(*present_dialogue)
      npc_two_dialogue()

user_13878034 · Answer

A few changes are needed to prevent the fade loop:

In the inhouse_oak function, reset the starting position when the player enters the room

When the player exits the room, just return to the main game loop

def inhouse_oak():
    global playerXxl
    global playerYxl
    playerXxl = 365  # reset starting position
    playerYxl = 480
    ...........
    while running:
        .................
        if player_rect.colliderect(out):
            return  # return to main loop
            # game()  # coming out of the house

In the main loop, when the player exits the room, move the player away from the door

  door3 = pygame.Rect(462, 348, 25, 5)
  if player_rect.colliderect(door3):
      fade(800, 600)
      inhouse_oak()  # Oak's Lab door
      playerY_change = playerX_change = 0  # stop player movement
      playerY += 10  # move away from door

To add a fade when exiting the room, make these changes:

Generalize the fade function.

def fade(x, y, rgw):  # last parameter is screen function to call
    fade = pygame.Surface((x, y))
    fade.fill((0, 0, 0))
    for alpha in range(0, 300):
        fade.set_alpha(alpha)
        rgw(True)  # fading = True
        scr.blit(fade, (0, 0))
        pygame.display.update()

Add the fading parameter to the main game function.
```
def redrawgamewindow(fading=False):
```

Add the fading parameter to the room function and check the parameter before updating the screen to prevent screen flash.

def redrawgamewindow_oak(fading=False):
    .........
    if not fading: pygame.display.update()  # prevent flash if fading

Update the fade call in the redrawgamewindow function.

  door3 = pygame.Rect(462, 348, 25, 5)
  if player_rect.colliderect(door3):
      fade(800, 600, redrawgamewindow)  # fade main game
      inhouse_oak()  # Oak's Lab door
      playerY_change = playerX_change = 0
      playerY += 10  #playerX_change

In redrawgamewindow_oak, when leaving the room, call the fade function.

  if player_rect.colliderect(out):
      fade(800, 600, redrawgamewindow_oak)  # fade room
      return  # return to main loop
      #game()  # coming out of the house

How do I create a "rpg door" effect in pygame, and what's wrong with my method?

1 Answers