How to add a boundary on areas inside the screen in pygame

Question

I've been trying to create a game screen but I can't seem to add a boundary around the houses on the screen so that the player doesn't walk over them. Below is my code

import pygame
import sys
from pygame import mixer

pygame.init()

playerImg = pygame.image.load('player.png')
WalkFront = [pygame.image.load('B1.png'), pygame.image.load('B2.png'),pygame.image.load('B3.png'),
         pygame.image.load('B4.png')]
WalkBack = [pygame.image.load('F1.png'), pygame.image.load('F2.png'), pygame.image.load('F3.png'),
        pygame.image.load('F4.png')]
WalkRight = [pygame.image.load('R1.png'), pygame.image.load('R2.png'), pygame.image.load('R3.png'),
         pygame.image.load('R4.png')]
WalkLeft = [pygame.image.load('L1.png'), pygame.image.load('L2.png'), pygame.image.load('L3.png'),
        pygame.image.load('L4.png')]
walkcount = 0
clock = pygame.time.Clock()


scr = pygame.display.set_mode((800, 600))
pygame.display.set_caption('Pokemon: Red')

logo = pygame.image.load('logo.png')
pygame.display.set_icon(logo)

background = pygame.image.load('BG.png')
pallet = pygame.image.load('pallet town.png')

mixer.music.load('Start menu.mp3')
mixer.music.play(100, 0, 0)


playerX = 200
playerY = 200
up = False
down = False
left = False
right = False


def redrawgamewindow():
    global walkcount
    scr.fill((0, 0, 0))
    scr.blit(pallet, (60, 0))
    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)

    pygame.display.update()


def player(x, y):
    scr.blit(playerImg, (x, y))


def start_menu():
    while True:
        scr.fill((255, 255, 255))
        scr.blit(background, (0, 0))

        for event in pygame.event.get():
            if event.type == pygame.KEYDOWN:
                game()

                if event.type == pygame.QUIT:
                    pygame.quit()
                    sys.exit()
                if event.type == pygame.KEYDOWN:
                    if event.key == pygame.K_ESCAPE:
                        pygame.quit()
                        sys.exit()

            pygame.display.update()


def game():
    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:
        for event in pygame.event.get():
            if event.type == pygame.QUIT:
                pygame.quit()
                sys.exit()
   
            if event.type == pygame.KEYDOWN:
                if event.key == pygame.K_UP:
                    global up
                    global down
                    global left
                    global right
                    up = True
                    down = False
                    playerY_change = -0.8
                elif event.key == pygame.K_DOWN:
                    up = False
                    down = True
                    playerY_change = 0.8
                else:
                    up = False
                    down = False
                    walkcount = 0
                if event.key == pygame.K_LEFT:
                    playerX_change = -1
                    left = True
                    right = False
                elif event.key == pygame.K_RIGHT:
                    playerX_change = 1
                    right = True
                    left = False
                else:
                    left = False
                    right = False
                    walkcount = 0

            if event.type == pygame.KEYUP:
                if event.key == pygame.K_UP or event.key == pygame.K_DOWN:
                    playerY_change = 0
                    up = False
                    down = False
                    left = False
                    right = False
                if event.key == pygame.K_LEFT or event.key == pygame.K_RIGHT:
                    playerX_change = 0
                    up = False
                    down = False
                    left = False
                    right = False

        playerX += playerX_change
        playerY += playerY_change

        if playerX <= 90:
            playerX = 90
        elif playerX >= 670:
            playerX = 670
        if playerY <= 40:
            playerY = 40
        elif playerY >= 540:
            playerY = 540
        redrawgamewindow()


start_menu()

the background image has an area on it with a house in the top left. See the background image below so you can get a better idea. what I want is for the player to not be able to walk on the house so he gets blocked at the edge.

Please consider including the relevant code in your post instead of the whole project as a link. — ewokx, Sep 15 '20 at 10:01
how do I add the code?, im sorry this is my first time using stackoverflow — python newbie, Sep 15 '20 at 10:10
Please read [How to create a Minimal, Reproducible Example](https://stackoverflow.com/help/minimal-reproducible-example) and [How do I ask a good question?](https://stackoverflow.com/help/how-to-ask). — Rabbid76, Sep 15 '20 at 10:18
I Think that your answer https://stackoverflow.com/questions/46742393/how-to-draw-a-border-around-a-sprite-or-image-in-pygame — Muhammad Rizwan Munawar, Sep 15 '20 at 10:44
no that's just drawing a border around it, I want it so that the player character shouldn't be able to move to that specific area at all kind of like a wall around an area — python newbie, Sep 15 '20 at 10:48

Rabbid76 · Accepted Answer · 2020-09-17T11:08:40.027

I recommend to define a rectangular area for the house. Use pygame.Rect. You have to find the values for hx, hy, hw and hh:

house_rect = pygame.Rect(hx, hy, hw, hh)

Create a rectangle for the player after the position of the player is changed. The size of the rectangle can be get from the pygame.Surface object which represents the player by get_rect(). The position has to be set by an keyword argument (topleft = (playerX, playerY)).
Use pygame.Rect.colliderect to evaluate if the player collides with the house and restrict the position of the player to the area outside the house:

playerX += playerX_change
player_rect = playerImg.get_rect(topleft = (playerX, playerY))

if player_rect.colliderect(house_rect):
    if playerX_change > 0:
        player_rect.right = house_rect.left
    elif playerX_change < 0:
        player_rect.left = house_rect.right
    playerX = player_rect.x

playerY += playerY_change
player_rect = playerImg.get_rect(topleft = (playerX, playerY))

if player_rect.colliderect(house_rect):
    if playerY_change < 0:
        player_rect.top = house_rect.bottom
    elif playerY_change > 0:
        player_rect.bottom = house_rect.top
    playerY = player_rect.y

it did work! but it seems you switched the lesser than and greater than signs in the X axis (first part) of the code, but it was a quick fix, thank you so much I spent like 3 days trying to fix this and tried so many kinds of logics! — python newbie, Sep 17 '20 at 11:05
@pythonnewbie I see, you're right. I've fixed that in the answer. — Rabbid76, Sep 18 '20 at 14:09

score 1 · Answer 2 · answered Sep 15 '20 at 13:34

1

I guess you have to patiently make the boundaries with x and y like this:

if x > boundaryX and y > boundaryY:
    xOfThePlayer -= moving

It is an example you have to change this according to your needs.

answered Sep 15 '20 at 13:34

Matteo Bianchi

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How to add a boundary on areas inside the screen in pygame

2 Answers2