How can I make a hitbox around my image?

Question

I'm really new to PyGame and trying to program a game, and I can't figure out how to make a hitbox that when this image hits the edge, the game stops it from going past the edges

import pygame
from pygame.math import Vector2

pygame.init
dis_width=1000
dis_height=1000
dis=pygame.display.set_mode((dis_width, dis_height))
pygame.display.set_caption("Snowperson game")
white=(255,255,255)
cyan=(153,255,255)
red=(255,0,0)


dis.fill(cyan)

class Snow:
    def __init__(self,newX, newY):
        self.x = newX
        self.y = newY
        self.image = pygame.image.load("Snowperson1.png")
        self.vel = Vector2(0,0)
        self.pos = Vector2(pos)
        self.rect = self.image.get_rect(center=pos)


    def x(self):
        self.x

    def y(self):
        self.y

    def draw(self, window):
        window.blit(self.image,(self.x,self.y))

    def snowRight(self):
        self.x +=10

    def snowLeft(self):
        self.x -=10

    def snowUp(self):
        self.y -= 10

    def snowDown(self):
        self.y += 10

pygame.key.set_repeat(100,100)


snowman = Snow(50,50)


while True:
    dis.fill(cyan)
    snowman.draw(dis)
    pygame.draw.rect(dis, red, (0,0, 1000, 1000), 2)
    pygame.display.update()
    snowman.snowLeft == True

    for event in pygame.event.get():

        if event.type==pygame.QUIT or (event.type==pygame.KEYUP and event.key==pygame.K_ESCAPE):
            pygame.quit()

        elif event.type == pygame.KEYDOWN:

            if event.key == pygame.K_UP:
                snowman.snowUp()
            elif event.key == pygame.K_DOWN:
                snowman.snowDown()
            elif event.key == pygame.K_RIGHT:
                snowman.snowRight()
            elif event.key == pygame.K_LEFT and snowman.snowLeft == True:
                snowman.snowLeft()

    if snowman.rect()== 0:
        while True:
            snowman.snowLeft == False
```

Answer 1

The simplest is to use self.rect in Snow and compare with window rect which you can get dis.get_rect()

dis_rect = dis.get_rect()

if snowman.rect.left < dis_rect.left:
   snowman.rect.left = dis_rect.left:

if snowman.rect.right > dis_rect.right:
   snowman.rect.right = dis_rect.right:

if snowman.rect.top < dis_rect.top:
   snowman.rect.top = dis_rect.top:

if snowman.rect.bottom < dis_rect.bottom:
   snowman.rect.bottom = dis_rect.bottom:

but this also need to keep position in self.rect instead of self.x, self.y

    def move_right(self):
        self.move(10, 0)
        
    def move_left(self):
        self.move(-10, 0)

    def move_up(self):
        self.move(0, -10)

    def move_down(self):
        self.move(0, 10)

    def move(self, dx, dy):
        self.rect.x += dx
        self.rect.y += dy

BTW: there is no need to use prefix snow in functions and variables in Snow. Later it can be simpler when all objects have the same names of functions - ie. .move_left() - because you can put all of objects on list and use for-loop to run the same function for all of objects. PyGame has even pygame.sprite.Group() for this.

---

Rect has also method to detect

• collision with point

  snowman.rect.colliderect(mouse_pos)
  

  which you can use to detect mouse on object or click on button

• collision with other rect

  snowman.rect.colliderect(zombie.rect)
  

  but it gives only True/False but it doesn't give information if it was collision on left, right, top or bottom - so common method is to check it in two steps. First move left/right and check collision - and if there was collision then: if speed_x > 0 (so you move right) then collision on right, if speed_y < 0 (so you move left) then collision on left. Second move top/bottom and check collision again - and if there was collision then: if speed_y > 0 (so you move down) then collision on bottom, if speed_y < 0 (so you move up) then collision on top.

---

EDIT:

Full working code

import pygame
#from pygame.math import Vector2

# --- constants ---  # PEP8: `UPPER_CASE_NAME` for constants

DIS_WIDTH  = 1000       # PEP8: spaces around `=`
DIS_HEIGHT = 1000

WHITE = (255, 255, 255)
CYAN  = (153, 255, 255)

RED   = (255,   0,   0)
GREEN = (  0, 255,   0)
BLUE  = (  0,   0, 255)

# --- classes ---  # PEP8: `CamelCaseName` for classes
                   # PEP8: `lower_case_name` for functions
                   
class Snow:
    def __init__(self, x, y, color):
        #self.image = pygame.image.load("Snowperson1.png")
        
        self.image = pygame.Surface((25, 75))
        self.image.fill(color)
        
        self.rect = self.image.get_rect(centerx=x, centery=y)
        
        self.vel_x = 0
        self.vel_y = 0

    def draw(self, window):
        window.blit(self.image, self.rect)

    def move_right(self):
        self.vel_x = 10
        
    def move_left(self):
        self.vel_x = -10

    def move_up(self):
        self.vel_y = -10

    def move_down(self):
        self.vel_y = 10

    def update(self, zombie):
        
        #print(self.vel_x, self.vel_y)
        
        # --- X ---
        
        self.rect.x += self.vel_x
        
        # window border - left,right
        
        if self.rect.left < dis_rect.left:
            self.rect.left = dis_rect.left

        if self.rect.right > dis_rect.right:
            self.rect.right = dis_rect.right
            
        # collisions with zombie - left,right
        
        if self.rect.colliderect(zombie.rect):
            if self.vel_x > 0:
                self.rect.right = zombie.rect.left
            elif self.vel_x < 0:
                self.rect.left = zombie.rect.right
    
        # --- Y ---

        self.rect.y += self.vel_y

        # window border - top,bottom

        if self.rect.top < dis_rect.top:
            self.rect.top = dis_rect.top

        if self.rect.bottom > dis_rect.bottom:
            self.rect.bottom = dis_rect.bottom

        # collisions with zombie - top,bottom
        
        if self.rect.colliderect(zombie.rect):
            if self.vel_y > 0:
                self.rect.bottom = zombie.rect.top
            elif self.vel_y < 0:
                self.rect.top = zombie.rect.bottom
            
# --- main ---

pygame.init()

dis = pygame.display.set_mode((DIS_WIDTH, DIS_HEIGHT))
dis_rect = dis.get_rect()

pygame.display.set_caption("Snowperson game")

pygame.key.set_repeat(100, 100)  # PEP8: space after comma

# - objects -

snowman = Snow(50, 50, BLUE)     # PEP8: space after `,`
zombie = Snow(150, 150, GREEN)  # PEP8: space after `,`

# - mainloop -

while True:
    
    # - draw -
    
    dis.fill(CYAN)

    snowman.draw(dis)
    zombie.draw(dis)
    
    pygame.draw.rect(dis, RED, (0, 0, 1000, 1000), 2)
    pygame.display.flip()
    
    # - move -
    
    snowman.vel_x = 0
    snowman.vel_y = 0
    
    for event in pygame.event.get():

        if event.type==pygame.QUIT:
            pygame.quit()

        elif event.type == pygame.KEYDOWN:
            if  event.key==pygame.K_ESCAPE:
                pygame.quit()
                
            elif event.key == pygame.K_UP:
                snowman.move_up()
            elif event.key == pygame.K_DOWN:
                snowman.move_down()
            elif event.key == pygame.K_RIGHT:
                snowman.move_right()
            elif event.key == pygame.K_LEFT:
                snowman.move_left()

    # - update - move and check collision -
    
    snowman.update(zombie)
```