TypeError: invalid destination position for blit

Question

Please help. I've been searching but i still don't quite grasp how to fix the problem. I don't know if i;m forgetting something or the values of x and y are not considered int's for some reason (i have put in past tries to fix it: int(x))

I want to create the dinosaur game from Google, but the .blit of the "Hidrante" class is failing (but the player one is functioning). I have put it normal values instead of self.x and self.y but still get the problem, i've tried to said it x and y are ints, tried to change the names, the image i'm loading, and replicate the code of the player but doesn't seem to work.

here is all the code

import pygame


pygame.init()

window = pygame.display.set_mode((1000, 1000))

pygame.display.set_caption("Dinosaurio")

clock = pygame.time.Clock()
char = pygame.image.load('dino.png')
bg = pygame.image.load('bg2.jpg')
img = pygame.image.load("H2.jpg")


class Player(object):
#values of player
    def __init__(self, x, y, width, height):
        self.x = x
        self.y = y
        self.width = width
        self.height = height
        self.vel = 5
        self.isJump = False
        self.jumpCount = 10
        self.hitbox = (self.x + 20, self.y, 30, 64)
#putting the player on screem
    def draw(self, window):
        window.blit(char, (self.x, self.y))
        self.hitbox = (self.x + 20, self.y, 30, 64)
        pygame.draw.rect(window, (255, 0, 0), self.hitbox, 2)

#Obstacle
class Hidrante(object):

    def __init__(self, x, y, width, height):
        self.x = x
        self.y = y
        self.width = width
        self. height = height
        self.vel = 8
        self.hitbox = (self.x + 17, self.y + 2, 31, 57)
        self.walkCount = 10
        self.path = 0
#putting the obstacle in screem
    def draw(self, win):
        if self.walkCount + 1 >= 33: #fill code, trying things not actual util
            self.walkCount = 0

        if self.vel > 0:
            window.blit(img, (self.x, self.y)) #here is the problem
            self.walkCount += 1
        else:
            window.blit(img, (self.x, self.y))#these too
            self.walkCount += 1
        self.hitbox = (self.x + 17, self.y + 2, 30, 60)  
        pygame.draw.rect(window, (255, 0, 0), self.hitbox, 2)


def gmv():
#putting on creem the objects
    window.blit(bg, (0, 0))
    dino.draw(window)
    hidrante.draw(window)
    pygame.display.update()

#creating the objects
dino = Player(110, 620, 64, 64)
hidrante = Hidrante(1100, 620, 64, 64)
run = True
neg = 1
while run:
    clock.tick(30) #frames
    hidrante.x = (hidrante.x ** 2) * -1 #Function to not jump infinit.

    for event in pygame.event.get():
        if event.type == pygame.QUIT: 
            run = False
#Space to jump
    keys = pygame.key.get_pressed()

    if not (dino.isJump):
        if keys[pygame.K_SPACE]:
            dino.isJump = True
    else:
        if dino.jumpCount >= -10:
            dino.y -= (dino.jumpCount * abs(dino.jumpCount)) * 0.5
            dino.jumpCount -= 1
        else:
            dino.jumpCount = 10
            dino.isJump = False

    gmv()


pygame.quit()

i've only want to know the reason why the values of object are interfering with .blit and learn how to fix it.

Answer 1

The coordinates which are passed to pygame.Surface.blit() have to be in a certain limit. It seems that the limit for a coordinate has to be within the range of the (ctypes) data type int, which is from -2147483648 to 2147483647.

You exceed this limit in the object hidrante, because of the line:

hidrante.x = (hidrante.x ** 2) * -1

Probably this formula doesn't do what you expect it to do.

Anyway, validate if hidrante.x is in bounds of thee screen, to solve the issue:

class Hidrante(object):

    # [...]

        def draw(self, win):
        if self.walkCount + 1 >= 33: #fill code, trying things not actual util
            self.walkCount = 0

        # validate if object is in the window
        if self.x > -30 and self.x < 1000:

            if self.vel > 0:
                window.blit(img, (self.x, self.y))
                self.walkCount += 1
            else:
                window.blit(img, (self.x, self.y))
                self.walkCount += 1
            self.hitbox = (self.x + 17, self.y + 2, 30, 60)  
            pygame.draw.rect(window, (255, 0, 0), self.hitbox, 2)