pygame: I want to calculate the distance between the player sprite and enemy1

Question

so this is my code:

import pygame

windowX = 1020
windowY = 500
speedX = 2
speedY = 2
Xpos = int(510)
Ypos = int(250)
playerWidth = 100
playerHeight = 95
keepAlive = True
goingDown = False
pygame.init()
window = pygame.display.set_mode((windowX, windowY))
player = pygame.image.load("player.PNG")
player = pygame.transform.scale(player, (playerWidth, playerHeight))

class enemy:
    X: int
    Y: int
    def __init__(self, x: int, y: int, sprite: str, sizeX: int, sizeY: int):
        self.X = x
        self.Y = y
        self.enemySprite = pygame.image.load(sprite)
        self.enemySprite = pygame.transform.scale(self.enemySprite, (sizeX, sizeY))
        window.blit(self.enemySprite, (x, y))

        


def hit():
    print('hit')
while(keepAlive):
    for event in pygame.event.get():
        if(event.type == pygame.QUIT):
            pygame.quit()

    keys = pygame.key.get_pressed()
    if(not Xpos >= windowX - 70):
        if(keys[pygame.K_RIGHT]):
            Xpos += speedX

    if(not -Xpos >= -windowX + 1050):
        if(keys[pygame.K_LEFT]):
            Xpos -= speedX
    else:
        print(-windowX + 510)
        print(-Xpos)


    if(-Ypos <= windowY - 450 and not goingDown):
        Ypos -= speedY
    else:
        goingDown = True
        Ypos += speedY

    if(-Ypos == -windowY + 100):
        goingDown = False

    window.fill((0, 0, 0))
    window.blit(player, (Xpos, Ypos))
    enemy1 = enemy(520, int(0), "player.PNG", 100, 100)
    pygame.display.update()
    pygame.display.flip()

and I want to calculate the distance between the player sprite and enemy1, if you could please help me I would be very happy, thanks a lot! I have been trying to do this for a long time now and this really means a lot to me, if you could specify: what libraries do I need? what functions do I use and is there any documentation, so again, I want to calculate the distance between to sprites, thanks!

user_5577765 · Answer

I suggest to use pygame.math.Vector2.distance_to:

dist = pygame.math.Vector2(Xpos, Ypos).distance_to((enemy1.x, enemy1.y))

See distance_to():

calculates the Euclidean distance to a given vector.

If you don't want to use the pygame.math module, you can compute the Euclidean distance with Pythagoras:

import math

dx = enemy1.x - Xpos
dy = enemy1.y - Ypos
dist = math.sqrt(dx*dx + dy*dy)

or the Hypotenuse

dist = math.hypot(enemy1.x - Xpos, enemy1.y - Ypos)

Class names should normally use the CapWords convention. See Naming Conventions.

Furthermore I suggest to instance the enemy object before the application loop, but add a draw method to the Enemy class:

class Enemy:
    X: int
    Y: int
    def __init__(self, x: int, y: int, sprite: str, sizeX: int, sizeY: int):
        self.X = x
        self.Y = y
        self.enemySprite = pygame.image.load(sprite)
        self.enemySprite = pygame.transform.scale(self.enemySprite, (sizeX, sizeY))

    def draw(self, target_surf):
        target_surf.blit(self.enemySprite, (self.x, self.y))

enemy1 = Enemy(520, int(0), "player.PNG", 100, 100)

while keepAlive:
    # [...]

    dist = math.hypot(enemy1.x - Xpos, enemy1.y - Ypos)
    print(dist)

    window.fill((0, 0, 0))
    window.blit(player, (Xpos, Ypos))
    enemy1.draw(window)
    pygame.display.update()

pygame: I want to calculate the distance between the player sprite and enemy1

1 Answers