Pygame Sprites Overlapping Issue

i'm learning python by myself, and started with a simple game with pygame. The game consists, so far, in a ball that's been chased by other balls, i have created a loop that avoid

Solution 1:

[...] then measures the distance between them, if the distance is less than the ball radius, it is moved away. It seems to work most of the time, but sometimes a ball overlaps. [...]

Of course.You only consider 2 balls when moving a ball away. This means that if you move a ball away from one ball, it can happen that you move it straight onto another ball. You need to check that there is no other ball in the position where you are moving the ball.

Make sure the balls don't overlap as they spawn:

requested_balls = 1

while not terminar:
    # [...]

    hit = pygame.sprite.spritecollide(pelota, perseguidor_grupo, True, pygame.sprite.collide_circle)
    if hit: 
        requested_balls = min(25, requested_balls+1)
    if len(perseguidor_grupo) < requested_balls:
        perseguidor = Perseguidor()
        if not pygame.sprite.spritecollide(perseguidor, perseguidor_grupo, True, pygame.sprite.collide_circle):
            all_sprites.add(perseguidor)
            perseguidor_grupo.add(perseguidor)
            perseguidores.append(perseguidor)

Only move a ball if the new position of the ball is not yet occupied by a ball:

class Perseguidor(pygame.sprite.Sprite):
    # [...]

    def update(self):
        # [...]

        old_rect = self.rect.copy()
        if self.dist>=1:
            self.rect.x += velocidadnalguis * self.speedx
            self.rect.y += velocidadnalguis * self.speedy

        hit = pygame.sprite.spritecollide(self, perseguidor_grupo, False, pygame.sprite.collide_circle)
        if len(hit) > 1: # at last 1, because the ball hits itself
            if random.randrange(2) == 0:
                self.rect.x = old_rect.x
            else:
                self.rect.y = old_rect.y
            hit = pygame.sprite.spritecollide(self, perseguidor_grupo, False, pygame.sprite.collide_circle)
            if len(hit) > 1:
                    self.rect = old_rect

Complete example:

import pygame, random, math
pygame.init()

ancho , alto = 800 , 600
negro = (0,0,0)
blanco=(255,255,255)
FPS = 60     
velocidad = 7
velocidadnalguis = velocidad - 2
contadordecolisiones = 1
perseguidores =  []

pantalla=pygame.display.set_mode((ancho,alto))
pygame.display.set_caption("un jueguito")
reloj=pygame.time.Clock()

class Pelota(pygame.sprite.Sprite):
    def __init__(self):
        pygame.sprite.Sprite.__init__(self)
        self.image = pygame.image.load("pelota.png").convert()
        self.image = pygame.transform.scale(self.image, (30, 30))
        self.image.set_colorkey(negro)
        self.rect = self.image.get_rect()
        self.rect.center = (ancho/2,alto/2) 
        self.speed = 0

    def update(self):
        self.speedx = 0
        self.speedy = 0
        tecla  = pygame.key.get_pressed()
        
        if tecla[pygame.K_LEFT]:
            self.speedx = -velocidad
        
        if tecla[pygame.K_RIGHT]:
            self.speedx = velocidad      

        if tecla[pygame.K_UP]:
            self.speedy = -velocidad

        if tecla[pygame.K_DOWN]:
            self.speedy = velocidad

        self.rect.x += self.speedx
        self.rect.y += self.speedy

        if self.rect.right > ancho:
            self.rect.right = ancho

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

        if self.rect.left < 0:
            self.rect.left = 0

        if self.rect.top < 0:
            self.rect.top = 0

pelota = Pelota()

class Perseguidor(pygame.sprite.Sprite):
    def __init__(self,):
        super().__init__()
        self.image = pygame.image.load('nalguis.png').convert()
        self.image = pygame.transform.scale(self.image, (30, 30))
        self.image.set_colorkey(negro)
        self.rect = self.image.get_rect()
        self.velocidad = velocidadnalguis
        self.radius = self.rect.width/2
        self.center = self.rect.center
        self.contadordecolisiones = 1
        self.enerandom = random.randint(0,4)

        if self.enerandom == 0:
             self.rect.center = (random.randrange(-130,-30),random.randrange(-130,alto+130))
        if self.enerandom == 1:
             self.rect.center = (random.randrange(-130,ancho+130),random.randrange(-130,-30))
        if self.enerandom == 2:
             self.rect.center = (random.randrange(ancho+30,ancho+130),random.randrange(-130,alto+130))
        if self.enerandom == 3:
            self.rect.center = (random.randrange(-130,ancho+130),random.randrange(alto+30,alto+130))

    def update(self):
        
        self.pely = pelota.rect.y
        self.pelx = pelota.rect.x
        self.perx = self.rect.x
        self.pery = self.rect.y

        self.dist = math.sqrt(((self.pely-self.pery)**2) + ((self.pelx-self.perx)**2))/velocidadnalguis

        self.angulo = math.atan2(self.pely-self.pery,self.pelx-self.perx)

        self.speedx = 0
        self.speedy = 0
        self.speedx = math.cos(self.angulo) 
        self.speedy = math.sin(self.angulo) 
        
        old_rect = self.rect.copy()
        if self.dist>=1:
            self.rect.x += velocidadnalguis * self.speedx
            self.rect.y += velocidadnalguis * self.speedy

        hit = pygame.sprite.spritecollide(self, perseguidor_grupo, False, pygame.sprite.collide_circle)
        if len(hit) > 1: # at last 1, because the ball hits itself
            if random.randrange(2) == 0:
                self.rect.x = old_rect.x
            else:
                self.rect.y = old_rect.y
            hit = pygame.sprite.spritecollide(self, perseguidor_grupo, False, pygame.sprite.collide_circle)
            if len(hit) > 1:
                    self.rect = old_rect

        

all_sprites = pygame.sprite.Group()
perseguidor_grupo = pygame.sprite.Group()
all_sprites.add(pelota)

terminar=False

requested_balls = 1

while not terminar:
    reloj.tick(FPS)
    for event in pygame.event.get():
        if event.type == pygame.QUIT:
            terminar=True
    
    if len(perseguidor_grupo)<1:
        perseguidor=Perseguidor()
        perseguidor_grupo.add(perseguidor)
        all_sprites.add(perseguidor)

    hit = pygame.sprite.spritecollide(pelota, perseguidor_grupo, True, pygame.sprite.collide_circle)
    if hit: 
        requested_balls = min(25, requested_balls+1)
    if len(perseguidor_grupo) < requested_balls:
        perseguidor = Perseguidor()
        if not pygame.sprite.spritecollide(perseguidor, perseguidor_grupo, True, pygame.sprite.collide_circle):
            all_sprites.add(perseguidor)
            perseguidor_grupo.add(perseguidor)
            perseguidores.append(perseguidor)
        
    dist=1
                                        
    if len(perseguidores)> len(perseguidor_grupo):
        del perseguidores [0]       
    
    all_sprites.update()
    pantalla .fill(negro)
    all_sprites.draw(pantalla)
    
    pygame.display.flip()
    
pygame.quit()
quit()