I've been working on some game code for school and was working through some tutorials and figured out how to make the player sprite tracks the mouse but now I'm having trouble figuring out how to spawn enemies from all sides of the screen instead of just the top. (To clarify code is in two parts/files, also completely unrelated). I was also wondering, how I could maybe have the mobs/NPCs chase and rotate towards the player?
import random
import math
import pygame as py
from PlayerSprite import *
WIDTH = 800
HEIGHT = 600
FPS = 60
# define colors
WHITE = (255, 255, 255)
BLACK = (0, 0, 0)
RED = (255, 0, 0)
GREEN = (0, 255, 0)
BLUE = (0, 0, 255)
# initialize pygame and create window
py.init()
py.mixer.init()
screen = py.display.set_mode((WIDTH, HEIGHT))
py.display.set_caption("Dimensional Drifter")
clock = py.time.Clock()
all_sprites = py.sprite.Group()
NPCs = py.sprite.Group()
player = Player()
all_sprites.add(player)
for i in range(8):
n = NPC()
all_sprites.add(n)
NPC.add(n)
# Game loop
running = True
while running:
# keep loop running at the right speed
clock.tick(FPS)
for event in py.event.get():
# check for closing window
if event.type == py.QUIT:
running = False
# Update
all_sprites.update()
#
mouse_x, mouse_y = py.mouse.get_pos()
player.rotate(mouse_x, mouse_y)
# render
screen.fill(BLACK)
all_sprites.draw(screen)
# flip the display
py.display.flip()
py.quit()
import pygame as py
import math
import random
WIDTH = 800
HEIGHT = 600
FPS = 60
# define colors
WHITE = (255, 255, 255)
BLACK = (0, 0, 0)
RED = (255, 0, 0)
GREEN = (0, 255, 0)
BLUE = (0, 0, 255)
class Player(py.sprite.Sprite):
def __init__(self):
py.sprite.Sprite.__init__(self)
self.image = py.Surface((50, 50), py.SRCALPHA)
self.image.fill(GREEN)
self.rect = self.image.get_rect()
self.rect.centerx = WIDTH / 2
self.rect.bottom = HEIGHT / 2
self.Yspeed = 0
self.rotatableimage = self.image
def update(self):
self.Xspeed = 0
self.Yspeed = 0
# line below allow for key press to equate to move of sprite
keypreesed = py.key.get_pressed()
if keypreesed[py.K_a]:
self.Xspeed = - 11
if keypreesed[py.K_d]:
self.Xspeed = 11
if keypreesed[py.K_w]:
self.Yspeed = - 11
if keypreesed[py.K_s]:
self.Yspeed = 11
self.rect.x += self.Xspeed
self.rect.y += self.Yspeed
# line below allow the sprite to wrap around the screen
if self.rect.left > WIDTH:
self.rect.right = 0
if self.rect.right < 0:
self.rect.left = WIDTH
if self.rect.top > HEIGHT:
self.rect.top = 0
if self.rect.bottom < 0:
self.rect.bottom = HEIGHT
def rotate(self, mouse_x, mouse_y):
rel_x = mouse_x - self.rect.x
rel_y = mouse_y - self.rect.y
angle = (180 / math.pi) * -math.atan2(rel_y, rel_x)
self.image = py.transform.rotate(self.rotatableimage, int(angle))
self.rect = self.image.get_rect(center=(self.rect.centerx, self.rect.centery))
return
class NPC(py.sprite.Sprite):
def __init__(self):
py.sprite.Sprite.__init__(self)
self.image = py.Surface((30, 30))
self.image.fill(RED)
self.rect = self.image.get_rect()
self.rect.x = random.randrange(WIDTH - self.rect.width)
self.rect.y = random.randrange(-100, -40)
self.Yspeed = random.randrange(1, 8)
def update(self):
self.rect.y += self.Yspeed
if self.rect.top > HEIGHT + 10:
self.rect.x = random.randrange(WIDTH - self.rect.width)
self.rect.y = random.randrange(-100, -40)
self.Yspeed = random.randrange(1, 8)
Thanks in advance.
You have to add a random direction and a separate speed (self.Xspeed, self.Yspeed) for the x and y direction:
self.direction = random.randrange(4)
and to set self.rect.x, self.rect.y, self.Xspeed and self.Yspeed dependent on the random direction:
if self.direction == 0:
self.rect.x = random.randrange(WIDTH - self.rect.width)
self.rect.y = random.randrange(-100, -40)
self.Xspeed = 0
self.Yspeed = random.randrange(1, 8)
elif self.direction == 1:
# [...]
elif self.direction == 2:
# [...]
elif self.direction == 3:
# [...]
Create a method spawn, which spawns a enemy with a random direction and a random speed and call it in the constructor of NPC:
class NPC(py.sprite.Sprite):
def __init__(self):
# [...]
self.spawn()
def spawn(self):
self.direction = random.randrange(4)
if self.direction == 0:
# [...]
In update the speed has to be and to the x and y position separately:
self.rect.x += self.Xspeed
self.rect.y += self.Yspeed
Furthermore, if the object is out of the window has to be evaluated dependent on the direction. If the object is out of the window, the call spawn() again, thus the object gets a new random direction, position and speed:
if self.direction == 0:
if self.rect.top > HEIGHT + 10:
self.spawn()
elif self.direction == 1:
if self.rect.bottom < -10:
self.spawn()
elif self.direction == 2:
if self.rect.left > WIDTH + 10:
self.spawn()
elif self.direction == 3:
if self.rect.right < -10:
self.spawn()
To rotate the image you have to create surface with per pixel alpha (convert_alpha()) and to keep the original surface:
self.image = py.Surface((30, 30)).convert_alpha()
self.image.fill(RED)
self.originalimage = self.image
Compute the angle from the enemy to the player and rotate the image by pygame.transform.rotate():
(See also How to rotate a triangle to a certain angle in pygame?)
dir_x, dir_y = player.rect.x - self.rect.x, player.rect.y - self.rect.y
self.rot = (180 / math.pi) * math.atan2(-dir_x, -dir_y)
self.image = py.transform.rotate(self.originalimage, self.rot)
Class NPC:
class NPC(py.sprite.Sprite):
def __init__(self, player):
py.sprite.Sprite.__init__(self)
self.player = player
self.image = py.Surface((30, 30)).convert_alpha()
self.image.fill(RED)
self.originalimage = self.image
self.rect = self.image.get_rect()
self.spawn()
def spawn(self):
self.direction = random.randrange(4)
if self.direction == 0:
self.rect.x = random.randrange(WIDTH - self.rect.width)
self.rect.y = random.randrange(-100, -40)
self.Xspeed = 0
self.Yspeed = random.randrange(1, 8)
elif self.direction == 1:
self.rect.x = random.randrange(WIDTH - self.rect.width)
self.rect.y = random.randrange(HEIGHT, HEIGHT+60)
self.Xspeed = 0
self.Yspeed = -random.randrange(1, 8)
elif self.direction == 2:
self.rect.x = random.randrange(-100, -40)
self.rect.y = random.randrange(HEIGHT - self.rect.height)
self.Xspeed = random.randrange(1, 8)
self.Yspeed = 0
elif self.direction == 3:
self.rect.x = random.randrange(WIDTH, WIDTH+60)
self.rect.y = random.randrange(HEIGHT - self.rect.height)
self.Xspeed = -random.randrange(1, 8)
self.Yspeed = 0
def update(self):
self.rect.x += self.Xspeed
self.rect.y += self.Yspeed
dir_x, dir_y = self.player.rect.x - self.rect.x, self.player.rect.y - self.rect.y
self.rot = (180 / math.pi) * math.atan2(-dir_x, -dir_y)
self.image = py.transform.rotate(self.originalimage, self.rot)
if self.direction == 0:
if self.rect.top > HEIGHT + 10:
self.spawn()
elif self.direction == 1:
if self.rect.bottom < -10:
self.spawn()
elif self.direction == 2:
if self.rect.left > WIDTH + 10:
self.spawn()
elif self.direction == 3:
if self.rect.right < -10:
self.spawn()
player = Player()
all_sprites.add(player)
for i in range(8):
n = NPC(player)
all_sprites.add(n)
NPC.add(n)