I am quite new to Pygame 2 (actually python in general), and I wanted to make a little game for school. I used the code from this, but I can't get it to move towards the cursor when I press SPACE. I don't want it to move in the x/y axis... This is the code btw
import sys, pygame, math
from pygame.locals import *
spaceship = ('spaceship.png')
mouse_c = ('cursor.png')
backg = ('background.jpg')
lazer = pygame.mixer.Sound("pew.WAV")
pygame.init()
display_width = 1280
display_height = 720
screen = pygame.display.set_mode((display_width,display_height))
pygame.display.set_caption("Space Survival")
bk = pygame.image.load(backg).convert_alpha()
space_ship = pygame.image.load(spaceship).convert_alpha()
mousec = pygame.image.load(mouse_c).convert_alpha()
clock = pygame.time.Clock()
pygame.mouse.set_visible(False)
Ammo = 20
Fuel = 200
while True:
for event in pygame.event.get():
if event.type == QUIT:
pygame.quit()
sys.exit()
elif event.type == MOUSEBUTTONDOWN and event.button == 1 and Ammo <= 20:
print("Pew")
pygame.mixer.Sound.play(lazer)
elif event.type == MOUSEBUTTONDOWN and event.button == 3 and Fuel <= 200:
print("Boost")
screen.blit(bk, (0, 0))
pos = pygame.mouse.get_pos()
angle = 270-math.atan2(pos[1]-(display_height/2),pos[0]-(display_width/2))*180/math.pi
rotimage = pygame.transform.rotate(space_ship,angle)
rect = rotimage.get_rect(center=((display_width/2),(display_height/2)))
screen.blit(rotimage,rect) #I need space_ship to rotate towards my cursor
screen.blit(mousec, (pos))
pygame.display.update()
clock.tick(60) #FPS
Running Pygame 2.0 on Python 3.8. Any tips will be much appreciated :)
Write a function that "follows2 an target:
def FollowMe(pops, fpos, step):
# [...]
I recommend to compute the distance between the spaceship and the mouse and the unit direction vector from (fpos
) to (pops
).
The distance can be get by computing the Euclidean distance. Pygame provides distance_to()
for that. Th unit direction vector can be computed by dividing the direction vector by the distance or by normalizing (normalize()
) the direction vector:
target_vector = pygame.math.Vector2(pops)
follower_vector = pygame.math.Vector2(fpos)
distance = follower_vector.distance_to(target_vector)
direction_vector = target_vector - follower_vector
if distance > 0:
direction_vector /= distance
Now you can define an exact step_distance
and move to follower in direction of the sprite:
if distance > 0:
new_follower_vector = follower_vector + direction_vector * step_distance.
Define a step
and ensure that the step distance is not grater than the step:
step_distance = min(distance, step)
The maximum step distance is
max_step = distance - minimum_distance
Put it all together:
def FollowMe(pops, fpos, step):
target_vector = pygame.math.Vector2(pops)
follower_vector = pygame.math.Vector2(fpos)
new_follower_vector = pygame.math.Vector2(fpos)
distance = follower_vector.distance_to(target_vector)
if distance > 0:
direction_vector = (target_vector - follower_vector) / distance
step_distance = min(distance, step)
new_follower_vector = follower_vector + direction_vector * step_distance
return (new_follower_vector.x, new_follower_vector.y)
See also How to make smooth movement in pygame.
Use the function to move the space ship in the direction of the mouse and pygame.key.get_pressed()
to move the ship when SPACE is pressed. pygame.key.get_pressed()
returns a list with the state of each key. If a key is held down, the state for the key is True
, otherwise False
. Use pygame.key.get_pressed()
to evaluate the current state of a button and get continuous movement:
ship_pos = display_width // 2, display_height // 2
while True:
# [...]
keys = pygame.key.get_pressed()
if keys[pygame.K_SPACE]:
ship_pos = FollowMe(pos, ship_pos, 3)
angle = 270-math.atan2(pos[1]-ship_pos[1],pos[0]-ship_pos[0])*180/math.pi
rotimage = pygame.transform.rotate(space_ship,angle)
rect = rotimage.get_rect(center=ship_pos)
For the rotation of an image see How to rotate an image(player) to the mouse direction? and How do I rotate an image around its center using PyGame?
See also Rotate towards target or mouse respectivley Move towards target and the answer to the question How do I rotate a sprite towards the mouse and move it?
Minimal example without any usage of external resources (sound and images):
import sys, pygame, math
from pygame.locals import *
pygame.init()
def FollowMe(pops, fpos, step):
target_vector = pygame.math.Vector2(pops)
follower_vector = pygame.math.Vector2(fpos)
new_follower_vector = pygame.math.Vector2(fpos)
distance = follower_vector.distance_to(target_vector)
if distance > 0:
direction_vector = (target_vector - follower_vector) / distance
step_distance = min(distance, step)
new_follower_vector = follower_vector + direction_vector * step_distance
return (new_follower_vector.x, new_follower_vector.y)
display_width = 1280
display_height = 720
screen = pygame.display.set_mode((display_width,display_height))
pygame.display.set_caption("Space Survival")
clock = pygame.time.Clock()
bk = pygame.Surface(screen.get_size())
space_ship = pygame.Surface((20, 50), pygame.SRCALPHA)
space_ship.fill((0, 255, 0))
mousec = pygame.Surface((20, 20), pygame.SRCALPHA)
mousec.fill((255, 0, 0))
ship_pos = display_width // 2, display_height // 2
while True:
clock.tick(60)
for event in pygame.event.get():
if event.type == QUIT:
pygame.quit()
pos = pygame.mouse.get_pos()
keys = pygame.key.get_pressed()
if keys[pygame.K_SPACE]:
ship_pos = FollowMe(pos, ship_pos, 3)
angle = 270-math.atan2(pos[1]-ship_pos[1],pos[0]-ship_pos[0])*180/math.pi
rotimage = pygame.transform.rotate(space_ship,angle)
rect = rotimage.get_rect(center=ship_pos)
screen.blit(bk, (0, 0))
screen.blit(rotimage,rect)
screen.blit(mousec, pos)
pygame.display.update()