I've been banging my head on this for a couple days now. I'm trying to rotate a sprite on its' center axis and have been referencing this previous post about the same issue:
How do I rotate an image around its center using Pygame?
I'm using the exact same code as described in the previous post and also utilizing a image_clean attribute as to not distort the image on successive rotations. When I try and rotate my sprite the center of the image oscillates back and forth between two points.
def rotate_center(image, angle):
"""rotate a Surface, maintaining position."""
loc = image.get_rect().center #rot_image is not defined
rot_img = pg.transform.rotate(image, angle)
print('')
print('>>> before: ' + str(rot_img.get_rect().center))
rot_img.get_rect().center = loc
print('>>> after: ' + str(rot_img.get_rect().center))
return rot_img
print statements verify that the line:
rot_sprite.get_rect().center = loc
Doesn't seem to assign the loc value to the image center. The output is always like this:
>>> before: (32, 32)
>>> after: (32, 32)
>>> before: (37, 37)
>>> after: (37, 37)
>>> before: (41, 41)
>>> after: (41, 41)
>>> before: (43, 43)
>>> after: (43, 43)
>>> before: (45, 45)
>>> after: (45, 45)
>>> before: (45, 45)
>>> after: (45, 45)
>>> before: (43, 43)
>>> after: (43, 43)
>>> before: (41, 41)
>>> after: (41, 41)
>>> before: (37, 37)
>>> after: (37, 37)
I always want the center to be at (32, 32) (I believe). Any help would be greatly appreciated.
Code:
def main():
pg.init()
# Screen Setup
size = (SCREEN_WIDTH, SCREEN_HEIGHT)
screen = pg.display.set_mode(size)
screen_flags = screen.get_flags()
pg.display.set_caption(GAME_NAME)
done = False
clock = pg.time.Clock()
# SPRITE GROUPS
all_sprites = pg.sprite.Group()
turrets = pg.sprite.Group()
turret = Tower2((SCREEN_WIDTH/2, SCREEN_HEIGHT/2))
turrets.add(turret)
all_sprites.add(turret)
# -------- Main Program Loop -----------
while not done:
# Process Incoming Events
for event in pg.event.get():
if event.type == pg.QUIT:
done = True
if event.type == pg.KEYDOWN:
if event.key == pg.K_q:
done = True
if event.key == pg.K_f:
if screen_flags & pg.FULLSCREEN == False:
screen_flags |= pg.FULLSCREEN
pg.display.set_mode(size, screen_flags)
else:
screen_flags ^= pg.FULLSCREEN
pg.display.set_mode(size, screen_flags)
turret.angle += 10
turret.image = rotate_center(turret.image_clean, turret.angle)
screen.fill(WHITE)
all_sprites.draw(screen)
pg.display.flip()
clock.tick(15)
pg.quit()
class Tower2(pg.sprite.Sprite):
def __init__(self, pos, image, tRange, attackSpeed=1):
super().__init__()
self.image = image
self.image_clean = image
self.rect = self.image.get_rect()
self.rect.center = pos
self.range = tRange
self.attackSpeed = attackSpeed
self.lastAttack = time.time()
self.angle = 0
def __iter__(self):
return self
def canAttack(self):
if time.time() - self.lastAttack > self.attackSpeed:
return True
else:
return False
def rotate(self):
pass
def update(self):
self.angle += 10
self.image = pg.transform.rotate(self.image_clean, self.angle)
self.image.get_rect().center = self.image_clean.get_rect().center
class Turret1(Tower2):
def __init__(self, pos):
TOWER_WIDTH = 64
TOWER_HEIGHT = 64
INIT_RANGE = 200
INIT_RATE = 1
SPEED = 1
tower_img = pg.image.load('imgs/test_rotate.png')
tower_img = pg.transform.scale(tower_img, (TOWER_WIDTH, TOWER_HEIGHT))
super().__init__(pos, tower_img, INIT_RANGE, SPEED)
You have to pass the rect of the sprite as well, because it holds the actual position of the sprite and then pass the center coords to .get_rect or assign them to the new rect's center. If you just call .get_rect(), you get a rect with the topleft coords (0, 0).
def rotate_center(image, rect, angle):
"""Rotate a Surface, maintaining position."""
rot_img = pg.transform.rotate(image, angle)
# Get a new rect and pass the center position of the old
# rect, so that it rotates around the center.
rect = rot_img.get_rect(center=rect.center)
return rot_img, rect # Return the new rect as well.
# In the main while loop.
turret.angle += 10
# Also pass the turret's rect which holds the position of the sprite.
image, rect = rotate_center(turret.image_clean, turret.rect, turret.angle)
turret.image = image # Assign the new image.
turret.rect = rect # Assign the new rect.
You could also do this in the update method of the sprite:
import pygame as pg
WHITE = pg.Color('white')
class Tower2(pg.sprite.Sprite):
def __init__(self, pos, tRange=1, attackSpeed=1):
super().__init__()
self.image = your_image
self.image_clean = self.image
self.rect = self.image.get_rect()
self.rect.center = pos
self.angle = 0
def update(self):
self.angle += 10
self.image = pg.transform.rotate(self.image_clean, self.angle)
self.rect = self.image.get_rect(center=self.rect.center)
def main():
pg.init()
SCREEN_WIDTH = 640
SCREEN_HEIGHT = 480
size = (SCREEN_WIDTH, SCREEN_HEIGHT)
screen = pg.display.set_mode(size)
done = False
clock = pg.time.Clock()
all_sprites = pg.sprite.Group()
turret = Tower2((SCREEN_WIDTH/2, SCREEN_HEIGHT/2))
all_sprites.add(turret)
while not done:
for event in pg.event.get():
if event.type == pg.QUIT:
done = True
all_sprites.update()
screen.fill(WHITE)
all_sprites.draw(screen)
pg.display.flip()
clock.tick(15)
main()
pg.quit()