使用pygame.transform.rotate时内存不足

Question

I wrote a script that allows a user to control the sprite of an eagle to fly around to learn pygame. It seemed fine until i implemented a rotation function that makes the sprite rotate according to the direction it is flying along. The sprite becomes really fuzzy after moving a short while and an error soon pops up saying out of memory (at this line: eagle_img = pygame.transform.rotate(eagle_img,new_angle-angle) )

My code:

# eagle movement script
import pygame, math, sys
from pygame.locals import *
pygame.init()
clock = pygame.time.Clock()

# terminate function
def terminate():
    pygame.quit()
    sys.exit()

# incircle function, check if mouse click is inside controller
def incircle(coordinates,cir_center,cir_out_rad):
    if math.sqrt((coordinates[0]-cir_center[0])**2+\
                 (coordinates[1]-cir_center[1])**2) <= cir_out_rad:
        return True
    return False

# speed function, translates the controller movement into eagle movement
def speed(position,cir_center,eagle_speed):
    x_dist = position[0] - cir_center[0]
    y_dist = position[1] - cir_center[1]
    dist = math.sqrt(x_dist**2+y_dist**2)   # distance from controller knob to center
    if dist != 0:
        return [(x_dist/dist)*eagle_speed,(y_dist/dist)*eagle_speed]
    else:
        return [0,0]

# rotation function, rotates the eagle image
def rotation(position,cir_center):
    x_dist = position[0] - cir_center[0]
    y_dist = position[1] - cir_center[1]
    new_radian = math.atan2(-y_dist,x_dist)
    new_radian %= 2*math.pi
    new_angle = math.degrees(new_radian)
    return new_angle

# screen
screenw = 1000
screenh = 700
screen = pygame.display.set_mode((screenw,screenh),0,32)
pygame.display.set_caption('eagle movement')

# variables
green = (0,200,0)
grey = (100,100,100)
red = (255,0,0)
fps = 60

# controller
cir_out_rad = 150    # circle controller outer radius
cir_in_rad = 30     # circle controller inner radius
cir_center = [screenw-cir_out_rad,int(screenh/2)]
position = cir_center    # mouse position

# eagle
eaglew = 100
eagleh = 60
eagle_speed = 3
eagle_pos = [screenw/2-eaglew/2,screenh/2-eagleh/2]
eagle = pygame.Rect(eagle_pos[0],eagle_pos[1],eaglew,eagleh)
eagle_img = pygame.image.load('eagle1.png').convert()
eagle_bg_colour = eagle_img.get_at((0,0))
eagle_img.set_colorkey(eagle_bg_colour)
eagle_img = pygame.transform.scale(eagle_img,(eaglew,eagleh))

# eagle controls
stop_moving = False # becomes True when player stops clicking
rotate = False      # becomes True when there is input
angle = 90          # eagle is 90 degrees in the beginning

# game loop
while True:
    # controls
    for event in pygame.event.get():
        if event.type == QUIT:
            terminate()
        if event.type == MOUSEBUTTONUP:
            stop_moving = True
            rotate = False

    mouse_input = pygame.mouse.get_pressed()
    if mouse_input[0]:
        coordinates = pygame.mouse.get_pos()    # check if coordinates is inside controller
        if incircle(coordinates,cir_center,cir_out_rad):
            position = pygame.mouse.get_pos()
            stop_moving = False
            rotate = True
        else:
            cir_center = pygame.mouse.get_pos()
            stop_moving = False
            rotate = True
    key_input = pygame.key.get_pressed()
    if key_input[K_ESCAPE] or key_input[ord('q')]:
        terminate()

    screen.fill(green)

    [dx,dy] = speed(position,cir_center,eagle_speed)
    if stop_moving:
        [dx,dy] = [0,0]
    if eagle.left > 0:
        eagle.left += dx
    if eagle.right < screenw:
        eagle.right += dx
    if eagle.top > 0:
        eagle.top += dy
    if eagle.bottom < screenh:
        eagle.bottom += dy

    if rotate:
        new_angle = rotation(position,cir_center)
        if new_angle != angle:
            eagle_img = pygame.transform.rotate(eagle_img,new_angle-angle)
            eagle = eagle_img.get_rect(center=eagle.center)
        rotate = False
        angle = new_angle

    outer_circle = pygame.draw.circle(screen,grey,(cir_center[0],cir_center[1]),\
                                  cir_out_rad,3)
    inner_circle = pygame.draw.circle(screen,grey,(position[0],position[1]),\
                                  cir_in_rad,1)
    screen.blit(eagle_img,eagle)
    pygame.display.update()
    clock.tick(fps)

Please tell me what's wrong here and how i can improve it. Feel free to try the code out using a sprite named "eagle1.png". Thanks!

Answer 1

the reason your eagle picture is becoming blurred is because your continually rotating the same png and not making a copy and rotating that copy while always keeping a non edited picture. here is a function i have always used when rotating square images

def rot_center(image, angle):
    """rotate an image while keeping its center and size"""
    orig_rect = image.get_rect()
    rot_image = pygame.transform.rotate(image, angle)
    rot_rect = orig_rect.copy()
    rot_rect.center = rot_image.get_rect().center
    rot_image = rot_image.subsurface(rot_rect).copy()
    return rot_image

here is one for any shape of picture

def rot_center(image, rect, angle):
        """rotate an image while keeping its center"""
        rot_image = pygame.transform.rotate(image, angle)
        rot_rect = rot_image.get_rect(center=rect.center)
        return rot_image,rot_rect

source from here

as for the "out of memory" error i don't know for sure but i assume the leak is being caused by the rotation of the same png file over and over again. From some research that seems to occur often with other people.

hope this helps clear some things up:)