Overview
The SimpleAnimation class provides a simple way to create animations by cyclically scrolling through a list of images and drawing them onto the screen at the same position. The animation can run indefinitely or for a specified duration.
Class: SimpleAnimation
Constructor
SimpleAnimation(screen, pos, images, scroll_period, duration=-1)
The screen surface to which the animation will be drawn
Position on the screen as a tuple (x, y) where the animation will be rendered
A list of pygame surface objects to cyclically scroll through during the animation
Scrolling period in milliseconds - controls how fast the animation cycles through images
Duration of the animation in milliseconds. If -1, the animation will have indefinite duration
Methods
is_active()
Checks whether the animation is currently active.
Returns: bool - True if the animation is active, False otherwise
An animation is active from the moment of its creation and until the duration has passed (if a duration was specified).
update()
def update(self, time_passed)
The time passed in milliseconds since the previous update
draw()
Draws the current animation frame onto the screen.
This method renders the current image from the animation sequence at the position specified during initialization. It only draws if the animation is active.
_inactivate()
Internal method - Deactivates the animation when the duration expires.
This method is called automatically by the internal timer and should not be called directly.
_advance_img()
Internal method - Advances to the next image in the animation sequence.
This method is called automatically by the scroll timer to cycle through images and should not be called directly.
Usage Example
Basic Explosion Animation
import pygame
from simpleanimation import SimpleAnimation
# Initialize pygame and create screen
pygame.init()
screen = pygame.display.set_mode((300, 300), 0, 32)
clock = pygame.time.Clock()
# Load and prepare animation images
explosion_img = pygame.image.load('images/explosion1.png').convert_alpha()
images = [explosion_img, pygame.transform.rotate(explosion_img, 90)]
# Create animation: cycles every 100ms, lasts 2120ms total
explosion = SimpleAnimation(screen, (100, 100), images, 100, 2120)
# Game loop
while True:
time_passed = clock.tick(50)
screen.fill((0, 0, 0))
for event in pygame.event.get():
if event.type == pygame.QUIT:
pygame.quit()
break
# Update and draw animation
explosion.update(time_passed)
explosion.draw()
pygame.display.flip()
Indefinite Animation
# Create an animation that runs forever
idle_frames = [frame1, frame2, frame3, frame4]
idle_animation = SimpleAnimation(
screen=game_screen,
pos=(50, 50),
images=idle_frames,
scroll_period=150,
duration=-1 # Runs indefinitely
)
# In your game loop
if idle_animation.is_active():
idle_animation.update(time_delta)
idle_animation.draw()
Multiple Animations
# Create multiple animations with different durations and speeds
animations = []
# Fast explosion (50ms per frame, 1 second total)
fast_explosion = SimpleAnimation(screen, (100, 100), explosion_frames, 50, 1000)
animations.append(fast_explosion)
# Slow glow effect (300ms per frame, 3 seconds total)
glow_effect = SimpleAnimation(screen, (200, 200), glow_frames, 300, 3000)
animations.append(glow_effect)
# Game loop
while running:
time_passed = clock.tick(60)
screen.fill((0, 0, 0))
# Update and draw all active animations
for anim in animations:
if anim.is_active():
anim.update(time_passed)
anim.draw()
pygame.display.flip()
Dependencies
- pygame: Required for surface rendering and display operations
- utils.Timer: Internal timer utility for managing animation timing