2D animation example in pyglet (python) looping through 2 images/sprites every x seconds

Question

Suppose you have two images: step1.png and step2.png .

Can anyone show me a very simple example in pyglet how to loop through those 2 images say every 0.5 seconds?

The character doesn't have to move, just a simple black screen with a fixed region wherein the two images continually change every 0.5 secs.

I know how to make a character move, shoot projectiles etc. but I just can't figure out how to control the looping speed of the images.

Answer 1

I use my own sprite class, which has an timer variable which accumulates the dtime in the update_frames() message. By this you have an exact timestamp and can easily change the image based on certain timings.I do not have a source available but I will add this later, if needed

Update: Here is a small piece of code: It loads two frames and displays flip flop it after a second. This will be done in update_frames(dt) (counter is a float between [0-2[, you can also multiply dt to have different timings )

Note that the print in on_draw will print on each frame, but count changes only 10 times a second, configured in pyglet.clock.schedule_interval(update_frames,1/10.0) (play with this value, you will see the duration of the animation will not change)

#!usr/bin/python
import pyglet
window = pyglet.window.Window()
counter=.0

def load_anim():
    arrImages=[]
    for i in range(2):
        tmpImg=pyglet.resource.image("step"+str(i)+".png")
        arrImages.append(tmpImg)
    return arrImages

def update_frames(dt):
    global counter
    counter=(counter+dt)%2

@window.event
def on_draw():
    print counter
    pyglet.gl.glClearColor(0,0,0,0)
    window.clear()
    frames[int(counter)].blit(320,200,0,
                              frames[int(counter)].width,
                              frames[int(counter)].height)

frames = load_anim()
pyglet.clock.schedule_interval(update_frames,1/10.0)
pyglet.app.run()

Answer 2

Like this:

import pyglet

# Create and open a window
window = pyglet.window.Window(200, 200)

# Load sprites
s0 = pyglet.resource.image('01.jpg')
s1 = pyglet.resource.image('02.jpg')
sprites = [s0, s1]

# Animation
anim = pyglet.image.Animation.from_image_sequence(sprites, 0.5, True)
sprite = pyglet.sprite.Sprite(anim)

@window.event
def on_draw():
  window.clear()
  sprite.draw()

if __name__ == '__main__':
  pyglet.app.run()

But you probably want to use a texture atlas instead of that, like this:

import pyglet

# Create and open a window
window = pyglet.window.Window(200, 200)

# Create a static sprite
sprite = pyglet.resource.image('cat.jpg')

# Cut our cat up into a 5x5 grid of images to move through (sprite sheet)
raw = pyglet.image.load('cat.jpg')
raw_seq = pyglet.image.ImageGrid(raw, 5, 5)
anim = pyglet.image.Animation.from_image_sequence(raw_seq, 0.1, True)
sprite2 = pyglet.sprite.Sprite(anim)

@window.event
def on_draw():
  window.clear()
  sprite.blit(25, 25, width=150, height=150)
  sprite2.draw()

if __name__ == '__main__':
  pyglet.app.run()