Sprite animation from sprite sheet at 8 FPS?

Vile

@JonB, I’ve already looked at the game tutorial, where it showed how to animate a walking sequence. However, that method only works when the sprite is changing its position in pixels on the screen, so it will not work for my sprite. This is because my sprite’s position is constantly at the centre of the screen.

The effect I’m trying to achieve is basically a GIF with a customisable frame speed, which is permanently in exactly the same position at the centre of the screen.

Vile

@JonB, I’ve also never used Action.wait before, so I’d appreciate an example of this, thanks.

Remember, I’m still a noob here lol

pulbrich

@Vile :

import time #this module is needed to get the system time

In your set-up code:

self.last_update = time.process_time()

In your update method:

current_time = time.process_time()
if current_time - self.last_update > 0.125:
	self.last_update = current_time
	modify_the_sprite

Vile

@pulbrich

I tried your method, but it seems that anything I put into the update function doesn’t get used...

Here’s the updated code:

from scene import *
import time

sprite_sheet = [
Texture('IMG_0227.png').subtexture(Rect(0,0,0.25,1)),
Texture('IMG_0227.png').subtexture(Rect(0.25,0,0.25,1)),
Texture('IMG_0227.png').subtexture(Rect(0.5,0,0.25,1)),
Texture('IMG_0227.png').subtexture(Rect(0.75,0,.25,1)),
]

class MyScene (Scene):
	def setup(self):
		self.screen="game"
		self.background_color = 'black'
		self.last_update = time.process_time()
		self.sprite = SpriteNode(sprite_sheet[0],
		scale = 1,
		position = self.size / 2,
		parent = self)
		self.add_child(self.sprite)
		n=0
		
		def update(self):
			current_time = time.process_time()
			if current_time - self.last_update > 0.125:
				self.last_update = current_time
				#modify_the_sprite
				self.sprite.texture=sprite_sheet[n]
				n=n+1
run(MyScene())

Vile

Wait it actually works, I just had the wrong indentation on the update function XD

Here’s the code:

from scene import *
import time

sprite_sheet = [
Texture('IMG_0227.png').subtexture(Rect(0,0,0.25,1)),
Texture('IMG_0227.png').subtexture(Rect(0.25,0,0.25,1)),
Texture('IMG_0227.png').subtexture(Rect(0.5,0,0.25,1)),
Texture('IMG_0227.png').subtexture(Rect(0.75,0,.25,1)),
]

class MyScene (Scene):
	def setup(self):
		self.screen="game"
		self.background_color = 'black'
		self.last_update = time.process_time()
		self.sprite = SpriteNode(sprite_sheet[0],
		scale = 1,
		position = self.size / 2,
		parent = self)
		self.add_child(self.sprite)
		self.n=0
		
	def update(self):
		#self.sprite.texture=sprite_sheet[1]
		current_time = time.process_time()
		if current_time - self.last_update > 0.05:
			self.last_update = current_time
			#modify_the_sprite
			self.sprite.texture=sprite_sheet[self.n]
			self.n=self.n+1
			if self.n > 3:
				self.n=0
run(MyScene())

Thanks a lot for your help!

JonB

dont use time.process_time. instead use scene.t -- scene includes t which is the time since the start of the scene, and dt, which is the time since last update.

Vile

@JonB, I tried using scene.t and scene.dt, but I can’t get it working...

pulbrich

Instead of using the time function that I suggested, put Scene.t (mind the capital S)

CORRECTION: it is self.t (instance attribute), thanks @JonB

self.dt is not directly suitable for your case; it gives you the time lapsed since the last call to update().

JonB

I think it should be self.t.
it is an instance attribute, not a class attrib, if memory serves -- the time is incremented in the running scene only.

cvp

Following @JonB advice, this works

.
.
.
        self.last_t = self.t
        
    def update(self):
        #self.sprite.texture=sprite_sheet[1]
        if (self.t-self.last_t) > 0.05:
            #modify_the_sprite
            self.last_t = self.t
.
.
.

Vile

@JonB and @cvp, thanks once again! It seems to work in the way I expected now.

It seems that scene.t uses a different time frame from time.process_time, because with the same number value, the animations appear to go at different speeds.

cvp

@Vile thank only @jonb 😀