Scrolling background slightly juddering at 60 FPS

[stevepaget]

Scrolling background slightly juddering at 60 FPS

I'm not sure, but the juddering may have something to do with repeated keyboard input not coming in that quickly at lower frame rates.

I also translated my example to PySFML. As you can see, it pretty much does the same thing as Pygame, the syntax and some concepts are just a little bit different. Scrolling is also not 100% accurate there, some artifact is running down the screen from time to time.
Maybe the background should also be redrawn in frames, when it hasn't been scrolled, I don't know.

#!/usr/bin/python
# coding: utf-8

from sfml import sf

class Background():

    def __init__(self, screen):
        self.screen = screen
        self.colour = sf.Color(0, 0, 0)

    def setTiles(self, tiles):

        if type(tiles) is str:
            self.tiles = [[self.loadImage(tiles)]]
        elif type(tiles[0]) is str:
            self.tiles = []
            t = []
            for i in tiles:
                t.append(self.loadImage(i))
            self.tiles.append(t)
        else:
            self.tiles = []
            for i in tiles:
                t = []
                for row in i:
                    t.append(self.loadImage(row))
                self.tiles.append(t)
        self.stagePosX = 0
        self.stagePosY = 0
        self.tileWidth  = int(self.tiles[0][0].global_bounds.width)
        self.tileHeight = int(self.tiles[0][0].global_bounds.height)
        self.screen.draw(self.tiles[0][0])

    def loadImage(self, fileName):
        texture = sf.Texture.from_file(fileName)
        sprite  = sf.Sprite(texture)
        sprite.position = (0, 0)
        return sprite

    def scroll(self, x, y):
        self.stagePosX -= x
        self.stagePosY -= y
        col = (self.stagePosX % (self.tileWidth * len(self.tiles[0]))) // self.tileWidth
        xOff = (0 - self.stagePosX % self.tileWidth)
        row = (self.stagePosY % (self.tileHeight * len(self.tiles))) // self.tileHeight
        yOff = (0 - self.stagePosY % self.tileHeight)

        col2 = ((self.stagePosX + self.tileWidth) % (self.tileWidth * len(self.tiles[0]))) // self.tileWidth
        row2 = ((self.stagePosY + self.tileHeight) % (self.tileHeight * len(self.tiles))) // self.tileHeight

        self.tiles[row][col].position = (xOff, yOff)
        self.screen.draw(self.tiles[row][col])

        self.tiles[row][col2].position = (xOff + self.tileWidth, yOff)
        self.screen.draw(self.tiles[row][col2])

        self.tiles[row2][col].position = (xOff, yOff + self.tileHeight)
        self.screen.draw(self.tiles[row2][col])

        self.tiles[row2][col2].position = (xOff + self.tileWidth, yOff + self.tileHeight)
        self.screen.draw(self.tiles[row2][col2])

screen = sf.RenderWindow(sf.VideoMode(600, 600), unicode("Scrolling Background"))
screen.position = (300, 30)
screen.framerate_limit = 60

background = Background(screen)
screen.clear(background.colour)
background.setTiles([["images/dungeonFloor1.png", "images/dungeonFloor2.png"],
                     ["images/dungeonFloor3.png", "images/dungeonFloor4.png"]])
scroll_by = 5

while screen.is_open:

    if sf.Keyboard.is_key_pressed(sf.Keyboard.ESCAPE):
        screen.close()
    if sf.Keyboard.is_key_pressed(sf.Keyboard.RIGHT):
        background.scroll(-scroll_by, 0)
    if sf.Keyboard.is_key_pressed(sf.Keyboard.DOWN):
        background.scroll(0, -scroll_by)
    if sf.Keyboard.is_key_pressed(sf.Keyboard.LEFT):
        background.scroll(scroll_by, 0)
    if sf.Keyboard.is_key_pressed(sf.Keyboard.UP):
        background.scroll(0, scroll_by)

    screen.display()

[StevePaget]

Thanks for this. I have not used pySFML, but it sounds interesting.
I'll close this as it's not really related to pygame_functions, more pygame in general.