spritesheet.py

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# CodeSkulptor is tested to run in recent versions of
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import simplegui

SHEET_URL = "http://www.cs.rhul.ac.uk/courses/CS1830/sprites/runnerSheet.png"
SHEET_WIDTH = 1440
SHEET_HEIGHT = 1480
SHEET_COLUMNS = 6
SHEET_ROWS = 5

class Spritesheet:
    def __init__(self, imgurl, width, height, columns, rows):

        self.img = simplegui.load_image(imgurl)

        self.width = width
        self.height = height
        self.columns = columns
        self.rows = rows

        self.frame_width = width / columns
        self.frame_height = height / rows
        self.frame_centre_x = self.frame_width / 2
        self.frame_centre_y = self.frame_height / 2

        self.frame_index = [0, 0]
        self.clock = Clock(0)
        print(self.rows)
        print(self.columns)

    def draw(self, canvas):
        source_centre = (
            self.frame_width * self.frame_index[1] + self.frame_centre_x,
            self.frame_height * self.frame_index[0] + self.frame_centre_y
        )
        source_size = (self.frame_width, self.frame_height)
        dest_centre = (300, 150)
        dest_size = (100, 100)

        canvas.draw_image(
            self.img,
            source_centre, source_size,
            dest_centre, dest_size
        )
        self.clock.tick()

        if(self.clock.transition(10)):
            self.next()

    def next(self):

        if(self.frame_index[1] + 1 >= self.columns):
            self.frame_index[0] = (self.frame_index[0] + 1)%self.rows

        self.frame_index[1] = (self.frame_index[1]+1)%self.columns

class Clock:

    def __init__(self, time):
        self.time = time

    def tick(self):
        self.time = self.time + 1

    def transition(self, frame_duration):
        if(self.time==frame_duration):
            self.time = 0
            return True
        else:
            return False

sheet = Spritesheet(
    SHEET_URL,
    SHEET_WIDTH, SHEET_HEIGHT,
    SHEET_COLUMNS, SHEET_ROWS
)

frame = simplegui.create_frame("Sprite", 600, 300)
frame.set_draw_handler(sheet.draw)

frame.start()