Fast Circle Using Viper Pointers

circle.py

@micropython.viper
def circle(x0:int, y0:int, radius:int):
    # From Adafruit GFX Arduino library
    # Circle drawing function.  Will draw a single pixel wide circle with
    # center at x0, y0 and the specified radius.
    # screen is bytearray (240x240) 
    screen_addr=ptr16(screen)
    color=0xffff
    f = 1 - radius
    ddF_x = 1
    ddF_y = -2 * radius
    x = 0
    y = radius
    
    y1=(y0+radius)*240
    y2=(y0-radius)*240
    screen_addr[y1+x0]=color
    screen_addr[y2+x0]=color
    y3=y0*240
    screen_addr[y3+x0+radius]=color
    screen_addr[y3+x0-radius]=color
    
    #LCD.pixel(x0, y0 + radius,color)
    #LCD.pixel(x0, y0 - radius,color)
    #LCD.pixel(x0 + radius, y0,color)
    #LCD.pixel(x0 - radius, y0,color)
    while x < y:
        if f >= 0:
            y -= 1
            ddF_y += 2
            f += ddF_y
        x += 1
        ddF_x += 2
        f += ddF_x
        x1=x0+x
        x2=x0-x
        y1=y0+y
        y2=y0-y
        screen_addr[y1*240+x1]=color
        screen_addr[y1*240+x2]=color
        screen_addr[y2*240+x1]=color
        screen_addr[y2*240+x2]=color
        x1=x0+y
        x2=x0-y
        y1=y0+x
        y2=y0-x
        screen_addr[y1*240+x1]=color
        screen_addr[y1*240+x2]=color
        screen_addr[y2*240+x1]=color
        screen_addr[y2*240+x2]=color
        #LCD.pixel(x0 + x, y0 + y,color)
        #LCD.pixel(x0 - x, y0 + y,color)
        #LCD.pixel(x0 + x, y0 - y,color)
        #LCD.pixel(x0 - x, y0 - y,color)
        
        #LCD.pixel(x0 + y, y0 + x,color)
        #LCD.pixel(x0 - y, y0 + x,color)
        #LCD.pixel(x0 + y, y0 - x,color)
        #LCD.pixel(x0 - y, y0 - x,color)