i=0
k=1
def setup():
    size(500,500)
    smooth()
    strokeWeight(30)
    background(0)
def draw():
    global i
    global k
    stroke(i,20)
    line(mouseX -50, mouseY -50, 100+ mouseX -50, 100+ mouseY -50)
    line (100+ mouseX -50, mouseY -50, mouseX -50, 100+ mouseY -50)
    i=i+k
    if(i==255):
        k=-1
    if(i==0):
        k=1

i=0
k=1
def setup():
    size(500,500)
    smooth()
    strokeWeight(30)
    background(0)
def draw():
    global i
    global k
    stroke(i,20)
    line(mouseX -50, mouseY -50, 100+ mouseX -50, 100+ mouseY -50)
    line (100+ mouseX -50, mouseY -50, mouseX -50, 100+ mouseY -50)
    i=i+k
    if(i==255):
        k=-1
    if(i==0):
        k=1
