[Beginner] Application of Lists

Processing.py
1

So, I am trying to write a program that draws white circles at mouseX, mouseY coordinates. When I press “p”, each circle is supposed to be randomly colored individually. When I click the mouse again, more white circles are drawn and the colored ones stay the same color, and if I press p again all circles are randomly colored again.

My code draws white circles fine, but when I press “p” the color for all the circles changes as one random color(not individually), and if I draw new circles, all colors become white.
Any help?

circle_x = []
circle_y = []
circle_size = 20

colour_r = []
colour_g = []
colour_b = []

# def circles(x,y,r,g,b):
#     global circle_x, circle_y, circle_size
#     fill(r,g,b)
    # ellipse(x, y, circle_size, circle_size)
    
def setup():
    size(400, 400)
    background(155)
    colour_r = [255]
    colour_g = [255]
    colour_b = [255]


def draw():
    global circle_x, circle_y, colour_r, colour_g, colour_b, circle_size
    background(155)
    fill(255)
    for z in range(0, len(colour_r)):
        fill(colour_r[z], colour_g[z], colour_b[z])
    for a in range(0, len(circle_x)):
        ellipse(circle_x[a], circle_y[a], circle_size, circle_size)
          
    
def mouseClicked():
    global circle_x, circle_y
    circle_x.append(mouseX)
    circle_y.append(mouseY)
    colour_r.append(255)
    colour_g.append(255)
    colour_b.append(255)
    
        
def keyPressed():
    if key == "p":
        for z in range(0, len(colour_r)):
            colour_r[z] = random(256)
        for a in range(len(colour_g)):
            colour_g[z] = random(256)
        for a in range(len(colour_b)):
            colour_b[z] = random(256)
3 Likes
2

I managed to fix it!! No need for responses

4 Likes
3

Would you like to post your own solution?

May I suggest some ideas?
Why create 3 lists for the color components?

colors = []
colors.append(color(255))

You could even have a single list for the circles… with a tuple inside :slight_smile:

circles = []
circles.append((mouseX, mouseY, 10, color(255)))

In a bigger project you might want to investigate Named Tuples so you can use legible fields like circle.x , circle.color !

2 Likes
4

IMO, when we’ve got a bunch of containers to describe the characteristics of a collection of objects, we should simply turn everything into 1 class, and then have 1 container of instances of that class. :bulb:

Although written for the Java Mode, this old article explains it w/ more details: :nerd_face:

3 Likes
5

Those two methods are very helpful for my other program that I’m working on! Thank you! I’ll post my solution!

2 Likes
6

I finished my program and I pasted it bellow:

#circle_x, circle_y are list that stores circles x,y coordinates
circle_x = [] 
circle_y = []
circle_size = 20 #circle diameter

#lists that stores r,g,b colors, respectivelly
colour_r = []
colour_g = []
colour_b = []
   
def setup():
    size(400, 400)
    background(155)

def draw():
    """draws circles at mouseclicked coords and assigns colours according to key 'p' pressed
    colors and coordinates are taken from the lists """
    global circle_x, circle_y, colour_r, colour_g, colour_b, circle_size
    background(155)
    fill(255)
    for z in range(0, len(colour_r)):
        fill(colour_r[z], colour_g[z], colour_b[z])
        ellipse(circle_x[z], circle_y[z], circle_size, circle_size)
          
    
def mouseClicked():
    """adds values to their list whenever mouse is clicked"""
    global circle_x, circle_y
    circle_x.append(mouseX)
    circle_y.append(mouseY)
    colour_r.append(255)
    colour_g.append(255)
    colour_b.append(255)
    
        
def keyPressed():
    """it changes the values of the lists for colours to random values"""
    if key == "p":
        for z in range(len(colour_r)):
            colour_r[z] = random(256)
            colour_g[z] = random(256)
            colour_b[z] = random(256)
4 Likes