How can I control rotations for a class?

kkomal17

Hey, this may seem like a minor question, but I'm having trouble on stopping rotations for a specific class. Mind you, this is processing 2.x, and I'm using Python.

` def setup(): size(400,400)

global angle
angle = 0

global bangle
bangle = 0

global cangle
cangle = 0

global dangle
dangle = 0

global stars
stars = []
for i in range(10):
    s = star()
    stars.append(s)

def draw(): global angle angle+=PI/72

global bangle
bangle+=PI/8

global cangle
cangle+=PI/36

global dangle
dangle+=PI

background(70)

#THE SUN
translate(200,200)
fill(255,255,0)
ellipse(0,0,50,50)

#MARS
rotate(angle)
fill(175,0,0)
ellipse(160,0,20,20)

#EARTH
rotate(cangle)
fill(0,0,255)
ellipse(100,0,20,20)
translate(100,0)

#MOON
rotate(cangle)
fill(128,128,128)
ellipse(30,20,10,10)
translate(30,20)

#MOON'S MOON
rotate(bangle)
fill(139,0,139)
ellipse(5,10,7,7)

for star in stars:
    star.noRotate()
    star.display()

class star: def init(self): self.xpos = random(width) self.ypos = random(height) self.color = color(255)

def display(self):
    fill(self.color)
    noStroke()
    ellipse(self.xpos,self.ypos,5,5)

def noRotate(self):
    rotate(dangle)`

My issue is the stars are rotating, and I was wondering how I could possibly stop them from doing so. Thank you in advance.

jeremydouglass

Without testing your code, my guess is that your stars are being drawn at the end of all your other rotations. Instead, you should either:

1. Draw your stars first before you do other rotating, or
2. Isolate your rotations so that they are undone after you finish your other celestial bodies -- use pushMatrix and popMatrix. http://py.processing.org/reference/pushMatrix.html

For details on how this works, see the main (non-Python) documentation

http://processing.org/reference/pushMatrix_.html

and the 2D Transformations tutorial

https://processing.org/tutorials/transform2d/