boxespy/boxes/parts.py

from math import *

def arcOnCircle(spanning_angle, outgoing_angle, r=1.0):
    angle = spanning_angle+2*outgoing_angle
    radius = r * sin(radians(0.5*spanning_angle))/sin(radians(180-outgoing_angle-0.5*spanning_angle))
    return angle, abs(radius)

class Parts:

    def __init__(self, boxes):
        self.boxes = boxes
    """
    def roundKnob(self, diameter, n=20, callback=None, move=""):
        size = diameter+diameter/n+2*spacing
        if self.move(size, size, move, before=True):
            return
        self.boxes.ctx.save()
        self.moveTo(size/2, size/2)
        self.cc(callback, None, 0, 0)
        
        self.boxes.ctx.restore()
        self.move(size, size, move, before=True)
    """

    def __getattr__(self, name):
        return getattr(self.boxes, name)
    
    def disc(self, diameter, callback=None, move=""):
        size = diameter
        r = diameter/2.0
        if self.move(size, size, move, before=True):
            return
        self.moveTo(size/2, size/2)
        self.cc(callback, None, 0, 0)
        self.moveTo(r+self.burn,0, 90)
        self.corner(360, r)
        self.move(size, size, move)
        
    def waivyKnob(self, diameter, n=20, angle=45, callback=None, move=""):
        size = diameter+pi*diameter/n
        if self.move(size, size, move, before=True):
            return
        self.moveTo(size/2, size/2)
        self.cc(callback, None, 0, 0)
        self.moveTo(diameter/2, 0, angle)
        a, r = arcOnCircle(360./n, angle, diameter/2)
        a2, r2 = arcOnCircle(360./n, -angle, diameter/2)
        for i in range(n//2):
            self.boxes.corner(a, r)
            self.boxes.corner(a2, r2)
        self.move(size, size, move, before=True)

    def concaveKnob(self, diameter, n=3, rounded=0.2, angle=70, callback=None, move=""):
        size = diameter
        if self.move(size, size, move, before=True):
            return
        self.rectangularHole(size/2, size/2, size, size)
        self.moveTo(size/2, size/2)
        self.cc(callback, None, 0, 0)
        self.moveTo(diameter/2, 0, 90+angle)
        a, r = arcOnCircle(360./n*(1-rounded), -angle, diameter/2)
        if abs(a) < 0.01: # avoid trying to make a straight line as an arc
            a, r = arcOnCircle(360./n*(1-rounded), -angle-0.01, diameter/2)            
        for i in range(n):
            self.boxes.corner(a, r)
            self.corner(angle)
            self.corner(360./n*rounded, diameter/2)
            self.corner(angle)

        self.move(size, size, move, before=True)