# FILENAME: fractreemodule.py
from visual import *

####### FUNCTION fractree - DON'T NEED TO MODIFY THIS FUNCTION DEFN.
## Arguments:
##   parentframe - frame for this tree or branch
##   shrink      - factor to shrink at each level
##   axislist    - list of branch orientations (3-tuples or vectors)
##   poslist     - position of subbranches along main branch
##   scale       - current length scale (how big branch is)
##   level       - how many generations to go.
## Returns:
##   a real number that is the surface area of the tree.
## returns surface area of tree for calculating
## the fractal dimension.
def fractree(parentframe,shrink,axislist,poslist,scale,level):
    newscale=scale*shrink
    ### draw a branch
    cylinder(frame=parentframe,
             radius=scale*0.1,
             axis=(scale,0,0))
    ### surface area of branch - not counting caps of cylinder.
    surfarea = 2.0 * pi * (scale * 0.1) * scale
    if (level == 0):
        ## draws a leaf - doesn't count as bark area - just decoration
        cylinder(radius=scale*0.5,axis=(newscale*0.2,0,0),
                 pos=(scale,0,0),
                 color=color.green,frame=parentframe)
    if (level != 0):
        for i in range(len(axislist)):
            childframe=frame(frame=parentframe,
                             axis=axislist[i],
                             x=poslist[i]*scale) 
            surfarea = surfarea + fractree(childframe,shrink,axislist,poslist,newscale,level-1)
    return surfarea