User Manual

Please install wxPython2.8 according to your python version first

The following two programs use wxPython2.8 for GUI

1.1             Drawing the Pythagorean Tree

Run step:

python pythagoras_tree.py

There are four drop list to control appearance of the Pythagorean Tree

1. Scale

Each recursion, the rectangle will scaled down as this parameter

1. Branching angle

This is the angle between left branch scaled down rectangle and parent rectangle

1. Color

The color of the tree

1. Depth

This is the recursion depth of the Pythagorean Tree

1.2             Drawing the Hilbert Curve

Run step:

python hilbert_curve.py

There are two drop list to control appearance of the Hilbert Curve

1. Unit length

The unit length of the Hilbert Curve, the size will be changed

1. Level

Level is the recursion depth, user can choose 1~6 to check different appearance of the Hilbert Curve

Code :

pythogoras.py

import wx, math

PI = 3.1415926

#LEFT_BRANCH_ANGLE = 30.0*PI/180

#MIN_WIDTH = 3

#SCALE = 0.75

# Four drop list user control id

SCALE_BOX_ID = 100

ANGLE_BOX_ID = 101

COLOR_BOX_ID = 102

DEPTH_BOX_ID = 103

# parameters available

scale = [‘0.75’, ‘0.6’, ‘0.3’]

branch_angle = [’30’, ’40’, ’45’, ’50’]

color = [“RED”, “GREEN”, “BLUE”]

depth = [‘1’, ‘2’, ‘3’, ‘6’, ‘8’, ’10’, ’12’]

scale_idx = 0

branch_angle_idx = 0

color_idx = 1

depth_idx = 5

# wx frame for GUI

class Frame(wx.Frame):

  def __init__(self, parent=None, id=-1,

         pos=wx.DefaultPosition, title=’Pythagoras Tree Demo!’):

    wx.Frame.__init__(self, parent, id, title, pos)

    size = (600, 360)

    self.SetClientSize(size)

    self.SetBackgroundColour(“BLACK”)

    self.canvas = Panel(self, -1, 600, 300)

    font = wx.Font(10, wx.MODERN, wx.NORMAL, wx.BOLD)

    label1 = wx.StaticText(self, -1, ‘scale:’, (10, 322))

    label1.SetFont(font)

    label1.SetForegroundColour(“WHITE”)

    box1 = wx.ComboBox(self, SCALE_BOX_ID, “”, (60, 320), (50, 30), scale, wx.CB_DROPDOWN)

    box1.SetSelection(scale_idx)

    label2 = wx.StaticText(self, -1, ‘branching angle:’, (124, 322))

    label2.SetFont(font)

    label2.SetForegroundColour(“WHITE”)

    box2 = wx.ComboBox(self, ANGLE_BOX_ID, “”, (256, 320), (40, 30), branch_angle, wx.CB_DROPDOWN)

    box2.SetSelection(branch_angle_idx)

    label3 = wx.StaticText(self, -1, ‘color:’, (316, 322))

    label3.SetFont(font)

    label3.SetForegroundColour(“WHITE”)

    box3 = wx.ComboBox(self, COLOR_BOX_ID, “”, (370, 320), (80, 30), color, wx.CB_DROPDOWN)

    box3.SetSelection(color_idx)

    label4 = wx.StaticText(self, -1, ‘depth:’, (472, 322))

    label4.SetFont(font)

    label4.SetForegroundColour(“WHITE”)

    box4 = wx.ComboBox(self, DEPTH_BOX_ID, “”, (520, 320), (60, 30), depth, wx.CB_DROPDOWN)

    box4.SetSelection(depth_idx)

    self.Bind(wx.EVT_COMBOBOX, self.OnSelect)

  def OnSelect(self, event):

    global scale_idx, branch_angle_idx, color_idx, depth_idx

    id = event.GetId()

    index = event.GetSelection()

    if SCALE_BOX_ID == id:

      scale_idx = index

    elif ANGLE_BOX_ID == id:

      branch_angle_idx = index

    elif COLOR_BOX_ID == id:

      color_idx = index

    elif DEPTH_BOX_ID == id:

      depth_idx = index

    self.canvas.Refresh()

# wx panel to draw Pythagoras Tree in OnPaint(…)

class Panel(wx.Panel):

  def __init__(self, parent=None, id=-1, width = 600, height = 320):

    wx.Panel.__init__(self, parent, id, size=(width, height))

    self.Bind(wx.EVT_PAINT, self.OnPaint)

    self.SetBackgroundColour(“BLACK”)

  def OnPaint(self, event):

    dc = wx.PaintDC(self)

    self.DrawPythagorasTree(dc, 270, 280, 60, 60, 0)

  # This is recursive function to draw a rectangle and it’s left&right branch

  def DrawRect(self, dc, level, left, bottom, width, height, angle):

    left_bottom = (left, bottom)

    right_bottom = (left+width*math.cos(angle), bottom-width*math.sin(angle))

    right_top = (right_bottom[0]-height*math.sin(angle), right_bottom[1]-height*math.cos(angle))

    left_top = (left-height*math.sin(angle), bottom-height*math.cos(angle))

    dc.SetPen(wx.RED_PEN)

    dc.DrawLine(left_bottom[0], left_bottom[1], right_bottom[0], right_bottom[1])

    dc.SetPen(wx.Pen(color[color_idx]))

    dc.DrawLine(right_bottom[0], right_bottom[1], right_top[0], right_top[1])

    dc.DrawLine(right_top[0], right_top[1], left_top[0], left_top[1])

    dc.DrawLine(left_top[0], left_top[1], left_bottom[0], left_bottom[1])

    #if width <= MIN_WIDTH or height <= MIN_WIDTH:

    if level >= int(depth[depth_idx]):

      return left_bottom, right_bottom, right_top, left_top

    lb1, rb1, rt1, lt1 = left_bottom, right_bottom, right_top, left_top

    left_branch_angle = float(branch_angle[branch_angle_idx])*PI/180

    # Draw left branch

    leftbranch_w, leftbranch_h = width*float(scale[scale_idx]), height*float(scale[scale_idx])

    leftbranch_ang = angle+left_branch_angle

    lb2, rb2, rt2, lt2 = self.DrawRect(dc, level+1, lt1[0], lt1[1], leftbranch_w, leftbranch_h, leftbranch_ang)

    # Draw right branch

    rightbranch_w = math.sqrt((rb2[0]-rt1[0])*(rb2[0]-rt1[0]) + (rb2[1]-rt1[1])*(rb2[1]-rt1[1]))

    rightbranch_ang = angle – math.asin(leftbranch_w*math.sin(left_branch_angle)/rightbranch_w)

    self.DrawRect(dc, level+1, rb2[0], rb2[1], rightbranch_w, rightbranch_w, rightbranch_ang)

    return left_bottom, right_bottom, right_top, left_top

  def DrawPythagorasTree(self, dc, left, bottom, width, height, angle):

    dc.SetPen(wx.GREEN_PEN)

    self.DrawRect(dc, 1, left, bottom, width, height, angle)

class App(wx.App):

  def OnInit(self):

    self.frame = Frame()

    self.frame.Show()

    self.SetTopWindow(self.frame)

    return True

def main():

  app = App()

  app.MainLoop()

if __name__ == ‘__main__’:

  main()