path: root/compare3lesson.py

# Copyright 2008 by Peter Moxhay and Wade Brainerd.  
# This file is part of Math.
#
# Math is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
# 
# Math is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
# 
# You should have received a copy of the GNU General Public License
# along with Math.  If not, see <http://www.gnu.org/licenses/>.
from objectarea import ObjectArea, Color
from vector import Vector

from shapeobject import ShapeObject
from symbolobject import SymbolObject
from linesegmentmovableobject import LineSegmentMovableObject
from linesegmentobject import LineSegmentObject
from droptargetobject import DropTargetObject
from signsdroptarget import SignsDropTarget
from linesegmentoriginobject import LineSegmentOriginObject
from signsoriginobject import SignsOriginObject
from linesegmentdroptarget import LineSegmentDropTarget
from answerobject import AnswerObject
from groupobject import GroupObject
from instructionsobject import InstructionsObject
from progressobject import ProgressObject
from threedobject import ThreeDObject
from nextproblemobject import NextProblemObject
from lengthproblem import LengthProblem
from amountproblem import AmountProblem
from areaproblem import AreaProblem
from massproblem import MassProblem
from volumeproblem import VolumeProblem
from cuttingproblem import CuttingProblem
import gtk, math, random, rsvg

MOON_SVG = rsvg.Handle('moon.svg')

PROBLEM_TYPES = ['length', 'amount', 'mass', 'volume', 'cutting', 'area']
COLOR_SCHEMES = [ 'red_green', 'green_blue', 'blue_red' ]

class Compare3Lesson(ObjectArea):
    """
    Lesson in which the user compares two objects in a given quantity, and represents the result
    of the measurement using a pair of line segments and the signs >, <, and =.
    """
    
    def __init__(self, activity):
        ObjectArea.__init__(self, activity)

        self.problem = 0
        self.level = 0
        self.problem_type = 'none'
        
        self.color_scheme = 'no_colors'
        self.last_color_scheme = 'no_colors'
        
        self.alphabetical_letter1 = 'A'
        self.alphabetical_letter2 = 'A'
        self.last_alphabetical_letter1 = 'A'
        self.last_alphabetical_letter2 = 'A'
        
        self.problem_number = -1
        self.recently_used = [-1, -1, -1, -1, -1, -1, -1, -1]
        
        self.progress = ProgressObject(Vector(10, 700), 30)
        self.add_object(self.progress)
 
        self.answer = 'equal'
        self.small_equal_sign = False
        
        self.drop_origin = None
        
        self.moons_visible = False
        
        self.n_errors = 0
        self.n_equals_problems_correct = 0
        self.n_greater_than_problems_correct = 0
        self.n_less_than_problems_correct = 0
        
        self.nextarrow = None
        
        self.pose_problem_stage1()
           
    #TODO- Put this code in the ShapeObjects themselves.
    def check_problem_solved(self):
        #print "Compare3Lesson: check_problem_solved called"
        if self.stage == 1:
            #print "   check_problem_solved calling problem_solved_stage1"
            if self.problem_solved_stage1():
                #print "Stage 1 Complete"
                self.finish_problem_stage1()
                self.pose_problem_stage2()
                
    def register_error(self):
        #print '\a'
        self.n_errors += 1
        #print "number of errors is now:", self.n_errors

    def pose_problem_stage1(self):
        #print "pose_problem_stage1: problem_type =", self.problem_type
        self.stage = 1
        
        self.n_errors = 0
        
        # Randomly choose between a length problem and an area problem.
        #self.problem_type = random.choice(PROBLEM_TYPES)
        
        self.last_color_scheme = self.color_scheme
        
        while (self.color_scheme == self.last_color_scheme):
            self.color_scheme = random.choice(COLOR_SCHEMES)
            
        self.last_alphabetical_letter1 = self.alphabetical_letter1
        self.last_alphabetical_letter2 = self.alphabetical_letter2
            
        # Choose two random letter to represent the two quantities
        while (self.alphabetical_letter1 == self.last_alphabetical_letter1 or self.alphabetical_letter1 == self.last_alphabetical_letter2 \
               or self.alphabetical_letter2 == self.last_alphabetical_letter1 or self.alphabetical_letter2 == self.last_alphabetical_letter2 ):
            self.alphabetical_letter1 = random.choice(['A', 'B', 'C', 'D', 'G', 'H', 'K', 'L', 'M', 'N', 'P', 'S', 'T'])
            self.alphabetical_letter2 = self.alphabetical_letter1
            while self.alphabetical_letter2 == self.alphabetical_letter1:
                self.alphabetical_letter2 = random.choice(['A', 'B', 'C', 'D', 'G', 'H', 'K', 'L', 'M', 'N', 'P', 'S', 'T'])
                
        #print "new problem: self.level is: ", self.level
      
        if self.level == 0:
            self.problem_type = 'length'
        elif self.level == 1:
            self.problem_type = 'area'
        elif self.level == 2:
            self.problem_type = 'volume'
        elif self.level == 3:
            self.problem_type = 'amount'
        elif self.level == 4:
            self.problem_type = 'mass'
        elif self.level == 5:
            self.problem_type = 'cutting'
        else:
            self.problem_type ='cutting'
        
        #print "... so self.problem_type is now: ", self.problem_type
        
        self.recently_used = []
            
        if self.problem_type == 'length':
            n_problems = 18
        elif self.problem_type == 'amount':
            n_problems = 8
        elif self.problem_type == 'mass':
            n_problems = 9
        elif self.problem_type == 'volume':
            n_problems = 12
        elif self.problem_type == 'cutting':
            n_problems = 12
        else:
            n_problems = 30
        
        for i in range(0, n_problems - 3):
            self.recently_used.append(-1)
        
        #print ""
        #print "self.recently_used = ", self.recently_used
                
        # Uncomment this to choose a particular problem type.   
        #self.problem_type = 'cutting'
          
        if self.problem_type == 'length':
            self.problem = LengthProblem(self, self.color_scheme, (self.alphabetical_letter1, self.alphabetical_letter2) )
        elif self.problem_type == 'amount':
            self.problem = AmountProblem(self, self.color_scheme, (self.alphabetical_letter1, self.alphabetical_letter2) )
        elif self.problem_type == 'mass':
            self.problem = MassProblem(self, self.color_scheme, (self.alphabetical_letter1, self.alphabetical_letter2) )
        elif self.problem_type == 'volume':
            self.problem = VolumeProblem(self, (self.alphabetical_letter1, self.alphabetical_letter2) )
        elif self.problem_type == 'cutting':
            self.problem = CuttingProblem(self, self.color_scheme, (self.alphabetical_letter1, self.alphabetical_letter2) )
        else:
            self.problem = AreaProblem(self, self.color_scheme, (self.alphabetical_letter1, self.alphabetical_letter2) )
           
        # Choose a random problem.
        while (self.problem_number in self.recently_used):
            self.problem_number = self.problem.problem_number
            
        #print "self.problem_number = ", self.problem_number  
        self.recently_used.insert(0, self.problem_number)
        self.recently_used.pop()  
        #print "Now self.recently_used = ", self.recently_used
               
        self.answer = self.problem.find_answer()
        self.problem_solved_stage1()
    
    def problem_solved_stage1(self):
        #print "Compare3Lesson: check_problem_solved called"
        #print "   self.problem  =", self.problem
        if self.problem:
            if self.problem.check_problem_solved():
                return True
    
        return False

    #TODO- Put this code in the problems themselves.
    def finish_problem_stage1(self):
        #print "finish_problem_stage1 called"
        # Put the shapes in an answer box.
        #print "finish_problem_stage1 called"
        
        if self.problem_type == 'amount':
            self.shapesanswer = AnswerObject(Vector(50, 100), Vector(1100, 250), '1.')
        else:
            self.shapesanswer = AnswerObject(Vector(50, 100), Vector(650, 650), '1.')
        
        self.shapesanswer.z = -100
        self.add_object(self.shapesanswer)
        
        if self.problem_type == 'area' or self.problem_type == 'length'  \
                                or self.problem_type == 'cutting':
            self.problem.shape1.in_answer_box = True
            self.problem.shape2.in_answer_box = True
        
            # Make the ShapeObjects inactive.
            self.problem.shape1.selected = False
            self.problem.shape1.draggable = False
            self.problem.shape2.selected = False
            self.problem.shape2.draggable = False

            # Scale and move both shapes to the answer box.
            #print "scaling the shapes..."
            #print "shape1 =",self.problem.shape1
            #print "shape2 =",self.problem.shape2
            v = Vector(275 + 100, 350 + 75) - self.problem.shape1.pos
            self.problem.shape1.pos += v
            self.problem.shape2.pos += v
            self.problem.shape1.calculate_bounds()
            self.problem.shape2.calculate_bounds()
        elif self.problem_type == 'amount':
            self.problem.finish_problem_stage1()
        elif self.problem_type == 'mass':
            self.problem.finish_problem_stage1()
            self.problem.shape1.calculate_bounds()
            self.problem.shape2.calculate_bounds()
            # Make the ShapeObjects inactive.
            self.problem.shape1.selected = False
            self.problem.shape1.draggable = False
            self.problem.shape2.selected = False
            self.problem.shape2.draggable = False
        elif self.problem_type == 'volume':
            self.problem.finish_problem_stage1()
            self.problem.shape1.calculate_bounds()
            self.problem.shape2.calculate_bounds()
            # Make the ShapeObjects inactive.
            self.problem.shape1.selected = False
            self.problem.shape1.draggable = False
            self.problem.shape2.selected = False
            self.problem.shape2.draggable = False
                
    def pose_problem_stage2(self):
        #print "pose_problem_stage2 called"
        self.stage = 2
        self.instructions.text = 'Show the result using line segments'
        #print "pose_problem_stage2: string to call find_answer"
        self.answer = self.problem.find_answer()
        #print "pose_problem_stage2: self.answer = ", self.answer
            
        # Add DropTargetObjects for the line segments.
        
        shift_x = -500
        shift_y = 250
        
        if self.problem_type == 'amount':
            self.drop1 = LineSegmentDropTarget(Vector(810 + shift_x, 140 + shift_y), self)
            self.drop2 = LineSegmentDropTarget(Vector(1010 + shift_x, 140 + shift_y), self)
            self.dropletter1 = SymbolObject(Vector(850 + shift_x, 450 + shift_y), self.letter1.symbol, None, None)
            self.dropletter2 = SymbolObject(Vector(1050 + shift_x, 450 + shift_y), self.letter2.symbol, None, None)
        else:
            self.drop1 = LineSegmentDropTarget(Vector(810, 140), self)
            self.drop2 = LineSegmentDropTarget(Vector(1010, 140), self)
            self.dropletter1 = SymbolObject(Vector(850, 450), self.letter1.symbol, None, None)
            self.dropletter2 = SymbolObject(Vector(1050, 450), self.letter2.symbol, None, None)           
            
        self.add_object(self.drop1)
        self.add_object(self.drop2)

        self.dropletter1.draggable = False
        self.dropletter1.selectable = False
        self.dropletter2.draggable = False
        self.dropletter2.selectable = False
        
        self.add_object(self.dropletter1)
        self.add_object(self.dropletter2)
        
        # Add a DropOrigin object to provide line segments for dropping.
        
        if self.problem_type == 'amount':
            self.drop_origin = LineSegmentOriginObject(Vector(910 + shift_x, 140 + shift_y), self, [self.drop1, self.drop2])
        else:
            self.drop_origin = LineSegmentOriginObject(Vector(910, 140), self, [self.drop1, self.drop2])
            
        self.add_object(self.drop_origin)
        
        self.drop1.drop_origin = self.drop_origin
        self.drop2.drop_origin = self.drop_origin
        
        self.drop1.drop_targets = [self.drop1, self.drop2]
        self.drop2.drop_targets = [self.drop1, self.drop2]
        
        self.drop1.answer = self.problem.find_answer()
        self.drop2.answer = self.problem.find_answer()
        
        self.select_object(self.drop_origin.line1)
        self.adjust_tab_order()
        
    def finish_problem_stage2(self):
        # Move the line segments in a little.
        
        shift_x = -500
        shift_y = 250

        if self.problem_type == 'amount':
            self.drop1.pos.x = 885 + shift_x
            self.drop2.pos.x = 985 + shift_x
            self.drop1.contents.pos.x = 900 + shift_x
            self.drop2.contents.pos.x = 1000 + shift_x
            self.drop1.contents.pos.y = self.drop1.pos.y + self.drop1.size.y - self.drop1.contents.length - 25
            self.drop2.contents.pos.y = self.drop2.pos.y + self.drop1.size.y - self.drop2.contents.length - 25
            self.dropletter1.pos.x = 900 + shift_x
            self.dropletter2.pos.x = 1000 + shift_x
        else:
            self.drop1.pos.x = 885
            self.drop2.pos.x = 985
            self.drop1.contents.pos.x = 900
            self.drop2.contents.pos.x = 1000
            self.drop1.contents.pos.y = self.drop1.pos.y + self.drop1.size.y - self.drop1.contents.length - 25
            self.drop2.contents.pos.y = self.drop2.pos.y + self.drop1.size.y - self.drop2.contents.length - 25
            self.dropletter1.pos.x = 900
            self.dropletter2.pos.x = 1000
        
        self.drop1.contents.selectable = False
        self.drop2.contents.selectable = False
        
        if self.drop1.contents.length == 100 and self.drop2.contents.length == 100:
            self.small_equal_sign = True
        else:
            self.small_equal_sign = False
        
        # Put the line segments in an answer box.
        
        shift_x = -500
        shift_y = 250
        
        if self.problem_type == 'amount':
            self.linesanswer = AnswerObject(Vector(750 + shift_x, 100 + shift_y), Vector(400, 400), '2.')
        else:
            self.linesanswer = AnswerObject(Vector(750, 100), Vector(400, 400), '2.')
            
        self.linesanswer.z = -100
        
        if self.small_equal_sign:
            self.linesanswer.answer = 'equals_small'
        else: 
            self.linesanswer.answer = self.answer
        
        self.add_object(self.linesanswer)
        
        self.drop_origin.remove_contents()
        self.clear_selection()
        self.remove_object(self.drop_origin)
        
        self.remove_object(self.drop1)
        self.remove_object(self.drop2)
        
        self.pose_problem_stage3()
          
    def pose_problem_stage3(self):
        self.stage = 3     
        self.instructions.text = 'Show the result using a sign'
        self.answer = self.problem.answer

        # Remove the Question mark.
        self.remove_object(self.questionmark)
        
        # Create the drop box for the symbol.
        self.symboldrop = SignsDropTarget(Vector(900, 600), self)
        self.add_object(self.symboldrop)
            
        # Add a DropOrigin object to provide signs for dropping.
        self.drop_origin = SignsOriginObject(Vector(850, 750), self, [self.symboldrop])
        self.add_object(self.drop_origin)
        
        self.symboldrop.drop_origin = self.drop_origin
        self.symboldrop.drop_targets = [self.symboldrop]
        
        self.symboldrop.answer = self.problem.find_answer()
                      
        #self.select_object(self.drop_origin.ltsymbol)
        self.adjust_tab_order()           
        
    def finish_problem_stage3(self):
        #print "Compare3Lesson: finish_problem_stage3 called"
        # This means the problem is done, so we don't check stage 3 twice.
        self.stage = 4
        
        i = 0
        for o in self.objects:
            if isinstance(o, ShapeObject) and o.selectable:
                i += 1
                o.selectable = False
        #print "Compare3Lesson:",i,"ShapeObjects were made not selectable"

        # Put it all in an answer box.
        self.symbolanswer = AnswerObject(Vector(400 + 350, 600 - 50), Vector(400, 200), '3.')
        self.symbolanswer.z = -100
        self.add_object(self.symbolanswer)

        #print "Get rid of the drop origin..."
        self.drop_origin.remove_contents()
        self.drop_origin.background_visible = False
        self.remove_object(self.drop_origin)

        #print "...and the drop targets."
        self.remove_object(self.symboldrop)

        if self.answer == 'greater':
            text = 'greater than'
        elif self.answer == 'less':
            text = 'less than'
        else:
            text = 'equal to'
            
        if self.problem_type == 'cutting':
            quantity_name = 'area'
        else:
            quantity_name = self.problem_type
               
        self.instructions.text = 'The ' + quantity_name + ' '  + self.letter1.symbol + ' is ' \
                                    + text + ' the ' + quantity_name  + ' ' + self.letter2.symbol
        if (self.n_errors == 0 and self.n_equals_problems_correct > 0 \
                and self.n_greater_than_problems_correct > 0 and self.n_less_than_problems_correct > 0):
            self.level += 1
            #print "self.level is now:", self.level
            self.recently_used = [-1, -1, -1, -1, -1, -1, -1, -1]
            self.progress.take_a_step()
            self.n_equals_problems_correct = 0
            self.n_greater_than_problems_correct = 0
            self.n_less_than_problems_correct = 0
        #else:
        #    print ""
        #    print "n_equals_problems_correct =", self.n_equals_problems_correct
        #    print "n_greater_than_problems_correct =", self.n_greater_than_problems_correct
        #    print "n_less_than_problems_correct =", self.n_less_than_problems_correct

        self.pose_next_problem_arrow()
        self.select_object(self.nextarrow)
        self.adjust_tab_order()
        
    def increment_n_equals_problems_correct(self):
        if self.n_errors == 0:
            self.n_equals_problems_correct += 1
    
    def increment_n_greater_than_problems_correct(self):
        if self.n_errors == 0:
            self.n_greater_than_problems_correct += 1
    
    def increment_n_less_than_problems_correct(self):
        if self.n_errors == 0:
            self.n_less_than_problems_correct += 1

    def pose_next_problem_arrow(self):
        #print "Compare3Lesson: pose_next_problem_arrow called"
        # Put it all in an answer box.
        self.nextarrow = NextProblemObject()
        self.add_object(self.nextarrow)

    def finish_next_problem_arrow(self):
        self.remove_object(self.nextarrow)
        self.clean_up()
        self.pose_problem_stage1()
        
    def show_hint(self):
        if self.linesanswer:
            self.linesanswer.show_hint = True
            
    def clean_up(self):     
        self.objects = []
        self.add_object(self.progress)
        self.moons_visible = False
            
    def adjust_tab_order(self):
        # Remove and add the shapes to put all objects in a better order for tabbing.
        #print "adjust_tab_order called"
            
        o_new = []
            
        i_next_problem = 0
        for o in self.objects:
            if isinstance(o, NextProblemObject) and o.selectable:
                i_next_problem += 1
                o_new.append(o)
        #print "Found ", i_shape ," NextProblemObject "
        
        i_shape = 0
        for o in self.objects:
            if isinstance(o, ShapeObject) and o.selectable:
                i_shape += 1
                o_new.append(o)
        #print "Found ", i_shape ," ShapeObjects "
        
        i_line_segment = 0
        for o in self.objects:
            if isinstance(o, LineSegmentObject) and o.selectable:
                i_line_segment += 1
                o_new.append(o)
        #print "Found ", i_line_segment ," LineSegmentObjects "
        
        i_line_segment_movable = 0
        for o in self.objects:
            if isinstance(o, LineSegmentMovableObject) and o.selectable:
                i_line_segment_movable += 1
                o_new.append(o)
        #print "Found ", i_line_segment_movable ," LineSegmentMovableObjects"
        
        i_sign = 0
        for o in self.objects:
            if isinstance(o, SymbolObject) and o.selectable:
                if o.symbol == "<" or o.symbol == "=" or o.symbol == ">":
                    i_sign += 1
                    o_new.append(o)
        #print "Found ", i_sign ," SymbolObjects"
                    
        i_group = 0
        for o in self.objects:
            if isinstance(o, GroupObject) and o.selectable:
                i_group += 1
                o_new.append(o)
        #print "Found ", i_group ," GroupObjects"
                    
        o_sorted = []
        o_sorted = sorted(o_new, cmp=self.sort_by_type)
        
        i = 0
        for o in o_sorted:
            i += 1
            
        #for o in o_sorted:
        #    print o
            
        # Find index of selected object.
        index_selected = 0
        i = 0
        for o in o_sorted:
            if isinstance (o, ShapeObject):
                if o.selected:
                    index_selected = i
            elif isinstance (o, ThreeDObject):
                if o.selected:
                    index_selected = i
            elif isinstance (o, LineSegmentObject):
                if o.selected:
                    index_selected = i
            elif isinstance (o, LineSegmentMovableObject):
                if o.selected:
                    index_selected = i
            elif isinstance (o, SymbolObject):
                if o.selected:
                    index_selected = i
            elif isinstance (o, GroupObject):
                if o.selected:
                    index_selected = i
            elif isinstance (o, NextProblemObject):
                if o.selected:
                    index_selected = i
            i += 1
            
        # Rotate the list.
        trans = index_selected
        while trans > 0:
            o_sorted.insert(0, o_sorted.pop(0))
            trans -= 1
            
        for o in o_new:
            self.remove_object(o)
            
        for o in o_sorted:
            self.add_object(o)
            
    # Sort objects by type.
    def sort_by_type(self, o1, o2):
        if isinstance(o1, ShapeObject) and isinstance(o2, LineSegmentObject):   
            return 1
        elif isinstance(o1, LineSegmentObject) and isinstance(o2, ShapeObject):   
            return -1
        
        elif isinstance(o1, ShapeObject) and isinstance(o2, LineSegmentMovableObject):   
            return 1
        elif isinstance(o1, LineSegmentMovableObject) and isinstance(o2, ShapeObject):   
            return -1
 
        elif isinstance(o1, LineSegmentObject) and isinstance(o2, LineSegmentMovableObject):   
            return -1
        elif isinstance(o1, LineSegmentMovableObject) and isinstance(o2, LineSegmentObject):   
            return 1
                  
        elif isinstance(o1, ShapeObject) and isinstance(o2, SymbolObject):   
            return 1
        elif isinstance(o1, SymbolObject) and isinstance(o2, ShapeObject):   
            return -1

        elif isinstance(o1, ShapeObject) and isinstance(o2, GroupObject):   
            return 1
        elif isinstance(o1, GroupObject) and isinstance(o2, ShapeObject):   
            return -1
        
        elif isinstance(o1, ShapeObject) and isinstance(o2, NextProblemObject):   
            return 1
        elif isinstance(o1, NextProblemObject) and isinstance(o2, ShapeObject):   
            return -1

        elif isinstance(o1, ShapeObject) and isinstance(o2, ShapeObject):   
            if o1.selected:
                return 1
            elif o2.selected:
                return -1
            else:
                if self.objects.index(o1) > self.objects.index(o2):
                    return 1
                elif self.objects.index(o1) < self.objects.index(o2):
                    return -1
                else:
                    return 0
                  
        elif isinstance(o1, LineSegmentObject) and isinstance(o2, LineSegmentObject):   
            if o1.length == 100:
                return -1
            else:
                return 1
            
        elif isinstance(o1, LineSegmentMovableObject) and isinstance(o2, LineSegmentMovableObject):   
            if o1.pos.x < o2.pos.x:
                return 1
            else:
                return -1
            
        elif isinstance(o1, SymbolObject) and isinstance(o2, SymbolObject):   
            if o1.symbol == '<':
                return  -1
            elif o2.symbol == '<':
                return  1
            elif o1.symbol == '=':
                return  -1
            elif o2.symbol == '=' :
                return  1
            elif o1.symbol == '>':
                return  -1
            elif o2.symbol == '<' :
                return  1
            else:
                return 1 
            
        else:
            return 0
        
    def draw_background(self, cr):
        if self.drop_origin:
            self.drop_origin.draw_background(cr)
            
        if self.moons_visible:
            self.draw_moons(cr)
            
    def draw_circle(self, cr, pos, color):   
        cr.save()
        # Draw the fill.
        cr.set_source_rgb(color[0], color[1], color[2])
        cr.arc(self.pos.x + pos.x, self.pos.y + pos.y, 35, 0.0, 2.0 * math.pi)
        cr.fill()
            
        # Draw the outline.
        cr.set_source_rgb(color[0]*0.75, color[1]*0.75, color[2]*0.75)
        cr.set_line_width(4.0)
        cr.arc(self.pos.x + pos.x, self.pos.y + pos.y, 35, 0.0, 2.0 * math.pi)
        cr.stroke()
        cr.restore()
        
    def draw_moons(self, cr):    
        cr.save()
        cr.translate(45, 165)
        cr.rotate(-math.pi/6)
        cr.scale(1.5, 1.5)
        
        MOON_SVG.render_cairo(cr)
        cr.restore()
        
        cr.save()
        cr.translate(145, 615)
        cr.rotate(-math.pi/6)
        cr.scale(1.5, 1.5)
        
        MOON_SVG.render_cairo(cr)
        cr.restore()