__init__.py

__pragma__ ('skip')
document = Math = setInterval = clearInterval = 0
__pragma__ ('noskip')

_debug = False

#def abs (vec2D):
#    return Math.sqrt (vec2D [0] * vec2D [0] + vec2D [1] * vec2D [1])

_ns = 'http://www.w3.org/2000/svg'
_svg = document.createElementNS (_ns, 'svg')

_defaultElement = document.getElementById ('__turtlegraph__')
if not _defaultElement:
    _defaultElement = document.body
_defaultElement.appendChild (_svg)

_width = None
_height = None
_offset = None

def _rightSize (self):
    nonlocal _width
    nonlocal _height
    nonlocal _offset
    
    _width = _defaultElement.offsetWidth
    _height = _defaultElement.offsetHeight
    _offset = [_width // 2, _height // 2]
    
    _svg.setAttribute ('width', _width)
    _svg.setAttribute ('height', _height)
    
window.onresize = _rightSize

_rightSize ()

def bgcolor (color):
    nonlocal _defaultElement

    _bgcolor = color
    _defaultElement.style.backgroundColor = _bgcolor

bgcolor ('white')
    
def setDefaultElement (element):
    nonlocal _defaultElement

    _defaultElement.removeChild (_svg)
    _defaultElement = element
    element.appendChild (_svg)
    
    _rightSize ()
    bgcolor ('white')

_allTurtles = []
    
class Turtle:
    def __init__ (self):
        _allTurtles.append (self)
        self._paths = []
        self.reset ()
        
    def reset (self):
        self._heading = Math.PI / 2
        self.pensize (1)
        self.color ('black', 'black')
        self.down ()
        self._track = []    # Need to make track explicitly because:
        self.home ()        #   Makes a position but needs a track to put in in
        self.clear ()       #   Makes a track but needs a position to initialize it with
        
    def clear (self):
        for path in self._paths:
            _svg.removeChild (path)
        self._paths = []
        
        self._track = []
        self._moveto (self._position)
        
    def _flush (self):
        if _debug:
            print ('Flush:', self._track)
    
        if len (self._track) > 1:
            path = document.createElementNS (_ns, 'path')
            path.setAttribute ('d', ' '.join (self._track))
            path.setAttribute ('stroke', self._pencolor if self._pencolor != None else 'none')
            path.setAttribute ('stroke-width', self._pensize)
            path.setAttribute ('fill', self._fillcolor if self._fill and self._fillcolor != None else 'none')           
            path.setAttribute ('fill-rule', 'evenodd')
            _svg.appendChild (path)
            self._paths.append (path)
                
            self._track = []
            self._moveto (self._position)   # _track should start with a move command
        
    def done (self):
        self._flush ()
        
    def pensize (self, width):
        self._flush ()
        if width == None:
            return self._pensize
        else:
            self._pensize = width
    
    def color (self, pencolor, fillcolor = None):
        self._flush ()
        self._pencolor = pencolor
        
        if fillcolor != None:
            self._fillcolor = fillcolor
    
    def goto (self, x, y = None):
        if y == None:
            self._position = x
        else:
            self._position = [x, y]
            
        self._track.append ('{} {} {}'.format (
            'L' if self._down else 'M',
            self._position [0] + _offset [0],
            self._position [1] + _offset [1])
        )
        
    def _moveto (self, x, y = None):
        wasdown = self.isdown ()
        self.up ()
        self.goto (x, y)
        if wasdown:
            self.down ()
            
    def home (self):
        self._moveto (0, 0)
        
    def position (self):
        return self._position [:]
        
    def pos (self):
        return self.position ()
        
    def distance (self, x, y = None):
        if y == None:
            other = x
        else:
            other = [x, y]
            
        dX = other [0] - self._position [0]
        dY = other [1] - self._position [1]
        
        return Math.sqrt (dX * dX + dY * dY)
            
    def up (self):
        self._down = False
        
    def down (self):
        self._down = True
        
    def isdown (self):
        return self._down
        
    def _predict (self, length):
        delta = [Math.sin (self._heading), Math.cos (self._heading)]
        return [self._position [0] + length * delta [0], self._position [1] + length * delta [1]]
        
    def forward (self, length):
        self._position = self._predict (length)
        
        self._track.append ('{} {} {}'.format (
            'L' if self._down else 'M',
            self._position [0] + _offset [0],
            self._position [1] + _offset [1])
        )
        
    def back (self, length):
        self.forward (-length)
        
    def circle (self, radius):
        self.left (90)
        opposite = self._predict (2 * (radius + 1) + 1)
        self.right (90)
    
        self._track.append ('{} {} {} {} {} {} {} {}'.format (
            'A',
            radius,
            radius,
            0,
            1,
            0,
            opposite [0] + _offset [0],
            opposite [1] + _offset [1]
        ))
        
        self._track.append ('{} {} {} {} {} {} {} {}'.format (
            'A',
            radius,
            radius,
            0,
            1,
            0,
            self._position [0] + _offset [0],
            self._position [1] + _offset [1]
        ))
        
    def left (self, angle):
        self._heading = (self._heading + Math.PI * angle / 180) % (2 * Math.PI)
            
    def right (self, angle): 
        self.left (-angle)
        
    def begin_fill (self):
        self._flush ()
        self._fill = True
    
    def end_fill (self):
        self._flush ()
        self._fill = False
        
    def speed (speed = None):
        pass
        
_defaultTurtle = Turtle ()
_timer = None
    
def reset ():
    nonlocal _timer, _allTurtles
    if _timer:
        clearTimeout (_timer)
    bgcolor ('white')
    for turtle in _allTurtles:
        turtle.reset ()
        turtle.done ()
        
def clear ():
    nonlocal _allTurtles
    for turtle in _allTurtles:
        turtle.clear ()
        
def ontimer (fun, t = 0):
    nonlocal _timer
    _timer = setTimeout (fun, t)

def done ():                            _defaultTurtle.done ()
def pensize (width):                    _defaultTurtle.pensize (width)
def color (pencolor, fillcolor = None): _defaultTurtle.color (pencolor, fillcolor)
def home ():                            _defaultTurtle.home ()
def goto (x, y = None):                 _defaultTurtle.goto (x, y)
def position ():                        return _defaultTurtle.position ()
def pos ():                             return _defaultTurtle.pos ()
def distance (x, y = None):             return _defaultTurtle.distance (x, y)
def up ():                              _defaultTurtle.up ()
def down ():                            _defaultTurtle.down ()
def forward (length):                   _defaultTurtle.forward (length)
def back (length):                      _defaultTurtle.back (length)
def circle (radius):                    _defaultTurtle.circle (radius)
def left (angle):                       _defaultTurtle.left (angle)
def right (angle):                      _defaultTurtle.right (angle)
def begin_fill ():                      _defaultTurtle.begin_fill ()
def end_fill ():                        _defaultTurtle.end_fill ()
def speed (speed):                      _defaultTurtle.speed (speed)