Drawing

- turtle art

simple

Primitive Alt Action
SetX x
SetY y
SetXY x y
SetPosition [x y]
Home


SetPos		 Move turtle to horizontal position x.
Move turtle to vertical position y.
Move turtle to position (x y).
Move turtle to position (x y).
Move turtle to home position (0 0), heading 0.
SetHeading h
SetPenWidth w
SetPenShape n		 SetH
SetPW
SetPS		 Set turtle heading to h degrees, (cwise from North).
Set width of pen nib to w pixels.
Set shape of pen nib to 0 (square) or 1 (round).
Window
Wrap
Fence
Perspective		   Turtle can move beyond the screen window edges.
Turtle wraps from screen edge to the opposite side.
Error message if turtle will move beyond the screen edge.
Turtle moves in 3D space. (see Perspective)
Circle r
Arc r h1 h2
Dot [x y]		   Draw circle of radius r steps. *
Draw arc of radius r, from heading h1 cwise to h2. *
Draw dot at position (x y) in pen color, shape and size. *
Fill
FillZone
FillPolygon [list]		   Fill all neighbouring pixels of same color with pen color.
As Fill, but until pen colored pixels are reached.
Fill shape defined by instructions in list.
LoadImage [list]

SaveImage "name		 LI

 Load image file specified in list and place upper left corner at turtles position. (file format .png or .jpg)
Save drawing area as name.png file.
Distance [x y]
Towards [x y]		   Return distance of turtle from point (x y), steps. *
Return turtle heading if turned towards (x y), degrees. *

Underlined Set can be removed from a primitive name in order to return information.
eg. SetHeading sets the heading of the turtle. Heading returns the heading of the turtle.

* turtle position and heading remain unchanged.

Note

  1. You use Towards like this:
    SetHeading Towards [0 0] -this will turn the turtle so that it is facing the origin.
  2. The following primitives can be used to draw without lowering the pen. They are transparent, as the turtles position and heading remain unchanged.
    Arc, Circle, Dot, Fill, FillPolygon, FillZone, FindColor, Label.
  3. Arcs are always drawn clockwise from Angle1 to Angle2. The radius must be a positive value. If negative, no arc is drawn. The whole primitive is ignored, without producing any error message.
  4. SetPW to a negative value is the same as a positive value. There is no upper limit.
  5. SetPS 0 The pen shape is always 'square' regardless of turtle orientation.
  6. Cannot use FillPolygon to fill shapes drawn with Circle or Arc.
  7. Arc :Rad 0 360 produces nothing. Arc :Rad 0 370 produces a 10 degree arc.