Canvas Turtle graphics using javascript

string id - id of container element for example Div

json config - some optional configurations:

• int width - width of canvas (default: 800)
• int height - height of canvas (default: 600)
• function onerror - callback function if canvas isn't supported (default: null)
• string turtle - path to turtle grpahic file (default: "./turtle.png")

string command - logo like command

exec("draw 100")

int units - how many units forward to move turtle

move(100)

int units - how many units forward to move turtle

draw(100)

int degree - amount of degree to turn turtle right

right(90)

int degree - amount of degree to turn turtle left

left(90)

int degree - degree where to point turtle

point(90)

string color - any valid css color (default: black)

color("#fff")

int thickness - line thickness in pixels (default: 1 pixel)

thick(10)

int alpha - value 0 to 100 percents of transparency (default: 100 - not transparent)

transparent(50)

int degree - degree where to point turtle

point(90)

string name - name of a variable

string value - value to save

let("a",100)

let a 100
move a
draw a*2

string stack - name of a stack

string value - value to save

push("stack1",100)

push stack1 100
pop stack1 a
draw a

string stack - name of a stack

string variable - name of variable where to save value

pop("stack1","a")

push stack1 100
pop stack1 a
draw a

showturtle()

draw 100
right 90
showturtle

hideturtle()

showturtle
draw 100
hideturtle
draw 100

int units - how many units to go forward and then turn left

int offset - offset from your current position, where you'll end up after turning left

goleft(100,100)

int units - how many units to go forward and then turn right

int offset - offset from your current position, where you'll end up after turning right

goright(100,100)

string text - text to print

print("Hello world")

string text - text to print

turtleprint("Hello world")

string font - font size and format

font("20px Arial")

string name - variable name where to store value

string id (optional) - id of input elements where to get value. If id isn't provided, then user will be prompted to enter value

get("a")

if var1 operation var2, else, endif

• Equal - = or ==
• Not equal - != or <>
• Greater, less - < or >
• Greater equal, less equal - <= or >=

if a>=10
draw 100
else
draw 50
endif

repeat iterations, next

repeat 4
draw 100
right 90
next

# label, return, go

# square
repeat 4
draw 50
right 90
next
return
go square

;

; this line is commented

showturtle

showturtle
draw 100

let

let a 100
draw a

push, pop

Factorial in LOGO Turtle:

# factorial

  if v == 0

    ; The factorial of 0 ("0!") is simply 1; we're done!
    let v 1

  else

    ; Push the current 'v' onto the stack1 stack, so we can pop it back later
    push stack1 v

    ; Now call the 'factorial' procedure again, with v-1...
    let v v-1
    go factorial

    ; Retrieve the factorial of v-1, and temporarily store it in vriable 'a'
    let a v

    ; Get the original v off of the stack1 stack
    pop stack1 v

    ; The answer (to this particular call of 'factorial')
    ; is that v! is v * (v-1)!
    let v v*a

  endif

return