The language reference lists the available functions for JavaScript Turtle Graphics.
Parameters are italicized included within parentheses '(' and ')' characters. The parentheses must be entered when coding. Optional parameters and separating commas are enclosed withing square bracket '[' and ']' characters. The square brackets in this case should not be included when coding.
Alternative forms of the functions are separated with the pipe '|' character. All forms are equivalent and use the same parameters.
Examples are shown in bold typewriter font. Each example may be clicked
to immediately execute it to see what it does.
-
forward(distance) | fd(distance)
Move the turtle forward distance pixels.
Example:
forward (10) -
backward(distance) | back(distance) | bk(distance)
Move the turtle backward distance pixels, but leave it pointing forward.
Example:
backward (10) -
right(angle) | rt(angle) | turn(angle)
Turn the turtle to the right angle degrees.
Example:
right (90) -
left(angle)
Turn the turtle to the left angle degrees.
Example:
left (90) -
penup() | up() | pu()
Lift the pen in the turtle so that it does not leave a mark as it moves.
Example:
penup() -
pendown() | down() | pd()
Lower the pen in the turtle so that it leaves a mark as it moves.
Example:
pendown() -
hideturtle() | ht()
Hide the turtle. It can still draw, but it isn't shown. Hiding the turtle is useful in complex drawing as there is significant speed up in not drawing the turtle.
Example:
hideTurtle() -
showturtle() | st()
Show the turtle.
Example:
showTurtle() -
home()
Move the turtle to its home in the center (x=0, y=0) and pointing toward the top (angle=0). Leave the graphics as they are.
Example:
home() -
clear()
Clear the graphics area, but leave the turtle where it is.
Example:
clear() -
reset()
Clear the graphics area and move the turtle to its home in the center (x=0, y=0) and pointing toward the top (angle=0).
Example:
reset() -
goto(x,y) | setposition(x,y) | setpos(x,y)
Move the turtle to the coordinates x pixels to the right of the center of the drawing area (or -x pixels to the left of the center) and y pixels above the center of the drawing area (or -y to below the center). This does not draw as the turtle is moved.
Example:
goto (20,10) -
setx(x)
Move the turtle horizontally to the coordinates x pixels to the right of the center of the drawing area (or -x pixels to the left of the center).
Example:
setx (0) -
sety(y)
Move the turtle vertically to the coordinates y pixels above the center of the drawing area (or -y to below the center). This does not draw on the way.
Example:
sety (0) -
angle(angle) | setheading(angle) | seth(angle)
Turn the turtle to to the absolute angle relative to top of the graphic area. 0 is the top, 0 is toward the top, 90 is toward the right, 180 is toward the bottom, and 270 -90 is toward the left.
Example:
angle (90) -
width(width) | pensize(width) | penwidth(width) |
Change the width of the turtle pen (in pixels).
Example:
width(5); -
color(colorcode)
Change the color of the turtle pen. The colorcode may be a number from 0 to 15 representing the more or less standard turtle graphics colors. These colors may be accessed from the JavaScript array "logoColors."
Example:
color("red")Example:
color(4)The colorcode may also be a quoted string with any acceptable CSS color code as in:
- "colorName" where colorName is any of the named CSS colors.
- "#RRGGBB" where RR, GG, and BB is the hexidecimal amount of red, green and blue respectively.
- "rgb(RR, GG, BB)" where RR, GG, and BB is the decimal amount of red, green and blue respectively.
- "rgba(RR, GG, BB, AA)" where RR, GG, and BB is the decimal amount of red, green and blue respectively and AA is the alpha channel for transparancy between 1.0 for opaque and 0.0 for totally transparent.
-
"hsl(hue, sat%, light%)"
where the values are hue is postion on the color wheel (0 to 360),
saturation percentage (sat), and lightness percentage (light).
For example:color("hsl(120, 100%, 50%)") -
"hsl(hue, sat%, light%, alpha)"
where the values are hue is postion on the color wheel (0 to 360),
saturation percentage, lightness percentage and alpha channel
for transparancy between 1.0 for opaque and 0.0 for totally
transparent.
For example:color("hsl(120, 100%, 50%, 1)")
-
write(string)
Places the text in the stringalong the projected path of the turtle. The string may be a set of characters enclosed by single or double quotation marks. The string may also be a value returned by a function.
Example:
write("Hello World") -
setfont(fontName)
Set the characteristics (style, variant, weight, size, and font-family desired for the font for subsequent writes.
Example:
setfont("italic small-caps bold 12px courier") -
curveright (radius[,extent])
Draw a circular curve from the turtle's postion. The center of the curve is to the right of the turtle at a perpendicular distance of radius pixels. The curve is a full circle unless extent is provided to limit the number of degrees of arc.
Example:
curveright(30)Example:
curveright(10,45) -
curveleft (radius[,extent])
Draw a circular curve from the turtle's postion. The center of the curve is to the left of the turtle at a perpendicular distance of radius pixels. The curve is a full circle unless extent is provided to limit the number of degrees of arc.
Example:
curveleft(20)Example:
curveleft(10,45) -
circle (radius[[,(extent],(CCW])
Draw a circle or arc centered on the turtle's postion. A full circle is drawn unless extent is provided to limit the number of degrees of arc. The arc is drawn clockwise unless a boolean CCW is supplied and has a value of false.
Example:
circle(10)Example:
circle(20,90)Example:
circle(30,-90,false) -
dot ([radius])
Draw a filled circle centered on the turtle's postion. The circle is drawn with a radius of radius) pixels. If radius) is not specified, it defaults to the larger of width plus 4 or twice the pensize).
Example:
dot()Example:
dot(10) -
beginShape()
Marks the begining of a shape to be filled. The shape consists of a set of line segments (forward, backward, right, left, curveright, curveleft). The set should be continuous and begin and end at the same point.
Example:
beginShape() -
fillShape([styl])
Fills the shape begun with the last beginShape() directive. The shape is filled with styl, which may be a logo color number, a normal HTML color definition (see color above), a gradient or a pattern. This defaults to the turtle color.
Example:
fillShape("blue") -
n = random([low,]high)
Pick a random number between low and high -1. If only one value high is provided, pick a number between 0 and high -1.
Example:
write(random(1,7)+ " ")Example:
write(random(6)+ " ") -
repeat(n, action)
Allows a function action or group of actions to be repeated n times.
Example:
repeat (4, function () {forward(10);right(90)})Example:
function el () {forward(10);right(90)}; repeat (4, el) -
wrap(bool)
Turns wrapping on and off at the edges of the graphic area by setting it true or false respecitively.
Example:
wrap(true)Example:
wrap(false) -
animate(action,ms)
Evalutes action every ms milliseconds.
Example:
animate ("forward(10)",100)Example:
animate ("forward(100);right(90);",100)Example:
function el () {forward(100);right(90)}; animate (el,100) -
delay(action,ms)
Evalutes action after a delay of ms milliseconds.
Example:
delay ("forward(10)",1000)Example:
delay ("forward(100);right(90);",1000)Example:
function el() {forward(100);right(90); delay (el,100)};el() -
n = minX()
Returns the minimum value of X of the current canvas in pixels.
Example:
write(minX()) -
n = maxX()
Returns the maximum value of X of the current canvas in pixels.
Example:
write(maxX()) -
n = minY()
Returns the minimum value of Y of the current canvas in pixels.
Example:
write(minY()) -
n = maxY()
Returns the maximum value of Y of the current canvas in pixels.
Example:
write(maxY())