Turtle graphics

Turtle graphics

Some simple "turtle graphics" functions are included. Functions to control the turtle begin with a capital letter: Forward, Turn, Circle, Orientation, Rectangle, Pendown, Penup, Pencolor, Penwidth, and Reposition.

Turtle

using Luxor

Drawing(1200, 1200, "/tmp/turtles.png")
origin()
background("black")

# let's have two turtles
raphael = Turtle(0, 0, true, 0, (1.0, 0.25, 0.25)) ; michaelangelo = Turtle(0, 0, true, 0, (1.0, 0.25, 0.25))

setopacity(0.95)
setline(6)

Pencolor(raphael, 1.0, 0.4, 0.2);       Pencolor(michaelangelo, 0.2, 0.9, 1.0)
Reposition(raphael, 500, -200);         Reposition(michaelangelo, 500, 200)
Message(raphael, "Raphael");            Message(michaelangelo, "Michaelangelo")
Reposition(raphael, 0, -200);           Reposition(michaelangelo, 0, 200)

pace = 10
for i in 1:5:400
    for turtle in [raphael, michaelangelo]
        Circle(turtle, 3)
        HueShift(turtle, rand())
        Forward(turtle, pace)
        Turn(turtle, 30 - rand())
        Message(turtle, string(i))
        pace += 1
    end
end

finish()
preview()
Luxor.Turtle — Type.
Turtle(xpos=0, ypos=0, pendown=true, orientation=0, pencolor=(1.0, 0.25, 0.25))

With a Turtle you can command a turtle to move and draw: turtle graphics.

The functions that start with a capital letter are: Forward, Turn, Circle, Orientation, Rectangle, Pendown, Penup, Pencolor, Penwidth, and Reposition.

There are also some other functions. To see how they might be used, see Lindenmayer.jl.

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Luxor.Forward — Function.
Forward(t::Turtle, d)

Move the turtle forward by d units. The stored position is updated.

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Luxor.Turn — Function.
Turn(t::Turtle, r)

Increase the turtle's rotation by r degrees. See also Orientation.

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Luxor.Circle — Function.
Circle(t::Turtle, radius)

Draw a filled circle centered at the current position with the given radius.

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Luxor.HueShift — Function.
HueShift(t::Turtle, inc = 1)

Shift the Hue of the turtle's pen forward by inc.

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Luxor.Message — Function.
Message(t::Turtle, txt)

Write some text at the current position.

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Luxor.Orientation — Function.
Orientation(t::Turtle, r)

Set the turtle's orientation to r degrees. See also Turn.

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Luxor.Randomize_saturation — Function.
Randomize_saturation(t::Turtle)

Randomize saturation of the turtle's pen color.

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Luxor.Rectangle — Function.
Rectangle(t::Turtle, width, height)

Draw a filled rectangle centered at the current position with the given radius.

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Luxor.Pen_opacity_random — Function.
Pen_opacity_random(t::Turtle)

Change the opacity of the pen to some value at random.

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Luxor.Pendown — Function.
Pendown(t::Turtle)

Put that pen down and start drawing.

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Luxor.Penup — Function.
Penup(t::Turtle)

Pick that pen up and stop drawing.

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Luxor.Pencolor — Function.
Pencolor(t::Turtle, r, g, b)

Set the Red, Green, and Blue colors of the turtle.

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Luxor.Penwidth — Function.
Penwidth(t::Turtle, w)

Set the width of the line drawn.

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Luxor.Point — Type.

The Point type holds two coordinates. Currently it's immutable, so remember not try to change the values of the x and y values directly.

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Luxor.Pop — Function.
Pop(t::Turtle)

Lift the turtle's position and orientation off a stack.

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Luxor.Push — Function.
Push(t::Turtle)

Save the turtle's position and orientation on a stack.

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Luxor.Reposition — Function.
Reposition(t::Turtle, x, y)

Reposition: pick the turtle up and place it at another position.

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