The shape-block method - blocks rotate in-place

Step 1

Type in the following code and run it:

def shape() {
    savePosHe()
    left(45)
    right(90, 100)
    right(90)
    right(90, 100)
    restorePosHe()
}

def block() {
    setFillColor(randomColor.fadeOut(0.7))
    shape()
    // rotate in place
    right(20)
}

clear()
setSpeed(fast)
setPenColor(cm.darkSlateGray)
repeat(18) {
    block()
}

Q1a Why does the shape command have a savePosHe at the beginning and a restorePosHe at the end.

Q1b In the above design, what’s the shape?

Q1c In the above design, what’s the block?

Q1d How many times is the block repeated to make the above design?

Explanation

Here’s how designs are made using this method:

• You define a shape.
• You define a block.
  • The block calls the shape, then rotates the turtle without changing its position, making it ready to make the next shape.
• You repeat the block the desired number of times to make the pattern.

Exercise

Use the above idea to make a design.