CS1112 Spring Project 6 (Part II) due Thursday 4/30 at 11pm
You must work either on your own or with one partner. You may discuss background issues and general solution
strategies with others, but the project you submit must be the work of just you (and your partner). If you work with
a partner, you and your partner must first register as a group in CMS and then submit your work as a group.
Objectives
Completing this part of the project will help you learn about recursion and how a plotter draws.
1 This turtle can draw!
Plotters are used often in industrial graphics. The two figures below show a general plotter and a seismograph,
which is a specialized plotter. A plotter has (at least) one āpenā that moves over the paper, sometimes
depositing āinkā during its travel.
nxtasy.org commons.wikimedia.org
Write a function turtleDraw that draws a diagram given an instruction string. The instruction string
comprises a subset of the instruction set typically used to control a plotter. This subset of instructions is
often called āTurtle Graphicsā: imagine a turtle with a pen walking and sometimes drawing on a sheet of
paper.
This pen-equipped turtle has a current location (x,y), a current heading hin radians, a set step length, and
set clockwise and counterclockwise turn angles. In order to produce graphics, it is given instructions such as
draw forward (pen down),turn clockwise,record current location,return to recorded location (pen up),...,
etc. Our function has this instruction set:
āDā Draw from current position in current heading one step length.
ā+ā Turn clockwiseāchange heading without drawing.
ā-ā Turn counterclockwiseāchange heading without drawing.
ā[ā Record current location and heading and scale (reduce) the step length.
ā]ā Return to most recently recorded location and heading without drawing. Re-scale (increase) the step
length.
For example, let the turtle be heading east (0 radians) and has clockwise and counterclockwise turn angle
Ļ/2. Then the instruction string āD-D+D+D-Dā produces this drawing:
The instructions ā[ā and ā]ā must appear in pairs. The following example demonstrates the return to the
most recently recorded position and heading as well as the scaling and re-scaling of the step length. Let the
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