Control through Input

Greetings procedure:

Write a procedure Greetings that greets a person (name to be given as input).

Erase "greetings

To greetings :person

TYPE :person

PRINT [!!]

PRINT [Pleased to meet you.]

END

? greetings "Anita

Anita!!

Pleased to meet you.

MYBACK procedure:

Write a procedure called MYBACK that behaves exactly like BACK (but without the help of BACK).

Erase "myback

To myback :d

RT 180 FD :d RT 180

End

? myback 200

Dashed line procedure:

Write a procedure that draws a dashed line. The input specifies number of dashes.

ERASE "dash

TO dash :count

REPEAT :count [

FD 50 PU FD 50 PD

]

END

? CS RT 90 dash 5

Procedure that draws “Hi”:

Write a procedure that draws “Hi” on the screen for the given number of times.

Erase "draw_hi

To draw_hi :number

Repeat :number [

FD 100 BK 50 RT 90 FD 50 LT 90 FD 50 BK 100

PU rt 90 fd 20 lt 90 pd Fd 80 pu fd 10

PD fd 10 pu bk 100 pd Pu rt 90 fd 20 lt 90 pd

]

End

? cs draw_hi 3

Waveform Procedure:

Add a 3rd input to the waveform procedure to control the height of each wavelet.

ERASE "waveform

TO waveform :count :w :h

REPEAT :count [

FD :H RT 90 FD :w RT 90 FD :H LT 90 FD :w LT 90

]

END

? CS waveform 5 30 60

Staircase Procedure with 2 inputs:

ERASE "staircase

TO staircase :count :s

REPEAT :count [

FD :s RT 90 FD :s LT 90

]

END

? CS STAIRCASE 5 60

Pointstar Procedure with 2 inputs:

ERASE "Pointstar

TO Pointstar :count :s

REPEAT :count [

FD :s BK :s RT 360/:count

]

END

? CS POINTSTAR 100 150

Night Sky with many Pointstars:

CS setbg 0 RT 90 setpc 4 ht

repeat 6 [POINTSTAR 80 30 pu FD 160 PD]

LT 90 PU FD 100 RT 90 PD SETPC 2

repeat 6 [POINTSTAR 80 30 pu FD 160 PD]

LT 90 PU FD 100 RT 90 PD SETPC 14

repeat 6 [POINTSTAR 80 30 pu FD 160 PD]

Collage of figures (as shown below):

;Procedures used in the program

Erase "PointStar

To PointStar :raysize :nrays

Repeat :nrays [

FD :raysize BK :raysize

RT quotient 360 :nrays

]

End

Erase "square

To square :size

Repeat 4 [FD :size RT 90]

End

Erase "pentagon

To pentagon :size

Repeat 5 [FD :size RT 360/5]

End

;------------------

;Program to draw the design

CS setbg 0 setpensize 2 HT

pu fd 200 Rt 90 BK 370 PD

setpc 2 pointstar 130 10 pu FD 230 PD

setpc 3 pointstar 80 20 pu FD 210 PD

setpc 6 pointstar 95 30 pu FD 180 PD

setpc 11 pointstar 45 40 pu FD 170 PD

setpc 12 pointstar 70 50

pu BK 850 LT 90 BK 320 PD setpc 7

BK 30*1/2 square 30*1 fd 30*1/2 pu RT 90 FD 30*1/2 LT 90 PD

BK 30*2/2 square 30*2 fd 30*2/2 pu RT 90 FD 30*2/2 LT 90 PD

bk 30*3/2 square 30*3 fd 30*3/2 pu RT 90 FD 30*3/2 LT 90 PD

bk 30*4/2 square 30*4 fd 30*4/2 pu RT 90 FD 30*4/2 LT 90 PD

bk 30*5/2 square 30*5 fd 30*5/2 pu RT 90 FD 30*5/2 LT 90 PD

bk 30*6/2 square 30*6 fd 30*6/2 pu RT 90 FD 30*6/2 LT 90 PD

bk 30*7/2 square 30*7 fd 30*7/2 pu RT 90 FD 30*7/2 LT 90 PD

setpc 8 pu RT 90 fd 200 Lt 90 BK 50 pd

pentagon 15*1

pentagon 15*2

pentagon 15*3

pentagon 15*4

pentagon 15*5

pentagon 15*6

pentagon 15*7

pentagon 15*8

pentagon 15*9

pentagon 15*10