Painting Our Designs

Painting a triangle:

Figure out how you can paint a triangle. Write a procedure ftriangle with size and color inputs.

In this case, getting the Turtle jump inside the triangle is tricky. We know that all angles are 60, so it would be safe to turn 30 and then jump.

ERASE "ftriangle

TO ftriangle :size :color

REPEAT 3 [FD :size RT 120]

PU RT 30 FD :size/2 PD SETPC :color FILL

PU BK :size/2 LT 30 PD

END

CS Setbg 7 setpc 0 Ftriangle 150 4

Painting a circle:

Figure out how you can paint a circle. Write a procedure fcircle with size and color inputs.

We know that the following procedure allows us to draw a circle of any circumference (using the input 'c').

ERASE "circle

TO circle :c

REPEAT 360 [FD :c/360 RT 1]

END

Now, to paint the circle, the Turtle can simply turn 90 and take a jump. The jump cannot be longer than the circle's diameter. As per our usual strategy, we will jump half of that (which is equal to the circle's radius).

We use half of this diameter to jump in and out in our circle procedure below. The relation between diameter and circumference is:

Circumference = Diameter * 3.14159, and so,

Diameter = Circumference / 3.14159

ERASE "f.circle

TO f.circle :c :color

REPEAT 360 [FD :c/360 RT 1]

PU RT 90 FD (:c/3.14159)/2 pd setpc :color FILL bk (:c/3.14159)/2 LT 90

END

CS Setbg 7 setpc 0 f.circle 350 14

Painting a polygon:

Write a procedure fpolygon that will draw a filled polygon. It will have two inputs: size specifying length of each side and N specifying type of polygon.

In this case, getting the Turtle jump inside the polygon is the main challenge. We know that the smallest angle is 60 (for a triangle), so it would be safe to turn 30 and then jump about half the length of each side.

ERASE "fpolygon

TO fpolygon :size :N

REPEAT :N [FD :size RT 360/:N]

PU RT 30 FD :size/2 PD FILL

PU BK :size/2 LT 30 PD

END

CS Setbg 7 setpc 11 Fpolygon 100 6

Logo Challenge:

The following program attempts to draw a circle filled green, then black, and then green again. When it is run, the last step doesn't work: the whole screen goes green. (Note: The screen background is black) Why is that?

ERASE "circle

TO circle :size

REPEAT 360 [FD :size/360 RT 1]

END

ERASE "greenlight

TO greenlight

SETPC 2 circle 100

SETPC 2 PU RT 90 FD 5 PD FILL BK 5 LT 90

SETPC 0 PU RT 90 FD 5 PD FILL BK 5 LT 90

SETPC 2 PU RT 90 FD 5 PD FILL BK 5 LT 90

END

CS setbg 0 setpc 7 Greenlight

Answer:

After the 2^nd step (of filling with black), the entire circle including its outline is erased, so there does not exist a circle any longer on the screen. The last FILL, as a result, fills the nearest closed area - which is the entire screen!

Collage of designs:

Write Logo programs to draw the designs shown in the image below.

;First the utility procedures that we will use for all designs.

;Make the Turtle jump w.r.t. the current position

ERASE "jump

TO jump :X :Y

PU RT 90 FD :X LT 90 FD :Y PD

END

;Draw a triangle. Input: length of each side

ERASE "triangle

TO triangle :size

REPEAT 3 [FD :size RT 360/3]

END

;Draw a triangle. Input: length of each side

ERASE "ftriangle

TO ftriangle :size

triangle :size

RT 30 PU FD :size/3 PD FILL BK :size/3 LT 30

END

;Draw the polygon star pattern.

; Input: n: type of polygon,

; size: length of each side

Erase "fpstar

To fpstar :n :size

REPEAT :n [

LT 60 ftriangle :size RT 60

FD :size

RT 360/:n

]

End

;Draw a square

ERASE "square

TO square :size

REPEAT 4 [FD :size RT 90]

END

;Draw a filled square

ERASE "fsquare

TO fsquare :size

REPEAT 4 [FD :size RT 90]

RT 45 PU FD :size/2 FILL BK :size/2 LT 45 PD

END

;---- Design 1 ----

ERASE "hexagon

TO hexagon :size

REPEAT 6 [FD :size RT 360/6]

END

ERASE "PSTAR

TO pstar :n :size

REPEAT :n [

LT 60 FD :size RT 120 FD :size LT 60

RT 360/:n

]

END

Erase "pstar.design1

To pstar.design1 :size

pstar 6 :size

hexagon :size

pu rt 60 fd :size pd setpc 12

fill pu bk :size lt 60

repeat 3 [

lt 30 fd :size/2 pd setpc 11 fill pu bk :size/2 rt 30

FD :size RT 60 FD :size RT 60

]

FD :size RT 60

repeat 3 [

lt 30 fd :size/2 pd setpc 10 fill pu bk :size/2 rt 30

FD :size RT 60 FD :size RT 60

]

pd setpc 12 hexagon :size

End

;---- Design 2: The block word FIT ----

ERASE "Bletter.F

TO Bletter.F :m

FD 100*:m RT 90 FD 60*:m

RT 90 FD 20*:m RT 90 FD 40*:m

LT 90 FD 20*:m LT 90 FD 40*:m

RT 90 FD 20*:m RT 90 FD 40*:m

LT 90 FD 40*:m RT 90 FD 20*:m RT 90

End

ERASE "Bletter.T

TO Bletter.T :m

FD 80*:m RT 90 FD 40*:m LT 90 FD 20*:m LT 90

FD 100*:m LT 90 FD 20*:m LT 90 FD 40*:m RT 90

FD 80*:m LT 90 FD 20*:m LT 90

End

ERASE "Bletter.I

TO Bletter.I :m

FD 20*:m LT 90 FD 30*:m RT 90

FD 60*:m RT 90 FD 30*:m LT 90 FD 20*:m LT 90

FD 80*:m LT 90 FD 20*:m LT 90 FD 30*:m RT 90

FD 60*:m RT 90 FD 30*:m LT 90 FD 20*:m LT 90

FD 80*:m LT 90

End

Erase "design

To design :m

setpensize round 12*:m setpc 7

bletter.F 2*:m

setpc 3 rt 45 pu fd 10*:m fill bk 10*:m lt 45 pd

jump 130*:m -250*:m

setpc 7 bletter.I 2*:m

setpc 3 lt 45 pu fd 10*:m fill bk 10*:m rt 45 pd jump 70*:m -120*:m

jump -120*:m -140*:m

setpc 7 bletter.T 2*:m

setpc 3 lt 45 pu fd 10*:m fill bk 10*:m rt 45 pd jump 70*:m -120*:m

end

;---- Design 3: Carrom board design ----

Erase "sqdesign

To sqdesign :o :t :c1 :c2 :c3

setpc :c1 fsquare :o

setpc :c2 repeat 4 [fsquare :t fd :o rt 90]

setpc :c3 jump :t :t fsquare :o-(2*:t)

jump -:t -:t

End

Erase "carrom.design

to carrom.design :m

jump -200*:m -200*:m sqdesign 400*:m 40*:m 13 4 1

jump 40*:m 40*:m sqdesign 320*:m 20*:m 3 4 5

jump 20*:m 20*:m fd 140*:m rt 45 sqdesign 1.414*140*:m 20*:m 3 4 12

end

;---- Design 4: House ----

;House

Erase "mywall

To mywall :size

Square :size

End

; corig is the original color

Erase "myroof

To myroof :size :corig

RT 30

setpc 8 ftriangle :size setpc :corig

LT 30

End

; corig is the original color

ERASE "mywindow

TO mywindow :SIZE :corig

REPEAT 4 [Square :size RT 90]

setpc 10

pu rt 45 fd :size/2 fill bk :size fill

fd :size/2 lt 45 pd

setpc :corig

END

; Put all parts together.

; corig is the original color

ERASE "myhouse

TO myhouse :SIZE :corig

mywall :SIZE

PU FD :SIZE/2 RT 90 FD :SIZE/2 LT 90 PD

mywindow :size/5 :corig

PU BK :SIZE/2 LT 90 FD :SIZE/2 RT 90 PD

FD :SIZE

myroof :size :corig

BK :SIZE

END

;---- Design 4: Chessboard ----

Erase "chessboard

To chessboard :m

setpc 7 fsquare 400*:m

setpc 9

jump -100*:m 0

repeat 4 [

jump 100*:m 0

repeat 4 [fsquare 50*:m jump 0 100*:m] jump 0 -400*:m

]

jump 100*:m -50*:m lt 90

repeat 4 [

jump 100*:m 0

repeat 4 [fsquare 50*:m jump 0 100*:m] jump 0 -400*:m

]

rt 90 jump -400*:m -350*:m

End

;--- Drawing all designs together in the collage format ------------

cs

jump -400 200 design 0.5

jump 150 300 setpc 7 setpensize 2 pstar.design1 75 ht

pu home jump 250 -100

carrom.design 0.75

pu home pd jump -200 -250

setpc 7 myhouse 150 7

jump 350 350 chessboard 0.5