05 clean the reef hard

7/26/2019 05 Clean the Reef Hard

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05 Clean the Reef with Tidy Turtle Try harder

Story Our Friend Tidy Turtle is on a mission. He is tired of seeing a lot of

garbage in his underwater sea home. Between oil cans, glass bottles, plastic

bottles and paper, he has had enough! He doesnt understand why humans

cant use garbage cans to keep their waste organied "hy do they ha#e to

dump it in his home the $%& He has set out to clean the ocean but so has

his predator the $hark. $harkie is cleaning the sea and looking forsomething tasty to eat. Turtle is determined, but a little slow by nature. "e

are making him slow by putting him through a mae where he can mo#e 'eft,

right, up or down.

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/n this game, $harkie too has to go through 0ae! Tidy turtle has 1 li#es

against $harkie and they are both on a contest to see how many trash items

they can clean up in 2 minutes!

Our ob is to speed up Tidy turtle to clean the sea and also protect him from

$harkie. &re you ready to code this super e3citing ad#enture

Learning Goals4 0ath, 'anguage, $cience, 5rogramming, 'ogic 6 &rtificial

/ntelligence 7&/8

Scratch Functions used here6 0otions, 'ooks, 9ata, %#ents, )ontrols, 0ore

Blocks, $ensing, Operators and $ound.

Key game comonents mastered

&nimation of characters

$harkie and Tidy Turtle make a lot of mo#ements as they mo#e around

cleaning the sea.

:andom life like mo#ements of $prites;)haracters.

&rtificial /ntelligence

$harkie chases the fish without the help of player using some

ad#anced logic

(enerate less code more function

:euse )ode multiple times using se data #ariables to $tore


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Code for the Shar!

Creating random mo"ements for Shar! to mo"e in the #a$e%

)reate ?ariables to store #alues for the @ * A a3is 6 $hark, $hark, $hark4

These are internal #ariables for the program to mo#e the shark without the

players help. $o we hide these #ariables. The player doesnt need to see it on



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the screen when the game is on. "e set the #ariables $hark CD, $harkC2,

$hark4C42.

"e set the #ariable &Shar!' to be a random #alue between 427$hark48 *

27$hark8.

"e use the $hark #ariables to first set the @ coordinates. /f the system

picks 4E or D, we set the $hark #alue to be 42. if it is E we set $hark to 2.

Till the shark touches the wall, we change the @ #alue by $hark #alue 742 or

28. $hark will mo#e all the way from 4E @ coordinate to 42D @ #alue unless it

hits another black wall going from 42,4,4G..42D. Or if it starts from E, it

will mo#e 2,,G..2D till it hits a black wall. /ts doing $/5 )O>+T/+( like

we learned in class! /t it reaches an edge, it will bounce. $witch its costume,

wait I a sec and mo#e again.



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/f it hits the wall of the mae, then it will ha#e to change its direction to

the opposite side. To do this we will ha#e to use our 0>'T/5'/)&T/O+ with

$igns.

4 times 4 C



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times C

4 times C 4

times 4 C 4

To change its direction and keep it following the same $/5 )O>+T/+(, we

multiply the @ #alue by 74E8. /f 3 was 42 and going right to left, @ times 74E8

will now become 2! $o it will mo#e from left to right! How cool is that!

The opposite will also work ust fine. /f 3 was 2 mo#ing from left to right, @

times 74E8 will make it 42! $o it will mo#e from right to left on the @ a3is. Aou

can mo#e the mouse on the scratch screen and check the #alues for @ * A on

the bottom right hand corner of the screen. This is a fun e3ercise to

understand your a3is and how to mo#e the characters!

+ow we ha#e created some really fun code to make the $hark mo#e on its

own in the mae!



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"e repeat the same code for the A a3is! 5lain and easy!

This time the mo#ement will be up and down. #e 2,, G through EJD goes up.

42,4,4G through 4EJD goes down.



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"e create more #ariables 6 2 for keeping score 6 $core Turtle * $core

$hark. E to track time in the game called Timer2 and another to gi#e Tidy

turtle 1 li#es called 'ife.

+ow comes the fun stuff to customie the game to include all kinds of

tracking!

Turtle(s li"es%/f the shark touches the turtle, we change the 'ife #ariable

by 4E. "e use plain old subtraction to reduce the life of the turtle which was

set to 1 when we started the game by E e#ery time they meet. "e make the

shark change his costume to open his mouth to make it look like he is eating

the turtle!

Timer in the Game%"e set each game to last 2 minutes 7E2D seconds8. "e

want to see who cleans the most trash in 2 minutes. "e use the 'ess than *

greater than, eKual to functions to show the correct message once the game

time is o#er. /f the turtles score is less than $harks score, we say


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Code for the Turtle

The code to move Tidy Turtle was adated from the !oo" # $cratch Programmi%g i% &asy $tes !y $ea% 'c'a%us



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)nimating Tidy Turtle%Tidy Turtle is animated by switching costumes,

one e#ery second. $ince we ha#e a mae in the game, we mo#e all sprites to

the front of the mae so the lines of the mae are behind the character and

not on top of it.

"e gi#e Tidy turtle a starting position of @ 4G * A EE. This is the fi3ed

position of Tidy turtle e#ery time the game starts.

Trac!ing turtle osition to na"igate in the #a$e% "e create 2 #ariables

called )urrent 5osition of @ * )urrent 5osition of A. "e use these #ariables

to store the current @ * A position of turtle as he mo#es around the mae.

"e initialie the Timer2 #ariable to start here at E second and Turtles life

#ariable to start with 1 full li#es!

Creating time to trac! the game * Timer+% /nstead of initialiing 7setting

to a start #alue8 and counting the #ariable timer when Flag clicked, we

initialie it on flag clicked, broadcast a message to start the timer. "hen

the timer recei#es the broadcast message, it will start storing the time in

seconds in the timer2 #ariable. "e repeat tracking time till the #ariable

stores E2D seconds. &t which time we e3ecute the code in the $hark

#ariable to stop the game and display the scores.

#o"ing the turtle in the ma$eL To mo#e him up, we use the


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if then else block. Aou can duplicate the blocks and change the keys instead

of writing them from scratch. $a#es time!

,re"ent the turtle to wal! o"er the ma$e lines%The main function here is

to stop turtle from walking o#er the lines. "e do this by checking to see if

he is touching the color black which is the color of the lines in the mae. /f

Tidy is touching black, we keep him in his current position instead of mo#ing

him in any direction. This is where the #ariables come to use. $ince the @

position * A position are changing all the time, the #ariables )urrent 5osition

of @ * )urrent 5osition of A help to store the e3act position of the @ * A

a3is. >sing these #ariables, helps us make Tidy change direction

7>p;down;left;right8 to a#oid crossing the line with the help of the player.

C-./ F-R TR)S



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The code for Trash has been adapted from our pre#ious tutorials where we

ha#e made the fish and worms mo#e.

"e create a block from 0ore Blocks called 0o#e Trash. This code helps us

release the trash from random places on the screen.

"e create a block because we are using the code to mo#e the trash 1 times

in the program. This will reduce the lines of )ode that we write.

Trash /nters Screen% The mo#e trash block works to mo#e the trash in

random directions. /t picks 1 random numbers C D,E,2. /f it is E, it is on the

right side of the @ a3is. /t sets the 3 position to be left corner 742D8 and

mo#es the trash from left to right 7MD deg8. /f it is D or 2, it sets the @



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position to the right corner of the screen 72D8 and points the trash from

right to left. The A a3is is set to pick a random #alue from the bottom of

the screen 74EJD8 to the top of the screen 7EJD8. The reason is to create a

random inflow of trash on the screen where the shark or turtle cannot know

where the trash will come from.

Once the trashs entry point is determined by the mo#e trash block, we

e3ecute a fore#er loop.

Trash touches turtle%/f the trash is touching the turtle, we increase

the score of the turtle, hide the trash to show that it is remo#ed. "e play a

sound to let the player know it was the turtle who scored. Then we wait

random seconds from E4N and then mo#e the trash again as a new item onto

the screen.

Trash touches Shar!%/f the trash is touching the shark, we increase

the score for the shark, hide the trash to show it is remo#ed. "e play a

sound that is different than the one used when the turtle gets the trash, to

let the player know that the shark scored this time! &fter making the trash

disappear 7hide8 and waiting random seconds we re4introduce it back into the

screen. The trash will keep re4appearing on the screen till the game ends or

the stop button is pressed.

Turning the Trash%"hen the trash cans are on the screen, we create

a random turning range for them between 4ED to ED degrees. "e ha#e the

trash mo#e 1 steps. +ow it appears as though the trash cans are floating in

the water. /f the trash cans reach the edge of the screen, we ha#e it

bounce back into the screen.



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)opy the same code on e#ery trash item that is created. 0ake sure that

each trash item has the rele#ant sounds selected in the sound tab to play

the music for the shark and the turtle.

/n the true spirit of writing the code, all the code has been recycled and

modified from the $cratch community. www.openclipart.org is used for

images not a#ailable in the $cratch library!

http://www.openclipart.org/http://www.littlecodeninja.com/http://www.openclipart.org/http://www.littlecodeninja.com/

05 clean the reef hard

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