Shared Data

1. Shared Data Gail Carmichael gail_c@scs.carleton.ca

2. Please Download: www.scs.carleton.ca/~gail_c/comp1005/Robots1.zip www.scs.carleton.ca/~gail_c/comp1005/Birds1.zip

3. About Me

4. Sharing Resources http://www.flickr.com/photos/marcosbessa/6260425373/

5. familyCar = new Car(“black”); mom.car = familyCar; dad.car = familyCar; teen.car = familyCar;

6. teen.car.crash(); // Now the family car is not drivable! if (!mom.car.drivable()) mom.isStranded(); if (!dad.car.drivable()) dad.isStranded();

7. Robots Example

8. Examine code in Robots1.pde www.scs.carleton.ca/~gail_c/comp1005/Robots1.zip

9. Beacon Beacon Beacon Robot Robot Robot

11. Pros and cons?

12. Let’s add movement (demo first)

13. Step 1: Trigonometry to move forward in current direction x = x + speed * cos(direction) y = y + speed * sin(direction)

14. Step 2: Change direction to head for beacon

15. crossProduct = (r'x- rx)(gy- ry) - (r'y- ry)(gx- rx)

16. Step 3: Add random error for realism amountToTurn = θ + random(θ/4) - (θ/4)/2

18. Try implementing the move() method… x = x + speed * cos(direction) y = y + speed * sin(direction) crossProduct = (r'x- rx)(gy- ry) - (r'y- ry)(gx- rx) positive → left hand turn negative → right hand turn amountToTurn= θ + random(θ/4) - (θ/4)/2

19. Let’s add drag-and-drop for the beacons (demo first) www.scs.carleton.ca/~gail_c/comp1005/Robots2.zip

20. What if we want multiple robots per beacon? www.scs.carleton.ca/~gail_c/comp1005/Robots3.zip

21. Beacon Beacon Robot Robot Robot

23. Implement multiple robots per beacon.

24. Bird Animation Example

25. Please Download: www.scs.carleton.ca/~gail_c/comp1005/Birds1.zip Study the code, run the program.

26. How is the data in the program set up? Pros and cons?

27. Where can data be shared?

28. Implement sharing so each bird points to the same set of animation frames.

29. Separating Shared Data

30. Person molly = new Person(“Molly”); Person henry = new Person(“Henry”); Person[] personList = new Person[2]; personList[0] = molly; personList[1] = henry;

31. Person[] personListCopy = new Person[2]; for (inti=0; i < personList.length; i++) { personListCopy[i] = personList[i]; }

32. personListCopy[0].name = “Mallory”; // Prints Mallory System.out.println(personList[0].name);

33. Person[] personListCopy = new Person[2]; for (inti=0; i < personList.length; i++) { personListCopy[i] = new Person(personList[i].name); }

34. personListCopy[1].name = “Harry”; // Still prints Henry since it’s unchanged System.out.println(personList[1].name);

35. Shallow Copies vs Deep Copies

36. Thanks! Gail Carmichael gail_c@scs.carleton.ca