Activity: Tracking a Sprite’s Position Using Variables

In this activity, we will track the change in Tobi’s position using the up, left, down, and right arrow keys on the keyboard. We will track his X and Y positions using variables.

Follow the steps below:

1. Open PictoBlox and create a New File.
2. Select the coding environment as Block Coding.
3. Create two variables X and Y. We’ll use them for Tobi X and Y positions respectively
4. Change the background to Xy- Grid to visualize the position.
   
5. Add the when flag clicked block to start the script.
6. Next, set the X and Y positions as 0 by setting the X and Y variables as 0 using the set () to () block.
7. Now, add a forever block below the when flag clicked block.
8. Then, from the Motion palette, add a go to x:() y:() block and drag and drop the X and Y variable blocks inside it as shown. This will set Tobi’s position to the current value of X and Y.Now, to make Tobi move around and track his position, we need to change the values of X and Y. How do we do that? Here’s how:
9. To move left, we will change X by -10 whenever the left key is pressed. Add a  when () key pressed block from the Events palette and change X by -10 by using a change () by () block.  
10. To move right, we will change X by 10 whenever the right key is pressed. Repeat the above step and select the right arrow key from the drop-down of the hat block and change X by 10 in the change () by () block.
11. To move up, we will change Y by 10 whenever the up key is pressed.
12. For down, we will change Y by -10 whenever the down key is pressed
13. Now run the script and enjoy it.
14. Save the file with the name Tracking a Sprite’s Position Using Variables.

Assignment

Before you move on to the next lesson, a small assignment awaits you!

You must upload the PictoBlox program you created in this activity to the website. Submitting the assignment is a must in order to receive the certificate after completing the course.

Follow the steps below to upload your assignment:

1. Click on Browse.
2. Search and Select your saved Project file(.sb3) and Click Open.
3. Click on Upload to submit the assignment.

The file type allowed is the SB3 file generated from the PictoBlox program. The maximum file size allowed is 5 MB.

Good luck!