Interactive Game Elements

Welcome to the "Interactive Game Elements" section of our platformer tutorial! Here, we're going to make our game world come alive by programming objects in the game to interact with each other! Ready to breathe life into your game? Let's go!

The playerIsTouching? block

ChromeEngine makes it super simple to check if the player is touching an object using the Interactions.playerIsTouching? block:

_touching? = Interactions.playerIsTouching? \( object name  [] label  [] \) :: custom

If the player touches the specified block it sets _touching? to true, and adds the specified label to the interactions list

Killing the player if they touch a hazard

We'll use the Interactions.playerIsTouching? block to check if the player is touching any of the hazards and if so add hazard to the ìnteractions list. Then we'll make it so that if interactions contains hazard or the player y is below the level of the ground plus a little bit, we reset the player back to the start and play a death sound effect.

Here's the code to do this:

_touching? = Interactions.playerIsTouching? \( object name  [Spike 1] label  [hazard] \) :: custom
_touching? = Interactions.playerIsTouching? \( object name  [Spike 2] label  [hazard] \) :: custom
_touching? = Interactions.playerIsTouching? \( object name  [Enemy] label  [hazard] \) :: custom
if <<[interactions v] contains [hazard] ?> or <(@player_y) < ((@ground_y) + [1])>> then
    set [@player_x v] to [0]
    set [@player_y v] to [1]
    set [@player_z v] to [0] 
    start sound [death_sound v]

For the death_sound, first download the below sound by clicking the triple dots then Download. Then you should import it into the Logic sprite:

Winning when touching the end platform

If the player is touching the end platform, we'll set a variable called has_won? to 1. We'll also must add the condition that has_won? must be 0, or they will repeatedly win the game! And again for dramatic effect lets play a happy sound. This time we directly use the _touching? variable instead of checking if the interactions list contains our label

_touching? = Interactions.playerIsTouching? \( object name  [End] label  [] \) :: custom
if <<(_touching?) = [1]> and <(has_won?) = [0]>> then
    set [has_won? v] to [1]
    start sound [win_sound v]

And again here's a sound byte for you to use for the win_sound:

Showing a win screen

Let's give the player a congratulatory message when they win! First make a costume titled win_screenin the GUI sprite and design your fantastic win message. Then just add the following to the Game GUI() script, in the GUI sprite, to show your message:

if <(has_won?) = [1]> then
    set size to [100] %
    go to x: [0] y: [0]
    switch costume to (win_screen v)
    stamp

This simply checks if we're in the has_won state and if so shows the win_screen.

Finished code for interactions

If you got stuck you can simply copy the finished code from below:

For more detailed information on object interactions in ChromeEngine, you can visit the guide Object Interactions

Our Platformer is Complete!

And there you have it! Our platformer game is now Complete! If you are struggling with any part we recommend you check out the Platformer Tutorial project on Scratch. If you click See Inside you can view all the final code and compare it to your own code.

We hope you enjoyed the tutorial and can't wait to see what you make with ChromeEngine! For now ... Keep on Scratching!