pxt-calliope/olddocs/lessons/catch-the-egg-game/activity.md

catch the egg game challenges

Before we get started

Your starting code should look like this:

let basketX = 2
let eggX = 2
let eggY = 0
basic.forever(() => {
    led.unplot(basketX, 4)
    led.unplot(eggX, eggY)
    eggY = eggY + 1
    led.plot(eggX, eggY)
    basic.pause(300)
    let accX = input.acceleration(Dimension.X)
    basketX = 2 + Math.min(2, Math.max(-2, accX / 200))
    led.plot(basketX, 4)
    if (eggY > 4) {
        eggY = -1
        eggX = Math.random(5)
    }
    basic.pause(300)
})

~avatar avatar impressed

Challenge 1

Let's use an IF statement to detect if the egg and the basket are lined up.

Now that we know when an egg is caught, we can keep track of the score! We need to use the add score function built into the game library to add 1 point for every egg that is caught. However, let's not forget to remove life if an egg falls off the display before it's caught!

~

let basketX1 = 2
let eggX1 = 2
let eggY1 = 0
basic.forever(() => {
    led.unplot(basketX1, 4)
    led.unplot(eggX1, eggY1)
    eggY1 = eggY1 + 1
    led.plot(eggX1, eggY1)
    basic.pause(300)
    let accX = input.acceleration(Dimension.X)
    basketX1 = 2 + Math.min(2, Math.max(-2, accX / 200))
    led.plot(basketX1, 4)
    if (eggY1 > 4) {
        eggY1 = -1
        eggX1 = Math.random(5)
    }
    if (eggY1 == 4) {
        if (basketX1 == eggX1) {
            game.addScore(1) 
        } else {
            game.removeLife(1)
        }
    }
    basic.pause(300)
})

• Press the run button to test out your game.

~avatar avatar encourage

Challenge 2

Catching eggs gets easier with practice so let's make the eggs fall faster every 5 catches. We can do this by tracking how long the egg pauses in each position while falling with a global variable called falling pause. Let's create this variable and set it to 300 initially. Don't forget to also create a condition that will be true every 5 catches.

~

let basketX2 = 2
let eggX2 = 2
let eggY2 = 0
let fallingPause = 300 // ***
basic.forever(() => {
    led.unplot(basketX2, 4)
    led.unplot(eggX2, eggY2)
    eggY2 = eggY2 + 1
    led.plot(eggX2, eggY2)
    basic.pause(300)
    let accX2 = input.acceleration(Dimension.X)
    basketX2 = 2 + Math.min(2, Math.max(-2, accX2 / 200))
    led.plot(basketX2, 4)
    if (eggY2 > 4) {
        eggY2 = -1
        eggX2 = Math.random(5)
    }
    if (eggY2 == 4) {
        if (basketX2 == eggX2) {
            game.addScore(1)
            if (game.score() %5 == 0) {
            }
        } else {
            game.removeLife(1)
        }
    }
    basic.pause(300)
})

~avatar avatar surprised

Challenge 3

Let's make the egg fall faster by decreasing the amount of time it pauses in each position by decreasing falling pause by 25 every 5 catches. Now, instead of pausing for 300 milliseconds we can pause for the value of falling pause.

let basketX3 = 2
let eggX3 = 2
let eggY3 = 0
let fallingPause1 = 300
basic.forever(() => {
    led.unplot(basketX3, 4)
    led.unplot(eggX3, eggY3)
    eggY3 = eggY3 + 1
    led.plot(eggX3, eggY3)
    basic.pause(300)
    let accX3 = input.acceleration(Dimension.X)
    basketX3 = 2 + Math.min(2, Math.max(-2, accX3 / 200))
    led.plot(basketX3, 4)
    if (eggY3 > 4) {
        eggY3 = -1
        eggX3 = Math.random(5)
    }
    if (eggY3 == 4) {
        if (basketX3 == eggX3) {
            game.addScore(1)
            if (game.score()% 5 == 0) {
                fallingPause1 = fallingPause1 - 25 // ***
            }
        } else {
            game.removeLife(1)
        }
    }
    basic.pause(fallingPause1) 
})

Fantastic! Your game is now ready to show off.

• Press the run button to see your finished game!