* undo buttonEvent * fetch microbit v2.2.30 Co-authored-by: Amerlander <gitkraken@juriwolf.de>
2.7 KiB
Snap the Dot
Introduction @unplugged
Snap the dot is a game of skill where the player has to press A exactly when the dot reaches the center of the screen.
This tutorial shows how to use the game engine.
Make a sprite variable @fullscreen
Create a new variable called sprite
. Drag a ||variables:set sprite to||
into the ||basic:on start||
on the workspace.
let sprite = 0
Create a sprite @fullscreen
Pull out a ||game:create sprite||
block and put it in ||variables:set sprite to||
replacing the 0
. A sprite is a single pixel that can move on the screen. It has an x
and y
position along with a direction of motion.
let sprite = game.createSprite(2, 2)
Move the dot @fullscreen
The sprite starts in the center facing right. Put a ||game:move||
block into the ||basic:forever||
to make it move. Notice how it moves to the right but does not bounce back.
let sprite = game.createSprite(2, 2)
basic.forever(function () {
sprite.move(1)
})
Bounce @fullscreen
Grab a ||game:if on edge, bounce||
block to make the sprite bounce on the side of the screen. Also, add a ||basic:pause||
block to slow down the sprite.
let sprite = game.createSprite(2, 2)
basic.forever(function () {
sprite.move(1)
sprite.ifOnEdgeBounce()
basic.pause(100)
})
Test and download
Use the simulator to find the best speed. If you have a @boardname@, press |Download|
to try it out on the device.
Button handling @fullscreen
When A is pressed, we test if the sprite is in the center or not.
Use a ||input:on button pressed||
block to handle the A button. Put in a ||logic:if||
block and test if ||game:x||
is equal to 2
.
let sprite = game.createSprite(2, 2)
input.onButtonPressed(Button.A, function () {
if (sprite.get(LedSpriteProperty.X) == 2) {
} else {
}
})
basic.forever(function () {
sprite.move(1)
basic.pause(100)
sprite.ifOnEdgeBounce()
})
Score and game over
Finally, pull out an ||game:add score||
and a ||game:game over||
block to handle both success (sprite in the center) and failure (sprite not in the center).
let sprite = game.createSprite(2, 2)
input.onButtonPressed(Button.A, function () {
if (sprite.get(LedSpriteProperty.X) == 2) {
game.addScore(1)
} else {
game.gameOver()
}
})
basic.forever(function () {
sprite.move(1)
basic.pause(100)
sprite.ifOnEdgeBounce()
})
Test and download
Your game is ready! If you have a @boardname@, press |Download|
to try it out on the device.