5.8 KiB
Sunday Drive
Open this tutorial in the editor!
{Introduction @unplugged}
Games often need actions to occur repeatedly - enemies and collectibles need to be created, winning conditions need to be checked, and so on. The ||game:on game update interval|| event allows you to set code to run on a set time period, so that it will occur repeatedly.
{Step 1 @fullscreen}
Remove anything that is currently in the workspace, and find ||game:on update interval 500 ms|| in ||game:Game||. Drag it into the workspace.
game.onUpdateInterval(500, function () {
})
{Step 2 @fullscreen}
In the ||game:on game update interval 500 ms||, replace the 500 with 1000. This will make it so the event occurs once every second, because 1 ms is a thousandth of a second.
game.onUpdateInterval(1000, function () {
})
{Step 3 @fullscreen}
Find ||sprites:projectile from side|| in ||sprites:Sprites||, and drag it into the ||game:on game update interval||. Open the image editor for ||variables:projectile||, and select or create an image of a car that is facing right.
let projectile: Sprite = null;
game.onUpdateInterval(1000, function () {
projectile = sprites.createProjectileFromSide(img`
. . . . . . . . . . . . . . . .
. . . . 2 2 2 2 2 2 2 2 . . . .
. . . 2 4 2 2 2 2 2 2 c 2 . . .
. . 2 c 4 2 2 2 2 2 2 c c 2 . .
. 2 c c 4 4 4 4 4 4 2 c c 4 2 d
. 2 c 2 e e e e e e e b c 4 2 2
. 2 2 e b b e b b b e e b 4 2 2
. 2 e b b b e b b b b e 2 2 2 2
. e e 2 2 2 e 2 2 2 2 2 e 2 2 2
. e e e e e e f e e e f e 2 d d
. e e e e e e f e e f e e e 2 d
. e e e e e e f f f e e e e e e
. e f f f f e e e e f f f e e e
. . f f f f f e e f f f f f e .
. . . f f f . . . . f f f f . .
. . . . . . . . . . . . . . . .
`, 50, 50)
})
{Step 4 @fullscreen}
In the ||sprites:projectile||, set the ||sprites:vy|| to 0, so that the cars drive only to the right.
let projectile: Sprite = null;
game.onUpdateInterval(1000, function () {
projectile = sprites.createProjectileFromSide(img`
. . . . . . . . . . . . . . . .
. . . . 2 2 2 2 2 2 2 2 . . . .
. . . 2 4 2 2 2 2 2 2 c 2 . . .
. . 2 c 4 2 2 2 2 2 2 c c 2 . .
. 2 c c 4 4 4 4 4 4 2 c c 4 2 d
. 2 c 2 e e e e e e e b c 4 2 2
. 2 2 e b b e b b b e e b 4 2 2
. 2 e b b b e b b b b e 2 2 2 2
. e e 2 2 2 e 2 2 2 2 2 e 2 2 2
. e e e e e e f e e e f e 2 d d
. e e e e e e f e e f e e e 2 d
. e e e e e e f f f e e e e e e
. e f f f f e e e e f f f e e e
. . f f f f f e e f f f f f e .
. . . f f f . . . . f f f f . .
. . . . . . . . . . . . . . . .
`, 50, 0)
})
{Step 5 @fullscreen}
Find ||sprites:set mySprite x to 0|| from ||sprites:Sprites||, and drag it after the ||variables:set projectile to||. Change ||variables:mySprite|| to ||variables:projectile||, and change ||sprites:x|| to ||sprites:y||.
let projectile: Sprite = null;
game.onUpdateInterval(1000, function () {
projectile = sprites.createProjectileFromSide(img`
. . . . . . . . . . . . . . . .
. . . . 2 2 2 2 2 2 2 2 . . . .
. . . 2 4 2 2 2 2 2 2 c 2 . . .
. . 2 c 4 2 2 2 2 2 2 c c 2 . .
. 2 c c 4 4 4 4 4 4 2 c c 4 2 d
. 2 c 2 e e e e e e e b c 4 2 2
. 2 2 e b b e b b b e e b 4 2 2
. 2 e b b b e b b b b e 2 2 2 2
. e e 2 2 2 e 2 2 2 2 2 e 2 2 2
. e e e e e e f e e e f e 2 d d
. e e e e e e f e e f e e e 2 d
. e e e e e e f f f e e e e e e
. e f f f f e e e e f f f e e e
. . f f f f f e e f f f f f e .
. . . f f f . . . . f f f f . .
. . . . . . . . . . . . . . . .
`, 50, 0)
projectile.y = 0
})
{Step 6 @fullscreen}
Find ||math:pick random 0 to 10|| in ||math:Math||, and replace the 0 in ||sprites:set projectile y to 0|| with the it.
This will place the ||variables:projectile|| in a random ||sprites:y|| position between 0 and 10.
let projectile: Sprite = null;
game.onUpdateInterval(1000, function () {
projectile = sprites.createProjectileFromSide(img`
. . . . . . . . . . . . . . . .
. . . . 2 2 2 2 2 2 2 2 . . . .
. . . 2 4 2 2 2 2 2 2 c 2 . . .
. . 2 c 4 2 2 2 2 2 2 c c 2 . .
. 2 c c 4 4 4 4 4 4 2 c c 4 2 d
. 2 c 2 e e e e e e e b c 4 2 2
. 2 2 e b b e b b b e e b 4 2 2
. 2 e b b b e b b b b e 2 2 2 2
. e e 2 2 2 e 2 2 2 2 2 e 2 2 2
. e e e e e e f e e e f e 2 d d
. e e e e e e f e e f e e e 2 d
. e e e e e e f f f e e e e e e
. e f f f f e e e e f f f e e e
. . f f f f f e e f f f f f e .
. . . f f f . . . . f f f f . .
. . . . . . . . . . . . . . . .
`, 50, 0)
projectile.y = randint(0, 10)
})
{Step 7 @fullscreen}
Find ||scene:screen height|| in ||scene:Scene||. Replace the 10 in ||math:pick random 0 to 10|| with it.
||scene:screen height|| is the height of the screen (120), so this will place the ||variables:projectile|| in a random position on the left side of the screen.
let projectile: Sprite = null;
game.onUpdateInterval(1000, function () {
projectile = sprites.createProjectileFromSide(img`
. . . . . . . . . . . . . . . .
. . . . 2 2 2 2 2 2 2 2 . . . .
. . . 2 4 2 2 2 2 2 2 c 2 . . .
. . 2 c 4 2 2 2 2 2 2 c c 2 . .
. 2 c c 4 4 4 4 4 4 2 c c 4 2 d
. 2 c 2 e e e e e e e b c 4 2 2
. 2 2 e b b e b b b e e b 4 2 2
. 2 e b b b e b b b b e 2 2 2 2
. e e 2 2 2 e 2 2 2 2 2 e 2 2 2
. e e e e e e f e e e f e 2 d d
. e e e e e e f e e f e e e 2 d
. e e e e e e f f f e e e e e e
. e f f f f e e e e f f f e e e
. . f f f f f e e f f f f f e .
. . . f f f . . . . f f f f . .
. . . . . . . . . . . . . . . .
`, 50, 0)
projectile.y = randint(0, scene.screenHeight())
})
{Complete}
Congratulations, you have made cars randomly drive across the screen! You can use this to start your own version of a road crossing game -- for example, making a chicken or duck cross the road. Just remember that ||sprites:projectiles|| are of kind ||sprites:Projectile|| by default.