UNPKG

pxt-common-packages

Version:
122 lines (96 loc) 3.41 kB
# bottom (property) Get or set the bottom position of the sprite on the screen. ## Get Get the bottom position of the sprite. ```block let mySprite: Sprite = null let bottomPosition = mySprite.bottom ``` ```typescript-ignore let bottomPosition = mySprite.bottom ``` ### Returns * a [number](/types/number) that is the current bottom position of sprite object on the screen. ## Set ```block let mySprite: Sprite = null mySprite.bottom = 0 ``` ```typescript-ignore mySprite.bottom = 0 ``` ### Parameter * **value**: the new bottom position for the sprite object on the screen. ## Sprite locations The sprite image forms a rectangle with some number of pixel rows. The **bottom** of the sprite is the vertical location of the last row of the sprite's pixels on the screen. The bottom of the sprite can have a value that is greater than the height of the screen. It can also have a value that is less than the top of the screen (the top is `0` and the value of the bottom side of the sprite in this case is negative). When this happens, some or all of the sprite isn't visible on the screen. ## Examples #example ### Side to side #ex1 Move a sprite to the top side of the screen. Wait 2 seconds and then move it to the bottom side. ```blocks namespace SpriteKind { export const Example = SpriteKind.create() } let mySprite = sprites.create(img` 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 2 2 2 2 2 2 2 2 2 2 2 2 7 7 7 5 7 2 2 2 2 2 2 2 2 2 2 7 4 7 7 5 5 7 2 2 2 2 2 2 2 2 7 4 4 7 7 5 5 5 7 2 2 2 2 2 2 7 4 4 4 7 7 5 5 5 5 7 2 2 2 2 7 4 4 4 4 7 7 5 5 5 5 5 7 2 2 7 4 4 4 4 4 7 7 5 5 5 5 5 5 7 7 4 4 4 4 4 4 7 7 5 5 5 5 5 5 7 7 4 4 4 4 4 4 7 7 5 5 5 5 5 7 8 8 7 4 4 4 4 4 7 7 5 5 5 5 7 8 8 8 8 7 4 4 4 4 7 7 5 5 5 7 8 8 8 8 8 8 7 4 4 4 7 7 5 5 7 8 8 8 8 8 8 8 8 7 4 4 7 7 5 7 8 8 8 8 8 8 8 8 8 8 7 4 7 7 7 8 8 8 8 8 8 8 8 8 8 8 8 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 `, SpriteKind.Example) forever(function () { mySprite.top = 0 pause(2000) mySprite.bottom = scene.screenHeight() pause(2000) }) ``` ### Stay in bounds #ex2 Send a sprite moving from the bottom side of the screen to the top. In an ``||game:on game update||`` loop, check to see if the the sprite touched the top side of the screen. If so, reset the sprite back to the bottom side of the screen. ```blocks namespace SpriteKind { export const Example = SpriteKind.create() } let mySprite = sprites.create(img` 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 2 2 2 2 2 2 2 2 2 2 2 2 7 7 7 5 7 2 2 2 2 2 2 2 2 2 2 7 4 7 7 5 5 7 2 2 2 2 2 2 2 2 7 4 4 7 7 5 5 5 7 2 2 2 2 2 2 7 4 4 4 7 7 5 5 5 5 7 2 2 2 2 7 4 4 4 4 7 7 5 5 5 5 5 7 2 2 7 4 4 4 4 4 7 7 5 5 5 5 5 5 7 7 4 4 4 4 4 4 7 7 5 5 5 5 5 5 7 7 4 4 4 4 4 4 7 7 5 5 5 5 5 7 8 8 7 4 4 4 4 4 7 7 5 5 5 5 7 8 8 8 8 7 4 4 4 4 7 7 5 5 5 7 8 8 8 8 8 8 7 4 4 4 7 7 5 5 7 8 8 8 8 8 8 8 8 7 4 4 7 7 5 7 8 8 8 8 8 8 8 8 8 8 7 4 7 7 7 8 8 8 8 8 8 8 8 8 8 8 8 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 `, SpriteKind.Example) mySprite.bottom = scene.screenHeight() mySprite.vy = -40 game.onUpdateInterval(500, function () { if (mySprite.bottom < 0) { mySprite.bottom = scene.screenHeight() mySprite.say("Reset!", 500) } }) ``` ## See also #seealso [left](/reference/sprites/sprite/left), [right](/reference/sprites/sprite/right), [top](/reference/sprites/sprite/top), [x](/reference/sprites/sprite/x), [y](/reference/sprites/sprite/y)