pxt-calliope/docs/reference/images/scroll-image.md
2016-04-15 15:02:26 -07:00

1.8 KiB

Scroll Image

The scroll image function.

Scrolls the frames within an Image on the LED screen.

Block Editor

KindScript

export function scrollImage(_this: micro_bit.Image, xOffsetPerStep: number, interval: number)

Parameters

  • x offset per step : Number - the number of columns to scroll at a time (horizontal offset). Use a positive number to scroll an image to the right and a negative number to scroll left. To jump from one image frame to the next, use an offset of 5 or -5.
  • interval (ms) : Number - the time (in milliseconds) before scrolling by x offset per step; the larger the number, the slower the scroll.

~hide

let img = images.createImage(`
. . # . . . # # # . . # # # .
. . # . . . . . # . . . . # .
. . # . . . . # . . . # # # .
. . # . . . # . . . . . . # .
. . # . . . # # # . . # # # .
`)

~

To scroll an image 1 column at a time to the right:

img.scrollImage(1, 1000)

To scroll an image 5 columns at a time (skip from frame to frame):

img.scrollImage(5, 1000)

To scroll an image 1 column at a time to the left:

img.scrollImage(-1, 500)

Example: scroll through frames

This example creates an image with 3 frames, then scrolls through the 3 frames:

img = images.createImage(`
. . # . . . # # # . . # # # .
. . # . . . . . # . . . . # .
. . # . . . . # . . . # # # .
. . # . . . # . . . . . . # .
. . # . . . # # # . . # # # .
`)
img.showImage(0)
img.scrollImage(5, 1000)

See also

show image, image, create image, show animation