pxt-calliope/docs/reference/images/scroll-image.md

Scroll Image

Scroll (slide) an image (picture) from one side to the other of the LED screen.

let item: Image = null;
item.scrollImage(5, 200);

Parameters

• a number that means how many LEDs to scroll at a time, from right to left or left to right. If you use a positive number like 2, the image will scroll from the right side of the screen to the left. If you use a negative number like -2, the image will scroll in the other direction. If you use 5 or -5, the image will scroll one frame at a time. (A frame is a part of the image. It is a square with five LEDs on a side). This is useful for animation.

• a number that means how many milliseconds to wait before scrolling the amount that offset says. (1000 milliseconds is one second.) The bigger you make this number, the slower the image will scroll.

Example

This program scrolls an image of two arrows five LEDs at a time, with a pause of 200 milliseconds between each time it scrolls. Because each frame is five LEDs wide, that means this program will look like it's animating one arrow flipping and flopping. Of course, you can use any two frames you want instead.

let arrows = images.createBigImage(`
    . . # . .   . . # . .
    . # # # .   . . # . .
    # . # . #   # . # . #
    . . # . .   . # # # .
    . . # . .   . . # . .
    `);
basic.forever(() => {
    arrows.scrollImage(5, 200);
});	

See also

show image, image, create image, show animation