ImageSource

Often you want external images loaded into your game, this is accomplished with ImageSource. In some other engines/frameworks this can be known as a Texture.

ImageSource represents the source bitmap and contains the logic for loading that image from a file. You can thing of this as the file representation in Excalibur for the image. Use Sprites to draw them to the screen.

Loading Images with the ImageSource Resource

Excalibur supports .png, .jpg, .gif, and .bmp image sources with partial support for .svg

  • .png and .svg will be completely lossless formats. For pixel art type games we recommend .png
  • .jpg and .gif are lossy formats, useful to optimize for download size.
  • .bmp are the biggest
  • base64 useful if you don't want to pay the loading time cost of your images at the expense of larger source download
    • data:image/png;base64,BASE64DATA...
const game = new Engine({...});
const spriteSheetImage = new ImageSource('./my/spritesheet.png');

const loader = new Loader([spriteSheetImage]);
await game.start([loader]);

const spriteSheet = SpriteSheet.fromImageSource({
  image: spriteFontImage,
  grid: {
    rows: 5,
    columns: 2,
    spriteWidth: 32, // pixels
    spriteHeight: 32 // pixels
  }
});

These images can be presented to the loader at the start of an Excalibur game

const game = new ex.Engine({ width: 800, height: 600 })

const image = new ex.ImageSource('./img/myimg.png')

const loader = new ex.Loader()
loader.addResource(image)

game.start(loader).then(() => {
  // resources like ImageSource loaded before game started
})

Or they can be loaded out of band Note: it is important to check that a ImageSource has been loaded before using it at runtime to avoid errors and visual bugs if your game is loading images this way.

const image = new ex.ImageSource('./img/myimg.png')

image.load().then(() => {
  // image loaded
  // good for use in sprites inside this function
})

if (image.isLoaded()) {
  // image.data is good for use in sprites
  const mySprite = image.toSprite()
}