An FP game engine for Scala.
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Fill Types

FillTypes tell Indigo how to fill the entity space when the texture and entity sizes are different.

The default behavior is normal, which just means render as much of the texture as you can. If the entity is too small, cut off the texture, if it's too large, just render transparent pixels outside the area.

tile tells Indigo to repeat the texture in all directions, while stretch unsurprisingly, stretches the texture to fill the space.

nineslice is a bit more complicated, but very handy for things like widow UIs and scaling backgrounds. You define a rectangle in the middle of the texture, and nine slice then chops the image into 9 squares where your rectangle is the center, as follows:

The texture is 64x64, so the center rectangle might be 32x32 at position 16x16.

material.nineSlice(Rectangle(16, 16, 32, 32))
  ________________
  |   |      |   |
  |___|______|___|
  |   |      |   |
  |   |      |   |
  |___|______|___|
  |   |      |   |
  |___|______|___|

When the entity scales up the corner sizes are preserved, but the sides and the middle scale, like this:

x       <--->       x
  _________________
  |   |       |   |
  |___|_______|___|
  |   |       |   |
^ |   |       |   | ^
| |   |  ↖ ↗  |   | |
| |   |  ↙ ↘  |   | |
˅ |   |       |   | ˅
  |___|_______|___|
  |   |       |   |
  |___|_______|___|
   
x       <---->       x

In this example, we set up four graphics with a bitmap material. The graphics are 128x128 in size, but the texture is only 64x64. Each one then has a different fill type applied to its material: normal (default), tile, stretch, and nineSlice.

Just so that we can see the boundaries of each graphic, a rectangle with a green border has been drawn around each one.

  val material = Material.Bitmap(Assets.assets.nineslice)

  def present(context: Context[Unit], model: Unit): Outcome[SceneUpdateFragment] =
    Outcome(
      SceneUpdateFragment(
        Graphic(0, 0, 128, 128, 1, material.normal).moveTo(0, 0),
        Graphic(0, 0, 128, 128, 1, material.tile).moveTo(128, 0),
        Graphic(0, 0, 128, 128, 1, material.stretch).moveTo(0, 128),
        Graphic(0, 0, 128, 128, 1, material.nineSlice(16, 16, 32, 32)).moveTo(128, 128),
        Shape.Box(Rectangle(128, 0, 128, 128), Fill.None, Stroke(1, RGBA.Green)),
        Shape.Box(Rectangle(0, 128, 128, 128), Fill.None, Stroke(1, RGBA.Green)),
        Shape.Box(Rectangle(0, 0, 128, 128), Fill.None, Stroke(1, RGBA.Green)),
        Shape.Box(Rectangle(128, 128, 128, 128), Fill.None, Stroke(1, RGBA.Green))
      )
    )