# `CauldronGPU.SpriteLayer`
[🔗](https://github.com/jaman/cauldron/blob/v0.3.3/cauldron_gpu/lib/cauldron_gpu/sprite_layer.ex#L1)

Sprites drawn in order into a target, one layer of a `{:layers, [layer]}` change.

  * `target` — `:frame` (the default), the window's picture, or a canvas handle
  * `clear` — `{r, g, b, a}` from 0 to 1 the target is filled with first; `nil` (the
    default) draws over what the target holds
  * `port` — `{x, y, width, height}` in the target's pixels; the sprites are drawn
    only inside it. `nil` (the default) is the whole target
  * `view` — `{x, y, width, height}`, the part of the sprites' space shown in the
    port, stretched to fill it. `nil` (the default) places sprites in pixels from the
    port's top-left corner
  * `sprites` — `CauldronGPU.Sprite`s, drawn first to last

The frame's layers are drawn over the 3D scene, a transparent picture laid over its
display colours. A renderer that has never been sent a `CauldronGPU.Camera` draws its
layers alone, on black, and skips the 3D passes.

    %CauldronGPU.SpriteLayer{
      clear: {0.0, 0.0, 0.0, 1.0},
      view: {0, 0, 320, 200},
      sprites: [%CauldronGPU.Sprite{texture: ship, position: {160, 100}, origin: {8, 8}}]
    }

# `rect`

```elixir
@type rect() :: {number(), number(), number(), number()}
```

# `t`

```elixir
@type t() :: %CauldronGPU.SpriteLayer{
  clear: {number(), number(), number(), number()} | nil,
  port: rect() | nil,
  sprites: [CauldronGPU.Sprite.t()],
  target: :frame | CauldronGPU.Handle.t(),
  view: rect() | nil
}
```

---

*Consult [api-reference.md](api-reference.md) for complete listing*