# `Cauldron2D.Projection.Glyphs`
[🔗](https://github.com/jaman/cauldron/blob/v0.2.2/cauldron_2d/lib/cauldron_2d/projection/glyphs.ex#L1)

A projection drawn as one of the atlas's two-character glyphs per slot.

    Cauldron2D.Projection.Glyphs.compose(:my_game, Cauldron2D.Projection.Iso,
      focus: {12.5, 8.5},
      cell: &MyGame.cell/1,
      size: {320, 200},
      step: {32, 32},
      facing: 1,
      facings: 4
    )

`module` must answer `ground_map/2`: `Cauldron2D.Projection.Iso` or
`Cauldron2D.Projection.Oblique`. Every option except `:step` is that projection's own,
and `:size` is the picture in pixels it would draw.

`:step` is `{across, down}`, the pixels of that picture one slot covers, so the grid is
`div(width, across)` slots wide and `div(height, down)` tall. A slot takes the glyph and
colour of the cell at the world point the projection shows at its middle, the last
standing art where a cell has any, as `Cauldron2D.Camera.glyphs/2` chooses them. Movers
and labels are drawn over that, each at the slot it projects into.

Returns rows of `{glyph, colour}`.

# `slot`

```elixir
@type slot() :: {String.t(), {byte(), byte(), byte()}}
```

# `compose`

```elixir
@spec compose(Cauldron2D.Atlas.name() | Cauldron2D.Atlas.t(), module(), keyword()) ::
  [[slot()]]
```

The grid, as the module documentation describes.

---

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