# `RasterExRatatui.PixelFormat.RGB565`
[🔗](https://github.com/mcass19/raster_ex_ratatui/blob/v0.4.0/lib/raster_ex_ratatui/pixel_format/rgb565.ex#L1)

16-bit RGB565, little-endian: red in the top 5 bits, green in the middle 6, blue in the low 5, low byte first. The usual depth of SPI LCDs and of Linux framebuffers configured with `framebuffer_depth=16`.

Cell colours resolve through a `RasterExRatatui.Palette` (named and indexed colours via its theme, `:reset` via its default foreground and background, `:bold` and `:reversed` applied); region pixels are packed as they come. Margins and skipped cells take the palette's default background.

## Options

Every `RasterExRatatui.Palette.new/1` option: `:theme`, `:reset_fg`, `:reset_bg`, `:bold_bright`.

## Examples

    iex> alias ExRatatui.CellSession.Cell
    iex> alias RasterExRatatui.PixelFormat.RGB565
    iex> config = RGB565.init([])
    iex> RGB565.cell_paints(%Cell{fg: {:rgb, 255, 0, 0}, bg: {:rgb, 0, 255, 0}}, config)
    {<<0, 248>>, <<224, 7>>}

# `blank`

```elixir
@spec blank(RasterExRatatui.Palette.t()) :: binary()
```

The palette's default background.

## Examples

    iex> RasterExRatatui.PixelFormat.RGB565.blank(RasterExRatatui.Palette.new(reset_bg: {0, 255, 0}))
    <<224, 7>>

# `bytes_per_pixel`

```elixir
@spec bytes_per_pixel(RasterExRatatui.Palette.t()) :: 2
```

2 bytes per pixel.

## Examples

    iex> RasterExRatatui.PixelFormat.RGB565.bytes_per_pixel(RasterExRatatui.Palette.new())
    2

# `cell_paints`

```elixir
@spec cell_paints(ExRatatui.CellSession.Cell.t(), RasterExRatatui.Palette.t()) ::
  {binary(), binary()}
```

The cell's foreground and background, resolved through the palette and packed.

## Examples

    iex> alias ExRatatui.CellSession.Cell
    iex> RasterExRatatui.PixelFormat.RGB565.cell_paints(%Cell{fg: :reset, bg: :reset, modifiers: [:reversed]}, RasterExRatatui.Palette.new(reset_fg: {255, 0, 0}, reset_bg: {0, 255, 0}))
    {<<224, 7>>, <<0, 248>>}

# `init`

```elixir
@spec init(keyword()) :: RasterExRatatui.Palette.t()
```

Builds the palette from `opts`.

## Examples

    iex> RasterExRatatui.PixelFormat.RGB565.init(reset_bg: {1, 2, 3}).reset_bg
    {1, 2, 3}

# `native_format`

```elixir
@spec native_format(RasterExRatatui.Palette.t()) :: :rgb565
```

`:rgb565`: regions are packed natively by `ExRatatui.Pixels.pack_rgb8/5`, which writes the same bytes as `rgb_pixel/6`.

## Examples

    iex> RasterExRatatui.PixelFormat.RGB565.native_format(RasterExRatatui.Palette.new())
    :rgb565

# `rgb_pixel`

```elixir
@spec rgb_pixel(
  0..255,
  0..255,
  0..255,
  non_neg_integer(),
  non_neg_integer(),
  RasterExRatatui.Palette.t()
) :: binary()
```

Packs an RGB pixel; the position is ignored.

## Examples

    iex> RasterExRatatui.PixelFormat.RGB565.rgb_pixel(255, 0, 0, 0, 0, RasterExRatatui.Palette.new())
    <<0, 248>>

# `rgb_row`

```elixir
@spec rgb_row(
  binary(),
  non_neg_integer(),
  non_neg_integer(),
  RasterExRatatui.Palette.t()
) :: binary()
```

Packs a row of RGB pixels in one pass; the position is ignored.

## Examples

    iex> RasterExRatatui.PixelFormat.RGB565.rgb_row(<<255, 0, 0, 0, 0, 255>>, 0, 0, RasterExRatatui.Palette.new())
    <<0, 248, 31, 0>>

# `unpack_row`

```elixir
@spec unpack_row(binary(), term()) :: binary()
```

Each 16-bit pixel as RGB8, the low bits filled from the high ones so full red is 255, not 248.

## Examples

    iex> RasterExRatatui.PixelFormat.RGB565.unpack_row(<<0, 248, 224, 7, 31, 0>>, RasterExRatatui.Palette.new())
    <<255, 0, 0, 0, 255, 0, 0, 0, 255>>

---

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