RasterExRatatui.Font.Generated (RasterExRatatui v0.4.0)

Glyphs derived from their Unicode geometry instead of drawn by hand, for any cell size.

Braille patterns, eighth blocks, and quadrants are exact subdivisions of the cell, so a font gets them for free: each function returns a %{codepoint => glyph} map for a {width, height} cell, ready to merge under the hand-drawn glyphs (hand-drawn wins on conflict when merged second).

Widgets lean on these: Canvas draws with braille by default, Sparkline and BarChart with eighth blocks, BigText with quadrants.

Summary

Types

size()

Functions

braille(size)

The braille block U+2800..U+28FF.

eighths(size)

Eighth blocks: lower ▁..▇ (U+2581..U+2587), left ▏..▉ (U+2589..U+258F), the right half ▐, the upper eighth ▔, and the right eighth ▕.

hatched(size)

A hatched checkerboard with a blank bottom row: the conventional "no glyph for this codepoint" placeholder, visibly different from a space.

quadrants(size)

The quadrant blocks ▖ ▗ ▘ ▙ ▚ ▛ ▜ ▝ ▞ ▟ (U+2596..U+259F), splitting the cell at half its width and height.

rasterise(arg, ink?)

Builds a {width, height} glyph from a per-pixel predicate ink?.(x, y).

Types

size()

@type size() :: {pos_integer(), pos_integer()}

Functions

braille(size)

@spec braille(size()) :: %{required(non_neg_integer()) => bitstring()}

The braille block U+2800..U+28FF.

The cell splits into two dot columns and four dot rows; each lit dot fills its whole sub-rectangle, so neighbouring dots merge into continuous lines rather than a dotted texture. Bit n of the codepoint offset lights dot n + 1: dots 1-2-3 run down the left column, 4-5-6 down the right, 7 and 8 are the bottom row.

Examples

iex> glyphs = RasterExRatatui.Font.Generated.braille({2, 4})
iex> map_size(glyphs)
256
iex> RasterExRatatui.Font.Art.render(glyphs[0x2801], {2, 4})
"#.\n..\n..\n..\n"
iex> RasterExRatatui.Font.Art.render(glyphs[0x2880], {2, 4})
"..\n..\n..\n.#\n"

eighths(size)

@spec eighths(size()) :: %{required(non_neg_integer()) => bitstring()}

Eighth blocks: lower ▁..▇ (U+2581..U+2587), left ▏..▉ (U+2589..U+258F), the right half ▐, the upper eighth ▔, and the right eighth ▕.

Fractions round to whole pixel rows or columns of the cell; the thin edges are at least one pixel.

Examples

iex> glyphs = RasterExRatatui.Font.Generated.eighths({4, 8})
iex> RasterExRatatui.Font.Art.render(glyphs[0x2583], {4, 8}) |> String.split("\n", trim: true) |> Enum.drop(4)
["....", "####", "####", "####"]
iex> RasterExRatatui.Font.Art.render(glyphs[0x258C], {4, 8}) |> String.split("\n", trim: true) |> hd()
"##.."

hatched(size)

@spec hatched(size()) :: bitstring()

A hatched checkerboard with a blank bottom row: the conventional "no glyph for this codepoint" placeholder, visibly different from a space.

Examples

iex> RasterExRatatui.Font.Art.render(RasterExRatatui.Font.Generated.hatched({4, 3}), {4, 3})
"#.#.\n.#.#\n....\n"

quadrants(size)

@spec quadrants(size()) :: %{required(non_neg_integer()) => bitstring()}

The quadrant blocks ▖ ▗ ▘ ▙ ▚ ▛ ▜ ▝ ▞ ▟ (U+2596..U+259F), splitting the cell at half its width and height.

Examples

iex> glyphs = RasterExRatatui.Font.Generated.quadrants({2, 2})
iex> RasterExRatatui.Font.Art.render(glyphs[0x259A], {2, 2})
"#.\n.#\n"

rasterise(arg, ink?)

@spec rasterise(size(), (non_neg_integer(), non_neg_integer() -> boolean())) ::
  bitstring()

Builds a {width, height} glyph from a per-pixel predicate ink?.(x, y).

Examples

iex> RasterExRatatui.Font.Generated.rasterise({3, 1}, fn x, _y -> x != 1 end)
<<0b101::3>>