Cauldron2D.Easel.Kino

This package shows Cauldron2D art in Livebook. It puts the atlas editor in a cell. It also shows a picture, an art directory as one sheet, an animation, or a camera moving across parallax layers.

Installation

Add the package in a notebook's setup cell:

Mix.install([{:cauldron_2d_easel_kino, "~> 0.3"}])

Usage

editor = Cauldron2D.Easel.Kino.Editor.new("priv/art/ship.pic", atlas: :game, tile: 16)
Cauldron2D.Easel.Kino.Editor.easel(editor)

Cauldron2D.Easel.Kino.image("priv/art/ship.pic", scale: 8)
Cauldron2D.Easel.Kino.sheet("priv/art", tile: 16, scale: 4)
Cauldron2D.Easel.Kino.animate("priv/art/flame.pic", scale: 8)

Cauldron2D.Easel.Kino.Editor.new/2 takes a .pic or .png path, or a Cauldron2D.Easel. The editor cell paints with the pointer. It has the same tools, palette, frames, onion skin, playback and undo as the other editors.

Its save button writes the file the cell was opened on, or the :save path. With :atlas and :tile, it then installs that file's directory as the atlas. A game running in the same notebook draws the change on its next frame. :zoom sets how many screen pixels show one picture pixel. The default is 16. Call easel/1 to get the document as it stands in a later cell.

The other functions of Cauldron2D.Easel.Kino:

• image/2 shows one picture. A picture is a Cauldron2D.Easel, a FrenchCurve.Raster, or the path of a .pic or .png. :scale enlarges every pixel. The default is 4.
• sheet/2 shows every art of a directory, or of a Cauldron2D.Atlas, on one sheet. Cauldron2D.Sheet packs it. :tile is required for a directory.
• animate/2 shows an easel's frames in turn. It plays at the easel's rate, or at :fps.
• parallax/3 moves a camera across Cauldron2D.Parallax.Layers. It takes the options of Cauldron2D.Parallax.Preview.frames/3, plus :zoom and :fps.
• png/2 returns a picture's PNG bytes at a scale.

Cauldron2D.Easel.derive/3 makes a new picture from one by a line, such as colour B #20c040; flip h; over hat 0 -1. Cauldron2D.Easel.Project.derive/3 keeps such a line in atlas.txt. One drawing can then give every recolouring and heading the game needs.

This is a pixel-art tool. A picture has a palette of up to ninety colours and a grid of keys. That is what .pic holds and what the terminal, the browser and the window draw. A .png with more colours is refused on load. It is not quantised.

The notebook

notebooks/easel.livemd is a tour. It opens the editor on a blank picture and on a file. It writes pictures as text and as code, and makes an animated one. It shows an art directory and its manifest. It derives many pictures from one drawing with Linocut. Last, it installs the directory as an atlas and composes a surface from it.

The badge above opens the notebook in Livebook. Its setup cell installs the package from Hex, and it needs nothing else. To run it from a checkout, give the setup cell {:cauldron_2d_easel_kino, path: "/absolute/path/to/cauldron_2d_easel_kino"} instead.

How it fits

The document and the art directory come from cauldron_2d_easel. The atlas it installs is the cauldron_2d Cauldron2D.Atlas a game draws from. The same editor runs in a browser outside Livebook with cauldron_2d_easel_web, and in a terminal with cauldron_2d_easel_drafter.

License

MIT