calcit_paint 0.0.8

(Toy)Calcit Paint

2D renderer for Calcit.

Usages

It runs Calcit and is driven by the canonical calcit.cirru Snapshot source.

./build.sh
calcit ./calcit.cirru

Available APIs:

calcit-paint.core/push-drawing-data! |reset-canvas! nil
calcit-paint.core/push-drawing-data! |render-canvas! shape-data

calcit-paint.core/launch-canvas! $ fn (event)
  println "|rendering to canvas..."

Native FFI / 原生 FFI

The C-safe buffer-v1 and blocking-callback descriptors, ownership rules, Cirru EDN transport, and adapters are provided by calcit_native_ffi. Paint keeps ownership of the Skia/winit event loop, rendering state, shape decoding, and callback scheduling. The module requires Calcit 0.13.57.

C-safe buffer-v1/blocking-callback descriptor、ownership 规则、Cirru EDN transport 与 adapter 由 calcit_native_ffi 统一维护。 Paint 仍负责 Skia/winit 事件循环、绘制状态、shape 解析和回调调度； 模块要求 Calcit 0.13.57。

A custom mirror may be used for Skia binaries when it is known to be healthy:

export SKIA_BINARIES_URL=https://cdn.tiye.me/skia-binaries/{tag}/skia-binaries-{key}.tar.gz

If the mirror is unavailable, unset SKIA_BINARIES_URL to use rust-skia's official GitHub release assets. CI deliberately leaves this variable unset.

只在镜像站可用时设置 SKIA_BINARIES_URL；镜像异常时取消该变量， 回退到 rust-skia 的 GitHub Release 产物。CI 不设置该变量。

Shapes

Position represented with [] x y. Color with [] h s l a?

Drawing with lyon 0.17.5:

• Rect, using rect or rectangle:

rect {
  position: Vec2,
  width: f32,
  height: f32,
  line_style: Option<(Color, f32)>,
  fill_style: Option<Color>,
},

• Group, using group

Group {
  position: Vec2,
  children: Vec<Shape>,
},

• Circle, using circle

Circle {
  position: Vec2,
  radius: f32,
  line_style: Option<(Color, f32)>,
  fill_style: Option<Color>,
},

Arc is not supported at current.

• Text, using text

Text {
  text: String,
  position: Vec2,
  size: f32,
  // weight: String, // TODO
  color: Color,
  // align: TextAlign,
},

• Paint operations, with ops

PaintOps {
  position: Vec2,
  path: Vec<PaintPathTo>,
  line_style: Option<(Color, f32)>,
  fill_style: Option<Color>,
},

It's rendered based on lyon SVG path builder. Only small subset:

[]
  [] :move-to ([] 1 2)
  [] :line-to ([] 3 4)
  [] :quadratic-bezier-to ([] 5 6) ([] 7 8)
  [] :cubic-bezier-to ([] 1 2) ([] 3 4) ([] 5 6)

Since then name is too long, I also use alies: bezier2-to -> quadratic-bezier-to, and bezier3-to -> cubic-bezier-to.

• Polyline, using polyline

Polyline {
  position: Vec2,
  stops: Vec<Vec2>,
  skip_first: bool,
  color: Color,
  width: f32,
  join: LineJoin,
  cap: LineCap,
},

• Image, using image, and Rect from Skia

Image {
  file_path: String,
  x: f32, y: f32, w: f32, h: f32,
  crop: Rect {
    x: f32, y: f32, w: f32, h: f32
  }
}

• Touch Area, using touch-area

For handling events:

TouchArea {
  path: Calcit,
  action: Calcit,
  data: Calcit,
  position: Vec2,
  // children: Vec<Shape>, // TODO
  area: TouchAreaShape,
  line_style: Option<(Color, f32)>,
  fill_style: Option<Color>,
},

• Key listener, using key-listener

KeyListener {
  key: String, // TODO modifier
  action: Calcit,
  path: Calcit,
  data: Calcit,
  // children: Vec<Shape>, // TODO
},

• Rotate

Rotate {
  radius: f32,
}

• Translate

Translate {
  x: f32,
  y: f32,
}

• Scale

Scale {
  factor: f32,
}

License

MIT