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Canvas

Canvas is an immediate-mode drawing surface for cell-based terminal graphics.

Canvas

Basic usage

Provide a Painter callback that draws into a CanvasContext:

new Canvas()
    .MinWidth(40).MaxWidth(40)
    .MinHeight(10).MaxHeight(10)
    .Painter(ctx =>
    {
        ctx.Clear();
        ctx.DrawBox(0, 0, ctx.Size.Width, ctx.Size.Height, LineGlyphs.Single, CellStyle.None);
        ctx.DrawLine(1, 1, 30, 8, new Rune('*'), CellStyle.None);
        ctx.WriteText(2, 2, "Hello Canvas!");
    });

Drawing primitives

CanvasContext provides common primitives:

  • SetPixel
  • DrawHLine / DrawVLine
  • DrawLine
  • FillRect / DrawRect
  • DrawBox (corner/edge glyphs via LineGlyphs)
  • DrawCircle
  • WriteText

Fine pixels (thin drawing)

Set UseFinePixels to render default-rune primitives (e.g. DrawLine(..., style) / DrawCircle(..., style)) using a sub-cell dot grid for thinner strokes:

new Canvas()
    .UseFinePixels(true)
    .Painter(ctx =>
    {
        ctx.Clear();
        ctx.DrawLine(1, 1, 30, 8, Style.None);
        ctx.DrawCircle(20, 6, 4, Style.None);
    });

Cell-based operations like FillRect and WriteText remain cell-based.

Defaults

  • Default alignment: HorizontalAlignment = Align.Stretch, VerticalAlignment = Align.Stretch

Styling

CanvasStyle controls the default rune and style used by primitives when you don't pass them explicitly:

new Canvas()
    .Style(CanvasStyle.Default with { DefaultRune = new Rune('█') });