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Documentation Index

Fetch the complete documentation index at: https://docs.tsdraw.com/llms.txt

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The CanvasRenderer draws shapes onto an HTML canvas using the Canvas 2D API. 
import { CanvasRenderer } from '@tsdraw/core'

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ICanvasRenderer interface

interface ICanvasRenderer {
  render(
    ctx: CanvasRenderingContext2D,
    shapes: Shape[],
    viewport: Viewport,
    theme: TsdrawRenderTheme
  ): void
}

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CanvasRenderer

The default implementation. Renders strokes using perfect-freehand for the draw dash style, and Canvas 2D setLineDash for other styles.

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Rendering pipeline

  1. Apply viewport transform (translate + scale)
  2. For each visible shape, decode segment paths and render strokes
  3. For closed shapes with fill, render the fill first, then the stroke

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TsdrawRenderTheme

interface TsdrawRenderTheme {
  resolveColor(colorKey: string): string
}
Maps palette keys (e.g. 'blue') to hex colors, adapting for the current light/dark theme.

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resolveThemeColor

import { resolveThemeColor } from '@tsdraw/core'

const hex = resolveThemeColor(theme, 'blue')

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Background renderer

import { renderCanvasBackground } from '@tsdraw/core'

type TsdrawBackgroundType = 'blank' | 'lines' | 'grid' | 'dots'
Draws a background pattern behind shapes. The pattern scales with the viewport zoom for consistent visual density. 
renderCanvasBackground(
  ctx: CanvasRenderingContext2D,
  viewport: Viewport,
  canvasWidth: number,
  canvasHeight: number,
  options: TsdrawBackgroundOptions
): void