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86d333ee94
* chore: Switch to Node 20 + Vitest * chore: migrate to vitest mock functions * chore: code style (switch to prettier) * test: re-enable long-running test Seems the switch to Node 20 and Vitest has vastly improved the code's and / or the test's runtime! see #1193 * chore: code style * chore: fix failing tests * Updated Documentation in README.md * Update contribution guidelines to state usage of Prettier * fix: set prettier printWidth back to 80 * chore: apply updated code style automatically * fix: set prettier line endings to lf again * chore: apply updated code style automatically --------- Co-authored-by: github-actions <${GITHUB_ACTOR}@users.noreply.github.com> Co-authored-by: Lars Müller <34514239+appgurueu@users.noreply.github.com>
62 lines
1.8 KiB
JavaScript
62 lines
1.8 KiB
JavaScript
import { Vector2, iterate } from './KochSnowflake'
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/**
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* Method to render the Koch snowflake to a canvas.
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*
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* @param canvasWidth The width of the canvas.
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* @param steps The number of iterations.
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* @returns The canvas of the rendered Koch snowflake.
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*/
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function getKochSnowflake(canvasWidth = 600, steps = 5) {
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if (canvasWidth <= 0) {
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throw new Error('canvasWidth should be greater than zero')
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}
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const offsetX = canvasWidth / 10.0
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const offsetY = canvasWidth / 3.7
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const vector1 = new Vector2(offsetX, offsetY)
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const vector2 = new Vector2(
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canvasWidth / 2,
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Math.sin(Math.PI / 3) * canvasWidth * 0.8 + offsetY
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)
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const vector3 = new Vector2(canvasWidth - offsetX, offsetY)
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const initialVectors = []
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initialVectors.push(vector1)
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initialVectors.push(vector2)
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initialVectors.push(vector3)
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initialVectors.push(vector1)
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const vectors = iterate(initialVectors, steps)
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return drawToCanvas(vectors, canvasWidth, canvasWidth)
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}
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/**
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* Utility-method to render the Koch snowflake to a canvas.
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*
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* @param vectors The vectors defining the edges to be rendered.
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* @param canvasWidth The width of the canvas.
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* @param canvasHeight The height of the canvas.
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* @returns The canvas of the rendered edges.
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*/
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function drawToCanvas(vectors, canvasWidth, canvasHeight) {
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const canvas = document.createElement('canvas')
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canvas.width = canvasWidth
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canvas.height = canvasHeight
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// Draw the edges
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const ctx = canvas.getContext('2d')
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ctx.beginPath()
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ctx.moveTo(vectors[0].x, vectors[0].y)
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for (let i = 1; i < vectors.length; i++) {
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ctx.lineTo(vectors[i].x, vectors[i].y)
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}
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ctx.stroke()
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return canvas
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}
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// plot the results if the script is executed in a browser with a window-object
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if (typeof window !== 'undefined') {
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const canvas = getKochSnowflake()
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document.body.append(canvas)
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}
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