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Create Patterns

These are the custom patterns that you can implement in your applications:

Rectangular​

There are many ways to define a rectangular pattern, the following are some examples based on the number of copies or the size-dependent variables. In both cases the pattern is separated into two functions: one for the positions and the other for the pattern sketch.

By Number Of Copies​

function getPatternPositions(nrCopiesVector: SKYMATH.Vector2D, distanceVector: SKYMATH.Vector2D) {
  const positions = []

  for (let i = 0; i < nrCopiesVector.x; i++) {
    for (let j = 0; j < nrCopiesVector.y; j++) {
      const position = new SKYMATH.Vector2D(i * distanceVector.x, j * distanceVector.y)
      positions.push(position)
    }
  }

  return positions
}

export function generateRectangularPatternSketch(
  sketchToUseInPattern: SKYCAD.Sketch,
  nrCopiesVector: SKYMATH.Vector2D,
  distanceVector: SKYMATH.Vector2D,
) {
  const patternSketch = new SKYCAD.Sketch()
  const patternPositions = getPatternPositions(nrCopiesVector, distanceVector)

  patternPositions.forEach((position) => {
    const clonedSketch = sketchToUseInPattern.clone()
    clonedSketch.translate(position.x, position.y)
    patternSketch.mergeSketch(clonedSketch)
  })

  return patternSketch
}

By Size​

export function getPatternPositions(
  lengthVector: SKYMATH.Vector2D,
  distanceBetweenVector: SKYMATH.Vector2D,
  holeSize: number,
  autocentered: boolean,
) {
  const nrCopiesX = Math.floor(lengthVector.x / (holeSize + distanceBetweenVector.x))
  const nrCopiesY = Math.floor(lengthVector.y / (holeSize + distanceBetweenVector.y))
  const nrCopiesVector = new SKYMATH.Vector2D(nrCopiesX, nrCopiesY)

  const startOffset = autocentered
    ? new SKYMATH.Vector2D(
        (lengthVector.x - nrCopiesX * holeSize - (nrCopiesX - 1) * distanceBetweenVector.x) / 2,
        (lengthVector.y - nrCopiesY * holeSize - (nrCopiesY - 1) * distanceBetweenVector.y) / 2,
      )
    : new SKYMATH.Vector2D(0, 0)

  const positions = []
  for (let i = 0; i < nrCopiesVector.x; i++) {
    for (let j = 0; j < nrCopiesVector.y; j++) {
      const position = new SKYMATH.Vector2D(
        startOffset.x + i * (holeSize + distanceBetweenVector.x),
        startOffset.y + j * (holeSize + distanceBetweenVector.y),
      )
      positions.push(position)
    }
  }

  return positions
}

export function generateRectangularPatternSketch(
  sketchToUseInPattern: SKYCAD.Sketch,
  lengthVector: SKYMATH.Vector2D,
  distanceBetweenVector: SKYMATH.Vector2D,
  holeSize: number,
  autocentered: boolean,
) {
  const patternSketch = new SKYCAD.Sketch()
  const patternPositions = getPatternPositions(lengthVector, distanceBetweenVector, holeSize, autocentered)

  patternPositions.forEach((position) => {
    const clonedSketch = sketchToUseInPattern.clone()
    clonedSketch.translate(position.x, position.y)
    patternSketch.mergeSketch(clonedSketch)
  })

  return patternSketch
}

Circular​

Here is an example of a circular pattern, separated into two functions: one for the positions and the other for the pattern sketch.

export function generateCircularPatternPositionStructs(
  radius: number,
  nrCopies: number,
  { startAngle = 0, endAngle = 2 * Math.PI, referenceAngle = 0, addLast = false } = {},
) {
  const positionStructs: { position: SKYMATH.Vector2D; angle: number }[] = []
  const NC = addLast ? nrCopies + 1 : nrCopies
  const angleRange = endAngle - startAngle

  for (let i = 0; i < NC; i++) {
    const angle = (angleRange * i) / nrCopies + startAngle + referenceAngle
    const position = new SKYMATH.Vector2D(radius * Math.cos(angle), radius * Math.sin(angle))
    positionStructs.push({ position, angle }) // the angle is pushed here so the sketch can be rotated accordingly later
  }

  return positionStructs
}

export function generateCircularPatternSketch(
  sketchToUseInPattern: SKYCAD.Sketch,
  radius: number,
  nrCopies: number,
  { startAngle = 0, endAngle = 2 * Math.PI, referenceAngle = 0, addLast = false } = {},
) {
  const positionStructs = generateCircularPatternPositionStructs(radius, nrCopies, {
    startAngle,
    endAngle,
    referenceAngle,
    addLast,
  })
  const circularPatternSketch = new SKYCAD.Sketch()

  positionStructs.forEach((struct) => {
    const { position, angle } = struct
    const patternSketch = sketchToUseInPattern.clone()
    patternSketch.scale(radius / 30) // scale sketch according to radius
    patternSketch.rotate(angle) // point inwards
    patternSketch.translate(position.x, position.y)
    circularPatternSketch.mergeSketch(patternSketch)
  })

  return circularPatternSketch
}