// 2x8 Lego Brick
// A standard Lego brick with 2 bumps wide and 8 bumps long.
// Define constants
lbumps = 10 // number of bumps long
wbumps = {{N}} // number of bumps wide
pitch = 8.0
clearance = 0.1
bumpDiam = 4.8
bumpHeight = 1.8
height = 9.6
t = (pitch - (2 * clearance) - bumpDiam) / 2.0
totalLength = lbumps * pitch - (2.0 * clearance)
totalWidth = wbumps * pitch - (2.0 * clearance)
// Create the plane for the pegs. This is a hack so that the pegs can be patterned along the face of the lego base.
pegFace = {
  origin = { x = 0, y = 0, z = height },
  xAxis = { x = 1, y = 0, z = 0 },
  yAxis = { x = 0, y = 1, z = 0 },
  zAxis = { x = 0, y = 0, z = 1 }
}
// Create the plane for the tubes underneath the lego. This is a hack so that the tubes can be patterned underneath the lego.
tubeFace = {
  origin = { x = 0, y = 0, z = height - t },
  xAxis = { x = 1, y = 0, z = 0 },
  yAxis = { x = 0, y = 1, z = 0 },
  zAxis = { x = 0, y = 0, z = 1 }
}
// Make the base
s = startSketchOn(XY)
  |> startProfile(at = [-totalWidth / 2, -totalLength / 2])
  |> line(end = [totalWidth, 0])
  |> line(end = [0, totalLength])
  |> line(end = [-totalWidth, 0])
  |> close()
  |> extrude(length = height)

// Sketch and extrude a rectangular shape to create the shell underneath the lego. This is a hack until we have a shell function.
shellExtrude = startSketchOn(s, "start")
  |> startProfile(at = [
       -(totalWidth / 2 - t),
       -(totalLength / 2 - t)
     ])
  |> line(end = [totalWidth - (2 * t), 0])
  |> line(end = [0, totalLength - (2 * t)])
  |> line(end = [-(totalWidth - (2 * t)), 0])
  |> close()
  |> extrude(length = -(height - t))

fn tr(@i) {
  j = i + 1
  x = (j/wbumps) * pitch
  y = (j % wbumps) * pitch
  return {
    translate = [x, y, 0],
  }
}

// Create the pegs on the top of the base
totalBumps = (wbumps * lbumps)-1
peg = startSketchOn(s, face = END)
  |> circle( center = [
       -(pitch*(wbumps-1)/2),
       -(pitch*(lbumps-1)/2)
     ], radius = bumpDiam / 2)
  |> patternLinear2d(
       axis = [1, 0],
       instances = wbumps,
       distance = pitch
     )
  |> patternLinear2d(
       axis = [0, 1],
       instances = lbumps,
       distance = pitch
     )
  |> extrude(length = bumpHeight)
  // |> patternTransform(instances = totalBumps-1, transform = tr)