Function transformPositions

stackgl_modules/index.js:39023–39094

(positions, options, size)

}

function transformPositions(positions, options, size) {
  var align = options.textAlign || "start"
  var baseline = options.textBaseline || "alphabetic"

  var lo = [1<<30, 1<<30]
  var hi = [0,0]
  var n = positions.length
  for(var i=0; i<n; ++i) {
    var p = positions[i]
    for(var j=0; j<2; ++j) {
      lo[j] = Math.min(lo[j], p[j])|0
      hi[j] = Math.max(hi[j], p[j])|0
    }
  }

  var xShift = 0
  switch(align) {
    case "center":
      xShift = -0.5 * (lo[0] + hi[0])
    break

    case "right":
    case "end":
      xShift = -hi[0]
    break

    case "left":
    case "start":
      xShift = -lo[0]
    break

    default:
      throw new Error("vectorize-text: Unrecognized textAlign: '" + align + "'")
  }

  var yShift = 0
  switch(baseline) {
    case "hanging":
    case "top":
      yShift = -lo[1]
    break

    case "middle":
      yShift = -0.5 * (lo[1] + hi[1])
    break

    case "alphabetic":
    case "ideographic":
      yShift = -3 * size
    break

    case "bottom":
      yShift = -hi[1]
    break

    default:
      throw new Error("vectorize-text: Unrecoginized textBaseline: '" + baseline + "'")
  }