modeling/src/text/vectorText.js

  1. const vectorChar = require('./vectorChar')
  2. const vectorParams = require('./vectorParams')
  4. // translate text line
  5. const translateLine = (options, line) => {
  6.   const { x, y } = Object.assign({ x: 0, y: 0 }, options || {})
  7.   const segments = line.segments
  8.   let segment = null
  9.   let point = null
  10.   for (let i = 0, il = segments.length; i < il; i++) {
  11.     segment = segments[i]
  12.     for (let j = 0, jl = segment.length; j < jl; j++) {
  13.       point = segment[j]
  14.       segment[j] = [point[0] + x, point[1] + y]
  15.     }
  16.   }
  17.   return line
  18. }
  20. /**
  21.  * Construct an array of character segments from a ascii string whose characters code is between 31 and 127,
  22.  * if one character is not supported it is replaced by a question mark.
  23.  * @param {Object|String} [options] - options for construction or ascii string
  24.  * @param {Float} [options.xOffset=0] - x offset
  25.  * @param {Float} [options.yOffset=0] - y offset
  26.  * @param {Float} [options.height=21] - font size (uppercase height)
  27.  * @param {Float} [options.lineSpacing=1.4] - line spacing expressed as a percentage of font size
  28.  * @param {Float} [options.letterSpacing=1] - extra letter spacing expressed as a percentage of font size
  29.  * @param {String} [options.align='left'] - multi-line text alignment: left, center, right
  30.  * @param {Float} [options.extrudeOffset=0] - width of the extrusion that will be applied (manually) after the creation of the character
  31.  * @param {String} [options.input='?'] - ascii string (ignored/overwrited if provided as seconds parameter)
  32.  * @param {String} [text='?'] - ascii string
  33.  * @returns {Array} characters segments [[[x, y], ...], ...]
  34.  * @alias module:modeling/text.vectorText
  35.  *
  36.  * @example
  37.  * let textSegments = vectorText()
  38.  * let textSegments = vectorText('OpenJSCAD')
  39.  * let textSegments = vectorText({ yOffset: -50 }, 'OpenJSCAD')
  40.  * let textSegments = vectorText({ yOffset: -80, input: 'OpenJSCAD' })
  41.  */
  42. const vectorText = (options, text) => {
  43.   const {
  44.     xOffset, yOffset, input, font, height, align, extrudeOffset, lineSpacing, letterSpacing
  45.   } = vectorParams(options, text)
  46.   let [x, y] = [xOffset, yOffset]
  47.   let i, il, char, vect, width, diff
  48.   let line = { width: 0, segments: [] }
  49.   const lines = []
  50.   let output = []
  51.   let maxWidth = 0
  52.   const lineStart = x
  53.   const pushLine = () => {
  54.     lines.push(line)
  55.     maxWidth = Math.max(maxWidth, line.width)
  56.     line = { width: 0, segments: [] }
  57.   }
  58.   for (i = 0, il = input.length; i < il; i++) {
  59.     char = input[i]
  60.     vect = vectorChar({ xOffset: x, yOffset: y, font, height, extrudeOffset }, char)
  61.     if (char === '\n') {
  62.       x = lineStart
  63.       y -= vect.height * lineSpacing
  64.       pushLine()
  65.       continue
  66.     }
  67.     width = vect.width * letterSpacing
  68.     line.width += width
  69.     x += width
  70.     if (char !== ' ') {
  71.       line.segments = line.segments.concat(vect.segments)
  72.     }
  73.   }
  74.   if (line.segments.length) {
  75.     pushLine()
  76.   }
  77.   for (i = 0, il = lines.length; i < il; i++) {
  78.     line = lines[i]
  79.     if (maxWidth > line.width) {
  80.       diff = maxWidth - line.width
  81.       if (align === 'right') {
  82.         line = translateLine({ x: diff }, line)
  83.       } else if (align === 'center') {
  84.         line = translateLine({ x: diff / 2 }, line)
  85.       }
  86.     }
  87.     output = output.concat(line.segments)
  88.   }
  89.   return output
  90. }
  92. module.exports = vectorText