abcjs/src/tablatures/tab-renderer.js

Renderer for abc music notation

/* eslint-disable no-debugger */
var VoiceElement = require('../write/creation/elements/voice-element');
var TabAbsoluteElements = require('./tab-absolute-elements');
var spacing = require('../write/helpers/spacing');

function initSpecialY() {
  return {
    tempoHeightAbove: 0,
    partHeightAbove: 0,
    volumeHeightAbove: 0,
    dynamicHeightAbove: 0,
    endingHeightAbove: 0,
    chordHeightAbove: 0,
    lyricHeightAbove: 0,
    lyricHeightBelow: 0,
    chordHeightBelow: 0,
    volumeHeightBelow: 0,
    dynamicHeightBelow: 0
  };
}

function getLyricHeight(voice) {
  var maxLyricHeight = 0;
  for (var ii = 0; ii < voice.children.length; ii++) {
    var curAbs = voice.children[ii];
    if (curAbs.specialY) {
      if (curAbs.specialY.lyricHeightBelow > maxLyricHeight) {
        maxLyricHeight = curAbs.specialY.lyricHeightBelow;
      }
    }
  }
  return maxLyricHeight; // add spacing
}

function buildTabName(self, dest) {
  var stringSemantics = self.plugin.semantics.strings;
  var controller = self.renderer.controller;
  var textSize = controller.getTextSize;
  var tabName = stringSemantics.tabInfos(self.plugin);
  var size = textSize.calc(tabName, 'tablabelfont', 'text instrumentname');
  dest.tabNameInfos = {
    textSize: size,
    name: tabName
  };
  return size.height;
}

/**
 * Laying out tabs
 * @param {*} renderer
 * @param {*} line
 * @param {*} staffIndex
 * @param {*} tablatureLayout
 */
function TabRenderer(plugin, renderer, line, staffIndex) {
  this.renderer = renderer;
  this.plugin = plugin;
  this.line = line;
  this.absolutes = new TabAbsoluteElements();
  this.staffIndex = staffIndex ;
  this.tabStaff = {
    clef: {
      type: 'TAB'
    }
  };
  this.tabSize = (plugin.linePitch * plugin.nbLines);
}

function islastTabInStaff(index, staffGroup) {
  if (staffGroup[index].isTabStaff) {
    if (index === staffGroup.length - 1) return true;
    if (staffGroup[index + 1].isTabStaff) {
      return false; 
    } else {
      return true;
    }
  }
  return false;
}

function getStaffNumbers(staffs) {
  var nbStaffs = 0; 
  for (var ii = 0; ii < staffs.length; ii++) {
    if (!staffs[ii].isTabStaff) {
      nbStaffs++;
    }
  }
  return nbStaffs;
}

function getParentStaffIndex(staffs, index) {
  for (var ii = index; ii >= 0; ii--) {
    if (!staffs[ii].isTabStaff) {
      return ii;
    }
  }
  return -1;
}


function linkStaffAndTabs(staffs) {
  for (var ii = 0; ii < staffs.length; ii++) {
    if (staffs[ii].isTabStaff) {
      // link to parent staff
      var parentIndex = getParentStaffIndex(staffs, ii);
      staffs[ii].hasStaff = staffs[parentIndex];
      if (!staffs[parentIndex].hasTab) staffs[parentIndex].hasTab = [];
      staffs[parentIndex].hasTab.push(staffs[ii]);
    }
  }
}

function isMultiVoiceSingleStaff(staffs , parent) {
  if ( getStaffNumbers(staffs) === 1) {
    if (parent.voices.length > 1) return true;
  }
  return false;
}


function getNextTabPos(self,staffGroup) {
  var tabIndex = self.staffIndex;
  var startIndex = 0;
  var handledVoices = 0;
  var inProgress = true;
  var nbVoices = 0;
  while (inProgress) {
    //for (var ii = 0; ii < staffGroup.length; ii++) {
    if (!staffGroup[startIndex])
      return -1;
    if (!staffGroup[startIndex].isTabStaff) {
      nbVoices = staffGroup[startIndex].voices.length; // get number of staff voices
    }
    if (staffGroup[startIndex].isTabStaff) {
      handledVoices++;
      if (islastTabInStaff(startIndex, staffGroup)) {
        if (handledVoices < nbVoices) return startIndex + 1;
      }
    } else {
      handledVoices = 0;
      if (startIndex >= tabIndex) {
        if (startIndex+1 == staffGroup.length) return startIndex +1;
        if (!staffGroup[startIndex + 1].isTabStaff) return startIndex + 1;
      }
    }
    startIndex++;
    // out of space case
    if (startIndex > staffGroup.length) return -1;
  }
}

function getLastStaff(staffs, lastTab) {
  for (var ii = lastTab; ii >= 0 ; ii-- ) {
    if (!staffs[ii].isTabStaff) {
      return staffs[ii];
    }
  }
  return null; 
}

function checkVoiceKeySig(voices, ii) {
  var curVoice = voices[ii];
  // on multivoice multistaff only the first voice has key signature
  // folling consecutive do not have one => we should provide the first voice key sig back then
  var elem0 = curVoice.children[0].abcelem;
  if (elem0.el_type === 'clef') return null;
  if (ii == 0) {
    // not found => clef=none case
    return 'none';
  }
  return voices[ii-1].children[0];
}

TabRenderer.prototype.doLayout = function () {
  var staffs = this.line.staff;
  if (staffs) {
    // give up on staffline=0 in key 
    var firstStaff = staffs[0];
    if (firstStaff) {
      if (firstStaff.clef) {
        if (firstStaff.clef.stafflines == 0) {
          this.plugin._super.setError("No tablatures when stafflines=0");
          return; 
        }
      }
    }
    staffs.splice(
      staffs.length, 0,
      this.tabStaff
    );
  }
  var staffGroup = this.line.staffGroup;

  var voices = staffGroup.voices;
  var firstVoice = voices[0];
  // take lyrics into account if any
  var lyricsHeight = getLyricHeight(firstVoice);
  var padd = 3;
  var prevIndex = this.staffIndex;
  var previousStaff = staffGroup.staffs[prevIndex];
  var tabTop = this.tabSize + padd - previousStaff.bottom - lyricsHeight;
  if (previousStaff.isTabStaff) {
    tabTop = previousStaff.top;
  }
  var staffGroupInfos = {
    bottom: -1,
    isTabStaff: true,
    specialY: initSpecialY(),
    lines: this.plugin.nbLines,
    linePitch: this.plugin.linePitch,
    dy: 0.15,
    top: tabTop,
  };
  var nextTabPos = getNextTabPos(this,staffGroup.staffs);
  if (nextTabPos === -1)
    return;
  staffGroupInfos.parentIndex = nextTabPos - 1;
  staffGroup.staffs.splice(nextTabPos, 0, staffGroupInfos);
  // staffGroup.staffs.push(staffGroupInfos);
  staffGroup.height += this.tabSize + padd;
  var parentStaff = getLastStaff(staffGroup.staffs, nextTabPos); 
  var nbVoices = 1;
  if (isMultiVoiceSingleStaff(staffGroup.staffs,parentStaff)) {
    nbVoices = parentStaff.voices.length;
  }  
  // build from staff
  this.tabStaff.voices = [];
  for (var ii = 0; ii < nbVoices; ii++) {
    var tabVoice = new VoiceElement(0, 0);
    var nameHeight = buildTabName(this, tabVoice) / spacing.STEP;
    nameHeight = Math.max(nameHeight, 1) // If there is no label for the tab line, then there needs to be a little padding
    staffGroup.staffs[this.staffIndex].top += nameHeight;
    staffGroup.height += nameHeight * spacing.STEP;
    tabVoice.staff = staffGroupInfos;
    voices.splice(voices.length, 0, tabVoice);
    var keySig = checkVoiceKeySig(voices, ii + this.staffIndex);
    this.tabStaff.voices[ii] = [];
    this.absolutes.build(this.plugin, voices, this.tabStaff.voices[ii], ii , this.staffIndex ,keySig);
  }
  linkStaffAndTabs(staffGroup.staffs); // crossreference tabs and staff
};


module.exports = TabRenderer;