Fantasy-Map-Generator/modules/ui/rivers-creator.js

'use strict';
function createRiver() {
  if (customization) return;
  closeDialogs();
  if (!layerIsOn('toggleRivers')) toggleRivers();

  document.getElementById('toggleCells').dataset.forced = +!layerIsOn('toggleCells');
  if (!layerIsOn('toggleCells')) toggleCells();

  tip('Click to add river point, click again to remove', true);
  debug.append('g').attr('id', 'controlCells');
  viewbox.style('cursor', 'crosshair').on('click', onCellClick);

  createRiver.cells = [];
  const body = document.getElementById('riverCreatorBody');

  $('#riverCreator').dialog({
    title: 'Create River',
    resizable: false,
    position: {my: 'left top', at: 'left+10 top+10', of: '#map'},
    close: closeRiverCreator
  });

  if (modules.createRiver) return;
  modules.createRiver = true;

  // add listeners
  document.getElementById('riverCreatorComplete').addEventListener('click', addRiver);
  document.getElementById('riverCreatorCancel').addEventListener('click', () => $('#riverCreator').dialog('close'));
  body.addEventListener('click', function (ev) {
    const el = ev.target;
    const cl = el.classList;
    const cell = +el.parentNode.dataset.cell;
    if (cl.contains('editFlux')) pack.cells.fl[cell] = +el.value;
    else if (cl.contains('icon-trash-empty')) removeCell(cell);
  });

  function onCellClick() {
    const cell = findCell(...d3.mouse(this));

    if (createRiver.cells.includes(cell)) removeCell(cell);
    else addCell(cell);
  }

  function addCell(cell) {
    createRiver.cells.push(cell);
    drawCells(createRiver.cells);

    const flux = pack.cells.fl[cell];
    const line = `<div class="editorLine" data-cell="${cell}">
      <span>Cell ${cell}</span>
      <span data-tip="Set flux affects river width" style="margin-left: 0.4em">Flux</span>
      <input type="number" min=0 value="${flux}" class="editFlux" style="width: 5em"/>
      <span data-tip="Remove the cell" class="icon-trash-empty pointer"></span>
    </div>`;
    body.innerHTML += line;
  }

  function removeCell(cell) {
    createRiver.cells = createRiver.cells.filter((c) => c !== cell);
    drawCells(createRiver.cells);
    body.querySelector(`div[data-cell='${cell}']`)?.remove();
  }

  function drawCells(cells) {
    debug
      .select('#controlCells')
      .selectAll(`polygon`)
      .data(cells)
      .join('polygon')
      .attr('points', (d) => getPackPolygon(d))
      .attr('class', 'current');
  }

  function addRiver() {
    const {rivers, cells} = pack;
    const {addMeandering, getApproximateLength, getWidth, getOffset, getName, getRiverPath, getBasin} = Rivers;

    const riverCells = createRiver.cells;
    if (riverCells.length < 2) return tip('Add at least 2 cells', false, 'error');

    const riverId = rivers.length ? last(rivers).i + 1 : 1;
    const parent = cells.r[last(riverCells)] || riverId;

    riverCells.forEach((cell) => {
      if (!cells.r[cell]) cells.r[cell] = riverId;
    });

    const source = riverCells[0];
    const mouth = parent === riverId ? last(riverCells) : riverCells[riverCells.length - 2];
    const sourceWidth = 0.05;
    const widthFactor = 1.2;

    const meanderedPoints = addMeandering(riverCells);

    const discharge = cells.fl[mouth]; // m3 in second
    const length = getApproximateLength(meanderedPoints);
    const width = getWidth(getOffset(discharge, meanderedPoints.length, widthFactor, sourceWidth));
    const name = getName(mouth);
    const basin = getBasin(parent);

    rivers.push({i: riverId, source, mouth, discharge, length, width, widthFactor, sourceWidth, parent, cells: riverCells, basin, name, type: 'River'});
    const id = 'river' + riverId;

    // render river
    lineGen.curve(d3.curveCatmullRom.alpha(0.1));
    viewbox.select('#rivers').append('path').attr('id', id).attr('d', getRiverPath(meanderedPoints, widthFactor, sourceWidth));

    editRiver(id);
  }

  function closeRiverCreator() {
    body.innerHTML = '';
    debug.select('#controlCells').remove();
    restoreDefaultEvents();
    clearMainTip();

    const forced = +document.getElementById('toggleCells').dataset.forced;
    document.getElementById('toggleCells').dataset.forced = 0;
    if (forced && layerIsOn('toggleCells')) toggleCells();
  }
}