bins.js

import scatterplot_component from './scatterplot_component';
import * as d3_hexbin from "d3-hexbin";

function bins(configObject) {
  scatterplot_component.call(this, configObject);

  // TODO: dirty hack to make bin size reasonable if set to 3 (scatterplot default)
  if (this.ptSize == 3) 
    this.ptSize = 15;
}
bins.prototype = Object.create(scatterplot_component.prototype);

bins.prototype.draw = function(container, skipTransition) {
  var that = this;
  var hexbin = d3_hexbin.hexbin()
      .x(function(d) { return that.scale.x(that.xValue(d)); })
      .y(function(d) { return that.scale.y(that.yValue(d)); })
      .extent([this.scale.x.range(), this.scale.x.range()])
      .radius(this.ptSize);
  
  var hexbins = hexbin(this.data);
  
  var attenuation = this.attenuation || d3.scale.log().range([0,1]);
  attenuation.domain([.1, d3.max(hexbins.map(function(d) { return d.length; }))]);

  container.selectAll('g.hexes')
    .data([1]).enter().append('g')
      .attr('class', 'hexes');

  container.selectAll('path.hex').remove();
  var hex = container.select('g.hexes').selectAll('path.hex')
    .data(hexbins);

  hex.exit().remove();
  hex.enter().append('path')
    .attr('class', 'hex')
    .attr('d', hexbin.hexagon(this.ptSize - 0.5))
    .attr('transform', function(d) { return "translate(" + d.x + "," + d.y + ")"; });
  hex.style('fill', function(d) {
    var counts = Array(that.foundGroups.length).fill(0);
    d.forEach(function(p) {
      counts[that.foundGroups.indexOf(that.grpValue(p))]++;
    });

    return counts.reduce(function(p,c,i) {
      return d3.interpolateLab(p, that.colorScale.range()[i])(c / d.length);
    }, "white");
  })
  .style('fill-opacity', function(d) { return attenuation(d.length); });

  this.attenuation = attenuation;
}

bins.prototype.update = function(container, skipTransition) {
  this.draw(container, skipTransition);
}

bins.prototype.highlight = function(container, selector) {
  console.warn("no highlight method implemented for bins");
  return;
}

bins.prototype.visualEncSelector = function() {
  return "path.hex";
}

export default bins;