"use strict";
(self["webpackChunk"] = self["webpackChunk"] || []).push([[6386],{

/***/ 86158:
/***/ (function(__unused_webpack___webpack_module__, __unused_webpack___webpack_exports__, __webpack_require__) {

/* harmony import */ var _src_ol_Map_js__WEBPACK_IMPORTED_MODULE_2__ = __webpack_require__(41376);
/* harmony import */ var _src_ol_source_Raster_js__WEBPACK_IMPORTED_MODULE_1__ = __webpack_require__(47486);
/* harmony import */ var _src_ol_View_js__WEBPACK_IMPORTED_MODULE_5__ = __webpack_require__(54354);
/* harmony import */ var _src_ol_source_XYZ_js__WEBPACK_IMPORTED_MODULE_0__ = __webpack_require__(31998);
/* harmony import */ var _src_ol_layer_js__WEBPACK_IMPORTED_MODULE_3__ = __webpack_require__(42010);
/* harmony import */ var _src_ol_layer_js__WEBPACK_IMPORTED_MODULE_4__ = __webpack_require__(86291);





var minVgi = 0;
var maxVgi = 0.5;
var bins = 10;
/**
 * Calculate the Vegetation Greenness Index (VGI) from an input pixel.  This
 * is a rough estimate assuming that pixel values correspond to reflectance.
 * @param {Array<number>} pixel An array of [R, G, B, A] values.
 * @return {number} The VGI value for the given pixel.
 */

function vgi(pixel) {
  var r = pixel[0] / 255;
  var g = pixel[1] / 255;
  var b = pixel[2] / 255;
  return (2 * g - r - b) / (2 * g + r + b);
}
/**
 * Summarize values for a histogram.
 * @param {numver} value A VGI value.
 * @param {Object} counts An object for keeping track of VGI counts.
 */


function summarize(value, counts) {
  var min = counts.min;
  var max = counts.max;
  var num = counts.values.length;

  if (value < min) {// do nothing
  } else if (value >= max) {
    counts.values[num - 1] += 1;
  } else {
    var index = Math.floor((value - min) / counts.delta);
    counts.values[index] += 1;
  }
}
/**
 * Use aerial imagery as the input data for the raster source.
 */


var key = 'get_your_own_D6rA4zTHduk6KOKTXzGB';
var attributions = '<a href="https://www.maptiler.com/copyright/" target="_blank">&copy; MapTiler</a> ' + '<a href="https://www.openstreetmap.org/copyright" target="_blank">&copy; OpenStreetMap contributors</a>';
var aerial = new _src_ol_source_XYZ_js__WEBPACK_IMPORTED_MODULE_0__/* ["default"] */ .Z({
  attributions: attributions,
  url: 'https://api.maptiler.com/tiles/satellite/{z}/{x}/{y}.jpg?key=' + key,
  maxZoom: 20,
  crossOrigin: ''
});
/**
 * Create a raster source where pixels with VGI values above a threshold will
 * be colored green.
 */

var raster = new _src_ol_source_Raster_js__WEBPACK_IMPORTED_MODULE_1__/* ["default"] */ .ZP({
  sources: [aerial],

  /**
   * Run calculations on pixel data.
   * @param {Array} pixels List of pixels (one per source).
   * @param {Object} data User data object.
   * @return {Array} The output pixel.
   */
  operation: function operation(pixels, data) {
    var pixel = pixels[0];
    var value = vgi(pixel);
    summarize(value, data.counts);

    if (value >= data.threshold) {
      pixel[0] = 0;
      pixel[1] = 255;
      pixel[2] = 0;
      pixel[3] = 128;
    } else {
      pixel[3] = 0;
    }

    return pixel;
  },
  lib: {
    vgi: vgi,
    summarize: summarize
  }
});
raster.set('threshold', 0.25);

function createCounts(min, max, num) {
  var values = new Array(num);

  for (var i = 0; i < num; ++i) {
    values[i] = 0;
  }

  return {
    min: min,
    max: max,
    values: values,
    delta: (max - min) / num
  };
}

raster.on('beforeoperations', function (event) {
  event.data.counts = createCounts(minVgi, maxVgi, bins);
  event.data.threshold = raster.get('threshold');
});
raster.on('afteroperations', function (event) {
  schedulePlot(event.resolution, event.data.counts, event.data.threshold);
});
var map = new _src_ol_Map_js__WEBPACK_IMPORTED_MODULE_2__/* ["default"] */ .Z({
  layers: [new _src_ol_layer_js__WEBPACK_IMPORTED_MODULE_3__/* ["default"] */ .Z({
    source: aerial
  }), new _src_ol_layer_js__WEBPACK_IMPORTED_MODULE_4__/* ["default"] */ .Z({
    source: raster
  })],
  target: 'map',
  view: new _src_ol_View_js__WEBPACK_IMPORTED_MODULE_5__/* ["default"] */ .ZP({
    center: [-9651695, 4937351],
    zoom: 13,
    minZoom: 12,
    maxZoom: 19
  })
});
var timer = null;

function schedulePlot(resolution, counts, threshold) {
  if (timer) {
    clearTimeout(timer);
    timer = null;
  }

  timer = setTimeout(plot.bind(null, resolution, counts, threshold), 1000 / 60);
}

var barWidth = 15;
var plotHeight = 150;
var chart = d3.select('#plot').append('svg').attr('width', barWidth * bins).attr('height', plotHeight);
var chartRect = chart.node().getBoundingClientRect();
var tip = d3.select(document.body).append('div').attr('class', 'tip');

function plot(resolution, counts, threshold) {
  var yScale = d3.scaleLinear().domain([0, d3.max(counts.values)]).range([0, plotHeight]);
  var bar = chart.selectAll('rect').data(counts.values);
  bar.enter().append('rect');
  bar.attr('class', function (count, index) {
    var value = counts.min + index * counts.delta;
    return 'bar' + (value >= threshold ? ' selected' : '');
  }).attr('width', barWidth - 2);
  bar.transition().attr('transform', function (value, index) {
    return 'translate(' + index * barWidth + ', ' + (plotHeight - yScale(value)) + ')';
  }).attr('height', yScale);
  bar.on('mousemove', function () {
    var index = bar.nodes().indexOf(this);
    var threshold = counts.min + index * counts.delta;

    if (raster.get('threshold') !== threshold) {
      raster.set('threshold', threshold);
      raster.changed();
    }
  });
  bar.on('mouseover', function (event) {
    var index = bar.nodes().indexOf(this);
    var area = 0;

    for (var i = counts.values.length - 1; i >= index; --i) {
      area += resolution * resolution * counts.values[i];
    }

    tip.html(message(counts.min + index * counts.delta, area));
    tip.style('display', 'block');
    tip.transition().style('left', chartRect.left + index * barWidth + barWidth / 2 + 'px').style('top', event.y - 60 + 'px').style('opacity', 1);
  });
  bar.on('mouseout', function () {
    tip.transition().style('opacity', 0).on('end', function () {
      tip.style('display', 'none');
    });
  });
}

function message(value, area) {
  var acres = (area / 4046.86).toFixed(0).replace(/\B(?=(\d{3})+(?!\d))/g, ',');
  return acres + ' acres at<br>' + value.toFixed(2) + ' VGI or above';
}

/***/ })

},
/******/ function(__webpack_require__) { // webpackRuntimeModules
/******/ var __webpack_exec__ = function(moduleId) { return __webpack_require__(__webpack_require__.s = moduleId); }
/******/ var __webpack_exports__ = (__webpack_exec__(9877), __webpack_exec__(86158));
/******/ }
]);
//# sourceMappingURL=raster.js.map