util.js

//links 2 number inputs together such that:
// - both inputs are limited within an overall min/max
// - value of second input is guaranteed to always be >= value of first input + margin
//assumes starting values (dft1, dft2) are sane under those restrictions
var LinkNumInputs = function(i1, i2, min, max, dft1, dft2, margin=0) {
	i1.data("linkedInput", i2);
	i2.data("linkedInput", i1);
	i1.data("linkedInputMargin", margin);
	i2.data("linkedInputMargin", margin);
	i1.change(function() {
		var newv = i1.val();
		i1.data("linkedInput").attr('min', newv*1+i1.data("linkedInputMargin")*1);
	});
	i2.change(function() {
		var newv = i2.val();
		i2.data("linkedInput").attr('max', newv*1-i2.data("linkedInputMargin")*1);
	});
	
	i1.attr('min', min);
	i1.attr('max', dft2-margin);
	i2.attr('min', dft1+margin);
	i2.attr('max', max);
	
	i1.val(dft1);
	i2.val(dft2);
}

//links any number of other controls [arri2] to an option input [i1] such that the other controls are hidden unless [i1]'s selected option has any of the values in [optsAllow]
var ParentOptionInput = function(i1, arri2, optsAllow) {
	i1.data("childInputCount", arri2.length);
	for(var i = 0; i < arri2.length; i++) {
		i1.data("childInput" + i, arri2[i]);
	}
	i1.change(function() {
		var doTogg = optsAllow.includes(i1.val());
		for(var i = 0; i < i1.data("childInputCount"); i++) {
			var iN = i1.data("childInput" + i);
			if(doTogg)
				iN.slideDown(100);
			else
				iN.slideUp(100);
		}
	});
}
var ParentCheckboxInput = function(i1, arrChk, arrOff) {
	i1.data("childInputOnCount", arrChk.length);
	for(var i = 0; i < arrChk.length; i++) {
		i1.data("childInputOn" + i, arrChk[i]);
	}
	i1.data("childInputOffCount", arrOff.length);
	for(var i = 0; i < arrOff.length; i++) {
		i1.data("childInputOff" + i, arrOff[i]);
	}
	i1.change(function(e) {
		var doTogg = i1.get(0).checked;
		for(var i = 0; i < i1.data("childInputOnCount"); i++) {
			var iN = i1.data("childInputOn" + i);
			if(doTogg)
				iN.slideDown(100);
			else
				iN.slideUp(100);
		}
		for(var i = 0; i < i1.data("childInputOffCount"); i++) {
			var iN = i1.data("childInputOff" + i);
			if(!doTogg)
				iN.slideDown(100);
			else
				iN.slideUp(100);
		}
	});
}
var ParentClickInput = function(i1, arrChk) {
	i1.data("childInputCount", arrChk.length);
	for(var i = 0; i < arrChk.length; i++) {
		i1.data("childInput" + i, arrChk[i]);
	}
	i1.click(function(e) {
		for(var i = 0; i < i1.data("childInputCount"); i++) {
			var iN = i1.data("childInput" + i);
			iN.slideToggle(100);
		}
	});
}

//% operator is signed remainder, not modulus -- works differently on negative numbers
var Mod = function(n, p) {
	return n - p * Math.floor(n/p);
}
   
var isPow2 = function(n) {
	return (n !== 0) && (n & (n - 1)) === 0;
}

var pctDone = function(x,a,b) {
	return ((x-a)/(b-a)*100).toFixed(1) + "%";
}

function download(filename, text) {
  var element = document.createElement('a');
  element.setAttribute('href', 'data:text/plain;charset=utf-8,' + encodeURIComponent(text));
  element.setAttribute('download', filename);

  element.style.display = 'none';
  document.body.appendChild(element);

  element.click();

  document.body.removeChild(element);
}
function BlobDownload(Filename, Bytes, Mimetype) {
	var filData = new Blob(Bytes, { type: Mimetype });
	if (window.navigator && window.navigator.msSaveOrOpenBlob) { // for IE
		window.navigator.msSaveOrOpenBlob(filData, Filename);
	} else { // for Non-IE (chrome, firefox etc.)
		var a = document.createElement("a");
		document.body.appendChild(a);
		a.style = "display: none";
		var filUrl = URL.createObjectURL(filData);
		a.href = filUrl;
		a.download = Filename;
		a.click();
		a.remove();
	}
};

//find the closest color in a colorset using the dE2000 algorithm
var ColorQuantize = function(color, colorset) {
	//expects color to be an array-RGBA value from 0-1, and colorset to be an array of such values
	//TODO: opacity doesn't work right yet
	var bestScore = Number.MAX_VALUE
	var bestIndex = 0; //fallback to the first color if something goes horribly wrong
	var bestColor = colorset[0];

	var colorLAB = Colour.RGBA2LAB(color[0]*255, color[1]*255, color[2]*255, color[3]);
	
	for(var i = 0; i < colorset.length; i++) {
		var matchLAB = Colour.RGBA2LAB(colorset[i][0]*255, colorset[i][1]*255, colorset[i][2]*255, colorset[i][3]);
		var thisScore = Colour.DeltaE00(colorLAB[0], colorLAB[1], colorLAB[2], matchLAB[0], matchLAB[1], matchLAB[2]);
		
		if(thisScore < bestScore) {
			bestScore = thisScore;
			bestIndex = i;
			bestColor = colorset[i];
		}
	}
	
	return {
		Closeness: bestScore,
		SetI: bestIndex,
		Color: bestColor
	}
}

//based on threejs implementation of randInt
var	fracToInt = function (low, high, src) {
	return low + Math.floor(src * ( high - low + 1 ));
}

var mapLocalIter2 = function(func, map, r, x, y, mx, my, bx, by) {
	var rxm = Math.max(x-r, mx);
	var rxp = Math.min(x+r, bx-1);
	var rym = Math.max(y-r, my);
	var ryp = Math.min(y+r, by-1);
	for(var i = rxm; i <= rxp; i++) {
		for(var j = rym; j <= ryp; j++) {
			func(map[i][j], i, j, (i == x) && (j == y), x-i, y-j);
		}
	}
}

var mapLocalIter3 = function(func, map, r, x, y, z, mx, my, mz, bx, by, bz) {
	var rxm = Math.max(x-r, mx);
	var rxp = Math.min(x+r, bx-1);
	var rym = Math.max(y-r, my);
	var ryp = Math.min(y+r, by-1);
	var rzm = Math.max(z-r, mz);
	var rzp = Math.min(z+r, bz-1);
	for(var i = rxm; i <= rxp; i++) {
		for(var j = rym; j <= ryp; j++) {
			for(var k = rzm; k <= rzp; k++) {
				func(map[i][j][k], i, j, k, (i == x) && (j == y) && (k == z));
			}
		}
	}
}