PTGS Calculator for Burning Wheel

ptgs-calc.html

<script language="JavaScript">
function verifyField(theField,maxValue,fieldName) {
	if ( parseInt(theField.value) > maxValue ) {
		theField.focus();
		alert( "You may not enter more than " + maxValue + " for " + fieldName );
	}
}

function calculatePTGS(theForm) {
	var forte = parseInt(theForm.forteExponent.value);
	var mwRaw = parseInt(theForm.mwExponent.value);
	if ( isNaN(forte) || isNaN(mwRaw) ) {
		alert("Check your numbers, pegboy!");
	} else {

		if ( theForm.mwShade[0].checked ) {
			// black
			calcPTGS(mwRaw,forte);
		} else if ( theForm.mwShade[1].checked ) {
			// grey
			calcPTGS(mwRaw+16,forte);
		} else if ( theForm.mwShade[2].checked ) {
			// white
			calcPTGS(mwRaw+32,forte);
		}

	}
	
}

function calcPTGS(mortal,forte) {
	var superficial,light,midi,severe,traumatic;
	if ( mortal > 32 ) {
		// white
		superficial = 2*forte;
		light = 2*superficial;
		traumatic = mortal - 1;
		severe = traumatic - 1;
		midi = severe - 2;
	} else if ( mortal > 16 ) {
		// grey
		superficial= forte;
		light = 2*superficial;
		traumatic = mortal -1;
		severe = traumatic - 1;
		midi = severe - 2;
	} else {
		// black
		var ptgsSpacer = Math.ceil(forte/2);
		superficial = Math.floor(forte/2) + 1;
		light = calcPTGSWound( superficial, ptgsSpacer, mortal, 3 );
		midi = calcPTGSWound( light, ptgsSpacer, mortal, 2 );
		severe = calcPTGSWound( midi, ptgsSpacer, mortal, 1 );
		traumatic = calcPTGSWound( severe, ptgsSpacer, mortal, 0 );		
	} 

	printPTGS(superficial,light,midi,severe,traumatic,mortal);
}

function printPTGS(superficial,light,midi,severe,traumatic,mortal) {
	var ptgs = 	" Su: " + formatPTGS(superficial) + 
			" Li: " + formatPTGS(light) + 
			" Mi: " + formatPTGS(midi) + 
			" Se: " + formatPTGS(severe) + 
			" Tr: " + formatPTGS(traumatic) + 
			" MW: " + formatPTGS(mortal);
	document.getElementById('ptgs').innerHTML = ptgs;
}

function formatPTGS(ptgsRaw) {
	if ( ptgsRaw > 32 ) {
		return "W"+(ptgsRaw-32);
	} else if ( ptgsRaw > 16 ) {
		return "G"+(ptgsRaw-16);
	} else {
		return "B"+(ptgsRaw);
	}
}

function calcPTGSWound( startW, spacing, maxWounds, remainingWounds ) {
	while ( spacing > 0 ) {
		if ( (startW + spacing + remainingWounds) < maxWounds ) {
			break;
		} else {
			spacing--;
		}
	}
	return startW + spacing;
}
</script>
<h3>PTGS Calculator</h3>
<form onsubmit="return false;">

<b>Mortal Wound:</b>
<input type="radio" name="mwShade" checked/> B
<input type="radio" name="mwShade" > G
<input type="radio" name="mwShade" > W
<input type="text" name="mwExponent" size="2" maxlength="2" onchange="verifyField(this,16,'Mortal Wound')"/>
<br/>
<b>Forte Exponent:</b>
<input type="text" name="forteExponent" size="2" maxlength="2" onchange="verifyField(this,10,'Forte')"/>

<br/><br/>
<input type="button" value="calculate" onclick="calculatePTGS(this.form)"/>
<br/><br/>
<b>results:</b> <span id="ptgs"></span> 
</form>