// ===========================================================================
// Copyright 2018 Autodesk, Inc. All rights reserved.
//
// Use of this software is subject to the terms of the Autodesk license
// agreement provided at the time of installation or download, or which
// otherwise accompanies this software in either electronic or hard copy form.
// ===========================================================================
global proc float convertMeasurement(
	float  $value,
	string $fromUnits,
	string $toUnits)
//
//	Description:
//		Convert a value from one unit of measurement to another.
//
//	Arguments:
//		value - Value to convert.
//		fromUnits - Units value is currently in.
//		toUnits - Units to convert value to. 
//
//	Valid units are:
//		"inches",
//		"cm",
//		"mm",
//		"points",
//		"picas"
//
{
	float $result = $value;
	float $kInchesInOneCentimeter = 0.393700787;
	float $kInchesInOneMillimeter = 0.0393700787;
	float $kInchesInOnePoint = 0.0138888889;
	float $kInchesInOnePicas = 0.166666667;

	//	Nothing to do if units are the same.
	//
	if ($fromUnits == $toUnits) return $result;

	// First convert the value from its current units to inches.
	//
	float $valueInInches;
	string $msg;
	switch ($fromUnits)
	{
		case "inches":
			$valueInInches = $value;
			break;
		case "cm":
			$valueInInches = $value * $kInchesInOneCentimeter;
			break;
		case "mm":
			$valueInInches = $value * $kInchesInOneMillimeter;
			break;
		case "points":
			$valueInInches = $value * $kInchesInOnePoint;
			break;
		case "picas":
			$valueInInches = $value * $kInchesInOnePicas;
			break;
		default:
			$msg = (uiRes("m_convertMeasurement.kCannotConvertFrom"));
			error (`format -stringArg $fromUnits $msg`);
	}

	// Now convert the value in inches to the desired units 
	//
	switch ($toUnits)
	{
		case "inches":
			$result = $valueInInches;
			break;
		case "cm":
			$result = $valueInInches / $kInchesInOneCentimeter;
			break;
		case "mm":
			$result = $valueInInches / $kInchesInOneMillimeter;
			break;
		case "points":
			$result = $valueInInches / $kInchesInOnePoint;
			break;
		case "picas":
			$result = $valueInInches / $kInchesInOnePicas;
			break;
		default:
			$msg = (uiRes("m_convertMeasurement.kCannotConvertTo"));
			error (`format -stringArg $toUnits $msg`);
	}
	return $result;
}