Merge pull request 'UnitFormatter class + several tests' (#123) from unit_formatter into master

Reviewed-on: https://git.madvoxel.net/OpenVulkano/OpenVulkano/pulls/123
Reviewed-by: Georg Hagen <georg.hagen@madvoxel.com>

openVulkanoCpp/Base/UnitFormatter.cpp

@@ -0,0 +1,93 @@
+/*
+* This Source Code Form is subject to the terms of the Mozilla Public
+* License, v. 2.0. If a copy of the MPL was not distributed with this
+* file, You can obtain one at https://mozilla.org/MPL/2.0/.
+*/
+
+#include "UnitFormatter.hpp"
+#include <string>
+#include <sstream>
+#include <iomanip>
+
+namespace
+{
+	template<typename T>
+	std::string FormatValue(T value, int precision, bool trimTrailingZeros, const std::string& suffix)
+	{
+		std::ostringstream out;
+		out << std::fixed << std::setprecision(precision) << value;
+		std::string result = out.str();
+
+		if (trimTrailingZeros && result.find('.') != std::string::npos)
+		{
+			result.erase(result.find_last_not_of('0') + 1);
+
+			if (result.back() == '.')
+			{
+				result.pop_back();
+			}
+		}
+		result += suffix;
+		return result;
+	}
+}
+
+namespace OpenVulkano
+{
+	UnitFormatter::UnitFormatter(bool useMetric, int precisionDigits, bool doTrimTrailingZeros)
+	    : metric(useMetric), precision(precisionDigits), trimTrailingZeros(doTrimTrailingZeros)
+	{
+	}
+
+	std::string UnitFormatter::Format(units::length::meter_t distance) const
+	{
+		if (metric)
+		{
+			if (distance > units::length::meter_t(0) && distance < units::length::meter_t(0.1))
+			{
+				return FormatValue(units::length::millimeter_t(distance).value(), precision, trimTrailingZeros, " mm");
+			}
+			else if (distance >= units::length::kilometer_t(1))
+			{
+				return FormatValue(units::length::kilometer_t(distance).value(), precision, trimTrailingZeros, " km");
+			}
+			return FormatValue(distance.value(), precision, trimTrailingZeros, " m");
+		}
+		else
+		{
+			auto distanceFeet = units::length::foot_t(distance).value();
+			auto distanceInches = units::length::inch_t(distance).value();
+
+			if (distanceFeet > 0 && distanceFeet < 0.1)
+			{
+				return FormatValue(distanceInches, precision, trimTrailingZeros, " in");
+			}
+			else if (distanceFeet >= 5280.0)
+			{
+				return FormatValue(units::length::mile_t(distance).value(), precision, trimTrailingZeros, " mi");
+			}
+			return FormatValue(distanceFeet, precision, trimTrailingZeros, " ft");
+		}
+	}
+
+	std::string UnitFormatter::Format(units::area::square_meter_t area) const
+	{
+		if (metric)
+		{
+			if (area >= units::area::square_kilometer_t(1))
+			{
+				return FormatValue(units::area::square_kilometer_t(area).value(), precision, trimTrailingZeros, " km²");
+			}
+			return FormatValue(area.value(), precision, trimTrailingZeros, " m²");
+		}
+		else
+		{
+			auto areaSquareFeet = units::area::square_foot_t(area).value();
+			if (areaSquareFeet >= 27878400.0)
+			{
+				return FormatValue(units::area::square_mile_t(area).value(), precision, trimTrailingZeros, " mi²");
+			}
+			return FormatValue(areaSquareFeet, precision, trimTrailingZeros, " ft²");
+		}
+	}
+}

openVulkanoCpp/Base/UnitFormatter.hpp

@@ -0,0 +1,24 @@
+/*
+* This Source Code Form is subject to the terms of the Mozilla Public
+* License, v. 2.0. If a copy of the MPL was not distributed with this
+* file, You can obtain one at https://mozilla.org/MPL/2.0/.
+*/
+#pragma once
+
+#include <units.h>
+#include <string>
+
+namespace OpenVulkano
+{
+	class UnitFormatter
+	{
+		bool metric = true;
+		int precision = 3;
+		bool trimTrailingZeros = true;
+
+	public:
+		UnitFormatter(bool useMetric = true, int precisionDigits = 3, bool doTrimTrailingZeros = true);
+		[[nodiscard]] std::string Format(units::length::meter_t distance) const;
+		[[nodiscard]] std::string Format(units::area::square_meter_t area) const;
+	};
+}