UnitConversionServer Example

INI-File Format

This conversion server uses an ini-file format where the:

• key: <unit>|<precision>
• value: <unit>,<multiplier>,<offset>,<precision>

There need to be 2 section available. One for Metric and the other Imperial unit conversion.

Example file:

[Metric]
m/s,0=m/s,1,0,0
m/s,2=mm/s,1000,0,-1
m/s,3=mm/s,1000,0,0
m/s,4=mm/s,1000,0,1
m/s,5=mm/s,1000,0,2
 
rad,0=deg,57.2958,0,0
rad,1=deg,57.2958,0,0
rad,2=deg,57.2958,0,1
rad,3=deg,57.2958,0,2
rad,4=deg,57.2958,0,3
rad,5=deg,57.2958,0,4
rad,6=deg,57.2958,0,5
 
[Imperial]
m/s,0="/s,39.37007874015748031496062992126,0,0
m/s,1="/s,39.37007874015748031496062992126,0,1
m/s,2="/s,39.37007874015748031496062992126,0,2
m/s,3="/s,39.37007874015748031496062992126,0,3
m/s,4="/s,39.37007874015748031496062992126,0,4
m/s,5="/s,39.37007874015748031496062992126,0,5
 
rad,0=deg,57.2958,0,0
rad,1=deg,57.2958,0,0
rad,2=deg,57.2958,0,1
rad,3=deg,57.2958,0,2
rad,4=deg,57.2958,0,3
rad,5=deg,57.2958,0,4
rad,6=deg,57.2958,0,5
 
°C|1=°F,1.8,32,1

Usage

Conversion Server

The instance of sf::UnitConversionServer is created some where in the application.

 ++
// Create input string stream with ini formatted data.
std::istringstream is(R"(
 
[Metric]
m/s|1=mm/s,1000,0,-2
m/s|2=mm/s,1000,0,-1
m/s|3=mm/s,1000,0,0
 
[Imperial]
m/s|0="/s,39.37007874015748031496062992126,0,0
m/s|1="/s,39.37007874015748031496062992126,0,1
m/s|2="/s,39.37007874015748031496062992126,0,2
°C|1=°F,1.8,32,1
 
)");
 
// Create and thus install unit conversion handler. 
sf::UnitConversionServer ucs(is);
 
// Use imperial units when converting.
ucs.setUnitSystem(sf::UnitConversionServer::usImperial);

Conversion Client

Calling global function #sf::getUnitConversion() is now handled by the singleton sf::UnitConversionServer instance.

 ++
// Variables to fill with conversion information.
double multiplier{0}, offset{0}, value{32.2};
int precision{0};
std::string unit;
 
// Using UTF-8 encoded source.
sf::getUnitConversion("", "°C", 1, multiplier, offset, unit, precision);
 
// Using ASCII only encoded source.
sf::getUnitConversion("", "\U000000B0C", 1, multiplier, offset, unit, precision);
 
// Print the converted value.
std::clog << stringf("%.*lf", multiplier * value + offset, precision) << std::endl;