log¶
fresa has a simple logging system using the fmt library. The function fresa::detail::log is a passthrough to fmt::print with extra parameters for special formatting.
fresa::detail::log<"NAME", LogLevel::LEVEL, fmt::color>("{}", ...);
> [NAME]: ...
The name template parameter is the type of log message, LogLevel::LEVEL is used to enable or disable log types, and a color can be passed to make the output more readable. The first function parameter must be an fmt::format_string. Simplifying, this means that it will behave as a regular string but everywhere there is a "{}" it will be replaced with the next argument. Custom printing formats can be passed, for example, as "{:.2f}". Leveraging the new features introduced in fmt with c++20, the passthrough can now use constant expressions to format at compile time.
log levels¶
The logging level can be specified using the engine_config.log_level() config parameter. Each log level is defined in a bitwise enum, so they can be granularly combined.
| log level | bit flag |
|---|---|
LogLevel::ERROR |
1 << 0 |
LogLevel::WARNING |
1 << 1 |
LogLevel::INFO |
1 << 2 |
LogLevel::GRAPHICS |
1 << 3 |
LogLevel::TEST |
1 << 4 |
LogLevel::DEBUG |
1 << 5 |
LogLevel::JOBS |
1 << 6 |
For example, log_level = 0b0010011 enables logging for errors, warnings and unit test results.
predefined log functions¶
There are a number of predetermined log functions as a convenience:
| function | name | log level | color |
|---|---|---|---|
log::error |
"ERROR" | LogLevel::ERROR |
red |
log::warn |
"WARN" | LogLevel::WARN |
gold |
log::info |
"INFO" | LogLevel::INFO |
cornflower_blue |
log::graphics |
"GRAPHICS" | LogLevel::GRAPHICS |
dark_turquoise |
log::debug |
"DEBUG" | LogLevel::DEBUG |
light_sky_blue |