This page documents some ways of logging and outputting text in the game, both within the engine and scripts. This is useful to know for debugging and when the user should be notified of something.

Engine

The coding conventions have some information regarding logging in the engine.

The engine is written in C++. Prefer the following functions for logging and outputting text:

• LOGMESSAGE(const wchar_t* format, ...)
• LOGMESSAGERENDER(const wchar_t* format, ...)

Use these functions to report possible misconfigurations or errors that can be caused by modding:

• LOGWARNING(const wchar_t* format, ...)
• LOGERROR(const wchar_t* format, ...)
• debug_printf(const wchar_t* format, ...)

Function	Game console	Rendered message	Main log	Interesting log	std::out*	std::err
LOGMESSAGE	N	N	Y	N	N	N
LOGMESSAGERENDER	Y	Y - green text	Y	N	N	N
LOGWARNING	Y	Y - yellow text	Y	Y	Y	N
LOGERROR	Y	Y - red text	Y	Y	Y	N
debug_printf	N	N	N	N	Y	N

* On Windows, the game writes debug output instead of std::out. Run the game in a debugger or use ​DebugView to view it.

Note: to use the LOG* functions, you must include ps/CLogger.h​.
Note: these functions accept standard printf formatting and arguments, and use wide characters, which requires prefixing string literals with 'L':

std::string name;
// ... some code here ...
debug_printf(L"This is not a very interesting message, %hs\n", name.c_str());

Scripts

The game's scripts are written in JavaScript, but they won't necessarily have the same functions available as in a web browser. Use these functions for outputting text:

• print(message)
• console.write(message)
• log(message)
• warn(message)
• error(message)

Function	Game console	Rendered message	Main log	Interesting log	std::out*	std::err
print	N	N	N	N	Y	N
console.write	Y	N	N	N	N	N
log	N	N	Y	N	N	N
warn	Y	Y - yellow text	Y	Y	Y	N
error	Y	Y - red text	Y	Y	Y	N

* On Windows, the game writes debug output instead of std::out. Run the game in a debugger or use ​DebugView to view it.