Constant Export

WarningThe scope of applications for UnigineScript is limited to implementing materials-related logic (material expressions, scriptable materials, brush materials). Do not use UnigineScript as a language for application logic, please consider C#/C++ instead, as these APIs are the preferred ones. Availability of new Engine features in UnigineScript (beyond its scope of applications) is not guaranteed, as the current level of support assumes only fixing critical issues.

Constant Export Example#

Constants are exported in the similar way as variables:

Create a pointer to an external constant via MakeExternConstant() .
Register the constant via Unigine::Interpreter::addExternVariable() .
All variables are exported into a global namespace. To limit the scope of variable, use library namespace.

Source code (C++)

#include <UnigineEngine.h>
#include <UnigineInterpreter.h>

using namespace Unigine;

int main(int argc,char **argv) {

	int i = 0;
	float f = 0.0f;

	// export a variable and specify a name to access it from Unigine scripts
	Interpreter::addExternVariable("int_constant",MakeExternConstant(i));
	// you can also specify a template parameter to make sure the proper type is passed
	Interpreter::addExternVariable("float_constant",MakeExternConstant<float>(f));
	
	Engine *engine = Engine::init(argc,argv);
	// enter the main loop
	while(engine->isDone() == 0) {
		engine->update();
		engine->render();
		engine->swap();		
		// if a variable value is changed after it was registered, the value in scripts will not be changed
		i = 42;
		f = 57.55f;
	}
	// engine shutdown 
	Engine::shutdown();

}

Access from Scripts#

After the registration, you can access constants from a script by their registered names:

Source code (UnigineScript)

// my_world.usc

log.message("Integer: %d\nFloat: %f\n",int_constant,float_constant);

Output#

The following results will be printed into the console:

Output

Integer: 0
Float: 0.000000

NoticeIf you reload the world, the values of the constants that have been changed on the C++ side will remain the same.

Last update: 2022-10-10

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Constant Export

In This Article:

Constant Export Example#

Access from Scripts#

Output#