Data Structure Export

Data Structure Export Example

Data structures are exported in the same way as C++ classes:

Create an external class based on your C++ data structure via MakeExternClass().
Add constructors to the external class.
Add methods to the external class.
Register the external class via Unigine::Interpreter::addExternClass().

Here is how different data structures can be exported from C++ into UnigineScript:

Source code (C++)

#include <string>
#include <map>

#include <Unigine.h>
#include <UnigineInterpreter.h>

/*
*/
using namespace Unigine;

/******************************************************************************\
*
* Data structure
*
\******************************************************************************/

/*
 */
typedef struct mydata{
	std::string name;
	ivec3 vec;
	const char *getName() const { return name.c_str(); }
} mydata;

std::map<std::string, mydata> mymap;

/*
 */
void get_data(const Variable &id) {

	void *interpreter = Interpreter::get();
	ArrayMap map = ArrayMap::get(interpreter,id);
	for(std::map<std::string,mydata>::iterator it = mymap.begin(); it != mymap.end(); ++it) {
		map.append(Variable(it->first.c_str()),Variable(interpreter,TypeInfo(TypeID<mydata*>()),&it->second));
	}
}

/*
 */
struct MyVector {
	
	MyVector() : x(0.0f), y(0.0f), z(0.0f), w(0.0f) {
		
	}
	
	float x;
	float y;
	float z;
	float w;
};

/******************************************************************************\
*
* Main
*
\******************************************************************************/

/*
*/
int main(int argc,char **argv) {
	
	// export a data structure as an extern class
	ExternClass<mydata> *mydata_export = MakeExternClass<mydata>();
	// add a default constructor
	mydata_export->addConstructor();
	// export structure accessor
	mydata_export->addFunction("getName",&mydata::getName);	
	// register the exported class
	Interpreter::addExternClass("mydata",mydata_export);
	// register the external function
	Interpreter::addExternFunction("get_data2",MakeExternFunction(&get_data,"[]"));
	
	// Fill a map
	mydata data;

	data.name = std::string("map_data_0");
	mymap[std::string("key_0")] = data;
	
	data.name = std::string("map_data_1");
	mymap[std::string("key_1")] = data;
	
	// export a data structure as an extern class
	ExternClass<MyVector> *my_vector = MakeExternClass<MyVector>();
	// add the constructor
	my_vector->addConstructor();
	// register structure accessors
	my_vector->addSetFunction("setX",&MyVector::x);
	my_vector->addGetFunction("getX",&MyVector::x);
	my_vector->addSetFunction("setY",&MyVector::y);
	my_vector->addGetFunction("getY",&MyVector::y);
	my_vector->addSetFunction("setZ",&MyVector::z);
	my_vector->addGetFunction("getZ",&MyVector::z);
	my_vector->addSetFunction("setW",&MyVector::w);
	my_vector->addGetFunction("getW",&MyVector::w);
	// register the external class
	Interpreter::addExternClass("MyVector",my_vector);

	// Initialize the engine.
	Engine *engine = Engine::init(UNIGINE_VERSION,0,argc,argv);
	
	// Enter the main loop and call update() function in the loaded world script.
	engine->main();
	
	// Shut down the engine and call shutdown() function in the loaded world script.
	Engine::shutdown();
	
	return 0;
}

Access from Scripts

After the registration, the exported data structure can be used in UnigineScript just like a usual class.

Source code (UnigineScript)

// my_world.cpp

int init() {
	
	// Get data from a map.
	mydata data2[];
	get_data2(data2);
	foreachkey(string key; data2) {
		log.message("%s: %s\n",key,data2[key].getName());
	}
	
	log.message("\n");
	
	// make extern struct
	MyVector vector = new MyVector();
	
	// set members
	vector.setX(1.0f);
	vector.setY(2.0f);
	vector.setZ(4.0f);
	vector.setW(8.0f);
	
	// get members
	log.warning("MyVector: (%g,%g,%g,%g)\n",vector.getX(),vector.getY(),vector.getZ(),vector.getW());
	
	// delete extern struct
	delete vector;
	
	// show console
	engine.console.setActivity(1);
	
	return 1;
}

Output

The following result will be printed into the console:

Output

key_0: map_data_0
key_1: map_data_1

MyVector: (1,2,3,4,8)

Last update: 2017-07-03

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Data Structure Export

In This Article:

See Also

Data Structure Export Example

Access from Scripts

Output