UnigineEditor
Interface Overview
Assets Workflow
Settings and Preferences
Adjusting Node Parameters
Setting Up Materials
Setting Up Properties
Landscape Tool
Using Editor Tools for Specific Tasks
FAQ
Programming
Fundamentals
Setting Up Development Environment
Usage Examples
C++
C#
UUSL (Unified UNIGINE Shader Language)
File Formats
Rebuilding the Engine and Tools
GUI
Double Precision Coordinates
API
Containers
Common Functionality
Controls-Related Classes
Engine-Related Classes
Filesystem Functionality
GUI-Related Classes
Math Functionality
Node-Related Classes
Networking Functionality
Pathfinding-Related Classes
Physics-Related Classes
Plugins-Related Classes
CIGI Client Plugin
Rendering-Related Classes

Interface Class

An interface is used to describe a behaviour, which is followed by all of the classes deriving from the interface. An interface class does not implement any functionality. It means that such a class contains only functions declaration. Interface class functions must be implemented by derived classes.

The interface is used to provide a polymorphism. It means that several classes can implement the same interface functions in different ways.

Interface Class

The interface class is declared as any other class in UnigineScript. In the example, the abstract virtual function declaration is used.

Source code (UnigineScript)
class Interface {
	// functions declaration
	void update() = 0;
	//...;
}
Note that the word Interface is not reserved.

Any class that is inherited from the Interface class must contain an implementation for its functions. For example:

Source code (UnigineScript)
class Bar : Interface {
	// implementation of the interface function for Bar
	void update() {
		log.message("Bar::update(): called\n");
	}
};
class Baz : Interface {
	// implementation of the interface function for Baz
	void update() {
		log.message("Baz::update(): called\n");
	}
};

Example

Let's suppose that there is an interface class, which describes an object:

Source code (UnigineScript)
class Interface {
	void update() = 0;
}
It means that each object must be updated.

Bar and Baz classes decribe two different objects. This classes are inherited from the Interface class, and also the Bar class is derived from the Foo class.

Source code (UnigineScript)
class Foo {
	void foo() = 0;
};
class Bar : Foo, Interface {
	void update() {
		log.message("Bar::update(): called\n");
	}
};
class Baz : Interface {
	void update() {
		log.message("Baz::update(): called\n");
	}
};

The interface is used to iterate objects of different types that implement that interface. So, you can create an array of the objects and update them all.

Source code (UnigineScript)
Interface interfaces[0];
interfaces.append(new Bar());
interfaces.append(new Baz());
foreach(Interface i; interfaces) {
	i.update();
}
The example displays the following:
Output
Bar::update(): called
Baz::update(): called

Abstract virtual function declaration

A virtual function is a function, which can be overridden in a derived class.

Notice
When a user class is inherited from another class, both automatically support virtual methods.

You can declare the virtual function the following way (C++ style):

Source code (UnigineScript)
class Foo {
	void foo() = 0;
};
In this case, the function has no any implementation, but the derived class must implement it.
Notice
Also you can declare the virtual function by using the virtual keyword, but it's optional.
Last update: 2018-04-26