Playing Sounds on Collisions

#include <core/unigine.h>

SoundSource sounds[0];

void contact_callback(Body body,int num)
{
	
	if (num >= body.getNumContacts())
		        return;

	// get coordinates of the contact point
	Vec3 position = body.getContactPoint(num);
	// get the relative impulse in the contact point
	float impulse = body.getContactImpulse(num);
	// calculate volume of the sound played for the contact
	float volume = impulse * 0.5f - 1.0f;

	// a flag indicating that no sounds have played yet
	int need_sound = 1;
	for (int i = 0; i < sounds.size(); i++)
	{
		if (sounds[i].isPlaying() == 0)
		{
			need_sound = 0;

			// reuse the existing sound source
			sounds[i].setEnabled(1);
			sounds[i].setGain(saturate(volume));
			sounds[i].setWorldTransform(translate(position));
			engine.sound.renderWorld(1);
			sounds[i].play();
			break;
		}
	}
	if (need_sound)
	{
		// create a new sound source
		SoundSource s = new SoundSource("static_impact_00.wav");
		// specify necessary settings for the sound source
		s.setOcclusion(0);
		s.setMinDistance(10.0f);
		s.setMaxDistance(100.0f);
		s.setGain(saturate(volume));
		s.setWorldTransform(translate(position));
		// play the sound source
		s.play();

		// append the sound to the vector of the playing sounds
		sounds.append(s);
	}
}

// method creating a box mesh with a physical body
void create_box(Vec3 position)
{
	
	Mesh mesh = new Mesh();
	mesh.addBoxSurface("box_0",vec3(0.5f));	
	ObjectMeshStatic object = node_remove(new ObjectMeshStatic(mesh));
	engine.editor.addNode(object);
	object.setWorldTransform(translate(position));
	object.setMaterial("mesh_base","*");
	
	BodyRigid body = class_remove(new BodyRigid(object));
	class_remove(new ShapeBox(body,vec3(0.5f)));
	// set a callback function that is run when a contact with the box occurs
	body.setContactCallback(functionid(contact_callback));
}

int init() {

	Player player = new PlayerSpectator();
	player.setPosition(Vec3(0.0f,-3.401f,1.5f));
	player.setDirection(Vec3(0.0f,1.0f,-0.4f));
	engine.game.setPlayer(player);
	
	// create box meshes
	for(int i = -5; i <= 5; i++) 
	{
		create_box(Vec3(0.0f,i * 2.0f,8.0f + i * 1.0f));
	}
	// create another box mesh
	create_box(Vec3(0.0f,0.0f,50.0f));
	
	return 1;
}

int update() {

	foreach(SoundSource s; sounds)
	{
		if(!s.isPlaying()) s.setEnabled(0);
	}
	
	return 1;
}

int render() {

	return 1;
}

int flush() {

	return 1;
}

int shutdown() {

	return 1;
}