播放背景音乐

The game must output some audio besides the bullet hit sound effect. To play the background music we will use the component system once again.游戏必须输出一些音频除了子弹击中音效。播放背景音乐,我们将再次使用的组件系统。

Let's create the node with a Music Player component that plays the looped music from the game start.让我们创建的节点Music Player组件从游戏开始,毛圈的音乐。

1. Create a new C# component and call it MusicPlayer. Open your IDE and copy the code below. Save your code in the IDE to ensure it's automatic compilation on switching back to UnigineEditor.创建一个新的c#组件和MusicPlayer调用它。打开你的IDE和复制下面的代码。保存在IDE中代码以确保它的自动切换回UnigineEditor编译。

   源代码 (C#)

   using System;
   using System.Collections;
   using System.Collections.Generic;
   using Unigine;
   
   #if UNIGINE_DOUBLE
   using Vec3 = Unigine.dvec3;
   using Mat4 = Unigine.dmat4;
   using Scalar = System.Double;
   #else
   	using Vec3 = Unigine.vec3;
   	using Mat4 = Unigine.mat4;
   	using Scalar = System.Single;
   #endif 
   [Component(PropertyGuid = "AUTOGENERATED_GUID")] // <-- this line is generated automatically for a new component
   public class PlayerController : Component
   {
   //========================== NEW - BEGIN ===============================
   	bool isNextLeft = false;
   
   	// mouse fire button 
   	public Input.MOUSE_BUTTON mouseFireKey = Input.MOUSE_BUTTON.RIGHT;
   
   	// asset file that contains the bullet
   	public AssetLinkNode bullet;
   
   	public Node leftSpawn, rightSpawn;
   //========================== NEW - END ===============================
   	Player player;
   
   	BodyRigid rigid;
   
   	Vec3 pos;
   
   	//a WorldIntersection object to store the information about the intersection
   	WorldIntersection intersection = new WorldIntersection();
   
   	void Init()
   	{
   		player = Game.Player; 
   
   		rigid = node.ObjectBodyRigid;
   		rigid.AngularScale = new vec3(0.0f, 0.0f, 0.0f); // restricting the rotation
   		rigid.LinearScale = new vec3(1.0f, 1.0f, 0.0f); // restricting Z movement
   		rigid.MaxLinearVelocity = 8.0f; // clamping the max linear velocity
   	}
   //========================== NEW - BEGIN ===============================
   	void Update() 
   	{
   		if (Input.IsMouseButtonDown(mouseFireKey) && bullet.IsFileExist)
   		{
   			// load the bullet and set its position 
   			if (isNextLeft)
   				bullet.Load(rightSpawn.WorldTransform);
   			else
   				bullet.Load(leftSpawn.WorldTransform);
   
   			// alternate between the left and the right gun
   			isNextLeft = !isNextLeft;
   		}
   
   		// press ESC button to close the game
   		if (Input.IsKeyDown(Input.KEY.ESC))
   		{
   			Engine.Quit();
   		}
   	}
   //========================== NEW - END ===============================
   	void UpdatePhysics() 
   	{
   		// forward
   		if (Input.IsKeyPressed(Input.KEY.W))
   			Move(player.GetWorldDirection(MathLib.AXIS.Y)); 
   
   		// backward
   		if (Input.IsKeyPressed(Input.KEY.S))
   			Move(player.GetWorldDirection(MathLib.AXIS.NY)); 
   		// left
   		if (Input.IsKeyPressed(Input.KEY.A))
   			Move(player.GetWorldDirection(MathLib.AXIS.NX)); 
   
   		// right
   		if (Input.IsKeyPressed(Input.KEY.D))
   			Move(player.GetWorldDirection(MathLib.AXIS.X)); 
   
   		// finding the positions of the cursor and the point moved 100 units away in the camera forward direction 
   		ivec2 mouse = Input.MousePosition;
   		Vec3 p0 = player.WorldPosition;
   		Vec3 p1 = p0 + new Vec3(player.GetDirectionFromMainWindow(mouse.x, mouse.y)) * 100; 
   
   		// casting a ray from p0 to p1 to find the first intersected object
   		Unigine.Object obj = World.GetIntersection(p0, p1, 1, intersection); // the first bit of the intersection mask is set to 1, the rest are 0s
   
   		// finding the intersection position, creating a transformation matrix to face this position and setting the transofrm matrix for the body preserving angular and linear velocities
   		if (obj)
   		{
   			pos = intersection.Point;
   			pos.z = rigid.Transform.Translate.z; // project the position vector to the Body Rigid pivot plane
   			Mat4 transform = MathLib.SetTo(rigid.Transform.Translate, pos, vec3.UP, MathLib.AXIS.Y);
   			rigid.SetPreserveTransform(transform);
   		}
   	}
   
   	// moving the rigid body with linear impulse in the specified direction
   	void Move(vec3 direction) 
   	{
   		//directon is a normalized camera axis vector 
   		rigid.AddLinearImpulse(direction);
   	}
   }

2. Create a new Dummy Node, rename it to "music_player", and place it somewhere in the world.创建一个新的Dummy Node,重命名它为"music_player",它在世界上的地位。
3. Add the MusicPlayer component to the music_player node.MusicPlayer组件添加到music_player节点。

4. Assign the imported music asset (programming_quick_start/music/ost.mp3) to the Background Music field of the MusicPlayer component.指定导入的音乐资源(programming_quick_start/music/ost.mp3)的Background Music字段MusicPlayer组件。

   

5. Save changes to the world, go to File->Save World or press Ctrl+S hotkey.拯救世界的变化,去File->Save World或者按Ctrl+S热键。

6. Run the project in the UnigineEditor to check out the background music.运行项目UnigineEditor检查背景音乐。