nokia3d.java

怎样做一个手机游戏上面有很多经验之谈

		VertexBuffer vb = tnl.getVertexBuffer();

		// Get vertex count
		int count = vb.getVertexCount();

		// We must check to see if this implementation supports 2 texture units, before we go any further.
		numTextureUnits = ((Integer) g3d.getProperties().get("numTextureUnits")).intValue();

		if(numTextureUnits > 1)
		{
			// Create a new array for texture coordinates (for texture #2, as the object has only one texture layer defined in swerve)
			tunnelTexCoords = new short[count * 2];
	
			// Init the array with some random values
			for (int a = 0 ; a < count*2; a++)
			{
				int i = (m_random.nextInt() & 0xFF);
				tunnelTexCoords[a] = (short) i;
			}
	
			// Create a new vertex array..
			tunnelTextureArray = new VertexArray(count, 2, 2);
	
			// Copy texture coordinate values to array
			tunnelTextureArray.set(0, count, tunnelTexCoords);
	
			// Assign texture coordinates to second texture unit.
			vb.setTexCoords(1, tunnelTextureArray, 0.0004f, null);

			// Load texture image ...
			tunnelTextureImage2 = new Image2D(Image2D.RGB, loadImage("/ttex2.png"));

			// Create texmap
			tunnelTexture2 = new Texture2D(tunnelTextureImage2);

			// Choose blending mode for the texture layer, additive by default
			tunnelTexture2.setBlending(Texture2D.FUNC_ADD);
		}

		// Backup first texture reference...
		tunnelTexture1 = ap.getTexture(0);

		// Update the textures...
		switchTunnelMode(1);

		// Create linear fog for the tunnel
		tunnelFog = new Fog();
        tunnelFog.setMode(Fog.LINEAR);
        tunnelFog.setColor(0x006080a0);
		tunnelFog.setLinear(10.0f, 25.0f);

	}

	//
	private void updateTunnelScene(int time, int delta)
	{
		//
		World scn = m_scenes[SCENE_TUNNEL];

		// Find the omni light
		Light l = (Light) scn.find(UID_TUNNEL_LIGHT);

		// Set the light's intensity
		l.setIntensity(m_lightIntensity);

		/** Fade out mode */
		if (m_tunnelFadeOut)
		{
			if (DEBUG)
				System.out.println(delta);

			// Drop intensity
			m_lightIntensity-=(delta * 0.001f);

			// Fade below zero.. Looks like we have ambient light somewhere?
			if (m_lightIntensity <= -2.0f)
			{
				//
				freeOldScene();
	
				//
				m_scenes[SCENE_POND] = loadScene("/pond_vilkutus2.m3g");
				preInitPondScene();
	
				//
				m_currentScene = SCENE_POND;
				m_currentTime = 0;
			}
		}
	}

	// Nulls references to objects which we found when initializing the tunnel.
	// This makes them available for garbage collection.

	private void removeTunnelScene()
	{
		tunnelTextureImage2 = null;
		tunnelFog = null;

	    tunnelTexture1 = null;
	    tunnelTexture2 = null;

		tunnelTextureArray = null;
		tunnelTexCoords = null;
	}

	// Switches between different texture depths
	private void switchTunnelMode(int tnlMode)
	{
		// Select the world...
		World w = m_scenes[SCENE_TUNNEL];

		// Find the tunnel mesh
		Mesh tnl = (Mesh) w.find(UID_TUNNEL_MESH);

		// Get the appearance from the mesh
		Appearance ap = tnl.getAppearance(0);

		// remove textures?
		if (tnlMode == NO_TEXTURE)
		{
			ap.setTexture(0, null);

			// We must always check before using texture unit 1.
            if(numTextureUnits>1)
				ap.setTexture(1, null);
		}
		else
		if (tnlMode == ONE_TEXTURE)
		{
			ap.setTexture(0, tunnelTexture1);

			// We must always check before using texture unit 1.
	        if(numTextureUnits>1)
				ap.setTexture(1, null);
		}
		else
		if (tnlMode == DUAL_TEXTURE)
		{
			ap.setTexture(0, tunnelTexture1);

			// We must always check before using texture unit 1.
			// Note that on an implementation with only 1 texture unit,
			// this is the same as ONE_TEXTURE mode.
	        if(numTextureUnits>1)
				ap.setTexture(1, tunnelTexture2);
		}
		else
		// Switch fog on/off
		if (tnlMode == TOGGLE_FOG)
		{
			if (!m_fogOn)
			{
				ap.setFog(tunnelFog);
				m_fogOn = true;
			}
			else
			{
				ap.setFog(null);
				m_fogOn = false;
			}
		}
	}

	// Picks some cameras etc
	private void preInitPondScene()
	{
		//
		World pond = m_scenes[SCENE_POND];

		// Default to first camera
		Camera c = (Camera) pond.find(UID_POND_CAMERA1);
		c.setPerspective(m_cameraFOVs[0], 1.0f, 0.1f,5);

		//
		m_currentCamera = 0;
		pond.setActiveCamera(c);

		// Target camera to the ant. Note that the y target axis is scene's z-axis because
		// the scene is exported from 3dsmax, in which z points up on world space

		// For this reason, it is more convenient to align the group in which the camera
		// is enclosed, rather than the camera itself. We rotate the camera 180 degrees
		// (using a scale) because alignment aligns the positive Z axis, and the camera
		// looks along the negative Z axis. If we do not do this, then the camera will
		// alway look *away* from the target, instead of towards it.

		Node n = (Node) pond.find(UID_POND_ANTHEAD);
		c.getParent().setAlignment(n, n.ORIGIN, pond, pond.Z_AXIS);
		c.scale(-1, 1, -1);

		// Set field-of-view and clip params by hand
		c = (Camera) pond.find(UID_POND_CAMERA2);
		c.setPerspective(m_cameraFOVs[1], 1.0f, 0.1f,5);

		c.getParent().setAlignment(n, Node.ORIGIN, pond, Node.Z_AXIS);
		c.scale(-1, 1, -1);

		c = (Camera) pond.find(UID_POND_CAMERA3);
		c.setPerspective(m_cameraFOVs[2], 1.0f, 0.1f,5);

		c.getParent().setAlignment(n, Node.ORIGIN, pond, Node.Z_AXIS);
		c.scale(-1, 1, -1);

		c = (Camera) pond.find(UID_POND_CAMERA4);
		c.setPerspective(m_cameraFOVs[3], 1.0f, 0.1f,5);

		c.getParent().setAlignment(n, Node.ORIGIN, pond, Node.Z_AXIS);
		c.scale(-1, 1, -1);
	}

	// Loads an image
	private Image loadImage(String name)
	{
		try
		{
			return Image.createImage(name);
		}
		catch (Exception e)
		{
			e.printStackTrace();
			return null;
		}
	}

	// Inits some snowflakes for the Nokia scene
	private void initSnowFlakes()
	{
		// First we init a vertex array with 3 components (X,Y,Z), size of each component is byte
		flakeVertexArray = new VertexArray(flakeVertices.length / 3, 3, 2);

		// Now, we copy the actual XYZ coordinates to the array
		flakeVertexArray.set(0, flakeVertices.length / 3, flakeVertices);

		// Init a texture coordinate array with same size as the coordinate array, but only two coords for each vertex (u,v)
		flakeTextureArray = new VertexArray(flakeTexCoords.length / 2, 2, 2);

		// Copy actual values again
		flakeTextureArray.set(0, flakeTexCoords.length / 2, flakeTexCoords);

		// Next we need to create a vertex buffer, to which we'll assign the texture coordinates and XYZ coordinates
		flakeVertexBuffer = new VertexBuffer();

		// No scale, no bias in XYZ coordinates
		flakeVertexBuffer.setPositions(flakeVertexArray, 0.01f, null);

		// Assign texture coordinates to first texture unit. Again, no scale & no bias is needed
		flakeVertexBuffer.setTexCoords(0, flakeTextureArray, 0.1f, null);

		// Next we need to create a triangle strip array which holds the polygon definitions for the flakes
		flakeTriangles = new TriangleStripArray(flakeStrip, flakeStripLengths);

		/** 
		*
		* We could also create the triangle strip implicitly, by defining the first vertex index as zero..
		* This saves some space when simple, continuous triangle strips are created.
		*
		* flakeTriangles = new TriangleStripArray(0, flakeStripLengths);
		*
		*/



		// First we need to create new appearance
		flakeAppearance = new Appearance();

		// Then we load a texture image ... We need to use alpha due to transparent pixels
		flakeTextureImage = new Image2D(Image2D.RGBA, loadImage("/snowflake.png"));

		// Then we create a texture map from the image
		flakeTexture = new Texture2D(flakeTextureImage);

		// Choose worst possible filtering type to gain more speed (actually it's already selected by default)
		flakeTexture.setFiltering(Texture2D.FILTER_BASE_LEVEL, Texture2D.FILTER_NEAREST);

		// Just replace the texel directly with the source for more speed
		flakeTexture.setBlending(Texture2D.FUNC_REPLACE);




		// Next, create a polygon mode definition
		flakePolyMode = new PolygonMode();

		// No, we don't need perspective correction for such small polygons
		flakePolyMode.setPerspectiveCorrectionEnable(false);

		// Shading should apply to whole polygon
		flakePolyMode.setShading(PolygonMode.SHADE_FLAT);

		// Disable visible side culling (both sides of flakes are seen)
		flakePolyMode.setCulling(PolygonMode.CULL_NONE);

		// Define winding as clockwise (actually it doesn't matter here since no culling is used...)
		flakePolyMode.setWinding(PolygonMode.WINDING_CW);

		// No, we don't want the flakes to be lit by camera light
		flakePolyMode.setLocalCameraLightingEnable(false);

		// Sincle no culling is used, we need to light both sides of the polygon
		flakePolyMode.setTwoSidedLightingEnable(true);




		// Let's define how the polygon is blended with the background
		flakeCompositing = new CompositingMode();

		// We want to use the alpha to blend the pixels to background
		flakeCompositing.setBlending(CompositingMode.ALPHA);

		// Don't write anything to alpha buffer
		flakeCompositing.setAlphaWriteEnable(false);




		// Set the texture map to the appearance's first texture unit
		flakeAppearance.setTexture(0, flakeTexture);

		// Assign the polygon mode to the appearance
		flakeAppearance.setPolygonMode(flakePolyMode);

		// Assign the compositing mode to the appearance
		flakeAppearance.setCompositingMode(flakeCompositing);



		// Get the world..
		World nokia = m_scenes[SCENE_NOKIA];

		// Finally, let's do some meshes from these definitions and add them to the scene
		m_snowFlakes = new Mesh[NUM_SNOWFLAKES];

		//
		for (int a = 0; a < NUM_SNOWFLAKES; a++)
		{
			m_snowFlakes[a] = new Mesh(flakeVertexBuffer, flakeTriangles, flakeAppearance);
			m_snowFlakes[a].translate(
				rnd(-SNOWFLAKE_SCALE, SNOWFLAKE_SCALE),
				rnd(-SNOWFLAKE_SCALE, SNOWFLAKE_SCALE),
				rnd(GROUND_LEVEL, GROUND_LEVEL + (SNOWFLAKE_SCALE/2.0f))
			);
			nokia.addChild(m_snowFlakes[a]);
		}
	}
	
	// Removes references to snowflake objects. These will then be garbage collected.
	private void removeSnowFlakes()
	{
		flakeAppearance = null;
		flakeMaterial = null;
		flakePolyMode = null;
		flakeCompositing = null;
		flakeTextureImage = null;
		flakeTexture = null;

		flakeVertexArray = null;
		flakeTextureArray = null;
		flakeVertexBuffer = null;
		flakeTriangles = null;

		m_snowFlakes = null;
	}

	//
	private float rnd(float min, float max)
	{
		float p = (float) (m_random.nextInt() & 0xFFF) / 4095.0f;
		float q = 1.0f - p;
		return p * max + q * min;
	}

	// Animates the snowflakes...
	private void animateSnowFlakes(int time)
	{
		float[] xyz = new float[3];
		for (int a = 0; a < NUM_SNOWFLAKES; a++)
		{
			// push the new position to the flake. Note that the scene is exported from 3dsmax, thus z points up.
			m_snowFlakes[a].translate(0,0, -0.1f);

			// get current snowflake position
			m_snowFlakes[a].getTranslation(xyz);

			// move the flakes a bit
			if (xyz[2] < GROUND_LEVEL)
			{
				// push the new position to the flake
				m_snowFlakes[a].translate(0,0, SNOWFLAKE_SCALE/2.0f);
			}
		}
	}


	// Definitions for a snowflake
    private Appearance			flakeAppearance;
	private Material			flakeMaterial;
	private PolygonMode			flakePolyMode;
	private CompositingMode		flakeCompositing;
    private Image2D				flakeTextureImage;
    private Texture2D			flakeTexture;

	// Arrays & buffers for snowflake
	private VertexArray			flakeVertexArray;
	private VertexArray			flakeTextureArray;
    private VertexBuffer		flakeVertexBuffer;
    private TriangleStripArray  flakeTriangles;

	// Meshes
	private Mesh[]				m_snowFlakes;

	// Vertex coordinates for a snowflake (a simple flat quad actually)
    private static final short flakeVertices[] =
	{
        (short) -10, (short) 0, (short)  10,
        (short) -10, (short) 0, (short) -10,
        (short)  10, (short) 0, (short)  10,
        (short)  10, (short) 0, (short) -10
    };

	// Texture coordinates for the snowflake
    private static final short flakeTexCoords[] =
	{
        (short) 0,  (short) 10,
        (short) 0, (short) 0,
        (short) 10, (short) 10,
        (short) 10,  (short) 0,
    };

	// Strip lengths for a simple snowflake
    private static final int flakeStripLengths[] = { 4 };

	// Triangle strip for the snowflake
    private static final int flakeStrip[] =
	{
        0, 1, 2, 3
    };

	// State for tunnel scene
	private int					numTextureUnits;
    private Image2D				tunnelTextureImage2;

	//
	private	Fog					tunnelFog;

	//
    private Texture2D			tunnelTexture1;
    private Texture2D			tunnelTexture2;

	// Arrays & buffers for the tunnel
	private VertexArray			tunnelTextureArray;

	// Texture coordinates for the tunnel
	private short[] tunnelTexCoords;
}