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山寨腾讯“爱消除”游戏之屏幕拾取技术

2014-01-07 00:53 393 查看
在山寨腾讯“爱消除”游戏项目中,我们使用了两种简单的屏幕拾取技术,这在第五天的教程及山寨腾讯“爱消除”游戏之菜单特效里已经有介绍。

很显然,对于一些有复杂不规则图案,或有层次感的场面,上面的技术并不能满足要求。今天我们将介绍另外一种屏幕拾取的方法。

如下图所示,这个是《教你玩魔方》游戏里的一个场景。

显然,由于以下的原因,用前面介绍的两种技术将很难完成准确的屏幕拾取。

1、中间的魔方体是可以随意缩放的;

2、魔方的每一个面都是可以转动的;

3、每个面在转动过程中,位置都是随时变化的;

4、转动结束后,面上每一个方块都会发生变化;

5、每个方块都有6个面,有些面是可见的,有些面是不可见的,触摸到不同的面,产生的动作效果应该是不一样的。



好,下面详细地看一下DisplaySingleCube函数,该函数分别将方块的6个面渲染出来。

1、DisplaySingleCube用于显示一个小方块,一个完整的魔方需要调用27次这个函数,最后一个参数cubeIndex指定了方块的索引(0~26)

2、DisplaySingleCube函数中的渲染操作分为DRAW和SELECT_PLATE两种模式,在屏幕拾取时,要将模式设置为SELECT_PLATE

3、DRAW模式下,使用纹理渲染;SELECT_PLATE模式下,使用色彩渲染,每个面分别渲染出不同的颜色,详细看下面代码的注释;根据选定的颜色,就可以知道触摸到的是哪一个面了。

//显示单个方块
    private void DisplaySingleCube(ST_DreamCube dreamcube, float fX, float fY,float fZ,float fRX,float fRY,float fRZ, int cubeIndex)
    {
    	E_WORKMODE eMode = GetGLMode();
        E_COLOR cU, cD, cF, cB, cL, cR;
        cU = dreamcube.cube_status[cubeIndex].Color.U;
        cD = dreamcube.cube_status[cubeIndex].Color.D;
        cF = dreamcube.cube_status[cubeIndex].Color.F;
        cB = dreamcube.cube_status[cubeIndex].Color.B;
        cL = dreamcube.cube_status[cubeIndex].Color.L;
        cR = dreamcube.cube_status[cubeIndex].Color.R;
        
        BindVertexAndTexture(cubeBuff, cubetexBuff);

        mGl.glLoadIdentity();                //可不要

        GLU.gluLookAt(mGl,
                -5.0f, 5.0f, 5.0f,
                0.0f, 0.0f, 0.0f,
                0.0f, 1.0f, 0.0f);

        mGl.glScalef(mCfg.cubeConfig.fZoomFactor, mCfg.cubeConfig.fZoomFactor, mCfg.cubeConfig.fZoomFactor);
        mGl.glTranslatef((float)0.3, (float)0.3-1, (float)-0.3);
        mGl.glFrontFace(GL10.GL_CCW);
        if (mCube.fYDegree != 0)
        {
            mGl.glRotatef(mCube.fYDegree, 0.0f, 1.0f, 0.0f);
        }
        if (fRX != 0 || fRY != 0 || fRZ != 0)
        {
            mGl.glRotatef(fRotate, fRX, fRY, fRZ);
        }

        mGl.glTranslatef(fX, fY, fZ);
       
        // FRONT AND BACK
        
                
        if (eMode == E_WORKMODE.DRAW)
        {
        	mGl.glBindTexture(GL10.GL_TEXTURE_2D, texture[cF.ordinal()]);
        }
        else if (eMode == E_WORKMODE.SELECT_PLATE)
        {
        	mGl.glColor4f(0, 0, 1, 1);     //RGB(0,0,1) 蓝

        }
        mGl.glNormal3f(0.0f, 0.0f, 1.0f);
        mGl.glDrawArrays(GL10.GL_TRIANGLE_STRIP, 0, 4);
        if (eMode == E_WORKMODE.DRAW)
        {
        	mGl.glBindTexture(GL10.GL_TEXTURE_2D, texture[cB.ordinal()]);
        }
        else if (eMode == E_WORKMODE.SELECT_PLATE)
        {
        	mGl.glColor4f(0, 1, 0, 1);    //RGB(0,1,0) 绿

        }
        mGl.glNormal3f(0.0f, 0.0f, -1.0f);
        mGl.glDrawArrays(GL10.GL_TRIANGLE_STRIP, 4, 4);

        // LEFT AND RIGHT

        if (eMode == E_WORKMODE.DRAW)
        {
        	mGl.glBindTexture(GL10.GL_TEXTURE_2D, texture[cL.ordinal()]);
        }       
        else if (eMode == E_WORKMODE.SELECT_PLATE)
        {
        	mGl.glColor4f(0, 1, 1, 1);    //RGB(0,0,1) 蓝+绿

        }

        mGl.glNormal3f(-1.0f, 0.0f, 0.0f);
        mGl.glDrawArrays(GL10.GL_TRIANGLE_STRIP, 8, 4);
        if (eMode == E_WORKMODE.DRAW)
        {
        	mGl.glBindTexture(GL10.GL_TEXTURE_2D, texture[cR.ordinal()]);
        }
        else if (eMode == E_WORKMODE.SELECT_PLATE)
        {
        	mGl.glColor4f(1, 0, 0, 1);     //RGB(0,0,1) 红

        }

        mGl.glNormal3f(1.0f, 0.0f, 0.0f);
        mGl.glDrawArrays(GL10.GL_TRIANGLE_STRIP, 12, 4);

        // TOP AND BOTTOM

        if (eMode == E_WORKMODE.DRAW)
        {
        	mGl.glBindTexture(GL10.GL_TEXTURE_2D, texture[cU.ordinal()]);
        }
        else if (eMode == E_WORKMODE.SELECT_PLATE)
        {
        	mGl.glColor4f(1, 0, 1, 1);     //RGB(0,0,1) 红+蓝

        }

        mGl.glNormal3f(0.0f, 1.0f, 0.0f);
        mGl.glDrawArrays(GL10.GL_TRIANGLE_STRIP, 16, 4);
        if (eMode == E_WORKMODE.DRAW)
        {
        	mGl.glBindTexture(GL10.GL_TEXTURE_2D, texture[cD.ordinal()]);
        }
        else if (eMode == E_WORKMODE.SELECT_PLATE)
        {
        	mGl.glColor4f(1, 1, 0, 1);     //RGB(0,0,1) 红+绿

        }

        mGl.glNormal3f(0.0f, -1.0f, 0.0f);
        mGl.glDrawArrays(GL10.GL_TRIANGLE_STRIP, 20, 4);
    }


接下来介绍选择物体的函数SelectObj,参数是手指触碰到屏幕的坐标值。

1、在进入SelectObj函数之前,需要将模式设置为PICK,这样DisplaySingleCube函数内部的DRAW及SELECT_PLATE将不起作用;

2、在绘制每一个小方块之前,调用glColor4f给这个方块设置颜色,每个方块都会设置成不同的颜色,详细看代码注释;

3、我们用(0,0,1)~(1,1,1)来表示不同的颜色,最多只能7种颜色,那么如何用7种颜色来识别27个方块呢?我们采用分组的方法来做到这一点的,详细见代码;

//对象选择操作
    E_SELECTION SelectObj(int x, int y)
    {
    	E_SELECTION eObj = E_SELECTION.SELE_INVALID;
    	int iObj = 0;
    	InitViewPortMain();    	
        mGl.glClear(GL10.GL_COLOR_BUFFER_BIT | GL10.GL_DEPTH_BUFFER_BIT);
        
        
    	{       
        	mCube.XChgDreamCube4Display(mCube.DREAM_CUBE_CACULATE);
    		mGl.glColor4f(0, 0, 1, 1);   // RGB(0,0,1)  蓝色
    		DisplaySingleCube(mCube.DREAM_CUBE_DISPLAY, -1.0f, 1.0f, 1.0f, 0.0f, 0.0f, 0.0f, 24);
    		mGl.glColor4f(0, 1, 0, 1);   // RGB(0,1,0)  绿色
    		DisplaySingleCube(mCube.DREAM_CUBE_DISPLAY, 0f, 1.0f, 1.0f, 0.0f, 0.0f, 0.0f, 25);
    		mGl.glColor4f(0, 1, 1, 1);   // RGB(0,1,1)  绿色+蓝色
    		DisplaySingleCube(mCube.DREAM_CUBE_DISPLAY, 1.0f, 1.0f, 1.0f, 0.0f, 0.0f, 0.0f, 26);
    		mGl.glColor4f(1, 0, 0, 1);   // RGB(1,0,0)  红色
    		DisplaySingleCube(mCube.DREAM_CUBE_DISPLAY, -1.0f, 0.0f, 1.0f, 0.0f, 0.0f, 0.0f, 15);
    		mGl.glColor4f(1, 0, 1, 1);   // RGB(1,0,1)  红色+蓝色
    		DisplaySingleCube(mCube.DREAM_CUBE_DISPLAY, 0f, 0.0f, 1.0f, 0.0f, 0.0f, 0.0f, 16);
    		mGl.glColor4f(1, 1, 0, 1);   // RGB(1,1,0)  红色+绿色
    		DisplaySingleCube(mCube.DREAM_CUBE_DISPLAY, 1.0f, 0.0f, 1.0f, 0.0f, 0.0f, 0.0f, 17);
    		iObj = GetObj(x, y);     //分组1
    		if(iObj != 0)
    		{
    			switch(iObj)
    			{
    			case 1:
    				eObj = E_SELECTION.SELE_BLK24;
    				break;
    			case 2:
    				eObj = E_SELECTION.SELE_BLK25;
    				break;
    			case 3:
    				eObj = E_SELECTION.SELE_BLK26;
    				break;
    			case 4:
    				eObj = E_SELECTION.SELE_BLK15;
    				break;
    			case 5:
    				eObj = E_SELECTION.SELE_BLK16;
    				break;
    			case 6:
    				eObj = E_SELECTION.SELE_BLK17;
    				break;
//    			default:
//    				eObj = -1;
//    				break;
    			}
    			return eObj;
    		}

    		mGl.glClear(GL10.GL_COLOR_BUFFER_BIT | GL10.GL_DEPTH_BUFFER_BIT);
    		
            mGl.glColor4f(0, 0, 1, 1);
    	    DisplaySingleCube(mCube.DREAM_CUBE_DISPLAY, -1.0f, -1.0f, 1.0f, 0.0f, 0.0f, 0.0f, 6);
    	    mGl.glColor4f(0, 1, 0, 1);
    		DisplaySingleCube(mCube.DREAM_CUBE_DISPLAY, 0f, -1.0f, 1.0f, 0.0f, 0.0f, 0.0f, 7);
    		mGl.glColor4f(0, 1, 1, 1);
    		DisplaySingleCube(mCube.DREAM_CUBE_DISPLAY, 1.0f, -1.0f, 1.0f, 0.0f, 0.0f, 0.0f, 8);
    		mGl.glColor4f(1, 0, 0, 1);
    		DisplaySingleCube(mCube.DREAM_CUBE_DISPLAY, 1.0f, 1.0f, 0.0f, 0.0f, 0.0f, 0.0f, 23);
    		mGl.glColor4f(1, 0, 1, 1);
    		DisplaySingleCube(mCube.DREAM_CUBE_DISPLAY, 1.0f, 0.0f, 0.0f, 0.0f, 0.0f, 0.0f, 14);
    	    mGl.glColor4f(1, 1, 0, 1);
    	    DisplaySingleCube(mCube.DREAM_CUBE_DISPLAY, 1.0f, -1.0f, 0.0f, 0.0f, 0.0f, 0.0f, 5);
    		iObj = GetObj(x, y);             //分组2
    		if(iObj != 0)
    		{
    			switch(iObj)
    			{
    			case 1:
    				eObj = E_SELECTION.SELE_BLK6;
    				break;
    			case 2:
    				eObj = E_SELECTION.SELE_BLK7;
    				break;
    			case 3:
    				eObj = E_SELECTION.SELE_BLK8;
    				break;
    			case 4:
    				eObj = E_SELECTION.SELE_BLK23;
    				break;
    			case 5:
    				eObj = E_SELECTION.SELE_BLK14;
    				break;
    			case 6:
    				eObj = E_SELECTION.SELE_BLK5;
    				break;
//    			default:
//    				eObj = -1;
//    				break;
    			}
    			return eObj;
    		}

    		mGl.glClear(GL10.GL_COLOR_BUFFER_BIT | GL10.GL_DEPTH_BUFFER_BIT);
    		
    		mGl.glColor4f(0, 0, 1, 1);
    	    DisplaySingleCube(mCube.DREAM_CUBE_DISPLAY, 1.0f, -1.0f, -1.0f, 0.0f, 0.0f, 0.0f, 2);
    		mGl.glColor4f(0, 1, 0, 1);
    		DisplaySingleCube(mCube.DREAM_CUBE_DISPLAY, 1.0f, 0.0f, -1.0f, 0.0f, 0.0f, 0.0f, 11);
    		mGl.glColor4f(0, 1, 1, 1);
    		DisplaySingleCube(mCube.DREAM_CUBE_DISPLAY, -1.0f, 1.0f, -1.0f, 0.0f, 0.0f, 0.0f, 18);
    		mGl.glColor4f(1, 0, 0, 1);
    		DisplaySingleCube(mCube.DREAM_CUBE_DISPLAY, 0.0f, 1.0f, -1.0f, 0.0f, 0.0f, 0.0f, 19);
    		mGl.glColor4f(1, 0, 1, 1);
    		DisplaySingleCube(mCube.DREAM_CUBE_DISPLAY, 1.0f, 1.0f, -1.0f, 0.0f, 0.0f, 0.0f, 20);
    		mGl.glColor4f(1, 1, 0, 1);
    		DisplaySingleCube(mCube.DREAM_CUBE_DISPLAY, -1.0f, 1.0f, 0.0f, 0.0f, 0.0f, 0.0f, 21);
    		mGl.glColor4f(1, 1, 1, 1);
    		DisplaySingleCube(mCube.DREAM_CUBE_DISPLAY, 0f, 1.0f, 0.0f, 0.0f, 0.0f, 0.0f, 22);
    		iObj = GetObj(x, y);              //分组3
    		if(iObj != 0)
    		{
    			switch(iObj)
    			{
    			case 1:
    				eObj = E_SELECTION.SELE_BLK2;
    				break;
    			case 2:
    				eObj = E_SELECTION.SELE_BLK11;
    				break;
    			case 3:
    				eObj = E_SELECTION.SELE_BLK18;
    				break;
    			case 4:
    				eObj = E_SELECTION.SELE_BLK19;
    				break;
    			case 5:
    				eObj = E_SELECTION.SELE_BLK20;
    				break;
    			case 6:
    				eObj = E_SELECTION.SELE_BLK21;
    				break;
    			case 7:
    				eObj = E_SELECTION.SELE_BLK22;
    				break;
//    			default:
//    				eObj = -1;
//    				break;
    			}
    			return eObj;
    		}    		
    	}
    	
    	mGl.glClear(GL10.GL_COLOR_BUFFER_BIT | GL10.GL_DEPTH_BUFFER_BIT);
		ShowUnseenPlate(mCube.DREAM_CUBE_CACULATE);        	
		
		iObj = GetObj(x, y);
		if(iObj != 0)
		{
			switch(iObj)
			{
			case 1:
				eObj = E_SELECTION.SELE_LEFT;
				break;
			case 2:
				eObj = E_SELECTION.SELE_RIGHT;
				break;
			case 3:
				eObj = E_SELECTION.SELE_DOWN;
				break;
//			default:
//				eObj = E_Selection.SELE_INVALID;
//				break;
			}
			return eObj;
		}

		mGl.glClear(GL10.GL_COLOR_BUFFER_BIT | GL10.GL_DEPTH_BUFFER_BIT);
        ShowLButton();
        	
		iObj = GetObj(x, y);
		if(iObj != 0)
		{
			switch(iObj)
			{
			case 1:
				eObj = E_SELECTION.SELE_MENU;
				break;
			case 2:
				eObj = E_SELECTION.SELE_HELP;
				break;
			case 3:
				eObj = E_SELECTION.SELE_ZOOMOUT;
				break;
			case 4:
				eObj = E_SELECTION.SELE_DISRUPT;
				break;
			case 5:
				eObj = E_SELECTION.SELE_AUTOPLAY;
				break;
			case 6:
				eObj = E_SELECTION.SELE_RESTART;
				break;
			case 7:
				eObj = E_SELECTION.SELE_STUDY;
				break;
			}
			return eObj;
		}
		
		mGl.glClear(GL10.GL_COLOR_BUFFER_BIT | GL10.GL_DEPTH_BUFFER_BIT);
        ShowRButton();
    	
		iObj = GetObj(x, y);
		if(iObj != 0)
		{
			switch(iObj)
			{
			case 1:
				eObj = E_SELECTION.SELE_ZOOMIN;
				break;
			case 2:
				eObj = E_SELECTION.SELE_SETUP;
				break;
			}
			return eObj;
		}

		mGl.glClear(GL10.GL_COLOR_BUFFER_BIT | GL10.GL_DEPTH_BUFFER_BIT);
		ShowProgressStars();        	
		iObj = GetObj(x, y);
		if(iObj != 0)
		{
			switch(iObj)
			{
			case 1:
				eObj = E_SELECTION.SELE_STAR;
				break;
			}
			return eObj;
		}
		
		mGl.glClear(GL10.GL_COLOR_BUFFER_BIT | GL10.GL_DEPTH_BUFFER_BIT);
		ShowCubeTip();
		iObj = GetObj(x, y);
		if(iObj != 0)
		{
			switch(iObj)
			{
			case 1:
				eObj = E_SELECTION.TIP_0;
				break;
			case 2:
				eObj = E_SELECTION.TIP_1;
				break;
			case 3:
				eObj = E_SELECTION.TIP_2;
				break;
			case 4:
				eObj = E_SELECTION.TIP_3;
				break;
			case 5:
				eObj = E_SELECTION.TIP_4;
				break;
			case 6:
				eObj = E_SELECTION.TIP_5;
				break;
			case 7:
				eObj = E_SELECTION.TIP_6;
				break;
			}
			return eObj;
		}

		mGl.glClear(GL10.GL_COLOR_BUFFER_BIT | GL10.GL_DEPTH_BUFFER_BIT);
    	ShowTime(miCubeClockSec);
		iObj = GetObj(x, y);
		if(iObj != 0)
		{
			switch(iObj)
			{
			case 1:
				eObj = E_SELECTION.SELE_TIMER;
				break;
			}
			return eObj;
		}
		
		mGl.glClear(GL10.GL_COLOR_BUFFER_BIT | GL10.GL_DEPTH_BUFFER_BIT);
    	ShowStep(mCube.GetStepBar());
		iObj = GetObj(x, y);
		if(iObj != 0)
		{
			switch(iObj)
			{
			case 1:
				eObj = E_SELECTION.SELE_STEP;
				break;
			}
			return eObj;
		}

		return eObj;
		
    }


下面介绍获取对象函数GetObj:

1、根据传入的坐标值,获取指定坐标出的色彩信息;

2、将色彩信息转换为1~7范围表示的数据,然后返回该信息;

3、为了保证获取指定像素处的颜色信息准确,我们仅适用简单颜色,而且没有适用ALPHA信息。如果适用较复杂的颜色,有可能会造成识别不准确。缺点是一次能表示的物体数量很少,当有很多物体需要识别时,需要进行分组。

//获取对象
    private int GetObj(int x, int y)
    {
    	mGl.glFinish();
    	mGl.glFinish();

    	Delay(miSelectDelay);
     	ByteBuffer pixel = ByteBuffer.allocate(4);
    	byte data[] = new byte[4];
    	mGl.glReadPixels(x , iScreenHeight - y, 1, 1, GL10.GL_RGBA, GL10.GL_UNSIGNED_BYTE, pixel);
    	data = pixel.array();

		data[0] = (byte) Math.abs(data[0]);
		data[1] = (byte) Math.abs(data[1]);
		data[2] = (byte) Math.abs(data[2]);
		data[0] = (byte) (data[0] << 2);
		data[1] = (byte) (data[1] << 1);
		
		int iObj = data[0] + data[1] + data[2];
		return iObj;
    }


调用GetObj得到颜色信息(1~7),根据该信息,我们可以确定手指触摸到的是哪个方块了:

iObj = GetObj(x, y);
    		if(iObj != 0)
    		{
    			switch(iObj)
    			{
    			case 1:
    				eObj = E_SELECTION.SELE_BLK24;
    				break;
    			case 2:
    				eObj = E_SELECTION.SELE_BLK25;
    				break;
    			case 3:
    				eObj = E_SELECTION.SELE_BLK26;
    				break;
    			case 4:
    				eObj = E_SELECTION.SELE_BLK15;
    				break;
    			case 5:
    				eObj = E_SELECTION.SELE_BLK16;
    				break;
    			case 6:
    				eObj = E_SELECTION.SELE_BLK17;
    				break;
//    			default:
//    				eObj = -1;
//    				break;
    			}
    			return eObj;
    		}


当触摸事件发生时,我们做了以下事情:

1、将模式设置为PICK

2、用不同颜色来渲染魔方体的各个方块,并拾取到手指触摸处的方块对象

3、将模式设置为DRAW模式

4、按正常的纹理渲染模式,将魔方体完整地渲染出来

case TOUCH:
    	        mCubeGL.SetGLMode(E_WORKMODE.PICK);
    	        GetTouchObj();
     	        mCubeGL.SetGLMode(E_WORKMODE.DRAW);
    	        mCubeGL.DisplayCube();				
 				break;


采用这种方法,只有模式为DRAW的图案会最终显示出来,PICK或SELECT_PLATE模式下的图案是不会显示的,因此,你不需要担心PICK模式下会破坏整体的渲染效果。

好了,完整的代码请参考我的另一个开源项目《教你玩魔方》

项目地址在GITHUB,欢迎你FORK.

https://github.com/3125788/CrazyCube3D
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