Android之多重纹理

谁践踏了优雅 2022-08-08 13:50 109阅读 0赞

效果：

![20150520175441071][]

顶点着色器（地球）：

//地球着色器
    uniform mat4 uMVPMatrix; //总变换矩阵
    uniform mat4 uMMatrix; //变换矩阵
    uniform vec3 uCamera;	//摄像机位置
    uniform vec3 uLightLocationSun;	//太阳光源位置
    attribute vec3 aPosition;  //顶点位置
    attribute vec2 aTexCoor;    //顶点纹理坐标
    attribute vec3 aNormal;    //法向量
    varying vec2 vTextureCoord;  //用于传递给片元着色器的变量
    varying vec4 vAmbient;
    varying vec4 vDiffuse;
    varying vec4 vSpecular;
    
    //定位光光照计算的方法
    void pointLight(					//定位光光照计算的方法
      in vec3 normal,				//法向量
      inout vec4 ambient,			//环境光最终强度
      inout vec4 diffuse,				//散射光最终强度
      inout vec4 specular,			//镜面光最终强度
      in vec3 lightLocation,			//光源位置
      in vec4 lightAmbient,			//环境光强度
      in vec4 lightDiffuse,			//散射光强度
      in vec4 lightSpecular			//镜面光强度
    ){
      ambient=lightAmbient;			//直接得出环境光的最终强度  
      vec3 normalTarget=aPosition+normal;	//计算变换后的法向量
      vec3 newNormal=(uMMatrix*vec4(normalTarget,1)).xyz-(uMMatrix*vec4(aPosition,1)).xyz;
      newNormal=normalize(newNormal); 	//对法向量规格化
      //计算从表面点到摄像机的向量
      vec3 eye= normalize(uCamera-(uMMatrix*vec4(aPosition,1)).xyz);  
      //计算从表面点到光源位置的向量vp
      vec3 vp= normalize(lightLocation-(uMMatrix*vec4(aPosition,1)).xyz);  
      vp=normalize(vp);//格式化vp
      vec3 halfVector=normalize(vp+eye);	//求视线与光线的半向量    
      float shininess=50.0;				//粗糙度，越小越光滑
      float nDotViewPosition=max(0.0,dot(newNormal,vp)); 	//求法向量与vp的点积与0的最大值
      diffuse=lightDiffuse*nDotViewPosition;				//计算散射光的最终强度
      float nDotViewHalfVector=dot(newNormal,halfVector);	//法线与半向量的点积 
      float powerFactor=max(0.0,pow(nDotViewHalfVector,shininess)); 	//镜面反射光强度因子
      specular=lightSpecular*powerFactor;    			//计算镜面光的最终强度
    }
    
    void main()     
    {                            		
       gl_Position = uMVPMatrix * vec4(aPosition,1); //根据总变换矩阵计算此次绘制此顶点位置  
       
       vec4 ambientTemp=vec4(0.0,0.0,0.0,0.0);
       vec4 diffuseTemp=vec4(0.0,0.0,0.0,0.0);
       vec4 specularTemp=vec4(0.0,0.0,0.0,0.0);   
       
       pointLight(normalize(aNormal),ambientTemp,diffuseTemp,specularTemp,uLightLocationSun,vec4(0.05,0.05,0.05,1.0),vec4(1.0,1.0,1.0,1.0),vec4(0.3,0.3,0.3,1.0));
       
       vAmbient=ambientTemp;
       vDiffuse=diffuseTemp;
       vSpecular=specularTemp;
       
       //将顶点的纹理坐标传给片元着色器
       vTextureCoord=aTexCoor;
    }

片元着色器（地球）：

//地球着色器
    precision mediump float;
    varying vec2 vTextureCoord;//接收从顶点着色器过来的参数
    varying vec4 vAmbient;
    varying vec4 vDiffuse;
    varying vec4 vSpecular;
    uniform sampler2D sTextureDay;//纹理内容数据
    uniform sampler2D sTextureNight;//纹理内容数据
    void main()                         
    {  
      //给此片元从纹理中采样出颜色值   
      vec4 finalColorDay;   
      vec4 finalColorNight;   
      
      finalColorDay= texture2D(sTextureDay, vTextureCoord);
      finalColorDay = finalColorDay*vAmbient+finalColorDay*vSpecular+finalColorDay*vDiffuse;
      finalColorNight = texture2D(sTextureNight, vTextureCoord); 
      finalColorNight = finalColorNight*vec4(0.5,0.5,0.5,1.0);
      
      if(vDiffuse.x>0.21)
      {
        gl_FragColor=finalColorDay;    
      } 
      else if(vDiffuse.x<0.05)
      {     
         gl_FragColor=finalColorNight;
      }
      else
      {
         float t=(vDiffuse.x-0.05)/0.16;
         gl_FragColor=t*finalColorDay+(1.0-t)*finalColorNight;
      }  
    }

java代码：

类Earth:

package com.bn.Sample7_4;
    import static com.bn.Sample7_4.ShaderUtil.createProgram;
    
    import java.nio.ByteBuffer;
    import java.nio.ByteOrder;
    import java.nio.FloatBuffer;
    import java.util.ArrayList;
    import android.opengl.GLES20;
    //表示地球的类，采用多重纹理
    public class Earth  {	
    	int mProgram;//自定义渲染管线程序id 
        int muMVPMatrixHandle;//总变换矩阵引用id   
        int muMMatrixHandle;//位置、旋转变换矩阵
        int maCameraHandle; //摄像机位置属性引用id  
        int maPositionHandle; //顶点位置属性引用id  
        int maNormalHandle; //顶点法向量属性引用id  
        int maTexCoorHandle; //顶点纹理坐标属性引用id  
        int maSunLightLocationHandle;//光源位置属性引用id      
        int uDayTexHandle;//白天纹理属性引用id  
        int uNightTexHandle;//黑夜纹理属性引用id  
        String mVertexShader;//顶点着色器    	 
        String mFragmentShader;//片元着色器
    	FloatBuffer   mVertexBuffer;//顶点坐标数据缓冲
    	FloatBuffer   mTexCoorBuffer;//顶点纹理坐标数据缓冲
        int vCount=0; 
        public Earth(MySurfaceView mv,float r){    	
        	//初始化顶点坐标与着色数据
        	initVertexData(r);
        	//初始化着色器        
        	initShader(mv);
        } 
        //初始化顶点坐标与纹理数据的方法
        public void initVertexData(float r){
        	//顶点坐标数据的初始化================begin============================    	
        	final float UNIT_SIZE=0.5f;
        	ArrayList<Float> alVertix=new ArrayList<Float>();//存放顶点坐标的ArrayList
        	final float angleSpan=10f;//将球进行单位切分的角度
        	for(float vAngle=90;vAngle>-90;vAngle=vAngle-angleSpan){//垂直方向angleSpan度一份
            	for(float hAngle=360;hAngle>0;hAngle=hAngle-angleSpan){//水平方向angleSpan度一份
            		//纵向横向各到一个角度后计算对应的此点在球面上的坐标
            		double xozLength=r*UNIT_SIZE*Math.cos(Math.toRadians(vAngle));
            		float x1=(float)(xozLength*Math.cos(Math.toRadians(hAngle)));
            		float z1=(float)(xozLength*Math.sin(Math.toRadians(hAngle)));
            		float y1=(float)(r*UNIT_SIZE*Math.sin(Math.toRadians(vAngle)));
            		xozLength=r*UNIT_SIZE*Math.cos(Math.toRadians(vAngle-angleSpan));
            		float x2=(float)(xozLength*Math.cos(Math.toRadians(hAngle)));
            		float z2=(float)(xozLength*Math.sin(Math.toRadians(hAngle)));
            		float y2=(float)(r*UNIT_SIZE*Math.sin(Math.toRadians(vAngle-angleSpan)));
            		xozLength=r*UNIT_SIZE*Math.cos(Math.toRadians(vAngle-angleSpan));
            		float x3=(float)(xozLength*Math.cos(Math.toRadians(hAngle-angleSpan)));
            		float z3=(float)(xozLength*Math.sin(Math.toRadians(hAngle-angleSpan)));
            		float y3=(float)(r*UNIT_SIZE*Math.sin(Math.toRadians(vAngle-angleSpan)));
            		xozLength=r*UNIT_SIZE*Math.cos(Math.toRadians(vAngle));
            		float x4=(float)(xozLength*Math.cos(Math.toRadians(hAngle-angleSpan)));
            		float z4=(float)(xozLength*Math.sin(Math.toRadians(hAngle-angleSpan)));
            		float y4=(float)(r*UNIT_SIZE*Math.sin(Math.toRadians(vAngle)));   
            		//构建第一三角形
            		alVertix.add(x1);alVertix.add(y1);alVertix.add(z1);
            		alVertix.add(x2);alVertix.add(y2);alVertix.add(z2);
            		alVertix.add(x4);alVertix.add(y4);alVertix.add(z4);        		
            		//构建第二三角形
            		alVertix.add(x4);alVertix.add(y4);alVertix.add(z4);
            		alVertix.add(x2);alVertix.add(y2);alVertix.add(z2);
            		alVertix.add(x3);alVertix.add(y3);alVertix.add(z3); 
            }} 	
            vCount=alVertix.size()/3;//顶点的数量为坐标值数量的1/3，因为一个顶点有3个坐标
            //将alVertix中的坐标值转存到一个float数组中
            float vertices[]=new float[vCount*3];
        	for(int i=0;i<alVertix.size();i++){
        		vertices[i]=alVertix.get(i);
        	}
            //创建顶点坐标数据缓冲
            ByteBuffer vbb = ByteBuffer.allocateDirect(vertices.length*4);
            vbb.order(ByteOrder.nativeOrder());//设置字节顺序
            mVertexBuffer = vbb.asFloatBuffer();//转换为int型缓冲
            mVertexBuffer.put(vertices);//向缓冲区中放入顶点坐标数据
            mVertexBuffer.position(0);//设置缓冲区起始位置
            //将alTexCoor中的纹理坐标值转存到一个float数组中
            float[] texCoor=generateTexCoor(//获取切分整图的纹理数组    
       			 (int)(360/angleSpan), //纹理图切分的列数
       			 (int)(180/angleSpan)  //纹理图切分的行数
            );
            ByteBuffer llbb = ByteBuffer.allocateDirect(texCoor.length*4);
            llbb.order(ByteOrder.nativeOrder());//设置字节顺序
            mTexCoorBuffer=llbb.asFloatBuffer();
            mTexCoorBuffer.put(texCoor);
            mTexCoorBuffer.position(0);    
        }
        public void initShader(MySurfaceView mv){ //初始化着色器
        	//加载顶点着色器的脚本内容       
            mVertexShader=ShaderUtil.loadFromAssetsFile("vertex_earth.sh", mv.getResources());
            ShaderUtil.checkGlError("==ss==");   
            //加载片元着色器的脚本内容
            mFragmentShader=ShaderUtil.loadFromAssetsFile("frag_earth.sh", mv.getResources());  
            //基于顶点着色器与片元着色器创建程序
            ShaderUtil.checkGlError("==ss==");      
            mProgram = createProgram(mVertexShader, mFragmentShader);
            //获取程序中顶点位置属性引用id  
            maPositionHandle = GLES20.glGetAttribLocation(mProgram, "aPosition");
            //获取程序中顶点纹理属性引用id   
            maTexCoorHandle=GLES20.glGetAttribLocation(mProgram, "aTexCoor");  
            //获取程序中顶点法向量属性引用id  
            maNormalHandle= GLES20.glGetAttribLocation(mProgram, "aNormal");
            //获取程序中总变换矩阵引用id
            muMVPMatrixHandle = GLES20.glGetUniformLocation(mProgram, "uMVPMatrix");   
            //获取程序中摄像机位置引用id
            maCameraHandle=GLES20.glGetUniformLocation(mProgram, "uCamera"); 
            //获取程序中光源位置引用id
            maSunLightLocationHandle=GLES20.glGetUniformLocation(mProgram, "uLightLocationSun");   
            //获取白天、黑夜两个纹理引用
            uDayTexHandle=GLES20.glGetUniformLocation(mProgram, "sTextureDay");  
            uNightTexHandle=GLES20.glGetUniformLocation(mProgram, "sTextureNight");  
            //获取位置、旋转变换矩阵引用id
            muMMatrixHandle = GLES20.glGetUniformLocation(mProgram, "uMMatrix");  
        }
        public void drawSelf(int texId,int texIdNight) {        
        	 //制定使用某套着色器程序
        	 GLES20.glUseProgram(mProgram);
             //将最终变换矩阵传入着色器程序
             GLES20.glUniformMatrix4fv(muMVPMatrixHandle, 1, false, MatrixState.getFinalMatrix(), 0);  
             //将位置、旋转变换矩阵传入着色器程序
             GLES20.glUniformMatrix4fv(muMMatrixHandle, 1, false, MatrixState.getMMatrix(), 0);    
             //将摄像机位置传入着色器程序   
             GLES20.glUniform3fv(maCameraHandle, 1, MatrixState.cameraFB);
             //将光源位置传入着色器程序   
             GLES20.glUniform3fv(maSunLightLocationHandle, 1, MatrixState.lightPositionFBSun);
             GLES20.glVertexAttribPointer(//为画笔指定顶点位置数据    
             		maPositionHandle,   
             		3, 
             		GLES20.GL_FLOAT, 
             		false,
                    3*4, 
                    mVertexBuffer   
             );       
             GLES20.glVertexAttribPointer(  //为画笔指定顶点纹理数据
            		maTexCoorHandle,  
             		2, 
             		GLES20.GL_FLOAT, 
             		false,
                    2*4,   
                    mTexCoorBuffer
             );   
             GLES20.glVertexAttribPointer    //为画笔指定顶点法向量数据  
             (
            		maNormalHandle, 
             		4, 
             		GLES20.GL_FLOAT, 
             		false,
                    3*4,   
                    mVertexBuffer
             );            
             //允许顶点位置数据数组
             GLES20.glEnableVertexAttribArray(maPositionHandle);  
             GLES20.glEnableVertexAttribArray(maTexCoorHandle);  
             GLES20.glEnableVertexAttribArray(maNormalHandle);           
             //绑定纹理
             GLES20.glActiveTexture(GLES20.GL_TEXTURE0);
             GLES20.glBindTexture(GLES20.GL_TEXTURE_2D, texId);    
             GLES20.glActiveTexture(GLES20.GL_TEXTURE1);
             GLES20.glBindTexture(GLES20.GL_TEXTURE_2D, texIdNight);            
             GLES20.glUniform1i(uDayTexHandle, 0);
             GLES20.glUniform1i(uNightTexHandle, 1);          
             //绘制三角形
             GLES20.glDrawArrays(GLES20.GL_TRIANGLES, 0, vCount); 
        }
        //自动切分纹理产生纹理数组的方法
        public float[] generateTexCoor(int bw,int bh){
        	float[] result=new float[bw*bh*6*2]; 
        	float sizew=1.0f/bw;//列数
        	float sizeh=1.0f/bh;//行数
        	int c=0;
        	for(int i=0;i<bh;i++){
        		for(int j=0;j<bw;j++){
        			//每行列一个矩形，由两个三角形构成，共六个点，12个纹理坐标
        			float s=j*sizew;
        			float t=i*sizeh;
        			result[c++]=s;
        			result[c++]=t;
        			result[c++]=s;
        			result[c++]=t+sizeh;
        			result[c++]=s+sizew;
        			result[c++]=t;    			
        			result[c++]=s+sizew;
        			result[c++]=t;
        			result[c++]=s;
        			result[c++]=t+sizeh;
        			result[c++]=s+sizew;
        			result[c++]=t+sizeh;    			
        	}}
        	return result;
    }
        }

具体渲染就不说了，比较简单。

源文件下载：http://download.csdn.net/detail/sh15285118586/8721269

[20150520175441071]: /images/20220805/88b5164760d74710bdadf211e88ba7ea.png