openGL es2.0 创建纹理灯光球

package com.gzdxid.utils;

import java.nio.ByteBuffer;
import java.nio.ByteOrder;
import java.nio.FloatBuffer;
import java.util.ArrayList;

import android.opengl.GLES20;

public class DrawBallTextureLight {

	int mProgram;
	int muMVPMatrixHandle;
	int muMMatrixHandle;
	int muLightLocationHandle;
	int muCameraHandle;
	
	int maPositionHandle;
	int maNormalHandle;
	int maTexCoorHandle;

	FloatBuffer mVertexBuffer;
	FloatBuffer mTexCoorBuffer;
	FloatBuffer mNormalBuffer;

	int vCount = 0;
	final float UNIT_SIZE = 1f;
	final float angleSpan = 10f;
	float R = 0;
	
	public float roateX;
	public float roateY;
	
	public DrawBallTextureLight(float r,int mProgram) {
		initVertex(r);
		initShader(mProgram);
	}

	private void initVertex(float r) {
		R = r;
		ArrayList<Float> alVertix = new ArrayList<Float>();
		for (float vAngle = 90; vAngle > -90; vAngle -= angleSpan) {
			for (float hAngle = 360; hAngle > 0; hAngle -= angleSpan) {
				float x1 = getCoor(0, vAngle, hAngle);
				float y1 = getCoor(1, vAngle, hAngle);
				float z1 = getCoor(2, vAngle, hAngle);

				float x2 = getCoor(0, vAngle - angleSpan, hAngle);
				float y2 = getCoor(1, vAngle - angleSpan, hAngle);
				float z2 = getCoor(2, vAngle - angleSpan, hAngle);

				float x3 = getCoor(0, vAngle - angleSpan, hAngle - angleSpan);
				float y3 = getCoor(1, vAngle - angleSpan, hAngle - angleSpan);
				float z3 = getCoor(2, vAngle - angleSpan, hAngle - angleSpan);

				float x4 = getCoor(0, vAngle, hAngle - angleSpan);
				float y4 = getCoor(1, vAngle, hAngle - angleSpan);
				float z4 = getCoor(2, vAngle, hAngle - angleSpan);

				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;
		
		float vertices[] = new float[vCount * 3];
		for (int i = 0; i < alVertix.size(); i++) {
			vertices[i] = alVertix.get(i);
		}
		ByteBuffer vbb = ByteBuffer.allocateDirect(vertices.length * 4);
		vbb.order(ByteOrder.nativeOrder());
		mVertexBuffer = vbb.asFloatBuffer();
		mVertexBuffer.put(vertices);
		mVertexBuffer.position(0);

		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);
		
		mNormalBuffer=mVertexBuffer;
	}

	private void initShader(int mProgram) {
		this.mProgram=mProgram;
		muMVPMatrixHandle=GLES20.glGetUniformLocation(mProgram, "uMVPMatrix");
		muMMatrixHandle = GLES20.glGetUniformLocation(mProgram, "uMMatrix"); 
		muLightLocationHandle=GLES20.glGetUniformLocation(mProgram, "uLightLocation");
		muCameraHandle=GLES20.glGetUniformLocation(mProgram, "uCamera"); 
        
		maPositionHandle=GLES20.glGetAttribLocation(mProgram, "aPosition");
		maNormalHandle= GLES20.glGetAttribLocation(mProgram, "aNormal");
		maTexCoorHandle=GLES20.glGetAttribLocation(mProgram, "aTexCoor");
	}
	
	public void drawSelf(int texId){
		MatrixState.rotate(roateX, 1, 0, 0);
		MatrixState.rotate(roateY, 0, 1, 0);
		
		GLES20.glUseProgram(mProgram);
		GLES20.glUniformMatrix4fv(muMVPMatrixHandle, 1, false, MatrixState.getFinalMatrix(), 0);
		GLES20.glUniformMatrix4fv(muMMatrixHandle, 1, false, MatrixState.getMMatrix(), 0);    
        GLES20.glUniform3fv(muLightLocationHandle, 1, MatrixState.lightPositionFB);
        GLES20.glUniform3fv(muCameraHandle, 1, MatrixState.cameraFB);
        
		GLES20.glVertexAttribPointer(maPositionHandle, 3, GLES20.GL_FLOAT, false, 3 * 4, mVertexBuffer);
		GLES20.glVertexAttribPointer(maTexCoorHandle, 2, GLES20.GL_FLOAT, false, 2 * 4, mTexCoorBuffer);
		GLES20.glVertexAttribPointer(maNormalHandle, 3, GLES20.GL_FLOAT, false, 3*4, mNormalBuffer);
		GLES20.glEnableVertexAttribArray(maPositionHandle);
		GLES20.glEnableVertexAttribArray(maNormalHandle);
		GLES20.glEnableVertexAttribArray(maTexCoorHandle);
		
		GLES20.glActiveTexture(GLES20.GL_TEXTURE0);
		GLES20.glBindTexture(GLES20.GL_TEXTURE_2D, texId);
		GLES20.glDrawArrays(GLES20.GL_TRIANGLES, 0, vCount);
	}
	

	private float getCoor(int which, float vAngle, float hAngle) {
		switch (which) {
		case 0:// x
			return (float) (R * UNIT_SIZE * Math.cos(Math.toRadians(vAngle)) * Math.cos(Math.toRadians(hAngle)));
		case 1:// y
			return (float) (R * UNIT_SIZE * Math.sin(Math.toRadians(vAngle)));
		case 2:// z
			return (float) (R * UNIT_SIZE * Math.cos(Math.toRadians(vAngle)) * Math.sin(Math.toRadians(hAngle)));
		}
		return 0;
	}

	// 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;
	}
		
}

<span style="font-family: Arial; font-size: 14px; line-height: 26px;">二、顶点着色器：</span>

<span style="font-family: Arial; font-size: 14px; line-height: 26px;"></span><pre name="code" class="cpp">uniform mat4 uMVPMatrix; //总变换矩阵
uniform mat4 uMMatrix; //变换矩阵
uniform vec3 uLightLocation;	//光源位置
uniform vec3 uCamera;	//摄像机位置
attribute vec3 aPosition;  //顶点位置
attribute vec3 aNormal;    //顶点法向量
attribute vec2 aTexCoor;    //顶点纹理坐标
//用于传递给片元着色器的变量
varying vec4 vAmbient;
varying vec4 vDiffuse;
varying vec4 vSpecular;
varying vec2 vTextureCoord;  
//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, diffuseTemp, specularTemp;   //存放环境光、散射光、镜面反射光的临时变量      
   pointLight(normalize(aNormal),ambientTemp,diffuseTemp,specularTemp,uLightLocation,
   vec4(0.8,0.8,0.8,1.0),vec4(0.8,0.8,0.8,1.0),vec4(1.0,1.0,1.0,1.0));
   
   vAmbient=ambientTemp;
   vDiffuse=diffuseTemp;
   vSpecular=specularTemp;
   vTextureCoord = aTexCoor;//将接收的纹理坐标传递给片元着色器
}                      

三、片源着色器：

<span style="font-family: Arial; font-size: 14px; line-height: 26px;"><span style="font-family: Arial; font-size: 14px; line-height: 26px;"></span></span><pre name="code" class="cpp">precision mediump float;
uniform sampler2D sTexture;//纹理内容数据
//接收从顶点着色器过来的参数
varying vec4 vAmbient;
varying vec4 vDiffuse;
varying vec4 vSpecular;
varying vec2 vTextureCoord;

void main()                         
{    
   //将计算出的颜色给此片元
   vec4 finalColor=texture2D(sTexture, vTextureCoord);    
   //给此片元颜色值
   gl_FragColor = finalColor*vAmbient+finalColor*vSpecular+finalColor*vDiffuse;

}