opengles之多重纹理与过程纹理

本例子包含若干shader文件，在项目assests文件夹下 

矩阵变换类

package test.com.opengles7_4;

import android.opengl.Matrix;

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

/**
 * Created by hbin on 2016/8/24.
 * 存储系统矩阵状态的类
 */
public class MatrixState {
    private static float[] mProjMatrix = new float[16];//4x4矩阵 投影用
    private static float[] mVMatrix = new float[16];//摄像机位置朝向9参数矩阵
    private static float[] currMatrix;//当前变换矩阵
    public static float[] lightLocationSun=new float[]{0,0,0};//太阳定位光光源位置
    public static FloatBuffer cameraFB;
    public static FloatBuffer lightPositionFBSun;


    public static Stack mStack=new Stack();//保护变换矩阵的栈

    public static void setInitStack()//获取不变换初始矩阵
    {
        currMatrix=new float[16];
        Matrix.setRotateM(currMatrix, 0, 0, 1, 0, 0);
    }

    public static void pushMatrix()//保护变换矩阵
    {
        mStack.push(currMatrix.clone());
    }

    public static void popMatrix()//恢复变换矩阵
    {
        currMatrix=mStack.pop();
    }

    public static void translate(float x,float y,float z)//设置沿xyz轴移动
    {
        Matrix.translateM(currMatrix, 0, x, y, z);
    }

    public static void rotate(float angle,float x,float y,float z)//设置绕xyz轴移动
    {
        Matrix.rotateM(currMatrix,0,angle,x,y,z);
    }


    //设置摄像机
    public static void setCamera
    (
            float cx,	//摄像机位置x
            float cy,   //摄像机位置y
            float cz,   //摄像机位置z
            float tx,   //摄像机目标点x
            float ty,   //摄像机目标点y
            float tz,   //摄像机目标点z
            float upx,  //摄像机UP向量X分量
            float upy,  //摄像机UP向量Y分量
            float upz   //摄像机UP向量Z分量
    )
    {
        Matrix.setLookAtM
                (
                        mVMatrix,
                        0,
                        cx,
                        cy,
                        cz,
                        tx,
                        ty,
                        tz,
                        upx,
                        upy,
                        upz
                );

        float[] cameraLocation=new float[3];//摄像机位置
        cameraLocation[0]=cx;
        cameraLocation[1]=cy;
        cameraLocation[2]=cz;

        ByteBuffer llbb = ByteBuffer.allocateDirect(3*4);
        llbb.order(ByteOrder.nativeOrder());//设置字节顺序
        cameraFB=llbb.asFloatBuffer();
        cameraFB.put(cameraLocation);
        cameraFB.position(0);
    }

    //设置透视投影参数
    public static void setProjectFrustum
    (
            float left,		//near面的left
            float right,    //near面的right
            float bottom,   //near面的bottom
            float top,      //near面的top
            float near,		//near面距离
            float far       //far面距离
    )
    {
        Matrix.frustumM(mProjMatrix, 0, left, right, bottom, top, near, far);
    }

    //设置正交投影参数
    public static void setProjectOrtho
    (
            float left,		//near面的left
            float right,    //near面的right
            float bottom,   //near面的bottom
            float top,      //near面的top
            float near,		//near面距离
            float far       //far面距离
    )
    {
        Matrix.orthoM(mProjMatrix, 0, left, right, bottom, top, near, far);
    }

    //获取具体物体的总变换矩阵
    public static float[] getFinalMatrix()
    {
        float[] mMVPMatrix=new float[16];
        Matrix.multiplyMM(mMVPMatrix, 0, mVMatrix, 0, currMatrix, 0);
        Matrix.multiplyMM(mMVPMatrix, 0, mProjMatrix, 0, mMVPMatrix, 0);
        return mMVPMatrix;
    }

    //获取具体物体的变换矩阵
    public static float[] getMMatrix()
    {
        return currMatrix;
    }

    //设置太阳光源位置的方法
    public static void setLightLocationSun(float x,float y,float z)
    {
        lightLocationSun[0]=x;
        lightLocationSun[1]=y;
        lightLocationSun[2]=z;
        ByteBuffer llbb = ByteBuffer.allocateDirect(3*4);
        llbb.order(ByteOrder.nativeOrder());//设置字节顺序
        lightPositionFBSun=llbb.asFloatBuffer();
        lightPositionFBSun.put(lightLocationSun);
        lightPositionFBSun.position(0);
    }
}

星空绘制类

package test.com.opengles7_4;

import android.opengl.GLES20;

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

/**
 * Created by hbin on 2016/8/24.
 * 表示星空天球的类
 */
public class Celestial {
    final float UNIT_SIZE=10.0f;//天球半径
    private FloatBuffer mVertexBuffer;//顶点坐标数据缓冲
    int vCount=0;//星星数量
    float yAngle;//天球绕Y轴旋转的角度
    float scale;//星星尺寸
    String mVertexShader;//顶点着色器
    String mFragmentShader;//片元着色器
    int mProgram;//自定义渲染管线程序id
    int muMVPMatrixHandle;//总变换矩阵引用id
    int maPositionHandle; //顶点位置属性引用id
    int uPointSizeHandle;//顶点尺寸参数引用

    public Celestial(float scale,float yAngle,int vCount,MySurfaceView mv){
        this.yAngle=yAngle;
        this.scale=scale;
        this.vCount=vCount;
        initVertexData();
        initShader(mv);
    }

    public void initVertexData(){
        //顶点坐标数据的初始化
        float vertices[]=new float[vCount*3];
        for(int i=0;i