android opengl es 雾化效果

本文主要是介绍android opengl es 雾化效果，希望对大家解决编程问题提供一定的参考价值，需要的开发者们随着小编来一起学习吧！

雾效果其实很容易实现，我先总结一下:

(1)首先肯定是将背景色设为我们雾的颜色

(2)打开雾效果

(3)设置雾的背景色

(4)设置雾方程式

雾方程式有三种表现形式 EXP(最老)，EXP2(EXP加强版)，LINEAR(雾的最好方程式，当然用这个)，如果要用LINEAR这种，则要多雾start,end的设置，表示雾从多远开始，从多远停止。像LINEAR这种称之为线性雾(不是我发明的，OPENGL超级宝典上这样说，设置稠密度无效)。

(5)最后，设置雾质量优先还是效率优先。

ok,上源码

(1)Activity

package sim.feel;

import android.app.Activity;
import android.content.res.Resources;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.opengl.GLSurfaceView;
import android.opengl.GLSurfaceView.Renderer;
import android.os.Bundle;

public class Fog extends Activity {
    /** Called when the activity is first created. */
    private GLSurfaceView surfaceView;
    private Renderer renderer;

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        // 载入图片
        BitGL.init(this.getResources());
        surfaceView = new GLSurfaceView(this);
        renderer = new MyRenderer(this);
        surfaceView.setRenderer(renderer);
        setContentView(surfaceView);
    }
}

class BitGL {
    public static Bitmap bitmap;

    public static void init(Resources resources) {
        bitmap = BitmapFactory.decodeResource(resources, R.drawable.img);
    }
}

(2)Renderer类

package sim.feel;

import java.nio.ByteBuffer;
import java.nio.ByteOrder;
import java.nio.IntBuffer;

import javax.microedition.khronos.egl.EGLConfig;
import javax.microedition.khronos.opengles.GL10;

import android.content.Context;
import android.graphics.Bitmap;
import android.opengl.GLSurfaceView.Renderer;
import android.opengl.GLUtils;

public class MyRenderer implements Renderer {
    // Context
    public Context context;
    // 顶点纹理相关
    private int one = 0x10000;
    // Bitmap
    private Bitmap bitmap;
    // 纹理相关
    private int[] textureids;
    // vertexBuffer
    private IntBuffer vertexBuffer;
    // texBuffer
    private IntBuffer texBuffer;
    // 旋转方向
    private float xrot, yrot, zrot;
    // 正方体顶点
    private int[] vertices = {
            -one,-one,one,
            one,-one,one,
            -one,one,one,
            one,one,one,


            one,-one,one,
            one,-one,-one,
            one,one,one,
            one,one,-one,


            one,-one,-one,
            -one,-one,-one,
            one,one,-one,
            -one,one,-one,


            -one,-one,-one,
            -one,-one,one,
            -one,one,-one,
            -one,one,one,


            -one,one,-one,
            one,one,-one,
            -one,one,one,
            one,one,one,


            -one,-one,-one,
            -one,-one,one,
            one,-one,-one,
            one,-one,one
        };

    //纹理点
    private int[] texCoords = {
            0, 0,
            one,0,
            0,one,
            one, one
    };

    // 雾模式
    private int fogMode[]={
            GL10.GL_EXP,
            GL10.GL_EXP2,
            GL10.GL_LINEAR
    };
    // 雾颜色为灰白色
    private float fogColor[]={
        0.5f,0.5f,0.5f,1.0f
    };
    public MyRenderer(Context context) {
        this.context = context;
        // 初始化
        textureids = new int[1];
        // 实例化bitmap
        bitmap = BitGL.bitmap;

        ByteBuffer vbb = ByteBuffer.allocateDirect(vertices.length * 4);
        vbb.order(ByteOrder.nativeOrder());
        vertexBuffer = vbb.asIntBuffer();
        vertexBuffer.put(vertices);
        vertexBuffer.position(0);

        ByteBuffer tbb = ByteBuffer.allocateDirect(texCoords.length * 4 * 6);
        tbb.order(ByteOrder.nativeOrder());
        texBuffer = tbb.asIntBuffer();
        //为每一个面贴上纹理
        for (int i = 0; i < 6; i++) {
            texBuffer.put(texCoords);
        }
        texBuffer.position(0);
    }

    @Override
    public void onDrawFrame(GL10 gl) {
        // 清除深度和颜色缓存
        gl.glClear(GL10.GL_DEPTH_BUFFER_BIT | GL10.GL_COLOR_BUFFER_BIT);
        gl.glLoadIdentity();

        gl.glEnableClientState(GL10.GL_VERTEX_ARRAY);
        gl.glEnableClientState(GL10.GL_TEXTURE_COORD_ARRAY);

        gl.glVertexPointer(3, GL10.GL_FIXED, 0, vertexBuffer);
        gl.glTexCoordPointer(2, GL10.GL_FIXED, 0, texBuffer); // Define

        //向z轴里移入6.0f
        gl.glTranslatef(0.0f, 0.0f, -5.0f);
        // 设置3个方向的旋转
        gl.glRotatef(xrot, one, 0.0f, 0.0f);
        gl.glRotatef(yrot, 0.0f, one, 0.0f);
        gl.glRotatef(zrot, 0.0f, 0.0f, one);

        // 绘制正方体
        for (int i = 0; i < 6; i++) {
            gl.glDrawArrays(GL10.GL_TRIANGLE_STRIP, i * 4, 4);
        }

        gl.glDisableClientState(GL10.GL_TEXTURE_COORD_ARRAY);
        gl.glDisableClientState(GL10.GL_VERTEX_ARRAY);

        // 设置旋转角度
        xrot += 0.5f;
        yrot += 0.6f;
        zrot += 0.3f;
    }

    @Override
    public void onSurfaceChanged(GL10 gl, int width, int height) {
        // 视角
        gl.glViewport(0, 0, width, height);
        float ratio = (float) width / height;
        // 观察模式
        gl.glMatrixMode(GL10.GL_PROJECTION);
        // 重置观察布局
        gl.glLoadIdentity();
        gl.glFrustumf(-ratio, ratio, -1, 1, 1, 10);
        gl.glMatrixMode(GL10.GL_MODELVIEW);
        gl.glLoadIdentity();
    }

    @Override
    public void onSurfaceCreated(GL10 gl, EGLConfig config) {
        // We'll Clear To The Color Of The Fog ( Modified )
        gl.glClearColor(0.5f,0.5f,0.5f,1.0f);
        //设置雾模式
        gl.glFogx(GL10.GL_FOG_MODE, fogMode[2]);
        //雾颜色
        gl.glFogfv(GL10.GL_FOG_COLOR, fogColor,0);
        //更好的外观，需求大的雾(反之为gl.glHint(GL10.GL_FOG_HINT, GL10.GL_FASTEST);)
        gl.glHint(GL10.GL_FOG_HINT, GL10.GL_NICEST);
        //雾密度在模式为LINEAR下无效
        //gl.glFogf(GL10.GL_FOG_DENSITY, 0.1f);
        //开始位置
        gl.glFogf(GL10.GL_FOG_START, 1.0f);
        //结束位置
        gl.glFogf(GL10.GL_FOG_END, 5.0f);
        //启用雾
        gl.glEnable(GL10.GL_FOG);

        // 告诉系统对透视进行修正
        gl.glHint(GL10.GL_PERSPECTIVE_CORRECTION_HINT, GL10.GL_FASTEST);
        // 启用阴影平滑
        gl.glShadeModel(GL10.GL_SMOOTH);

        // 清除深度缓存
        gl.glClearDepthf(one);
        // 启用深度测试
        gl.glEnable(GL10.GL_DEPTH_TEST);
        // 所做深度测试的类型
        gl.glDepthFunc(GL10.GL_LEQUAL);

        gl.glEnable(GL10.GL_TEXTURE_2D);
        // 创建纹理
        gl.glGenTextures(1, textureids, 0);
        // 绑定要使用的纹理
        gl.glBindTexture(GL10.GL_TEXTURE_2D, textureids[0]);
        // 生成纹理
        GLUtils.texImage2D(GL10.GL_TEXTURE_2D, 0, bitmap, 0);
        // 线性滤波
        gl.glTexParameterx(GL10.GL_TEXTURE_2D, GL10.GL_TEXTURE_MIN_FILTER,
                GL10.GL_LINEAR);
        gl.glTexParameterx(GL10.GL_TEXTURE_2D, GL10.GL_TEXTURE_MAG_FILTER,
                GL10.GL_LINEAR);
    }
}