android中的三角形opengl

Question

I am new to the opengl so i am using guide of the android developer.I have done all thing that they says but it is showing an error to force to close.

In my log cat file it is showing the following error

03-30 20:13:14.342: E/AndroidRuntime(317): FATAL EXCEPTION: GLThread 8
03-30 20:13:14.342: E/AndroidRuntime(317): java.lang.IllegalArgumentException: No configs match configSpec
03-30 20:13:14.342: E/AndroidRuntime(317):  at android.opengl.GLSurfaceView$BaseConfigChooser.chooseConfig(GLSurfaceView.java:760)
03-30 20:13:14.342: E/AndroidRuntime(317):  at android.opengl.GLSurfaceView$EglHelper.start(GLSurfaceView.java:916)
03-30 20:13:14.342: E/AndroidRuntime(317):  at android.opengl.GLSurfaceView$GLThread.guardedRun(GLSurfaceView.java:1246)
03-30 20:13:14.342: E/AndroidRuntime(317):  at android.opengl.GLSurfaceView$GLThread.run(GLSurfaceView.java:1116)

my manifest file is as follow

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.example.opengl"
    android:versionCode="1"
    android:versionName="1.0" >

    <uses-sdk android:minSdkVersion="8" />
    <uses-feature android:glEsVersion="0x00020000" android:required="true" />

    <application
        android:icon="@drawable/ic_launcher"
        android:label="@string/app_name" >
        <activity
            android:name=".HelloOpenGLES20"
            android:label="@string/app_name" >
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />

                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
    </application>

</manifest>

my activity class is as follow

import android.app.Activity;
import android.content.Context;
import android.opengl.GLSurfaceView;
import android.os.Bundle;

public class HelloOpenGLES20 extends Activity {

    private GLSurfaceView mGLView;

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);

        // Create a GLSurfaceView instance and set it
        // as the ContentView for this Activity
        mGLView = new HelloOpenGLES20SurfaceView(this);
        setContentView(mGLView);
    }

    @Override
    protected void onPause() {
        super.onPause();
        // The following call pauses the rendering thread.
        // If your OpenGL application is memory intensive,
        // you should consider de-allocating objects that
        // consume significant memory here.
        mGLView.onPause();
    }

    @Override
    protected void onResume() {
        super.onResume();
        // The following call resumes a paused rendering thread.
        // If you de-allocated graphic objects for onPause()
        // this is a good place to re-allocate them.
        mGLView.onResume();
    }
}

class HelloOpenGLES20SurfaceView extends GLSurfaceView {

    public HelloOpenGLES20SurfaceView(Context context){
        super(context);

        // Create an OpenGL ES 2.0 context.
        setEGLContextClientVersion(2);
        // Set the Renderer for drawing on the GLSurfaceView
        setRenderer(new HelloOpenGLES20Renderer());
    }
}

my surface class is as follow

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

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

import android.opengl.GLES20;
import android.opengl.GLSurfaceView;

public class HelloOpenGLES20Renderer implements GLSurfaceView.Renderer {

    private FloatBuffer triangleVB;

     private final String vertexShaderCode = 
                "attribute vec4 vPosition; \n" +
                "void main(){              \n" +
                " gl_Position = vPosition; \n" +
                "}                         \n";

            private final String fragmentShaderCode = 
                "precision mediump float;  \n" +
                "void main(){              \n" +
                " gl_FragColor = vec4 (0.63671875, 0.76953125, 0.22265625, 1.0); \n" +
                "}                         \n";

            private int mProgram;
            private int maPositionHandle;

    public void onSurfaceCreated(GL10 unused, EGLConfig config) {

        // Set the background frame color
        GLES20.glClearColor(0.5f, 0.5f, 0.5f, 1.0f);

     // initialize the triangle vertex array
        initShapes();

        int vertexShader = loadShader(GLES20.GL_VERTEX_SHADER, vertexShaderCode);
        int fragmentShader = loadShader(GLES20.GL_FRAGMENT_SHADER, fragmentShaderCode);

        mProgram = GLES20.glCreateProgram();             // create empty OpenGL Program
        GLES20.glAttachShader(mProgram, vertexShader);   // add the vertex shader to program
        GLES20.glAttachShader(mProgram, fragmentShader); // add the fragment shader to program
        GLES20.glLinkProgram(mProgram);                  // creates OpenGL program executables

        // get handle to the vertex shader's vPosition member
        maPositionHandle = GLES20.glGetAttribLocation(mProgram, "vPosition");
    }

    public void onDrawFrame(GL10 unused) {

        // Redraw background color
        GLES20.glClear(GLES20.GL_COLOR_BUFFER_BIT | GLES20.GL_DEPTH_BUFFER_BIT);
        // Add program to OpenGL environment
        GLES20.glUseProgram(mProgram);

        // Prepare the triangle data
        GLES20.glVertexAttribPointer(maPositionHandle, 3, GLES20.GL_FLOAT, false, 12, triangleVB);
        GLES20.glEnableVertexAttribArray(maPositionHandle);

        // Draw the triangle
        GLES20.glDrawArrays(GLES20.GL_TRIANGLES, 0, 3);
    }

    public void onSurfaceChanged(GL10 unused, int width, int height) {
        GLES20.glViewport(0, 0, width, height);
    }

    private void initShapes(){

        float triangleCoords[] = {
            // X, Y, Z
            -0.5f, -0.25f, 0,
             0.5f, -0.25f, 0,
             0.0f,  0.559016994f, 0
        }; 

        // initialize vertex Buffer for triangle  
        ByteBuffer vbb = ByteBuffer.allocateDirect(
                // (# of coordinate values * 4 bytes per float)
                triangleCoords.length * 4); 
        vbb.order(ByteOrder.nativeOrder());// use the device hardware's native byte order
        triangleVB = vbb.asFloatBuffer();  // create a floating point buffer from the ByteBuffer
        triangleVB.put(triangleCoords);    // add the coordinates to the FloatBuffer
        triangleVB.position(0);            // set the buffer to read the first coordinate

    }

    private int loadShader(int type, String shaderCode){

        // create a vertex shader type (GLES20.GL_VERTEX_SHADER)
        // or a fragment shader type (GLES20.GL_FRAGMENT_SHADER)
        int shader = GLES20.glCreateShader(type); 

        // add the source code to the shader and compile it
        GLES20.glShaderSource(shader, shaderCode);
        GLES20.glCompileShader(shader);

        return shader;
    }

}

Answer 1

The reason you are getting this error is because the device you are testing on doesn't support OpenGL ES 2.0. You're probably testing this on the emulator, which doesn't support that version of OpenGL.

Just try testing it on a real device and you'll see it will work fine.

Answer 2

出现此问题的原因是任何Android虚拟设备都不支持3d图像。如果任何人想要运行3d图像，那么他或她应该使用任何物理设备。