尝试用 vaos 和 vbos 渲染一个正方形

Question

我正在努力学习如何使用 vaos 和 vbos。现在我正在尝试渲染一个正方形，但屏幕上没有任何渲染。我正在使用 android 工作室和 OpenGL ES 3。

这是我的 MainActivity：

package com.example.karno.androidgameprojectv3;

import android.app.Activity;
import android.os.Bundle;
import android.util.Log;

import renderEngine.DisplayManager;
import renderEngine.MainRenderer;

public class MainActivity extends Activity {

    DisplayManager gameView;
    MainRenderer renderer;

    @Override
    protected void onCreate(Bundle savedInstanceState) {

        super.onCreate(savedInstanceState);
        renderer = new MainRenderer();
        gameView = new DisplayManager(this);

        gameView.setEGLContextClientVersion(3);

        gameView.setRenderer(renderer);
        this.setContentView(gameView);
    }

    @Override
    protected void onDestroy(){

//        Log.d("------test", "in on destroy");
        renderer.loader.cleanUp();
        super.onDestroy();
    }

}

这是我绑定 vaos 和 vbos 的加载器 class:

package renderEngine;

import android.opengl.GLES11;
import android.opengl.GLES20;
import android.opengl.GLES30;
import android.util.Log;

import java.nio.FloatBuffer;
import java.nio.IntBuffer;

public class Loader {

    private int [] vaos;
    private int [] vbos;
    private int countVbos = -1;
    private int countVaos = -1;

    public Loader( int neededVAOs, int neededVBOs){
        vaos = new int[neededVAOs];
        vbos = new int[neededVBOs];

    }

    public RawModel loadToVAO(float[] position) {

        int vaoID = createVAO();
        storeDataInAttributeList(0, 3, position);

        unbindVAO();
        Log.d("looking for null---", "position = " + position);
        return new RawModel(vaoID, position.length/3);
    }

    private int createVAO() {

        countVaos++;
        GLES30.glGenVertexArrays(1, vaos, 0);
        GLES30.glBindVertexArray(vaos[countVaos]);
        return vaos[countVaos];
    }

    private void storeDataInAttributeList(int attributeNumber, int coordinateSize, float[] data) {

        countVbos++;
//        GLES30.glGenBuffers(1, vbos);
        GLES20.glGenBuffers(1, vbos,0);
//        Log.d("------vbo", "vbo id = " + vbos.get(countVbos));
        GLES30.glBindBuffer(GLES30.GL_ARRAY_BUFFER, vbos[countVbos]);
        FloatBuffer buffer = storeDataInFloatBuffer(data);
//        Log.d("looking for null arg", "arg2 = " + vbos.get(countVbos) + ", arg3 = " + buffer);
        GLES30.glBufferData(GLES30.GL_ARRAY_BUFFER, vbos[0], buffer, GLES30.GL_STATIC_DRAW);
        GLES30.glVertexAttribPointer(attributeNumber, coordinateSize, GLES30.GL_FLOAT, false, 0, 0);
        GLES30.glBindBuffer(GLES30.GL_ARRAY_BUFFER, 0);
    }

    private FloatBuffer storeDataInFloatBuffer(float[] data) {

        FloatBuffer buffer = FloatBuffer.allocate(data.length);
        buffer.put(data);
        buffer.flip();
        return buffer;
    }

    private void unbindVAO() {
        // this will unbind the VAO
        GLES30.glBindVertexArray(0);
    }

    public void cleanUp() {
        Log.d("--------", "in clean up");
        for (int vao : vaos) {
            GLES30.glDeleteBuffers(vao, vaos, 0);
        }
        countVaos = -1;
        for (int vbo : vbos) {
            GLES20.glDeleteBuffers(vbo, vbos,0);
        }
        countVbos = -1;
        Log.d("--------", "cleaned up.");
    }
}

MainRenderer：

package renderEngine;

import android.opengl.GLES20;
import android.opengl.GLSurfaceView;
import android.util.Log;

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


public class MainRenderer implements GLSurfaceView.Renderer {

    public Loader loader;
    Renderer renderer;
    RawModel model;

    private static final int NEEDED_VAOS = 1;
    private static final int NEEDED_VBOS = 1;

    //square
    float[] vertecies = {
            -0.5f, 0.5f, 0f,
            -0.5f, -0.5f, 0f,
            0.5f, -0.5f, 0f,

            0.5f, -0.5f, 0f,
            0.5f, 0.5f, 0f,
            -0.5f, 0.5f, 0f,
    };

    @Override
    public void onDrawFrame(GL10 arg0){

//        GLES20.glClearColor(0,1,0,1);
//        GLES20.glClear(GLES20.GL_COLOR_BUFFER_BIT);
        renderer.prepare();
        renderer.render(model);
    }

    @Override
    public void onSurfaceChanged(GL10 arg0, int height, int width){

    }

    @Override
    public void onSurfaceCreated(GL10 arg0, EGLConfig config){

//        Log.d("check------", "in on surface created.");
        loader = new Loader(NEEDED_VAOS, NEEDED_VBOS);
        renderer = new Renderer();
        model = loader.loadToVAO(vertecies);
    }
}

观点：

package renderEngine;

import android.content.Context;
import android.opengl.GLSurfaceView;

public class DisplayManager extends GLSurfaceView {

    public DisplayManager(Context context){
        super(context);
    }
}

渲染class：

package renderEngine;

import android.opengl.GLES11;
import android.opengl.GLES20;
import android.opengl.GLES30;
import android.util.Log;

public class Renderer {

    public void prepare(){

        GLES11.glClearColor(0,1,0,1);
        GLES11.glClear(GLES11.GL_COLOR_BUFFER_BIT);
    }

    public void render(RawModel model) {

//        Log.d("------render","model.getVaoID() = "+ model.getVaoID());
        GLES30.glBindVertexArray(model.getVaoID());
        GLES30.glEnableVertexAttribArray(0);
        GLES11.glDrawArrays(GLES11.GL_TRIANGLES, 0, model.getVertexCount());
        GLES20.glDisableVertexAttribArray(0);
        GLES30.glBindVertexArray(0);
    }
}

3d 模型。

package renderEngine;

public class RawModel
{
    private int vaoID;
    private int vertexCount;

    public RawModel(int vaoID, int vertexCount)
    {
        this.vaoID = vaoID;
        this.vertexCount = vertexCount;
    }

    /**
     * @return the vaoID
     */
    public int getVaoID() {
        return vaoID;
    }

    /**
     * @return the vertexCount
     */
    public int getVertexCount() {
        return vertexCount;
    }
}

在 logcat 我得到：

2019-01-06 20:33:43.667 4618-4657/com.example.karno.androidgameprojectv3 E/emuglGLESv2_enc: a vertex attribute index out of boundary is detected. Skipping corresponding vertex attribute. buf=0x7c2911e22a00
2019-01-06 20:33:43.667 4618-4657/com.example.karno.androidgameprojectv3 E/emuglGLESv2_enc: Out of bounds vertex attribute info: clientArray? 0 attribute 0 vbo 1 allocedBufferSize 1 bufferDataSpecified? 1 wantedStart 0 wantedEnd 72

我们将不胜感激。

Answer 1

GLES30.glBufferData 的第二个参数必须是以字节为单位的缓冲区大小，而不是命名的缓冲区对象。
另见 Java Code Examples for android.opengl.GLES20.glBufferData() and glBufferData:

GLES30.glBufferData(GLES30.GL_ARRAY_BUFFER, 
     buffer.capacity() * BYTES_PER_FLOAT, buffer, GLES30.GL_STATIC_DRAW);

注意 glBufferData 为当前由 glBindBuffer 绑定的缓冲区对象创建并初始化缓冲区对象的数据存储。

尝试用 vaos 和 vbos 渲染一个正方形

Trying to render a square with vaos and vbos

android-studio

opengl-es

opengl-es-3.0