Question

我试图在每个椎体上使用不同的颜色，但是什么时候我运行程序它没有绘制任何东西.GLES20.getError（）;函数返回INVALID_VALUE错误，但我不知道它可能在哪里。任何人都可以帮我解决错误，请？

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


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

import javax.microedition.khronos.opengles.GL10;

public class glDraw {
    private float[] vertecies={
            0.0f,2.0f,0.0f,
            1.0f,0.0f,0.0f,
           -1.0f,0.0f,0.0f
    };
    private float[] colors={
            1.0f,0.0f,0.0f,0.5f,
            0.0f,1.0f,0.0f,0.5f,
            0.0f,0.0f,1.0f,0.5f
    };
    private FloatBuffer vertexBuffer;
    private FloatBuffer colorBuffer;
    private final String vertexShaderCode=
            "uniform mat4 uMVPMatrix;"+
            "attribute vec4 vPosition;"+
            "attribute vec4 a_Color"+
            "varying vec4 v_Color"+
            "void main(){"+
            "   v_Color=a_Color;"+
            "   gl_Position = uMVPMatrix * vPosition;"+
            "   gl_PointSize=10.0;"+
            "}";
    private final String fragmentShaderCode=
            "precision mediump float;"+
            "varying vec4 v_Color;"+
            "void main(){"+
            "   gl_FragColor=v_Color;"+
            "}";
    private int ShaderProgram;
    public static int glLoadShader(int Type,String shaderCode){
        int shader=GLES20.glCreateShader(Type);
        GLES20.glShaderSource(shader, shaderCode);
        GLES20.glCompileShader(shader);
        return shader;
    }
    private int matrixHandle;
    public glDraw(){
        ByteBuffer vbb= ByteBuffer.allocateDirect(vertecies.length*4);
        vbb.order(ByteOrder.nativeOrder());
        vertexBuffer=vbb.asFloatBuffer();
        vertexBuffer.put(vertecies);
        vertexBuffer.position(0);

        ByteBuffer cbb= ByteBuffer.allocateDirect(colors.length * 4);
        vbb.order(ByteOrder.nativeOrder());
        colorBuffer=cbb.asFloatBuffer();
        colorBuffer.put(colors);
        colorBuffer.position(0);

        int vertexShader=glLoadShader(GLES20.GL_VERTEX_SHADER,vertexShaderCode);
        int fragmentShader=glLoadShader(GLES20.GL_FRAGMENT_SHADER,fragmentShaderCode);
        ShaderProgram=GLES20.glCreateProgram();
        GLES20.glAttachShader(ShaderProgram, vertexShader);
        GLES20.glAttachShader(ShaderProgram, fragmentShader);
        GLES20.glLinkProgram(ShaderProgram);
    }
    public void drawTriangle(float[] mvpMatrix,float[] color){
        GLES20.glUseProgram(ShaderProgram);
        int PositionAttrib = GLES20.glGetAttribLocation(ShaderProgram, "vPosition");
        int ColorAttrib = GLES20.glGetAttribLocation(ShaderProgram,"a_Color");
        GLES20.glEnableVertexAttribArray(PositionAttrib);
        GLES20.glEnableVertexAttribArray(ColorAttrib);
        GLES20.glVertexAttribPointer(PositionAttrib, 3, GLES20.GL_FLOAT, false, 0, vertexBuffer);
        GLES20.glVertexAttribPointer(ColorAttrib, 4, GLES20.GL_FLOAT, false, 0, colorBuffer);
        matrixHandle= GLES20.glGetUniformLocation(ShaderProgram,"uMVPMatrix");
        GLES20.glUniformMatrix4fv(matrixHandle, 1, false, mvpMatrix, 0);
        Integer a=GLES20.glGetError();
        Log.e("szar",a.toString());
        GLES20.glDrawArrays(GLES20.GL_TRIANGLES, 0, vertecies.length / 3);
        GLES20.glDisableVertexAttribArray(PositionAttrib);
    }
}

而且这是我的Renderer课程：

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

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

/**
 * Created by Lacko on 2015.07.29..
 */
public class GLRenderer implements GLSurfaceView.Renderer {

    private final float[] mMVPMatrix = new float[16];
    private final float[] mProjectionMatrix = new float[16];
    private final float[] mViewMatrix = new float[16];

    @Override
    public void onSurfaceCreated(GL10 gl, EGLConfig config) {
        GLES20.glClearColor(0f,0,0,0);
    }

    @Override
    public void onSurfaceChanged(GL10 gl, int width, int height) {
        GLES20.glViewport(0, 0, width, height);
        float ratio=(float) width/(float)height;
        Matrix.frustumM(mProjectionMatrix, 0, -ratio, ratio, -1, 1, 0.1f, 500);
    }
    public int x=0;
    @Override
    public void onDrawFrame(GL10 gl) {
        Matrix.setLookAtM(mViewMatrix, 0, 0, 0, -1, 0, 1.78f, 0, 0, 1, 0);
        Matrix.multiplyMM(mMVPMatrix, 0, mProjectionMatrix, 0, mViewMatrix, 0);
        GLES20.glClear(GLES20.GL_COLOR_BUFFER_BIT|GLES20.GL_DEPTH_BUFFER_BIT);
        GLES20.glEnable(GLES20.GL_BLEND);
        GLES20.glEnable(GLES20.GL_DEPTH_TEST);
        GLES20.glBlendFunc(GLES20.GL_SRC_ALPHA, GLES20.GL_ONE_MINUS_SRC_ALPHA);
        GLES20.glEnable(GLES20.GL_TEXTURE_2D);
        glDraw draw =new glDraw();
        Matrix.translateM(mMVPMatrix,0,0,0,-3);
        draw.drawTriangle(mMVPMatrix,new float[]{ 1,0,0,1f});
        Matrix.rotateM(mMVPMatrix,0,x,0,1,0);
        Matrix.translateM(mMVPMatrix, 0, 0, 0, -1);
        draw.drawTriangle(mMVPMatrix,new float[]{1,1,0,0.5f});
        x++;
    }
}

Answer 1

我对JAVA OpenGL了解不多，但我想让你检查两件事。

如果您需要创建FBO并将其绑定为渲染目标。
如果您忘记放置视口（）。

<强>更新

1。

2，但我建议无论如何都要调用它。

根据@Reto Koreadi所提到的，你在顶点着色器中错过了分号。

OpenGl ES 2.0 invalid_Value

1 个答案: