OpenGL 顶点数组抛出无效操作错误

Question

我最近开始使用 OpenGL 和 LWJGL，但自从我试图弄乱 with/add 顶点数组对象后，我就一遍又一遍地遇到同样的错误：

GL_INVALID_OPERATION

我很难理解为什么，但我设法将问题归结为这些方法：

glEnableClientState(GL_VERTEX_ARRAY);
vao = glGenVertexArrays();

glBindVertexArray(vao);
glEnableVertexAttribArray(vao);     
glVertexAttribPointer(0, count, GL_FLOAT, false, Float.SIZE * 2, 0);

glBindVertexArray(0);

...所以基本上任何与顶点数组有关的东西都会抛出这个错误。如果有人能指出我到底做错了什么，那就太好了。这是我的其余代码：

import static org.lwjgl.opengl.GL11.*;
import static org.lwjgl.opengl.GL15.*;
import static org.lwjgl.opengl.GL20.*;
import static org.lwjgl.opengl.GL30.*;

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

import org.lwjgl.BufferUtils; 

public class Model {

    private int count;
    private int ibo, vao;

    public Model(float[] vertices, int[] indices) {

        count = indices.length;

        glEnableClientState(GL_VERTEX_ARRAY);
        vao = glGenVertexArrays();

        glBindVertexArray(vao);
        glEnableVertexAttribArray(vao);
        glVertexAttribPointer(0, count, GL_FLOAT, false, Float.SIZE * 2, 0);

        glBindVertexArray(0);

        FloatBuffer vBuffer = BufferUtils.createFloatBuffer(vertices.length);
        vBuffer.put(vertices).flip();

        int vbo = glGenBuffers();
        glBindBuffer(GL_ARRAY_BUFFER, vbo);
        glBufferData(GL_ARRAY_BUFFER, vBuffer, GL_STATIC_DRAW);

        IntBuffer iBuffer = BufferUtils.createIntBuffer(indices.length);
        iBuffer.put(indices).flip();

        ibo = glGenBuffers();
        glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, ibo);
        glBufferData(GL_ELEMENT_ARRAY_BUFFER, iBuffer, GL_STATIC_DRAW);

        glBindBuffer(GL_ARRAY_BUFFER, 0);
        glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, 0);

    }
    public void draw() {

        glBindVertexArray(vao);
        glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, ibo);

        glDrawElements(GL_TRIANGLES, count, GL_UNSIGNED_INT, 0);

    }
}

Answer 1

glEnableVertexAttribArray参数为属性索引。这意味着您必须像这样更改代码：

glBindVertexArray( vao );
glEnableVertexAttribArray( 0 ); // <--- attribute index instead of object name

或者您可以使用 glEnableVertexArrayAttrib:

glEnableVertexArrayAttrib( vao, 0 );

OpenGL 4.6 core profile specification, 10.3. VERTEX ARRAYS, page 354:

An individual generic vertex attribute array in a vertex array object is enabled with the commands
void EnableVertexAttribArray( uint index );
void EnableVertexArrayAttrib( uint vaobj, uint index );

请注意，glEnableClientState is part of the deprecated fixed function pipeline. If you want to use the fixed function pipeline and glEnableClientState, then you have to use glVertexPointer 而不是 glVertexAttribPointer。

OpenGL 顶点数组抛出无效操作错误

OpenGL vertex arrays throw invalid operation error

java

eclipse

opengl

lwjgl