Java使用VAO的现代OpenGL访问违规异常

Question

我目前正在遵循ThinMatrix的OpenGL教程，使用VAO和VBOS进行渲染。我几乎完全复制了代码（唯一的区别是我使工厂类成为静态的，而不仅仅是正常的）。我可以看到我的程序版本和他的程序版本之间唯一的技术区别是我使用lwjgl 3而不是lwjgl 2。

以下是我的源代码:

/*************
    MAIN
*************/
import Render.ModelLoader;
import Render.Render;
import Render.RawModel;
import org.lwjgl.Version;
import org.lwjgl.glfw.Callbacks;
import org.lwjgl.glfw.GLFWErrorCallback;
import org.lwjgl.glfw.GLFWVidMode;
import org.lwjgl.opengl.GL;

import static  org.lwjgl.opengl.GL11.*;
import static org.lwjgl.glfw.GLFW.*;
import static org.lwjgl.system.MemoryUtil.NULL;

public class Main {

    private static long window;
    private static ModelLoader modelLoader;
    private static Render renderer;


    private static final int WIDTH = 1280;
    private static final int HEIGHT = 720;

    public static void main(String[] args) {

        float[] vertices = {
                //Bottom left triangle
                -.5f,.5f,0f,
                -.5f,-.5f,0f,
                .5f,-.5f,0f,
                //Top right triangle
                .5f,-.5f,0f,
                .5f,.5f,0f,
                -.5f,.5f,0f
        };

        RawModel model = modelLoader.loadToVAO(vertices);

        initApp();

        //Main Loop
        while (!glfwWindowShouldClose(window)){
            glfwPollEvents();
            renderer.prepare();
            renderer.render(model);
            glfwSwapBuffers(window);
        }

        cleanUp();
    }

    public static void initApp(){
        System.out.println("LWJGL " + Version.getVersion());
        //Set the error callback routine to use System.err
        GLFWErrorCallback.createPrint(System.err).set();

        //Init GLFW
        if (!glfwInit()){
            throw new IllegalStateException("Could not initialise GLFW.");
        }

        //Create the window
        glfwDefaultWindowHints();
        glfwWindowHint(GLFW_RESIZABLE,GLFW_FALSE);
        window = glfwCreateWindow(WIDTH, HEIGHT, "My Display", NULL, NULL);
        if (window == NULL){
            throw new IllegalStateException("Could not create window");
        }

        //Center the window
        GLFWVidMode vidMode = glfwGetVideoMode(glfwGetPrimaryMonitor());
        glfwSetWindowPos(window, (vidMode.width()-WIDTH)/2, (vidMode.height()-HEIGHT)/2);

        //Link window's context to current thread
        glfwMakeContextCurrent(window);
        //VSync
        glfwSwapInterval(1);
        glfwShowWindow(window);

        GL.createCapabilities();
        System.out.println("OpenGL " + glGetString(GL_VERSION));
    }

    public static void cleanUp(){
        modelLoader.cleanUp();
        Callbacks.glfwFreeCallbacks(window); //Release callbacks
        glfwDestroyWindow(window); //Destroy the window
        glfwTerminate(); //Terminate GLFW
        glfwSetErrorCallback(null).set();
    }

}
/*************
   RAWMODEL
*************/
package Render;

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

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

    public int getVaoID() {
        return vaoID;
    }

    public int getVertexCount() {
        return vertexCount;
    }
}
/*************
  MODELLOADER
*************/
package Render;

import org.lwjgl.BufferUtils;
import java.nio.FloatBuffer;
import java.util.ArrayList;
import java.util.List;

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

public class ModelLoader {

    private static List<Integer> vaos = new ArrayList<>();
    private static List<Integer> vbos = new ArrayList<>();

    public static RawModel loadToVAO(float[] positions){
        int vaoID = createVAO();
        vaos.add(vaoID);
        storeDataInAttribList(0,positions);
        unbindVAO();
        return new RawModel(vaoID, positions.length/3);
    }

    private static int createVAO(){
        int vaoID = glGenVertexArrays();
        glBindVertexArray(vaoID);
        return vaoID;
    }

    private static void storeDataInAttribList(int attribNum, float[] data){
        int vboID = glGenBuffers();
        vbos.add(vboID);
        glBindBuffer(GL_ARRAY_BUFFER,vboID);
        FloatBuffer buffer = storeDataInFB(data);
        glBufferData(GL_ARRAY_BUFFER,buffer,GL_STATIC_DRAW);
        glVertexAttribPointer(attribNum,3,GL_FLOAT,false,0,0);
        glBindBuffer(GL_ARRAY_BUFFER,0);
    }

    private static FloatBuffer storeDataInFB(float[] data){
        FloatBuffer buffer = BufferUtils.createFloatBuffer(data.length);
        buffer.put(data);
        buffer.flip();
        return buffer;
    }

    private static void unbindVAO(){
        glBindVertexArray(0);
    }

    public static void cleanUp(){
        for (int vao:vaos) {
            glDeleteVertexArrays(vao);
        }
        for (int vbo:vbos) {
            glDeleteBuffers(vbo);
        }
    }
}
/*************
    RENDER
*************/
package Render;

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

public class Render {

    public static void prepare(){
        glClearColor(0.0f,0.4f,0.6f,1.0f);
        glClear(GL_COLOR_BUFFER_BIT);
    }

    public static void render(RawModel model){
        glEnableClientState(GL_VERTEX_ARRAY);
        glBindVertexArray(model.getVaoID());
        glEnableVertexAttribArray(0);
        glDrawArrays(GL_TRIANGLES,0,model.getVertexCount());
        glDisableVertexAttribArray(0);
        glBindVertexArray(0);
        glDisableClientState(GL_VERTEX_ARRAY);
    }
}

我遇到的问题是，每当我试图运行项目时，它就会崩溃，并显示以下错误消息:

Connected to the target VM, address: '127.0.0.1:49390', transport: 'socket'

 A fatal error has been detected by the Java Runtime Environment:

  EXCEPTION_ACCESS_VIOLATION (0xc0000005) at pc=0x00007ffffa09862d, pid=12556, tid=0x00000000000020ac

 JRE version: Java(TM) SE Runtime Environment (8.0_121-b13) (build 1.8.0_121-b13)
 Java VM: Java HotSpot(TM) 64-Bit Server VM (25.121-b13 mixed mode windows-amd64 compressed oops)
 Problematic frame:
 C  [lwjgl_opengl.dll+0x862d]

 Failed to write core dump. Minidumps are not enabled by default on client versions of Windows

 An error report file with more information is saved as:
 C:\Users\TokenGuard\IdeaProjects\ModernOpenGLTutorial\hs_err_pid12556.log

 If you would like to submit a bug report, please visit:
   http://bugreport.java.com/bugreport/crash.jsp
 The crash happened outside the Java Virtual Machine in native code.
 See problematic frame for where to report the bug.

Disconnected from the target VM, address: '127.0.0.1:49390', transport: 'socket'

Process finished with exit code 1

环顾四周，我发现了这个stackoverflow帖子:Java OpenGL EXCEPTION _ ACCESS _ VIOLATION on gldraw arrays only on NVIDIA，它似乎也有同样的问题，这个问题的OP实际上发布了一个解决方案。

我正在使用AMD显卡，但我仍然尝试了一下，看看它是否解决了我的问题，但是它什么也不做，因为它仍然会出现相同的错误消息。

在里面放一些断点，我发现问题出在 createVAO（） 方法上，更具体地说，调用 glGenVertexArrays（） 会因为某种原因而失败。我曾尝试明确告诉glfw使用OpenGL 3.0，但它仍然没有帮助。

在这一点上，我完全没有想法了。对我该怎么做有什么指导吗？

Answer 1

问题是这样的：

RawModel model = modelLoader.loadToVAO(vertices);
initApp();

你需要把它翻转过来：

initApp();
RawModel model = modelLoader.loadToVAO(vertices)

问题在于，当您调用＜code＞modelLoader时。loadToVAO（顶点）它调用＜code＞glgenvertexarray（）（正如您所观察到的）。然而，此时您没有当前的上下文集。您可以在＜code＞initApp（）中使用＜code＞glfwMakeContextCurrent（）

在调用任何OpenGL函数之前，您必须有一个当前的上下文设置。