当前线程中没有当前的 OpenGL ES 上下文 - LWJGL 使用 OpenGL ES 3.0

Question

我正在尝试使用入门示例（来自 https://www.lwjgl.org/guide {which unaltered works fine}）来使用 LWJGL，但对其进行了更改，使其改为使用 OpenGL ES 3.0（出于与此问题无关的原因）。

我正在使用最新的 LWJGL 版本 3.1.1，选择 Minimal OpenGL ES 作为我的预设（来自 https://www.lwjgl.org/download）并使用 windows 本机。 (我是运行ning Windows 10 64bit)

我被卡住了——我不确定如何解决它，并把它带到运行。

我得到的错误是：

线程异常"main"java.lang.IllegalStateException：当前线程中没有OpenGL ES上下文。

完整错误：

Exception in thread "main" java.lang.IllegalStateException: There is no OpenGL ES context current in the current thread.
at org.lwjgl.opengles.GLES.createCapabilities(GLES.java:222)
at com.test.desktop.HelloWorld.loop(HelloWorld.java:93)
at com.test.desktop.HelloWorld.run(HelloWorld.java:31)
at com.test.desktop.HelloWorld.main(HelloWorld.java:112)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:498)
at com.intellij.rt.execution.application.AppMain.main(AppMain.java:144)

完整来源：

package com.test.desktop;

import org.lwjgl.*;
import org.lwjgl.glfw.*;
//import org.lwjgl.opengl.*;
import org.lwjgl.opengles.GLES;
import org.lwjgl.system.*;

import java.nio.*;

import static org.lwjgl.glfw.Callbacks.*;
import static org.lwjgl.glfw.GLFW.*;
//import static org.lwjgl.opengl.GL11.*;
import static org.lwjgl.opengles.GLES20.*;
import static org.lwjgl.opengles.GLES30.*;
import static org.lwjgl.system.MemoryStack.*;
import static org.lwjgl.system.MemoryUtil.*;

public class HelloWorld {

    // The window handle
    private long window;

    static final int WIDTH = 1024;
    static final int HEIGHT = 768;

    public void run() {
        System.out.println("Hello LWJGL " + Version.getVersion() + "!");

        init();
        loop();

        // Free the window callbacks and destroy the window
        glfwFreeCallbacks(window);
        glfwDestroyWindow(window);

        // Terminate GLFW and free the error callback
        glfwTerminate();
        glfwSetErrorCallback(null).free();
    }

    private void init() {
        // Setup an error callback. The default implementation
        // will print the error message in System.err.
        GLFWErrorCallback.createPrint(System.err).set();

        // Initialize GLFW. Most GLFW functions will not work before doing this.
        if ( !glfwInit() )
            throw new IllegalStateException("Unable to initialize GLFW");

        // Configure GLFW
        glfwDefaultWindowHints(); // optional, the current window hints are already the default
        glfwWindowHint(GLFW_VISIBLE, GLFW_FALSE); // the window will stay hidden after creation
        glfwWindowHint(GLFW_RESIZABLE, GLFW_TRUE); // the window will be resizable

        // Create the window
        window = glfwCreateWindow(WIDTH, HEIGHT, "Hello World!", NULL, NULL);
        if ( window == NULL )
            throw new RuntimeException("Failed to create the GLFW window");

        // Setup a key callback. It will be called every time a key is pressed, repeated or released.
        glfwSetKeyCallback(window, (window, key, scancode, action, mods) -> {
            if ( key == GLFW_KEY_ESCAPE && action == GLFW_RELEASE )
                glfwSetWindowShouldClose(window, true); // We will detect this in the rendering loop
        });

        // Get the resolution of the primary monitor
        GLFWVidMode vidmode = glfwGetVideoMode(glfwGetPrimaryMonitor());

        // Center the window
        glfwSetWindowPos(
                window,
                (vidmode.width() - WIDTH) / 2,
                (vidmode.height() - HEIGHT) / 2
        );

        // Make the OpenGL context current
        glfwMakeContextCurrent(window);

        // Enable v-sync
        glfwSwapInterval(1);

        // Make the window visible
        glfwShowWindow(window);
    }

    private void loop() {
        // This line is critical for LWJGL's interoperation with GLFW's
        // OpenGL context, or any context that is managed externally.
        // LWJGL detects the context that is current in the current thread,
        // creates the GLCapabilities instance and makes the OpenGL
        // bindings available for use.
        GLES.createCapabilities();
        // GL.createCapabilities();

        // Set the clear color
        glClearColor(1.0f, 0.0f, 0.0f, 0.0f);

        // Run the rendering loop until the user has attempted to close
        // the window or has pressed the ESCAPE key.
        while ( !glfwWindowShouldClose(window) ) {
            glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT); // clear the framebuffer

            glfwSwapBuffers(window); // swap the color buffers

            // Poll for window events. The key callback above will only be
            // invoked during this call.
            glfwPollEvents();
        }
    }

    public static void main(String[] args) {
        new HelloWorld().run();
    }
}

是否值得注意...如果我取消注释：

import org.lwjgl.opengl.*;

然后，更改：

GLES.createCapabilities();

并且，请改用以下内容：

GL.createCapabilities();

我收到这个错误：

线程异常 "main" java.lang.IllegalStateException：没有为当前线程设置 GLESCapabilities 实例。可能的解决方案：

Answer 1

设法找到解决方案（来自 http://bedroomcoders.co.uk/gles2-0-everywhere-thanks-to-lwjgl3/）。

我取消评论：

import org.lwjgl.opengl.*;

在init()函数中调用glfwCreateWindow函数之前，添加：

glfwWindowHint(GLFW_CONTEXT_VERSION_MAJOR, 3);
glfwWindowHint(GLFW_CONTEXT_VERSION_MINOR, 0);
glfwWindowHint(GLFW_CLIENT_API, GLFW_OPENGL_ES_API);

并且，在 init() 函数的末尾添加了以下内容：

// Bypasses the default create() method.
Configuration.OPENGLES_EXPLICIT_INIT.set(true);
GLES.create(GL.getFunctionProvider());

之所以有效，是因为它使用 org.lwjgl.opengles.GL 函数地址而不是 org.lwjgl.opengles.GLES。在 Windows 上，他们无论如何都使用 OpenGL 本机函数地址（有一些例外）。

"OpenGL 4.3 provides full compatibility with OpenGL ES 3.0"（来自 https://en.wikipedia.org）。

当前线程中没有当前的 OpenGL ES 上下文 - LWJGL 使用 OpenGL ES 3.0

There is no OpenGL ES context current in the current thread - LWJGL using OpenGL ES 3.0

java

lwjgl