glMakeContextCurrent/glViewport致命错误

Question

我在网上关注一本关于如何开始使用GLFW的书。作为参考，我使用的是Java。

我在书中写了一些代码，但我得到了这个错误：FATAL ERROR in native method: Thread[main,5,main]: No context is current or a function that is not available in the current context was called。我的代码如下：

import org.lwjgl.glfw.GLFW;
import org.lwjgl.opengl.GL11;
import org.lwjgl.system.MemoryUtil;
public class Window {
private long window;

public Window()
{

}

public void init()
{
GLFW.glfwWindowHint(GLFW.GLFW_CONTEXT_VERSION_MAJOR, 3);
GLFW.glfwWindowHint(GLFW.GLFW_CONTEXT_VERSION_MINOR, 3);
GLFW.glfwWindowHint(GLFW.GLFW_OPENGL_PROFILE, GLFW.GLFW_OPENGL_CORE_PROFILE);

if(!GLFW.glfwInit())
{
throw new IllegalStateException("Could not initialize glfw");
}

window = GLFW.glfwCreateWindow(800, 600, "window", MemoryUtil.NULL, MemoryUtil.NULL);

if(window == MemoryUtil.NULL)
{
throw new IllegalStateException("Could not initialize window");
}

GLFW.glfwMakeContextCurrent(window);

GL11.glViewport(0, 0, 800, 600);

GLFW.glfwSetFramebufferSizeCallback(window,  (window, width, height) -> {
GL11.glViewport(0, 0, width, height);
});
}

public void gameLoop()
{
while(!GLFW.glfwWindowShouldClose(window))
{
GLFW.glfwSwapBuffers(window);
GLFW.glfwPollEvents();
}

GLFW.glfwTerminate();
}

public void cleanup() {
GLFW.glfwDestroyWindow(window);
}
}

我应该如何修复此错误？此外，如果我的代码结构不好，请告诉我。

谢谢！

Answer 1

在GLFW.glfwMakeContextCurrent()之后需要GL.createCapabilities()。

官方示例代码中提到了这一点(https://www.lwjgl.org/guide)。

// 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.
GL.createCapabilities();