Question

我正在尝试编写一个可以显示三角形的简单程序，我无法弄清楚导致空指针异常的原因。

以下是代码：

public class Cut {
private static long window;
public static final long FRAME_RENDER_TIME_TARGET = 1000 / 60;

private static final float[] tridata = {
   -1.0f, -1.0f, 0.0f,
   1.0f, -1.0f, 0.0f,
   0.0f,  1.0f, 0.0f
};

public static void main(String[] args) {    
    ResourceLoader.init();

    System.out.println("If you started this from the command line it probably crashed.\nRerun it with the JVM argument \"-XstartOnFirstThread\"");

    glInit();
    loop();
    glDeinit();
}

private static void glInit() {
    GLFWErrorCallback.createPrint(System.err).set();

    System.out.println("GLFW version: " + GLFW.glfwGetVersionString());
    if (!GLFW.glfwInit()) {
        System.err.println("Unable to initialize GLFW");
        System.exit(-1);
    }

    GLFW.glfwDefaultWindowHints();

    GLFW.glfwWindowHint(GLFW.GLFW_CONTEXT_VERSION_MAJOR, 4);
    GLFW.glfwWindowHint(GLFW.GLFW_CONTEXT_VERSION_MINOR, 1);
    GLFW.glfwWindowHint(GLFW.GLFW_OPENGL_FORWARD_COMPAT, GLFW.GLFW_TRUE);
    GLFW.glfwWindowHint(GLFW.GLFW_OPENGL_PROFILE, GLFW.GLFW_OPENGL_CORE_PROFILE);

    window = GLFW.glfwCreateWindow(1024, 768, "Cut", NULL, NULL);
    if (window == NULL) {
        System.err.println("Unable to create OpenGL window");
        GLFW.glfwTerminate();
        System.exit(-1);
    }
    GLFW.glfwMakeContextCurrent(window);
    //Enable v-sync
    GLFW.glfwSwapInterval(1);
    //GL.createCapabilities();
    GLFW.glfwShowWindow(window);

    GL.createCapabilities();

    System.out.println("OpenGL version: " + GL11.glGetString(GL11.GL_VERSION));
}
private static void glDeinit() {
    GLFW.glfwTerminate();
}

private static void loop() {
    int vao = GL30.glGenVertexArrays();
    GL30.glBindVertexArray(vao);

    int vbo = GL15.glGenBuffers();
    GL15.glBindBuffer(GL15.GL_ARRAY_BUFFER, vbo);
    FloatBuffer buffer = FloatBuffer.wrap(tridata);
    GL15.glBufferData(GL15.GL_ARRAY_BUFFER, buffer, GL15.GL_STATIC_DRAW);

    GL20.glEnableVertexAttribArray(0);
    GL15.glBindBuffer(GL15.GL_ARRAY_BUFFER, vbo);
    GL20.glVertexAttribPointer(0, 3, GL11.GL_FLOAT, false, 0, 0);

    while (!GLFW.glfwWindowShouldClose(window)) {
        update();
        render();
    }
}
private static void render() {
    GLFW.glfwSwapBuffers(window);
    GLFW.glfwPollEvents();
}
private static void update() {

}

}

这是错误消息：

Exception in thread "main" java.lang.NullPointerException
    at org.lwjglx.debug.opengl.GL30.glGenVertexArrays(GL30.java:107)
    at cut.Cut.render(Cut.java:83)
    at cut.Cut.loop(Cut.java:76)
    at cut.Cut.main(Cut.java:31)

我正在使用macOS 10.13和Java 8.我知道macOS因OpenGL问题而闻名。我使用VM参数“-XstartOnFirstThread”。

LWJGL3 GL30.glGenVertexArrays（）返回null

0 个答案: