[SOLVED] Native crash in GL15.glGenBuffers

[jorrit]

Hi, I'm a new LWJGL user and I'm having trouble with glGenBuffers. I first started with the simple tutorial (the one that shows a red window) from the main site and that works fine. However, then I wanted to extend it to draw a triangle but my program now crashes in GL15.glGenBuffers():

# A fatal error has been detected by the Java Runtime Environment:
#
#  EXCEPTION_ACCESS_VIOLATION (0xc0000005) at pc=0x000007fee6321f1d, pid=4320, tid=10784
#
# JRE version: Java(TM) SE Runtime Environment (8.0_91-b14) (build 1.8.0_91-b14)
# Java VM: Java HotSpot(TM) 64-Bit Server VM (25.91-b14 mixed mode windows-amd64 compressed oops)
# Problematic frame:
# C  [lwjgl_opengl.dll+0x11f1d]
#
# 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:\Personal\projects\Orbis\hs_err_pid4320.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.

My code:

import org.lwjgl.glfw.GLFWErrorCallback;
import org.lwjgl.glfw.GLFWVidMode;
import org.lwjgl.opengl.GL;
import org.lwjgl.opengl.GL15;
import org.lwjgl.opengl.GL20;
import org.lwjgl.system.MemoryStack;

import java.nio.IntBuffer;

import static org.lwjgl.glfw.Callbacks.glfwFreeCallbacks;
import static org.lwjgl.glfw.GLFW.*;
import static org.lwjgl.opengl.GL11.*;
import static org.lwjgl.system.MemoryStack.stackPush;
import static org.lwjgl.system.MemoryUtil.NULL;


public class Main {

    private long window;
    int vertexBuffer;

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

    private void run() {
        init();
        loop();

        glfwFreeCallbacks(window);
        glfwDestroyWindow(window);

        glfwTerminate();
        glfwSetErrorCallback(null).free();
    }

    private void init() {
        GLFWErrorCallback.createPrint(System.err).set();
        if (!glfwInit()) {
            throw new IllegalStateException("Unable to initialize GLFW");
        }

        glfwDefaultWindowHints();
        glfwWindowHint(GLFW_VISIBLE, GLFW_FALSE);
        glfwWindowHint(GLFW_RESIZABLE, GLFW_TRUE);

        window = glfwCreateWindow(300, 300, "Hello World", NULL, NULL);
        if (window == NULL) {
            throw new RuntimeException("Failed to create the GLFW window");
        }


        glfwSetKeyCallback(window, (window, key, scancode, action, mods) -> {
            if (key == GLFW_KEY_ESCAPE && action == GLFW_RELEASE) {
                glfwSetWindowShouldClose(window, true);
            }
        });

        try (MemoryStack stack = stackPush() ) {
            IntBuffer pWidth = stack.mallocInt(1);
            IntBuffer pHeight = stack.mallocInt(1);

            glfwGetWindowSize(window, pWidth, pHeight);

            GLFWVidMode vidmode = glfwGetVideoMode(glfwGetPrimaryMonitor());

            glfwSetWindowPos(window,
                    (vidmode.width() - pWidth.get(0)) / 2,
                    (vidmode.height() - pHeight.get(0)) / 2);
        }

        glfwMakeContextCurrent(window);

        glfwSwapInterval(1);
        glfwShowWindow(window);

        setupGeometry();
    }

    private void setupGeometry() {
        vertexBuffer = GL15.glGenBuffers();                 // <----- CRASH HERE
        GL15.glBindBuffer(GL15.GL_ARRAY_BUFFER, vertexBuffer);
        GL15.glBufferData(GL15.GL_ARRAY_BUFFER, DATA, GL15.GL_STATIC_DRAW);
    }

    private void loop() {
        GL.createCapabilities();

        glClearColor(1.0f, 0.0f, 0.0f, 0.0f);

        while (!glfwWindowShouldClose(window)) {
            glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);

            drawTriangles();

            glfwSwapBuffers(window);
            glfwPollEvents();
        }
    }

    private void drawTriangles() {
        GL20.glEnableVertexAttribArray(0);
        GL15.glBindBuffer(GL15.GL_ARRAY_BUFFER, vertexBuffer);
        GL20.glVertexAttribPointer(
                0,
                3,
                GL_FLOAT,
                false,
                0,
                0L);
        glDrawArrays(GL_TRIANGLES, 0, 3);
        GL20.glDisableVertexAttribArray(0);
    }

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

This is on Windows btw. Any idea what could be wrong?

Thanks!

[Kai]

You are using OpenGL functions (in setupGeometry() called from init()) before calling GL.createCapabilities().
You must only use OpenGL functions after calling glfwMakeContextCurrent() as well as GL.createCapabilities().

[jorrit]

Oh thank you! I'll try that out.

Yes. It works! Thanks you