I have looked at several other questions on stack about this and it mentions de-referencing null pointers but I don't understand if that applies to my code.
The code crashes at line 33 in the World.cpp when trying to generate a VAO:
glGenVertexArrays(1, &vao); giving me the error shown in the title. If I comment out that line the program runs fine.
PhaseEngineMain.cpp
#include "PhaseEngineMain.h" #include "PhaseEngineController.h" int main(int argc, char *argv[]) { PhaseEngineController engine; engine.start(); return 0; } PhaseEngineController.h
#pragma once #include "SDL.h" #include "glew.h" #include "World.h" #include <iostream> class PhaseEngineController { public: PhaseEngineController(); ~PhaseEngineController(); void InitialiseEngine(); void IntitialseOpenGL(); void InitialiseSDL(Uint32 x, Uint32 y, Uint32 width, Uint32 height, Uint32 flags); void InitialiseGLEW(); void SetClearColour(float r, float g, float b, float a); void PrintIntialisationInfo(); void start(); void stop(); void run(); void UpdateLoop(); void RenderLoop(); void SwapBackBuffer(); private: SDL_Window* window; SDL_GLContext opengl_context; World world; bool running = false; }; PhaseEngineController.cpp
#include "PhaseEngineController.h" PhaseEngineController::PhaseEngineController() { InitialiseEngine(); InitialiseSDL(500, 500, 900, 600, SDL_WINDOW_SHOWN | SDL_WINDOW_OPENGL); IntitialseOpenGL(); InitialiseGLEW(); PrintIntialisationInfo(); world.addMesh(); } PhaseEngineController::~PhaseEngineController() { SDL_GL_DeleteContext(opengl_context); SDL_DestroyWindow(window); SDL_Quit(); } void PhaseEngineController::InitialiseEngine() { std::cout << "Intialising...\n" << std::endl; } void PhaseEngineController::IntitialseOpenGL() { opengl_context = SDL_GL_CreateContext(window); glClearColor(0, 0,0, 1); glEnable(GL_DEPTH_TEST); glDepthFunc(GL_LESS); std::cout << "gl initialised - rendering ready" << std::endl; } void PhaseEngineController::InitialiseSDL(Uint32 x, Uint32 y, Uint32 w, Uint32 h, Uint32 f) { int error = SDL_Init(SDL_INIT_EVERYTHING); SDL_GL_SetAttribute(SDL_GL_DOUBLEBUFFER, 1); SDL_GL_SetAttribute(SDL_GL_CONTEXT_MAJOR_VERSION, 4); SDL_GL_SetAttribute(SDL_GL_CONTEXT_MINOR_VERSION, 4); window = SDL_CreateWindow("Phaze Engine", x, y, w, h, f); std::cout << "SDL initialised - window created" << std::endl; } void PhaseEngineController::InitialiseGLEW() { GLenum err = glewInit(); if (GLEW_OK != err) { /* Problem: glewInit failed, something is seriously wrong. */ fprintf(stderr, "Error: %s\n", glewGetErrorString(err)); } else { std::cout << "GlEW Intialised - library ready" << std::endl; } } void PhaseEngineController::SetClearColour(float r, float g, float b, float a) { glClearColor(r, g, b, a); } void PhaseEngineController::start() { if (running) return; running = true; run(); } void PhaseEngineController::stop() { if (!running) return; running = false; } void PhaseEngineController::run() { while (running) { //std::cout << "working" << std::endl; RenderLoop(); //UpdateLoop(); } } void PhaseEngineController::UpdateLoop() { SDL_Event event; while (running) { /* Check for new events */ while (SDL_PollEvent(&event)) { /* If a quit event has been sent */ if (event.type == SDL_QUIT) { /* Quit the application */ running = false; } } } world.update(); } void PhaseEngineController::RenderLoop() { world.render(); SwapBackBuffer(); } void PhaseEngineController::SwapBackBuffer() { SDL_GL_SwapWindow(window); } void PhaseEngineController::PrintIntialisationInfo() { std::cout << "\nEngine Initialized...\n" << std::endl; } World.cpp
#include <iostream> unsigned int vbo = 0; unsigned int vao = 0; float points[] = { 0.0f, 0.5f, 0.0f, 0.5f, -0.5f, 0.0f, -0.5f, -0.5f, 0.0f }; World::World() { std::cout << "world created" << std::endl; } World::~World() { std::cout << "world destroyed" << std::endl; } void World::addMesh() { glGenBuffers(1, &vbo); glBindBuffer(GL_ARRAY_BUFFER, vbo); glBufferData(GL_ARRAY_BUFFER, 9 * sizeof (float), points, GL_STATIC_DRAW); glGenVertexArrays(1, &vao); //// <-- crashes here, this is line 33 std::cout << "mesh added " << std::endl; } void World::update() { } void World::render() { }