This is my code:

#define GLEW_STATIC
#include <GL/glew.h>
#include <GLFW/glfw3.h>

const int IMAGE_SIZE = 32;

GLFWwindow* window;
GLuint vao;
GLuint vbo;

int initWindow() {
    // Initialize GLFW
    if (!glfwInit()) {
        cerr << "Error: Failed to initialize GLFW." << endl;
        return 1;
    }

    // Set up GLFW window hints for OpenGL 3.3
    glfwWindowHint(GLFW_CONTEXT_VERSION_MAJOR, 3);
    glfwWindowHint(GLFW_CONTEXT_VERSION_MINOR, 3);
    glfwWindowHint(GLFW_OPENGL_PROFILE, GLFW_OPENGL_CORE_PROFILE);
    glfwWindowHint(GLFW_OPENGL_FORWARD_COMPAT, GL_TRUE);

    // Create window
    window = glfwCreateWindow(IMAGE_SIZE * 20, IMAGE_SIZE * 20   60, "PBM Image", NULL, NULL);
    if (!window) {
        cerr << "Error: Failed to create GLFW window." << endl;
        glfwTerminate();
        return 1;
    }
    // Create context
    glfwMakeContextCurrent(window);
    // Set color and blendmode
    glClearColor(1.0f, 1.0f, 1.0f, 1.0f);
    glEnable(GL_BLEND);
    glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);

    // Create and bind VAO and VBO
    glGenVertexArrays(1, &vao);
    glBindVertexArray(vao); // Here is the spot where I get the exception
    glGenBuffers(1, &vbo);
    glBindBuffer(GL_ARRAY_BUFFER, vbo);

    return 0;
}

void renderImage(vector<unsigned char> vertices) {
    // Update VBO data
    glBufferData(GL_ARRAY_BUFFER, vertices.size(), vertices.data(), GL_STATIC_DRAW);
    // Set vertex attribute pointers
    glVertexAttribPointer(0, 3, GL_UNSIGNED_BYTE, GL_FALSE, 3 * sizeof(unsigned char), (void*)0);
    glEnableVertexAttribArray(0);
    // Unbind VBO and VAO
    glBindBuffer(GL_ARRAY_BUFFER, 0);
    glBindVertexArray(0);
    // Set up projection matrix
    glMatrixMode(GL_PROJECTION);
    glLoadIdentity();
    glOrtho(0.0, IMAGE_SIZE, 0.0, IMAGE_SIZE, 0.0, 1.0);
    // Clear screen
    glClear(GL_COLOR_BUFFER_BIT);
    // Bind VAO
    glBindVertexArray(vao);
    // Draw points
    glDrawArrays(GL_POINTS, 0, vertices.size() / 3);
    // Unbind VAO
    glBindVertexArray(0);
    // Swap buffers
    glfwSwapBuffers(window);
}

int main() {
    if (initWindow()) return 1;
    // Here comes the code that generates vector<unsigned char> vertices
    renderImage(vertices);
    getchar();
    // Delete VAO and VBO
    glDeleteVertexArrays(1, &vao);
    glDeleteBuffers(1, &vbo);
    // Terminate GLFW
    glfwTerminate();
    return 0;
}

It uses glew to setup opengl and glfw for window handling. After initializing the window it generates vector<unsigned char> vertices which renderImage takes in. Afterwards it removes VAO, VBO and terminates GLFW. But it won't even come to that point because it throws the following exception at glBindVertexArray(vao);:

Exception thrown at 0x0000000000000000 in generator.exe: 0xC0000005: Access violation executing location 0x0000000000000000.

Here are my lib and include settings and folders:

VC Directories

Input

Lib Folder

Lib x64 Folder

Include GL

Include GLFW

CodePudding user response：

glew needs to be initialized (see Initializing GLEW). If glew is not initialized, the OpenGL API function pointers are not set. Call glewInit() right after glfwMakeContextCurrent(window):

glfwMakeContextCurrent(window);
if (glewInit() != GLEW_OK)
    return 1;