c++ - glGenBuffers 访问冲突异常

Question

我正在使用 GLFW 和 GLEW。 但是在我的对象初始化期间 glGenBuffers 抛出异常

void Character::init2D(glm::vec3 top, glm::vec3 bottom_left, glm::vec3 bottom_right)
{
    glm::vec3 Vertices[3];
    Vertices[0] = bottom_left;
    Vertices[1] = top;
    Vertices[2] = bottom_right;

    this->top = top;
    this->left_front = bottom_left;
    this->right_front = bottom_right;

    glGenBuffers(1, &VBO); //throws an exception 0xC0000005: Access violation
    glBindBuffer(GL_ARRAY_BUFFER, VBO);
    glBufferData(GL_ARRAY_BUFFER, sizeof(Vertices), Vertices, GL_STATIC_DRAW);

    CompileShaders(shaderProgram, "vertex.shader", "fragment.shader");
}

我这样声明我的类 Character

#include <GL\glew.h>
#include <GLFW\glfw3.h>
#include <glm\glm.hpp>
#include <glm\gtc\type_ptr.hpp>
#pragma comment(lib, "glfw3.lib")
#pragma comment(lib, "glew32.lib")

class Character
{
private:
    glm::vec3   top, 
                left_front, 
                right_front, 
                left_back, 
                right_back;
    GLuint VBO;
    GLuint shaderProgram;
public:
    Character();
    void init2D(glm::vec3 top, 
                glm::vec3 bottom_left, 
                glm::vec3 bottom_right);
    void draw();
    void move();
    void action();
    ~Character() {};
};

我的 main.cpp 看起来像这样

#include <iostream>
#include "character.h"
#define WIDTH 600
#define HEIGHT 600

using namespace std;

Character simple;

void render()
{
    simple.draw();
}

int main(int argc, char** argv)
{
    GLFWwindow *window;

    if (!glewInit())
        exit(EXIT_FAILURE);

    if (!glfwInit())
        exit(EXIT_FAILURE);

    window = glfwCreateWindow(WIDTH, HEIGHT, "Imensia", NULL, NULL);
    if (!window) { glfwTerminate(); exit(EXIT_FAILURE); }

    glm::vec3 left(-0.5, 0, 0);
    glm::vec3 top(0, 0.5, 0);
    glm::vec3 right(0.5, 0, 0);

    simple.init2D(top, left, right);

    glfwMakeContextCurrent(window);
    while(!glfwWindowShouldClose(window))
    {
        glViewport(0, 0, WIDTH, HEIGHT); 
        glClear(GL_COLOR_BUFFER_BIT);
        glMatrixMode(GL_PROJECTION);
        glLoadIdentity();
        glOrtho(-1, 1, -1, 1, 1, -1);
        glMatrixMode(GL_MODELVIEW);
        glLoadIdentity();

        render();

        glfwSwapBuffers(window);
        glfwPollEvents();
    }

    glfwDestroyWindow(window);
    glfwTerminate();

    return 0;
};

是初始化有问题还是什么？ 在项目的 properties 中，我设置了 include 和 library 目录...

Answer 1

Glew 初始化应该在创建 windows/opengl 上下文之后完成。

对于给定的代码，glewInit 可以移动到 glfwCreateWindow 的正下方:

int main(int argc, char** argv)
{
    GLFWwindow *window;

    if (!glfwInit())
        exit(EXIT_FAILURE);

    window = glfwCreateWindow(WIDTH, HEIGHT, "Imensia", NULL, NULL);
    if (!window) { glfwTerminate(); exit(EXIT_FAILURE); }

    if (!glewInit())
        exit(EXIT_FAILURE);
    :
    :
}