VAO VBO EBO

GLuint VBO, VA0, EBO;
    {
        GLfloat pts[] =
        {
            0.5f, 0.5f, 0.0f, 1, 0, 0,   // 右上角
            0.5f, -0.5f, 0.0f, 0, 1, 0, // 右下角
            -0.5f, -0.5f, 0.0f, 0, 0, 1, // 左下角
            -0.5f, 0.5f, 0.0f, 1, 1, 0 // 左上角
        };

        GLuint indices[] =
        { // 注意索引从0开始!
            0, 1, 3, // 第一个三角形
            1, 2, 3  // 第二个三角形
        };

        glGenVertexArrays(1, &VA0);
        glGenBuffers(1, &VBO);
        glGenBuffers(1, &EBO);

        glBindVertexArray(VA0);
        glBindBuffer(GL_ARRAY_BUFFER, VBO);
        glBufferData(GL_ARRAY_BUFFER, sizeof(pts), pts, GL_STATIC_DRAW);

        glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, EBO);
        glBufferData(GL_ELEMENT_ARRAY_BUFFER, sizeof(indices), indices, GL_STATIC_DRAW);

        glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, 6 * sizeof(GLfloat), (void*)0);

        glVertexAttribPointer(1, 3, GL_FLOAT, GL_FALSE, 6 * sizeof(GLfloat),    (void*) (3 * sizeof(GLfloat)));
        glEnableVertexAttribArray(0);
        glEnableVertexAttribArray(1);

        glBindBuffer(GL_ARRAY_BUFFER, 0);
        glBindVertexArray(0);
    }

while (!glfwWindowShouldClose(window))
    {
        glfwPollEvents();

        glClearColor(color1, color2, color3, 1);
        glClear(GL_COLOR_BUFFER_BIT);

        glBindVertexArray(VA0);
        shader->Use();
        //glDrawArrays(GL_TRIANGLES, 0, 3);
        glDrawElements(GL_TRIANGLES, 6, GL_UNSIGNED_INT, 0);
        glBindVertexArray(0);

        glfwSwapBuffers(window);
    }