vao

I am trying to understand these two, how to use them and how they are related. Let's say I want to create a simple terrain and a textured cube. For both objects I have the array of triangles vertices and for the cube I have an array containing the texture's data. My question is: how do I use VAOs and VBOs to create and render these two? Would I have to create a VAO and VBO for each object? or should create a VAO for each object's VBO (vertices, texture data, etc.)? There are many tutorials and books but I still don't get the very idea of how these concepts must be understood and used.

#define GLEW_STATIC #include <GL\glew.h> #include <GLFW\glfw3.h> #include <GL\glew.h> #include <glm.hpp> #include <iostream> #include <fstream> #include <string> #define WIDTH 800 #define HEIGHT 600 #define TITLE "Dynamic" GLFWwindow* window; int vaoID; float vertices[] = {-0.5f, 0.5f, 0, -0.5f, -0.5f, 0, 0.5f, 0.5f, 0, 0.5f, 0.5f, 0, -0.5f, -0.5f, 0, 0.5f, -0.5f, 0}; void loadToVAO(float vertices[]); void update() { loadToVAO(vertices); while (!glfwWindowShouldClose(window)) { glfwPollEvents(); glClear(GL_COLOR_BUFFER_BIT); glClearColor(1, 0, 0, 1); glDrawArrays(GL_TRIANGLES, 0, 6);

I am just starting to learn OpenGL today from this tutorial: http://openglbook.com/the-book/ I got to chapter 2, where I draw a triangle, and I understand everything except VAOs (is this acronym OK?). The tutorial has this code: glGenVertexArrays(1, &VaoId); glBindVertexArray(VaoId); While I understand that the code is necessary, I have no clue what it does. Although I never use VaoId past this point (except to destroy it), the code does not function without it. I am assuming this is because it is required to be bound, but I don't know why. Does this exact code just need to be part of every

Im facing an issue which I believe to be VAO-dependant, but Im not sure.. I am not sure about the correct usage of a VAO, what I used to do during GL initialization was a simple glGenVertexArrays(1,&vao) followed by a glBindVertexArray(vao) and later, in my drawing pipeline, I just called glBindBuffer(), glVertexAttribPointer(), glEnableVertexAttribArray() and so on.. without caring about the initally bound VAO is this a correct practice? VAOs act similarly to VBOs and textures with regard to how they are bound. Having a single VAO bound for the entire length of your program will yield no

I would like to know the attribute locations inside fixed pipeline (no shader attached) for nVidia OpenGL drivers: glVertex = 0 glColor = 3 glNormal = ? glTexCoord = ? glMultiTexCoord 0..7 = ? glSecondaryColor = ? glFog = ? Empirically I found the Vertex and primary Color locations but still will be nice to know them all. If you want to know why, then for compatibility reasons and even for GLSL debugging (just to see if I pass the correct data to correct locations when shader not works yet) and so on ... Outside of NVIDIA drivers, this does not work (reliably). Compliant drivers will only