#include <GL/glfw.h>
#include <err.h>
#include <stdio.h>

int
main (void)
{
  int e;
  int buffer;

  if (glfwInit() != GL_TRUE)
    errx(1, "glfwInit");

  glfwOpenWindowHint(GLFW_OPENGL_VERSION_MAJOR, 3);
  glfwOpenWindowHint(GLFW_OPENGL_VERSION_MINOR, 1);
  if (glfwOpenWindow(640, 480, 8, 8, 8, 0, 24, 8, GLFW_WINDOW) != GL_TRUE)
    errx(1, "glfwOpenWindow");

  printf("renderer : %s\n", glGetString(GL_RENDERER));
  printf("version  : %s\n", glGetString(GL_VERSION));
  printf("vendor   : %s\n", glGetString(GL_VENDOR));

  glGenBuffers(1, &buffer);
  if (glGetError() != GL_NO_ERROR) errx(1, "glGenBuffers");
  glBindBuffer(GL_ARRAY_BUFFER, buffer);
  if (glGetError() != GL_NO_ERROR) errx(1, "glBindBuffer");
  glBufferData(GL_ARRAY_BUFFER, 4 * 32, NULL, GL_STATIC_DRAW);
  if (glGetError() != GL_NO_ERROR) errx(1, "glBufferData");
  glEnableVertexAttribArray(1);
  if (glGetError() != GL_NO_ERROR) errx(1, "glEnableVertexAttribArray");
  glVertexAttribPointer(1, 4, GL_FLOAT, 0, 0, 0L);

  e = glGetError();
  printf("glVertexAttribPointer: %x\n", e);

  glfwTerminate();
  return 0;
}