window - debug - specific

// import stdio and rendering libraries
#include <cstdio>
#include <GL/glew.h>
#include <GLFW/glfw3.h>

// given an error, put it into the error buffer
#define GL_ERROR_CASE(glerror) \
  case glerror:                \
    snprintf(error, sizeof(error), "%s", #glerror)

// while there are errors, print error, which file it came from, and which line of code.
inline void gl_debug(const char *file, int line)
{
  GLenum err;
  while ((err = glGetError()) != GL_NO_ERROR)
  {
    char error[128];
    // put error description in the buffer
    switch (err)
    {
      GL_ERROR_CASE(GL_INVALID_ENUM);
      break;
      GL_ERROR_CASE(GL_INVALID_VALUE);
      break;
      GL_ERROR_CASE(GL_INVALID_OPERATION);
      break;
      GL_ERROR_CASE(GL_INVALID_FRAMEBUFFER_OPERATION);
      break;
      GL_ERROR_CASE(GL_OUT_OF_MEMORY);
      break;
    default:
      snprintf(error, sizeof(error), "%s", "UNKNOWN_ERROR");
      break;
    }
    // print "error - file: line\n"
    fprintf(stderr, "%s - %s: %d\n", error, file, line);
  }
}

#undef GL_ERROR_CASE

// ...

  // if we see the below log statements, we've successfully attached OpenGL to the window
  // query the openGL version
  int glVersion[2] = {-1, 1};
  glGetIntegerv(GL_MAJOR_VERSION, &glVersion[0]);
  glGetIntegerv(GL_MINOR_VERSION, &glVersion[1]);

  gl_debug(__FILE__, __LINE__);

  // print some information about our version of OpenGL.
  printf("Using OpenGL: %d.%d\n", glVersion[0], glVersion[1]);
  printf("Renderer used: %s\n", glGetString(GL_RENDERER));
  printf("Shading Language: %s\n", glGetString(GL_SHADING_LANGUAGE_VERSION));

// ...