// Remove the header lines if you include this file in your program.
// Keep the header files if this is a separate file.

#include <stdio.h>
#include <GL/glut.h>

void CheckErr()
{
  int err;
  char errors[7][21] =
      { "GL_INVALID_ENUM", "GL_INVALID_VALUE", "GL_INVALID_OPERATION",
    "GL_STACK_OVERFLOW", "GL_STACK_UNDERFLOW", "GL_OUT_OF_MEMORY",
    "GL_TABLE_TOO_LARGE"
  };

  err = -1;
  switch (glGetError()) {
  case GL_NO_ERROR:
    break;                      // do nothing
  case GL_INVALID_ENUM:
    err = 0;
    break;
  case GL_INVALID_VALUE:
    err = 1;
    break;
  case GL_INVALID_OPERATION:
    err = 2;
    break;
  case GL_STACK_OVERFLOW:
    err = 3;
    break;
  case GL_STACK_UNDERFLOW:
    err = 4;
    break;
  case GL_OUT_OF_MEMORY:
    err = 5;
    break;
  case GL_TABLE_TOO_LARGE:
    err = 6;
  }

  if (err >= 0)
    printf("%s\n", errors[err]);
}