# include <stdlib.h>
# include <stdio.h>
# include <stdbool.h>
# include <math.h>
# include <time.h>

# include <GL/glut.h>

int main ( int argc, char *argv[] );
void box_draw ( int i, int j, bool state_ij );
void display ( );
int i4_max ( int i1, int i2 );
int i4_min ( int i1, int i2 );
int i4_uniform_ab ( int a, int b );
void my_init ( ) ;
void my_mouse ( int btn, int mouse_state, int x, int y );
int r4_nint ( float x );
void state_randomize ( int moves, int m, int n, bool state[] );
void state_update ( int m, int n, bool state[], int i, int j );
void timestamp ( );
/*
  Global data.
*/
  int box_size;
  bool *state;
  int m;
  int n;
  int pixel_height;
  int pixel_width;

/******************************************************************************/

int main ( int argc, char *argv[] )

/******************************************************************************/
/*
  Purpose:

    lights_out_opengl() runs the Lights Out puzzle.

  Licensing:

    This code is distributed under the MIT license. 

  Modified:

    01 April 2023

  Author:

    John Burkardt
*/
{
  int moves;

  timestamp ( );

  printf ( "\n" );
  printf ( "lights_out_opengl():\n" );
  printf ( "  C version\n" );
  printf ( "  This program sets up a version of the \"LIGHTS OUT\" puzzle.\n" );
  printf ( "  Your goal is to turn all the lights out.\n" );
  printf ( "  Clicking a square switches it from ON to OFF or vice versa.\n" );
  printf ( "  But it also switches the four neighbors.\n" );
  printf ( "\n" ); 
  printf ( "  Compiled on %s at %s.\n", __DATE__, __TIME__ );
/*
  Initialize the random number generator.
*/
  srand48 ( ( long int ) time ( NULL ) );
/*
  Expect width N.
*/
  if ( argc <= 1 ) 
  {
    printf ( "\n" );
    printf ( "  Enter the WIDTH of the board, (10 is a good value).\n" );

    scanf ( "%i", &n );
  }
  else 
  {
    n = atoi ( argv[1] );
  }
/*
  Expect height M.
*/
  if ( argc <= 2 ) 
  {
    printf ( "\n" );
    printf ( "  Enter the HEIGHT of the board, (10 is a good value).\n" );

    scanf ( "%i", &m );
  }
  else 
  {
    m = atoi ( argv[2] );
  }
/*
  Expect number of randomized moves MOVES.
*/
  if ( argc <= 3 ) 
  {
    printf ( "\n" );
    printf ( "  Enter the number of scrambling steps.\n" );
    printf ( "  (Use a low number like 3 for beginners.)\n" );

    scanf ( "%i", &moves );
  }
  else 
  {
    moves = atoi ( argv[3] );
  }
/*
  Randomize the state.
*/
  state = ( bool * ) malloc ( m * n * sizeof ( bool ) );

  state_randomize ( moves, m, n, state );

  printf ( "\n" );
  printf ( "  The board will be %d boxes wide by %d boxes high.\n", n, m );

  glutInit ( &argc, argv );
/*
  Use double buffering; otherwise the screen jitters when the user
  updates it.
*/
  glutInitDisplayMode ( GLUT_DOUBLE | GLUT_RGB );
/*
  Set up the screen, using 800 pixels in the long dimension.
*/
  if ( m == n )
  {
    box_size = ( 800 / m );
    pixel_width = 800;
    pixel_height = 800;
  }
  else if ( m < n )
  {
    box_size = ( 800 / n );
    pixel_width = n * box_size;
    pixel_height = m * box_size;
  }
  else if ( n < m )
  {
    box_size = ( 800 / m );
    pixel_width = n * box_size;
    pixel_height = m * box_size;
  }
  printf ( "  Box size = %d\n", box_size );
  printf ( "  Pixels(WxH):  %d  %d\n", pixel_width, pixel_height );
/*
  Now call OpenGL to get going.
*/
  glutInitWindowSize ( pixel_width, pixel_height );
  glutInitWindowPosition ( 0, 0 );

  glutCreateWindow ( "Lights Out!" );
  glutDisplayFunc ( display );
  my_init ( );
  glutMouseFunc ( my_mouse );
  glutMainLoop ( );
/*
  Free memory.
*/
  free ( state );
/*
  Terminate.
*/
  printf ( "\n" );
  printf ( "lights_out_opengl()\n" );
  printf ( "  Normal end of execution.\n" );

  printf ( "\n" );
  timestamp ( );

  return 0;
}
/******************************************************************************/

void box_draw ( int i, int j, bool state_ij ) 

/******************************************************************************/
/*
  Purpose:

    box_draw() draws one box of the Lights Out array.

  Licensing:

    This code is distributed under the MIT license. 

  Modified:

    16 January 2009

  Author:

    John Burkardt

  Parameters:

    Input, int I, J, the row and column of the box.

    Input, bool STATE_IJ, is TRUE if the box is "ON".
*/
{
  float p[2];
  GLfloat a;
  GLfloat b;
  GLfloat c;
  GLfloat gray[3] = { 0.8, 0.8, 0.8 };
  GLfloat yellow[3] = { 1.0, 1.0, 0.0 };
/*
  Set the color.
*/
  if ( state_ij )
  {
    glColor3fv ( yellow );
  }
  else
  {
    glColor3fv ( gray );
  }
/*
  Locate (A,B), the lower left corner of the box.

    A,B+C---A+C,B+C
     |         |
     |         |
    A,B-----A+C,B
*/
  c = box_size;
  a =                      j   * c;
  b = ( m - 1 - i ) * c;
/*
  Fill the box with color, but leave a margin of 3 pixels.
*/
  glBegin ( GL_POLYGON );
    p[0] = a + 3;
    p[1] = b + 3;
    glVertex2fv ( p );
    p[0] = a + c - 3;
    p[1] = b + 3;
    glVertex2fv ( p );
    p[0] = a + c - 3;
    p[1] = b + c - 3;
    glVertex2fv ( p );
    p[0] = a + 3;
    p[1] = b + c - 3;
    glVertex2fv ( p );
  glEnd ( );
/*
  Draw box boundaries in BLUE.
*/
  glColor3f ( 0.0, 0.0, 1.0 );

  glBegin ( GL_LINE_LOOP );
    p[0] = a;
    p[1] = b;
    glVertex2fv ( p );
    p[0] = a + c;
    p[1] = b;
    glVertex2fv ( p );
    p[0] = a + c;
    p[1] = b + c;
    glVertex2fv ( p );
    p[0] = a;
    p[1] = b + c;
    glVertex2fv ( p );
  glEnd ( );
/*
  Clear all the buffers.
*/
  glFlush ( );

  return;
}
/******************************************************************************/

void display ( ) 

/******************************************************************************/
/*
  Purpose:

    DISPLAY generates the graphics output.

  Licensing:

    This code is distributed under the MIT license. 

  Modified:

    16 January 2009

  Author:

    John Burkardt
*/
{
  int i;
  int j;
/*
  Clear the window.
*/
  glClear ( GL_COLOR_BUFFER_BIT );
/*
  Draw each box.
*/
  for ( j = 0; j < n; j++ )
  {
    for ( i = 0; i < m; i++ )
    {
      box_draw ( i, j, state[i+j*m] );
    }
  }
  glFlush ( );
/*
  Time to swap buffers.
*/
  glutSwapBuffers ( );

  return;
}
/******************************************************************************/

int i4_max ( int i1, int i2 )

/******************************************************************************/
/*
  Purpose:

    I4_MAX returns the maximum of two I4's.

  Licensing:

    This code is distributed under the MIT license.

  Modified:

    29 August 2006

  Author:

    John Burkardt

  Parameters:

    Input, int I1, I2, are two integers to be compared.

    Output, int I4_MAX, the larger of I1 and I2.
*/
{
  int value;

  if ( i2 < i1 )
  {
    value = i1;
  }
  else
  {
    value = i2;
  }
  return value;
}
/******************************************************************************/

int i4_min ( int i1, int i2 )

/******************************************************************************/
/*
  Purpose:

    I4_MIN returns the smaller of two I4's.

  Licensing:

    This code is distributed under the MIT license.

  Modified:

    29 August 2006

  Author:

    John Burkardt

  Parameters:

    Input, int I1, I2, two integers to be compared.

    Output, int I4_MIN, the smaller of I1 and I2.
*/
{
  int value;

  if ( i1 < i2 )
  {
    value = i1;
  }
  else
  {
    value = i2;
  }
  return value;
}
/******************************************************************************/

int i4_uniform_ab ( int a, int b )

/******************************************************************************/
/*
  Purpose:

    i4_uniform_ab() returns a scaled pseudorandom I4 between A and B.

  Discussion:

    The pseudorandom number should be uniformly distributed
    between A and B.

  Licensing:

    This code is distributed under the MIT license. 

  Modified:

    24 May 2012

  Author:

    John Burkardt

  Reference:

    Paul Bratley, Bennett Fox, Linus Schrage,
    A Guide to Simulation,
    Second Edition,
    Springer, 1987,
    ISBN: 0387964673,
    LC: QA76.9.C65.B73.

    Bennett Fox,
    Algorithm 647:
    Implementation and Relative Efficiency of Quasirandom
    Sequence Generators,
    ACM Transactions on Mathematical Software,
    Volume 12, Number 4, December 1986, pages 362-376.

    Pierre L'Ecuyer,
    Random Number Generation,
    in Handbook of Simulation,
    edited by Jerry Banks,
    Wiley, 1998,
    ISBN: 0471134031,
    LC: T57.62.H37.

    Peter Lewis, Allen Goodman, James Miller,
    A Pseudo-Random Number Generator for the System/360,
    IBM Systems Journal,
    Volume 8, Number 2, 1969, pages 136-143.

  Input:

    int A, B, the limits of the interval.

  Output:

    int I4_UNIFORM_AB, a number between A and B.
*/
{
  int c;
  float r;
  int value;
/*
  Guarantee A <= B.
*/
  if ( b < a )
  {
    c = a;
    a = b;
    b = c;
  }

  r = drand48 ( );
/*
  Scale R to lie between A-0.5 and B+0.5.
*/
  r = ( 1.0 - r ) * ( ( float ) ( a ) - 0.5 ) 
    +         r   * ( ( float ) ( b ) + 0.5 );
/*
  Round R to the nearest integer.
*/
  value = round ( r );
/*
  Guarantee that A <= VALUE <= B.
*/
  if ( value < a )
  {
    value = a;
  }
  if ( b < value )
  {
    value = b;
  }

  return value;
}
/******************************************************************************/

void my_init ( ) 

/******************************************************************************/
/*
  Purpose:

    MY_INIT initializes OpenGL state variables dealing with viewing and attributes.

  Licensing:

    This code is distributed under the MIT license. 

  Modified:

    16 January 2009

  Author:

    John Burkardt
*/
{
  glClearColor ( 1.0, 1.0, 1.0, 0.0 );

  glMatrixMode ( GL_PROJECTION );
  glLoadIdentity ( );
/*
  Change this to proportions for MxN
*/
  gluOrtho2D ( 0.0, ( double ) pixel_width, 0.0, ( double ) pixel_height );
  glMatrixMode ( GL_MODELVIEW );

  return;
}
/******************************************************************************/

void my_mouse ( int btn, int mouse_state, int x, int y )

/******************************************************************************/
/*
  Purpose:

    MY_MOUSE reacts to mouse events.

  Discussion:

    Right now, the only mouse event is a click on a box inside the board,
    which causes that box and its neighbors to change state.

  Licensing:

    This code is distributed under the MIT license. 

  Modified:

    15 January 2009

  Author:

    John Burkardt

  Parameters:
*/
{
  int i;
  int j;
/*
  (I,J) are the coordinates of the point where we have clicked the mouse.
*/
  i = y / box_size;
  j = x / box_size;
/*
  Update the board, so that box (I,J) and its neighbors are switched.
*/
  if ( btn == GLUT_LEFT_BUTTON && mouse_state == GLUT_DOWN )
  {
    state_update ( m, n, state, i, j );
  }
  else if ( btn == GLUT_MIDDLE_BUTTON && mouse_state == GLUT_DOWN )
  {
    state_update ( m, n, state, i, j );
  }
  else if ( btn == GLUT_RIGHT_BUTTON && mouse_state == GLUT_DOWN )
  {
    state_update ( m, n, state, i, j );
  }
/*
  Redisplay the screen.
  Since this causes a jerky screen, it would be best to double buffer!
*/
  display ( );

  return;
}
/******************************************************************************/

int r4_nint ( float x )

/******************************************************************************/
/*
  Purpose:

    R4_NINT returns the nearest integer to an R4.

  Example:

        X         R4_NINT

      1.3         1
      1.4         1
      1.5         1 or 2
      1.6         2
      0.0         0
     -0.7        -1
     -1.1        -1
     -1.6        -2

  Licensing:

    This code is distributed under the MIT license.

  Modified:

    05 May 2006

  Author:

    John Burkardt

  Parameters:

    Input, float X, the value.

    Output, int R4_NINT, the nearest integer to X.
*/
{
  int s;
  int value;

  if ( x < 0.0 )
  {
    s = - 1;
  }
  else
  {
    s = + 1;
  }
  value = s * ( int ) ( fabs ( x ) + 0.5 );

  return value;
}
/******************************************************************************/

void state_randomize ( int moves, int m, int n, bool state[] )

/******************************************************************************/
/*
  Purpose:

    STATE_RANDOMIZE randomizes the state.

  Licensing:

    This code is distributed under the MIT license. 

  Modified:

    16 January 2009

  Author:

    John Burkardt

  Parameters:

    Input, int MOVES, the number of moves to make.

    Input, int M, N, the number of rows and columns.

    Output, bool STATE[M*N], the Lights Out state.
*/
{
  int i;
  int j;
  int k;
/*
  Start with all boxes OFF.
*/
  for ( j = 0; j < n; j++ )
  {
    for ( i = 0; i < m; i++ )
    {
      state[i+j*m] = false;
    }
  }
/*
  Choose a box at random, and update it (and its four neighbors).
*/
  for ( k = 0; k < moves; k++ )
  {
    i = i4_uniform_ab ( 0, m - 1 );
    j = i4_uniform_ab ( 0, n - 1 );
    state_update ( m, n, state, i, j );
  }

  return;
}
/******************************************************************************/

void state_update ( int m, int n, bool state[], int i, int j )

/******************************************************************************/
/*
  Purpose:

    state_update() updates the state after button (I,J) has been pressed.

  Discussion:

    Reverse the states of 

               (I-1,J)
      (I,J-1)  (I,  J)  (I,J+1)
               (I+1,J)

  Licensing:

    This code is distributed under the MIT license. 

  Modified:

    15 January 2009

  Author:

    John Burkardt

  Parameters:

    Input, int M, N, the number of rows and columns.

    Input/output, bool STATE[M*N], the Lights Out state.

    Input, int I, J, the row and column that were pressed.
*/
{
  int center;
  int down;
  int left;
  int right;
  int up;

  if ( i < 0 || m <= i )
  {
    fprintf ( stderr, "\n" );
    fprintf ( stderr, "STATE_UPDATE - Fatal error!\n" );
    fprintf ( stderr, "  Illegal row index I.\n" );
    exit ( 1 );
  }

  if ( j < 0 || n <= j )
  {
    fprintf ( stderr, "\n" );
    fprintf ( stderr, "STATE_UPDATE - Fatal error!\n" );
    fprintf ( stderr, "  Illegal column index J.\n" );
    exit ( 1 );
  }
/*
  Locate the center box and its four neighbors.
*/
  up     = ( i - 1 ) +   j       * m;
  down   = ( i + 1 ) +   j       * m;
  center =   i       +   j       * m;
  left   =   i       + ( j - 1 ) * m;
  right  =   i       + ( j + 1 ) * m;
/*
  Reverse the center, and reverse each neighbor, as long as
  we don't have to go outside the legal range.
*/
  if ( 0 < i )
  {
    state[up] = !state[up];
  }

  if ( 0 < j )
  {
    state[left] = !state[left];
  }

  state[center] = !state[center];

  if ( j < n - 1 )
  {
    state[right] = !state[right];
  }

  if ( i < m - 1 )
  {
    state[down] = !state[down];
  }

  return;
}
/******************************************************************************/

void timestamp ( void )

/******************************************************************************/
/*
  Purpose:

    TIMESTAMP prints the current YMDHMS date as a time stamp.

  Example:

    31 May 2001 09:45:54 AM

  Licensing:

    This code is distributed under the MIT license.

  Modified:

    24 September 2003

  Author:

    John Burkardt

  Parameters:

    None
*/
{
# define TIME_SIZE 40

  static char time_buffer[TIME_SIZE];
  const struct tm *tm;
  time_t now;

  now = time ( NULL );
  tm = localtime ( &now );

  strftime ( time_buffer, TIME_SIZE, "%d %B %Y %I:%M:%S %p", tm );

  fprintf ( stdout, "%s\n", time_buffer );

  return;
# undef TIME_SIZE
}