/* Simulation of 2-D mesh grid for CPSC 601.08           */
/*                                                       */
/* Written by Carey Williamson, University of Calgary    */
/*                                                       */
/* Usage: gcc -o grid2 grid2.c                           */
/*        ./grid2                                        */

#include <stdio.h>
#include <stdlib.h>
#include <math.h> /* use man 3 log for the math functions */

#define NUM_POINTS 1000   /* Number of WSN nodes to scatter */

#define X_RANGE 1.0 /* Distance in kilometers */
#define Y_RANGE 1.0 /* Distance in kilometers */

#define X_LINES 10
#define Y_LINES 10

/* Debugging output */
/* #define DEBUG 1 */

/***********************************************************************/
/*                 RANDOM NUMBER GENERATION STUFF                      */
/***********************************************************************/

/* Parameters for random number generation. */
#define MAX_INT 2147483647       /* Maximum positive integer 2^31 - 1 */

/* Generate a random floating point value uniformly distributed in [0,1] */
float Uniform01()
  {
    float randnum;

    /* get a random positive integer from random() */
    randnum = (float) 1.0 * random();

    /* divide by max int to get something in 0..1  */
    randnum = (float) randnum / (1.0 * MAX_INT); 

    return( randnum );
  }

/***********************************************************************/
/*                 MAIN PROGRAM                                        */
/***********************************************************************/

int main()
  {
    int i, j, xind, yind;
    float xcoord[NUM_POINTS];
    float ycoord[NUM_POINTS];
    int nodes[X_LINES][Y_LINES];

    /* Initialize */
    for( i = 0; i < X_LINES; i++ )
      {
	for( j = 0; j < Y_LINES; j++ )
	  {
	    nodes[i][j] = 0;
	  }
      }
    srandom(time(NULL));

#ifdef DEBUG
    printf("Placing %d WSN nodes into %d x %d sub-regions...\n",
	   NUM_POINTS, X_LINES, Y_LINES);
#endif

    /* Generate random placement of WSN nodes */
    for( i = 0; i < NUM_POINTS; i++ )
      {
	xcoord[i] = Uniform01() * X_RANGE;
	ycoord[i] = Uniform01() * Y_RANGE;

	/* count them up per sub-region */
	xind = xcoord[i] / (X_RANGE / X_LINES);
	yind = ycoord[i] / (Y_RANGE / Y_LINES);
	nodes[xind][yind]++;

#ifdef DEBUG
	printf("Placed WSN node at (%8.6f,%8.6f) in region [%d][%d]\n",
	       xcoord[i], ycoord[i], xind, yind);
#endif
      }


    /* Print results */
    for( i = 0; i < X_LINES; i++ )
      {
	for( j = 0; j < Y_LINES; j++ )
	  {
	    printf(" %3d ", nodes[i][j]);
	    printf("\n");
	  }
      }


  }