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

typedef struct pixel_type
{
   unsigned char r;
   unsigned char g;
   unsigned char b;
} pixel_t;

typedef struct image_type
{
   char filename[64];     /* name of disk resident file */
   char id[4];            /* P5 gray or P6 color        */
   int  width;            /* Width in pixel cols        */
   int  height;           /* depth in pixel rows        */
   pixel_t *pixels;       /* Address of the pixel data */
}  image_t;


/* We can create a 5 x 4 pixel image for testing in this way */
/* Each {x, y, z} triple encodes the r, g, b components of   */
/* a single pixel                                            */

pixel_t pixmap[20] =
{
   {33, 44, 51}, {31, 45, 11}, {23, 34, 41}, {53, 64, 71}, {23, 44, 31},
   {33, 44, 51}, {32, 46, 21}, {23, 34, 41}, {53, 64, 71}, {23, 44, 31},
   {33, 44, 51}, {33, 47, 31}, {23, 34, 41}, {53, 64, 71}, {23, 44, 31},
   {33, 44, 51}, {34, 48, 41}, {23, 34, 41}, {53, 64, 71}, {23, 44, 31}
};

/* We can initialize an image structure in this way   */
/* By specifically enumerating the structure elements */
/* we wish to configure we don't have to initialize   */
/* the entire structure                               */

/* Format is -  element_name: element_vale,           */

image_t image =
{
   width:  5,
   height: 4,
   pixels: pixmap
};

/* Read values into the 3 x 3 filter from the standard input */

int read_filter(
double filt[3][3])
{

-----------------------------------

}

/* Print the values of the filter */

void print_filter(
double filt[3][3])
{
   int i, j;

   for (i = 0; i < 3; i++)
   {
      for (j = 0; j < 3; j++)
      {
         fprintf(stdout, "%8.3lf ", filt[i][j]);
      }
      fprintf(stdout, "\n");
   }
}

/* Apply fliter to the pixel and location (row, col) */
/* in the image.. Fill in and return the filtered    */
/* pixel in "result"                                 */

pixel_t apply_filter(
image_t *image,
double filt[3][3],
int row,
int col)
{
   pixel_t result = {0, 0, 0};
   int i, j, ndx;

   double rsum = 0.0;  // Accumulate red, green and blue
   double gsum = 0.0;  //   channel sums here
   double bsum = 0.0;

   for (i = 0; i < 3; i++)
   {
     for (j = 0; j < 3; j++)
     {
     /* For each iteration of the inner loop add the product of     */
     /* filt[i][j] with the r, g, b components of the corresponding */
     /* image pixel to rsum, gsum, and bsum                         */

     --------------------------------------

     }
   }

/* Construct the result pixel and return it */

   -------------------------------------

   return(result);
}

int main()
{
   pixel_t ans;
   int row, col;

   double filter[3][3];

   read_filter(filter);
   print_filter(filter);

/* Read in the location of the pixel to be filtered * /

// fscanf(stdin, "%d %d", &row, &col);

/* Apply the filter to the pixel */

// ans = apply_filter(&image, filter, row, col);

/* Print out the value of the filtered pixel */

// fprintf(stdout, " R = %d  G = %d  B = %d \n",
//               ans.r, ans.g,  ans.b);

   return(0);
}