/* grid.c */
/*

Riccardo Schmid
Created 2-10-04
Last Update 2 - 16- 04
*/


#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <limits.h>

#include "grid.h"

void gmultf(Grid *g, float mul) {
  int rows = g->nrows, cols = g->ncols, nodata = g->nodataval, i, j;
  int **tbl = g->tbl, *crt;

  for (i=0; i<rows; i++) {
    crt = *tbl;
    for (j=0; j<cols; j++) {
      if (*crt != nodata)
	*crt = mul * (float)(*crt);
      crt++;
    }
    tbl++;
  }
  g->minval *= mul;
  g->maxval *= mul;

}

void gmult(Grid *g, int mul) {
  int rows = g->nrows, cols = g->ncols, nodata = g->nodataval, i, j;
  int **tbl = g->tbl, *crt;

  for (i=0; i<rows; i++) {
    crt = *tbl;
    for (j=0; j<cols; j++) {
      if (*crt != nodata)
	*crt *= mul;
      crt++;
    }
    tbl++;
  }
  g->minval *= mul;
  g->maxval *= mul;

}


/* prints the table to the screen */
void gprint(Grid *g) {
  int i, j, rows, cols;
  rows = g->nrows;
  cols = g->ncols;
  
  int **tbl = g->tbl, *crt;

  for (i=0;i<rows; i++) {
    crt = *tbl;
    for (j=0; j<cols; j++) {
      printf("%d ", *crt);
      crt++;
    }
    printf("\n");
    tbl++;
  }
}


/* open the file containing the grid and store it
   in the grid argument.
   an integer > 0 is returned if error:
   1: File I/O error
   2: File read error
   3: Memory allocation error
*/
int gopen(Grid *g, char *filename) {
  
  FILE *fp;
  int rows, cols, nodata, minval = INT_MAX, maxval = INT_MIN;
  
  if (!(fp = fopen(filename,"r"))) 
    return 1;
  
  if (fscanf(fp, "ncols %d\n", &cols) != 1)
    return 2;
  g->ncols = cols;

  if (fscanf(fp, "nrows %d\n", &rows) != 1)
    return 2;
  g->nrows = rows;

  if (fscanf(fp,"xllcorner %f\n", &g->xllcorner) != 1)
    return 2;

  if (fscanf(fp,"yllcorner %f\n", &g->yllcorner) != 1)
    return 2;

  if (fscanf(fp,"cellsize %f\n", &g->cellsize) != 1)
    return 2;
  
  if (fscanf(fp, "NODATA_value %d\n", &nodata) != 1)
    return 2;
  g->nodataval = nodata;

  int **table, *crt;

  
  if (!(g->tbl = table = (int **)malloc(sizeof(int *) * rows)))
    return 3;

  int i, j;
  for (i=0; i<rows; i++) {
    if (!(*table = crt = (int *)malloc(sizeof(int) * cols)))
      return 3;
    for (j=0; j<cols; j++) {
      if (fscanf(fp, "%d", crt) != 1)
	return 2;
      
      if (*crt != nodata && *crt > maxval)
	maxval = *crt;
      else if (*crt != nodata && *crt < minval)
	minval = *crt;

      crt++;
    }
    fscanf(fp, "\n");
    table++;

    
  }
  
  
  g->minval = minval;
  g->maxval = maxval;

  fclose(fp);
  return 0;
  
}


/* save the grid to a file filename creates the file 
   if it does not exist
*/
int gsave(Grid *g, char *filename) {
  int i, j, rows = g->nrows, cols = g->ncols;
  FILE *fp;
  
  if (!(fp = fopen(filename, "w")))
    return 1;  

  /* print the headers */
  fprintf(fp,"ncols\t%d\n", g->ncols);
  fprintf(fp,"nrows\t%d\n", g->nrows);
  fprintf(fp,"xllcorner\t%f\n", g->xllcorner);
  fprintf(fp,"yllcorner\t%f\n", g->yllcorner);
  fprintf(fp,"cellsize\t%f\n", g->cellsize);
  fprintf(fp,"NODATA_value\t%d\n", g->nodataval);

  int **tbl = g->tbl, *crt;
  
/*   write the table */
  for (i=0;i<rows;i++) {
    crt = *tbl;
    for(j=0;j<cols;j++) {
      fprintf(fp, "%d ", *crt);
      crt++;
    }
    fprintf(fp, "\n");
    tbl++;
  }
  
  fclose(fp);
  return 0;
}

/* closes the grid and deallocates the memory
   used to store the grid
*/
void gkill(Grid *g) {
  int rows, i;
  rows = g->nrows;

  int **table;
  table = g->tbl;
  
  for (i=0; i<rows; i++)
    free(table[i]);

  free(table);
}