/* pbmminkowsky.c - read a portable bitmap and calculate the Minkowski Integrals

**

** Copyright (C) 2000 by Luuk van Dijk/Mind over Matter

**

** Based on pbmlife.c,

** Copyright (C) 1988,1 1991 by Jef Poskanzer.

**

** Permission to use, copy, modify, and distribute this software and its

** documentation for any purpose and without fee is hereby granted, provided

** that the above copyright notice appear in all copies and that both that

** copyright notice and this permission notice appear in supporting

** documentation.  This software is provided "as is" without express or

** implied warranty.

*/

#include "pbm.h"

#define ISWHITE(x) ((x) == PBM_WHITE)

int main(int argc, const char ** argv) {

    FILE * ifP;

    bit * prevrow;

    bit * thisrow;

    bit * tmprow;

    int row;

    int col; 

    int countTile;

    int countEdgeX;

    int countEdgeY;

    int countVertex;

    int rows;

    int cols;

    int format;

    int area, perimeter, eulerchi;

    pm_proginit(&argc, argv);

    if (argc > 2)

        pm_usage("[pbmfile]");

    if (argc == 2)

        ifP = pm_openr(argv[1]);

    else

        ifP = stdin;

    pbm_readpbminit(ifP, &cols, &rows, &format);

    prevrow = pbm_allocrow(cols);

    thisrow = pbm_allocrow(cols);

    /* first row */

    pbm_readpbmrow(ifP, thisrow, cols, format);

    countTile   = 0;

    countEdgeX  = 0;

    countEdgeY  = 0;

    countVertex = 0;

    /* tiles */

    for (col = 0; col < cols; ++col) 

        if (ISWHITE(thisrow[col]))

            ++countTile;

    /* shortcut: for the first row, edgeY == countTile */

    countEdgeY = countTile;

    /* x-edges */

    if (ISWHITE(thisrow[0]))

        ++countEdgeX;

    for (col = 0; col < cols-1; ++col) 

        if (ISWHITE(thisrow[col]) || ISWHITE(thisrow[col+1]))

            ++countEdgeX;

    if (ISWHITE(thisrow[cols-1]))

        ++countEdgeX;

    /* shortcut: for the first row, countVertex == countEdgeX */

    countVertex = countEdgeX;

    for (row = 1; row < rows; ++row) {  

        tmprow  = prevrow; 

        prevrow = thisrow;

        thisrow = tmprow;

        pbm_readpbmrow(ifP, thisrow, cols, format);

        /* tiles */

        for (col = 0; col < cols; ++col) 

            if (ISWHITE(thisrow[col]))

                ++countTile;

        /* y-edges */

        for (col = 0; col < cols; ++col) 

            if (ISWHITE(thisrow[col]) || ISWHITE(prevrow[col]))

                ++countEdgeY;

        /* x-edges */

        if (ISWHITE(thisrow[0]))

            ++countEdgeX;

        for (col = 0; col < cols-1; ++col) 

            if (ISWHITE(thisrow[col]) || ISWHITE(thisrow[col+1]))

                ++countEdgeX;

        if (ISWHITE(thisrow[cols-1]))

            ++countEdgeX;

        /* vertices */

        if (ISWHITE(thisrow[0]) || ISWHITE(prevrow[0]))

            ++countVertex;

        for (col = 0; col < cols-1; ++col) 

            if (ISWHITE(thisrow[col]) || ISWHITE(thisrow[col+1]) 

                || ISWHITE(prevrow[col]) || ISWHITE(prevrow[col+1]))

                ++countVertex;

        if (ISWHITE(thisrow[cols-1]) || ISWHITE(prevrow[cols-1]))

            ++countVertex;

    } /* for row */

    /* now thisrow contains the top row*/

    /* tiles and x-edges have been counted, now y-edges and top

       vertices remain

    */

    /* y-edges */

    for (col = 0; col < cols; ++col) 

        if (ISWHITE(thisrow[col]))

            ++countEdgeY;

    /* vertices */

    if (ISWHITE(thisrow[0]))

        ++countVertex;

    for (col = 0; col < cols-1; ++col) 

        if (ISWHITE(thisrow[col]) || ISWHITE(thisrow[col+1]))

            ++countVertex;

    if (ISWHITE(thisrow[cols-1]))

        ++countVertex;

    /* cleanup */

    pm_close(ifP);

    /* print results */

    printf("   tiles:\t%d\n x-edges:\t%d\n y-edges:\t%d\nvertices:\t%d\n",

           countTile, countEdgeX, countEdgeY,countVertex);

    area      = countTile;

    perimeter = 2*countEdgeX + 2*countEdgeY - 4*countTile;

    eulerchi  = countTile - countEdgeX - countEdgeY + countVertex;

    printf("    area:\t%d\nperimeter:\t%d\n eulerchi:\t%d\n",

           area, perimeter, eulerchi );

    return 0;

}