/*
 *  $Header: /cvs/faces/faces/compface/gen.c,v 1.2 2002/01/15 22:58:46 devface Exp $
 *
 *  Compface - 48x48x1 image compression and decompression
 *
 *  Copyright (c) 1990-2002 James Ashton - Sydney University
 *
 *  Permission is given to distribute these sources, as long as the
 *  copyright messages are not removed, and no monies are exchanged. 
 *
 *  No responsibility is taken for any errors on inaccuracies inherent
 *  either to the comments or the code of this program, but if reported
 *  to me, then an attempt will be made to fix them.
 */

#include "compface.h"

#define GEN(g) F[h] ^= G.g[k]; break

static void Gen P((char *)) ;

static void
Gen(f)
register char *f;
{
	register int m, l, k, j, i, h;

	for (j = 0; j < HEIGHT;  j++)
	{
		for (i = 0; i < WIDTH;  i++)
		{
            h = i + j * WIDTH;
            k = 0;
			for (l = i - 2; l <= i + 2; l++)
				for (m = j - 2; m <= j; m++)
				{
					if ((l >= i) && (m == j))
                        continue;
					if ((l > 0) && (l <= WIDTH) && (m > 0))
                        k = *(f + l + m * WIDTH) ? k * 2 + 1 : k * 2;
                    }
			switch (i)
			{
                case 1 :
					switch (j)
					{
                        case 1 : GEN(g_22);
                        case 2 : GEN(g_21);
                        default : GEN(g_20);
                    }
                    break;
                case 2 :
					switch (j)
					{
                        case 1 : GEN(g_12);
                        case 2 : GEN(g_11);
                        default : GEN(g_10);
                    }
                    break;
                case WIDTH - 1 :
					switch (j)
					{
                        case 1 : GEN(g_42);
                        case 2 : GEN(g_41);
                        default : GEN(g_40);
                    }
                    break;
                case WIDTH :
					switch (j)
					{
                        case 1 : GEN(g_32);
                        case 2 : GEN(g_31);
                        default : GEN(g_30);
                    }
                    break;
                default :
					switch (j)
					{
                        case 1 : GEN(g_02);
                        case 2 : GEN(g_01);
                        default : GEN(g_00);
                    }
                    break;
            }
        }
    }
}

void
GenFace()
{
    static char new[PIXELS];
	register char *f1;
	register char *f2;
	register int i;

    f1 = new;
    f2 = F;
    i = PIXELS;
	while (i-- > 0)
        *(f1++) = *(f2++);
    Gen(new);
}

void
UnGenFace()
{
    Gen(F);
}