/*
		graphic effect lib.
		  Noise Filter

		h. Toda 1994 5 9
*/

#include <stdio.h>
#include <stdlib.h>
#include <egb.h>
#include "g_eff.h"

#define NOERR 0		/* no error */

static int mx ;
static int aSen ;
static int mSen ;
static int cMax ;
static int aMax ;
static int x1 ;
static int y1 ;
static int x2 ;
static int y2 ;
static int (*read1)() ;
static int (*write)() ;
static int (*mask)() ;

g_medianFilter( BASICPARA *para, int mode )
{
	mx = para->mix ;
	aSen = para->alphaSen ;
	mSen = para->maskSen ;
	cMax = para->colorMax ;
	aMax = para->alphaMax ;
	x1 = para->lupx ;
	y1 = para->lupy ;
	x2 = para->rdwx ;
	y2 = para->rdwy ;
	read1 = para->read1 ;
	write = para->write ;
	mask = para->mask ;

	if( mode == 0 )
		mode0() ;
	else
		mode1() ;

	return NOERR ;
}

static int mode0()
{
	unsigned char a[10][4] ;
	int i, x, y ;
	int n ;

	for( y = y1 ; y <= y2 ; y++ )
	{
		for( x=x1 ; x <= x2 ; x++ )
		{
			read1( x-1, y-1, a[0] ) ;
			read1( x,   y-1, a[1] ) ;
			read1( x+1, y-1, a[2] ) ;
			read1( x-1, y,   a[3] ) ;
			read1( x,   y,   a[4] ) ;
			read1( x+1, y,   a[5] ) ;
			read1( x-1, y+1, a[6] ) ;
			read1( x,   y+1, a[7] ) ;
			read1( x+1, y+1, a[8] ) ;

			for( i=0 ; i<3 ; i++ )
			{
				n = ck9(
						 a[0][i], a[1][i], a[2][i],
						 a[3][i], a[4][i], a[5][i],
						 a[6][i], a[7][i], a[8][i]
					   ) ;
				a[9][i] = a[n][i] ;
			}
			mixWrite( x, y, a[9], a[4] ) ;
		}
	}

	return NOERR ;
}

static int mode1()
{
	unsigned char a[6][4] ;
	int i, x, y ;
	int n ;

	for( y = y1 ; y <= y2 ; y++ )
	{
		for( x=x1 ; x <= x2 ; x++ )
		{
			read1( x,   y-1, a[0] ) ;
			read1( x-1, y,   a[1] ) ;
			read1( x,   y,   a[2] ) ;
			read1( x+1, y,   a[3] ) ;
			read1( x,   y+1, a[4] ) ;

			for( i=0 ; i<3 ; i++ )
			{
				n = ck5(
						 a[0][i], a[1][i], a[2][i],
						 a[3][i], a[4][i]
					   ) ;
				a[5][i] = a[n][i] ;
			}
			mixWrite( x, y, a[5], a[2] ) ;
		}
	}

	return NOERR ;
}

static mixWrite( int x, int y, unsigned char *a, unsigned char *b )
{
	unsigned char c[4] ;
	int mix ;

	if( mSen )
	{
		if( mask( x, y ) >= mSen )
			return NOERR ;
	}

	mix = mx ;
	if( aSen )
	{
		mix = mix * b[3] / aMax ;
	}

	c[0] = ( a[0] * mix + b[0] * ( 256 - mix ) + 0x80 ) >> 8 ;
	c[1] = ( a[1] * mix + b[1] * ( 256 - mix ) + 0x80 ) >> 8 ;
	c[2] = ( a[2] * mix + b[2] * ( 256 - mix ) + 0x80 ) >> 8 ;
	c[3] = b[3] ;

	if( mix )
	{
		write( x, y, c ) ;
	}

	return NOERR ;
}

static ck9( int a0, int a1, int a2, int a3,
			int a4, int a5, int a6, int a7, int a8 )
{
	int temp ;
	int m[9] ;
	int a[9] ;
	int i, j ;

	for( i=0 ; i<9 ; i++ )m[i] = i ;

	a[0] = a0 ; a[1] = a1 ; a[2] = a2 ; a[3] = a3 ; a[4] = a4 ;
	a[5] = a5 ; a[6] = a6 ; a[7] = a7 ; a[8] = a8 ;

	for( j=1 ; j<6 ; j++ )
	{
		for( i=j ; i<9 ; i++ )
		{
			if( a[j-1] > a[i] )
			{
				temp = a[i] ;
				a[i] = a[j-1] ;
				a[j-1] =temp ;

				temp = m[i] ;
				m[i] = m[j-1] ;
				m[j-1] =temp ;
			}
		}
	}

	return m[4] ;
}

static ck5( int a0, int a1, int a2, int a3, int a4 )
{
	int temp ;
	int m[5] ;
	int a[5] ;
	int i, j ;

	for( i=0 ; i<5 ; i++ )m[i] = i ;

	a[0] = a0 ; a[1] = a1 ; a[2] = a2 ; a[3] = a3 ; a[4] = a4 ;

	for( j=1 ; j<4 ; j++ )
	{
		for( i=j ; i<5 ; i++ )
		{
			if( a[j-1] > a[i] )
			{
				temp = a[i] ;
				a[i] = a[j-1] ;
				a[j-1] =temp ;

				temp = m[i] ;
				m[i] = m[j-1] ;
				m[j-1] =temp ;
			}
		}
	}

	return m[2] ;
}