/*
		graphic effect lib.
		  Soft

		h. Toda 1994 8 22
*/

#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_softnessFilter( BASICPARA *para, int rate )
{
	unsigned char a[10][4] ;
	int i, x, y ;
	int n ;
	int k1, k2 ;

	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 ;

	k1 = rate >> 3 ;
	k2 = 256 - k1*8 ;

	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++ )
			{
				int total ;

				total = k1*( (int)(a[0][i]) + a[1][i] + a[2][i] +
							       a[3][i]            + a[5][i] +
							       a[6][i]  + a[7][i] + a[8][i]
						   ) +
						k2*( (int)(a[4][i]) ) ;
				total = (total + 128) >> 8 ;
				if( total < 0 )total = 0 ;
				if( total > 255 )total = 255 ;
				a[9][i] = total ;
			}
			mixWrite( x, y, a[9], a[4] ) ;
		}
	}

	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 ;
}