/*
		graphic effect lib.

		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 (*read2)() ;
static int (*write)() ;
static int (*mask)() ;

g_s_c_Filter( BASICPARA *para, int rate )
{
	unsigned char a[3][4] ;
	int add[256] ;
	int i, x, y ;
	int n ;

	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 ;
	read2 = para->read2 ;
	write = para->write ;
	mask = para->mask ;

	for( i=0 ; i<256 ; i++ )
	{
		if( i < rate )
			add[i] = 0 ;
		else if( i < rate*3 )
			add[i] = (i-rate)*(i-rate)*(-2*i + 9*rate)/(4*rate*rate) ;
		else if( i < 256 )
			add[i] = i ;
	}

	for( y = y1 ; y <= y2 ; y++ )
	{
		for( x=x1 ; x <= x2 ; x++ )
		{
			read1( x, y, a[0] ) ;
			read2( x, y, a[1] ) ;

			for( i=0 ; i<3 ; i++ )
			{
				int del ;

				del = a[0][i] - a[1][i] ;

				if( del >= 0 )
					a[2][i] = a[1][i] + add[ del ] ;
				else
					a[2][i] = a[1][i] - add[ -del ] ;
			}
			mixWrite( x, y, a[2], a[0] ) ;
		}
	}

	return NOERR ;
}

g_c_m_Filter( BASICPARA *para, int rate )
{
	unsigned char a[3][4] ;
	int add[256] ;
	int i, x, y ;
	int n ;

	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 ;
	read2 = para->read2 ;
	write = para->write ;
	mask = para->mask ;

	for( i=0 ; i<256 ; i++ )
	{
		if( i < rate )
			add[i] = 0 ;
		else if( i < rate*3 )
			add[i] = (i-rate)*(i-rate)*(-2*i + 9*rate)/(4*rate*rate) ;
		else if( i < 256 )
			add[i] = i ;
	}

	for( y = y1 ; y <= y2 ; y++ )
	{
		for( x=x1 ; x <= x2 ; x++ )
		{
			read2( x, y, a[0] ) ;
			read1( x, y, a[1] ) ;

			for( i=0 ; i<3 ; i++ )
			{
				int del ;

				del = a[0][i] - a[1][i] ;

				if( del >= 0 )
					a[2][i] = a[1][i] + add[ del ] ;
				else
					a[2][i] = a[1][i] - add[ -del ] ;
			}
			mixWrite( x, y, a[2], a[1] ) ;
		}
	}

	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 ;
}