<?php

ini_set('memory_limit','128M');

if( $_GET['game'] == 'chaos' )
{
	$rom = fopen("C:\Dev\SMS\SC.gg", "r");
	$map_index = 0x5159;
	$tile_index = 0x7CEF; // Hardcoded
	$palette_address = 0x3B8F3;
	$foreground_address = 0x3B713;
}
else
{
	$rom = fopen("C:\Dev\SMS\STT.gg", "r");
	$map_index = 0x4367;
	$tile_index = 0x6B678; // Hardcoded
	$palette_address = 0x3BABC;
	$foreground_address = 0x3B99C;
}

$colors = array();
$blockcolors = array();
$map = array();
$tiles = array();
$tilelocs = array();
$blocks = array();


if( !isset( $_GET['level'] ) || (int) $_GET['level'] == 0 )
{
	$level = 0;
}
else
{
	$level = $_GET['level'];
}

// Getting level data

fseek( $rom, $map_index + 2*$level );
$level_address = getWord($rom);

fseek( $rom, $level_address);

$block_bank = getByte($rom);
$block_address = getWord($rom) + $block_bank * 0x4000 - 0x8000;

$map_bank = getByte($rom);
$map_address = getWord($rom) + $map_bank * 0x4000 - 0x8000;

$level_width = getWord($rom);

if( $_GET['game'] == 'chaos' )
{
	loadSCMap($map_address);
}
else
{
	loadSTTMap($map_address);
}

$level_height = sizeof($map) / $level_width;


fseek( $rom, $tile_index + $level*7 );
$tile_bank = getByte($rom);
$unknown = getWord($rom);
$tile_address = getWord($rom) + $tile_bank * 0x4000 - 0x8000;

fseek( $rom, $tile_address );

$unknown = getWord($rom);
$tile_num = getWord($rom);
$guideloc = getWord($rom) + $tile_address;
$tileloc = $tile_address + 6;


$image = imagecreatetruecolor( $level_width*32, $level_height*32 );
$blockimage = imagecreatetruecolor( 32*256, 32 );

// Creating the palette

fseek( $rom, $palette_address + floor($level/3) * 0x20 );

for( $c=0; $c<32; $c++ )
{
	if( $c == 16 )
		fseek( $rom, $foreground_address + floor($level/3) * 0x20 );

	$color  = ord(fread( $rom, 1 ));
	$color2 = ord(fread( $rom, 1 ));
	
	$red = 16 * ($color % 16);
	$green = 16 * floor($color / 16);
	$blue = 16 * ($color2 % 16);

	if( $_GET['gray'] == 1 )
	{
		$red = 16*($c%16);
		$green = 16*($c%16);
		$blue = 16*($c%16);
	}

	$colors[$c] = imagecolorallocate( $image, $red, $green, $blue );
	$blockcolors[$c] = imagecolorallocate( $blockimage, $red, $green, $blue );
}

// Loading tiles

$p = 3;
$guidebyte = 0;

for( $t=192; $t<448; $t++ )
{
	$data = array();
	$strings = array();

	$p++;
	if( $p == 4 )
	{
		fseek( $rom, $guideloc++ );
		$guidebyte = getByte( $rom );
		$p = 0;
	}


	$guide = bittest( $guidebyte, 2*$p ) + 2* bittest( $guidebyte, 2*$p+1 );

	$tilelocs[$t] = dechex($tileloc).':'.$guide;

	if( $guide == 0 )
	{
		$tiles[$t] = '';
	}

	if( $guide == 1 )
	{
		fseek( $rom, $tileloc );
		$tiles[$t] = fread( $rom, 32 );
		$tileloc += 32;
	}

	if( $guide == 2 )
	{
		$tiles[$t] = decodeTile( $tileloc );
	}

	if( $guide == 3 )
	{
		$tiles[$t] = decodeTile( $tileloc );

		$ix = 0;
		for( $b=7; $b>0; $b-- )
		{
			$tiles[$t][$ix+2] = $tiles[$t][$ix+0] ^ $tiles[$t][$ix+2];
			$tiles[$t][$ix+3] = $tiles[$t][$ix+1] ^ $tiles[$t][$ix+3];
			$tiles[$t][$ix+18] = $tiles[$t][$ix+16] ^ $tiles[$t][$ix+18];
			$tiles[$t][$ix+19] = $tiles[$t][$ix+17] ^ $tiles[$t][$ix+19];

			$ix += 2;
		}
	}

}

// Loading tile blocks

for( $b = 0; $b < 256; $b++)
{
	$blocks[$b] = array();

	fseek( $rom, $block_address + 2*$b );
	$loc = ord(fread($rom,1)) + ord(fread($rom,1))*256;
	fseek( $rom, $block_bank * 0x4000 - 0x8000 + $loc );


	for( $i = 0; $i < 16; $i++)
	{
		$t = ord( fread( $rom, 1 ) );
		$d = ord( fread( $rom, 1 ) );

		$blocks[$b][$i] = $d * 256 + $t;
	}
}


// Caching the blocks in a second image

for( $b = 0; $b < 256; $b++ )
{
	createBlock( $blockimage, $b, $b*32,0);
}

if( $_GET['blocks'] == 1 )
{
 // Show blocks

	$b = 0;

	for( $c = 0; $c < 16; $c++ )
	for( $r = 0; $r < 16; $r++ )
	{
		displayBlock( $image, $b, $c*64,$r*32);
		imagestring( $image, 1, $c*64+36, $r*32+14, dechex($b), $colors[15] );
		$b++;
	}

}
elseif( isset( $_GET['tiles'] ) )
{
 // Show tiles

	$t = 192;

	for( $i=0; $i<8; $i++ )
	for( $j=0; $j<8; $j++ )
	{
		imagestring( $image, 1, $j*100 + 20, $i*24, ($tilelocs[$t]), $colors[15] );
		imagestring( $image, 1, $j*100 + 20, $i*24 + 10, ($tilelocs[$t+1]), $colors[15] );
		imagestring( $image, 1, $j*100 + 60, $i*24, ($tilelocs[$t+2]), $colors[15] );
		imagestring( $image, 1, $j*100 + 60, $i*24 + 10, ($tilelocs[$t+3]), $colors[15] );
		displayTile( $image, $tiles[$t+0], 0, $j*100+0, $i*24 );
		displayTile( $image, $tiles[$t+1], 0, $j*100+0, $i*24 +8 );
		displayTile( $image, $tiles[$t+2], 0, $j*100+8, $i*24 );
		displayTile( $image, $tiles[$t+3], 0, $j*100+8, $i*24 +8 );
		$t += 4;
	}

}
else
{
 // Show map

	$m = 0;

	for( $r = 0; $r < $level_height; $r++ )
	for( $c = 0; $c < $level_width; $c++ )
	{
		displayBlock( $image, $map[$m++], $c*32,$r*32);
	}
}

// Output

header('Content-type: image/png');
imagepng($image);

////////////////////////////////////////////////////////

// Functions

function decodeTile( &$data_address )
{
	global $rom;

	fseek( $rom, $data_address );

	$dataflags = fread( $rom, 4 );
	$data_address += 4;

	$data = '';
	
	for( $i=0; $i<32; $i++ )
	{
		$b = $i % 8;
		$c = (int) ($i/8);

		if( ord($dataflags[$c]) & pow(2,$b) )
		{
			$data .= fread( $rom, 1 );
			$data_address++;
		}
		else
		{
			$data .= chr(0);
		} 
		
	}

	 return $data;

}

function binhex( $data )
{
	$str = '';

	for( $i=0; $i<strlen($data); $i++)
	{
		
		$num = ord($data[$i]);
		if( $num < 16 ) $str .= '0';
		$str .= dechex($num);
	}
	return strtoupper($str);
}

function displayTile( $image, $data, $flags, $x, $y )
{
	global $colors;

	if( bittest( $flags, 3 ) )
		$palette = 16;
	else
		$palette = 0;


	for( $r=0; $r < 8; $r++ )
	{
		$row = array();

		for($b=0; $b<8; $b++)
			$row[$b] = 0;


		for( $p=0; $p<4; $p++ )
		{
			for($b=0; $b<8; $b++)
			{
				$bitvalue = (pow(2,$b) & ord($data[$r*4+$p])) * pow(2,($p-$b));
				$bitvalue = bittest( ord($data[$r*4+$p]), $b ) * pow(2,$p); // test
				$row[$b] += $bitvalue;
			}
		}

		for( $c=0; $c<8; $c++ )
		{
			if( !bittest( $flags, 1 ) ) { $hi = 7 - $c; }
			else			{	$hi = $c; }
			if( bittest( $flags, 2 ) ) { $vi = 7 - $r; }
			else			{	$vi = $r; }			
			imagesetpixel( $image, $x+$hi, $y+$vi, $colors[$row[$c] + $palette]);
		}

	}
		
}

function createBlock ($image, $b, $x, $y)
{
	global $blocks, $tiles;

	$i = 0;

	for( $br = 0; $br < 4; $br++)
	for( $bc = 0; $bc < 4; $bc++)
	{
		$t = $blocks[$b][$i] % 256;
		$d = $blocks[$b][$i] / 256; 
		$t += 256 * bittest( $d, 0 );
		displayTile( $image, $tiles[$t],$d, $x + $bc*8, $y + $br*8 );

		$i++;
	}

}

function displayBlock ($image, $b, $x, $y)
{
	global $blockimage;

	imagecopy( $image, $blockimage, $x, $y, $b*32, 0, 32, 32 );
}


function bittest( $num, $bit )
{
	if( $num & pow( 2,$bit) ) return true;
	return false;
}

function loadSCMap( $position )
{
	global $map, $rom;
	fseek( $rom, $position );

	$done = 0;

	$m = 0;

	do
	{

		$byte = getByte( $rom );

		if( $byte < 255 )
		{
			$map[$m++] = $byte;
		}
		else
		{
			$byte = getByte( $rom );
			$length = getByte( $rom );
	
			if( $byte == 255 && $length == 0 )
			{
				$done = 1;
			}
			else
			{
				for( $i=0; $i<$length; $i++ )
				{
					$map[$m++] = $byte;
				}

			}
		}		
	}
	while( $done == 0 );

}

function loadSTTMap( $position )
{
	global $map, $rom;
	fseek( $rom, $position );

	$m = 0;

	$maskbit = 8;
	$done = 0;

	while( $done == 0 )
	{
		if( $maskbit == 8 )
		{
			$mask = getByte( $rom );
			$maskbit = 0;
		}

		if( bittest( $mask, $maskbit++ ) )
		{
			$map[$m++] = getByte( $rom );
		}
		else
		{
			$byte1 = getByte( $rom );
			$byte2 = getByte( $rom );

			if( $byte1 + $byte2 == 0 )
			{
				$done = 1;
			}
			else
			{

				$m2 = $m + ($byte1 + ( $byte2 | (0xF0) ) * 0x100) - 0x10000;

				$i = floor( ($byte2 & 0xF0)/16 ) + 3;
		
				for( $i; $i>0; $i-- )
				{
					$map[$m++] = $map[$m2++];
				}
			}
		}
	}
}

function getByte( &$source )
{
	return ord( fread( $source,1 ) );
}

function getWord( &$source )
{
	return getByte( $source ) + getByte( $source ) * 0x100;
}


?>