<?php
/*
 * NxN ImageCube by Joël van Noort
 * 21th februari 2007
 *
 * A PHP script for generating static 3D views of the NxNxN Cube .
 *
 * This script is inspired by Imagecube and Imagerevenge, by Lars Vandenbergh.
 */

//This function makes lines between 4 points. Use this function twice can form a grid on one face.
function makelines(&$image, $n, $col_poly, $scalepx, $x1, $y1, $x2,$y2, $x3,$y3, $x4, $y4){
	$vector_x = ($x3-$x1);	$vector_y = ($y3-$y1);
	$vector_a = ($x4-$x2);	$vector_b = ($y4-$y2);
	
	for($i=1;$i < $n; $i++)
		imageline($image,($x1+$vector_x*($i/$n))*$scalepx,($y1+$vector_y*($i/$n))*$scalepx,($x2+$vector_a*($i/$n))*$scalepx,($y2+$vector_b*($i/$n))*$scalepx,$col_poly);
}

//This function calculates the coordinates of the stickers of one face:
function calculate_coordinates(&$datax,&$datay,$n, $x1,$y1,$x2,$y2,$x3,$y3,$x4,$y4) {
	//The calculation will be based on vectors. Calculating the first two here. 
	//These vectors will help us to locate the stickers:
	$vector_Vx = ($x3-$x1);	$vector_Vy = ($y3-$y1);
	$vector_Wx = ($x4-$x2);	$vector_Wy = ($y4-$y2);

	$number=0;

	for($j=0; $j <$n+1; $j++){

	    //Making the 3rd vector... This one changes all the time...:
		$local_x1 = $x1 + $vector_Vx*($j/$n);
		$local_y1 = $y1 + $vector_Vy*($j/$n);
		$local_x2 = $x2 + $vector_Wx*($j/$n);
		$local_y2 = $y2 + $vector_Wy*($j/$n);
		$directionx = $local_x2 - $local_x1;
		$directiony = $local_y2 - $local_y1;

		for($i=0; $i < $n+1; $i++){
			$datax[$number] = $local_x1 + ($directionx)*($i/$n)  ;
			$datay[$number] = $local_y1 + ($directiony)*($i/$n)  ;
			$number++;
		}
	}
}

//This function fills up the coordinates of one face. We will use the result of the previous function to do this.
//To locate the center of a facelet, I use 2 coordinates, and go to the 'middle'...
function fill_up(&$im,$n, $scalepx, $datax, $datay, $colors, $stickers){

	$colorcount=0;
	$count=0;

	while($count < $n*($n+1) ){

		$xx = ($datax[$count] + $datax[$count+$n+2])/2;
		$yy = ($datay[$count] + $datay[$count+$n+2])/2;
	       if( ($count+1)%($n+1) != 0){
			imagefill($im,$scalepx*$xx, $scalepx*$yy, $colors[substr($stickers,$colorcount,1)]);

			$colorcount++;
		}
		$count++;
	}
}

// initialize paramaters... Adjust parameters if they are too small/big/not integers... We don't want someone like Lars to enter $n = 2.5 :)
import_request_variables("PG","");

$size=intval($size);
$n=intval($n);
$scale=intval($scale);
$thickness=intval($thickness);

if(!$size)	
	$size=300;
if($size>750)	
	$size=750;
if($size<10)	
	$size=10;

if(!$n)		
	$n=3;
if($n>25)	
	$n=25;
if($n<1)	
	$n=1;

if(!$scale)		
	$scale=3;
if($scale>4)	
	$scale=4;
if($scale<1)	
	$scale=1;

if(!$thickness)		
	$thickness=1;
if($thickness>3)	
	$thickness=3;
if($thickness<1)	
	$thickness=1;

if(!$stickers){
	
	for($i = 1; $i<=$n*$n;$i++){
		$stickers .= "y";
	}
	for($i = 1; $i<=$n*$n;$i++){
		$stickers .= "r";
	}
	for($i = 1; $i<=$n*$n;$i++){
		$stickers .= "g";
	}
}

$scalepx=$size*$scale/220;
$im = imagecreate($size*$scale,$size*$scale);
imageantialias ($im,true);
imagesetthickness($im,$thickness);

// Define coordinates of the 6 'key'-points that define the cube shape cube:
//Default orientation of the cube, based on ImageRevenge:
if(!$orient){
$x1=89; 	$y1=18;		$x2=200;	$y2=31;
$x3=14;		$y3=59;		$x4=138;	$y4=77;
$x5=29;		$y5=185;	$x6=147;	$y6=211;
$x7=206;	$y7=151;
}

//Alternative orientation of the cube, based on ImageCube:
if($orient=="1"){
	$x1=78; 	$y1=16;		$x2=183;	$y2=28;
	$x3=15;		$y3=62;		$x4=134;	$y4=78;	
	$x5=31;		$y5=168;	$x6=141;	$y6=194;
	$x7=185;	$y7=133;
}

// Allocate colors:
$back = imagecolorallocate($im, 255, 255, 255);
$col_poly = imagecolorallocate($im, 0, 0, 0);
$red = imagecolorallocate($im, 200, 0, 0);
$orange = imagecolorallocate($im, 255, 161, 0);
$blue = imagecolorallocate($im, 0, 0, 182);
$green = imagecolorallocate($im, 0, 182, 72);
$white = imagecolorallocate($im,247,247,247);
$yellow = imagecolorallocate($im, 239, 239, 0);
$grey = imagecolorallocate($im, 200, 200, 200);
$colors=array("r"=>$red,
	   "o"=>$orange,
       "b"=>$blue,
       "g"=>$green,
       "w"=>$white,
       "y"=>$yellow,
       "x"=>$grey);

// Draw cube silhouette:
	imagepolygon($im,
             array (
                   $x2*$scalepx, $y2*$scalepx,
                   $x1*$scalepx, $y1*$scalepx,
                   $x3*$scalepx, $y3*$scalepx,
                   $x5*$scalepx, $y5*$scalepx,
                   $x6*$scalepx, $y6*$scalepx,
                   $x7*$scalepx, $y7*$scalepx
		),
             6,
             $col_poly);

//finishing the basic 1x1 cube shape, by drawing 3 more lines...
imageline($im,$x4*$scalepx,$y4*$scalepx,$x3*$scalepx,$y3*$scalepx,$col_poly);
imageline($im,$x4*$scalepx,$y4*$scalepx,$x2*$scalepx,$y2*$scalepx,$col_poly);
imageline($im,$x4*$scalepx,$y4*$scalepx,$x6*$scalepx,$y6*$scalepx,$col_poly);

//Making the grid on all 3 faces. For one grid, the makelines function is used 2 times, as
//that function draws lines in only 1 direction:
makelines($im, $n, $col_poly, $scalepx, $x1, $y1, $x2, $y2, $x3,$y3, $x4, $y4);
makelines($im, $n, $col_poly, $scalepx, $x1, $y1, $x3, $y3, $x2,$y2, $x4, $y4);
makelines($im, $n, $col_poly, $scalepx, $x3, $y3, $x4, $y4, $x5,$y5, $x6, $y6);
makelines($im, $n, $col_poly, $scalepx, $x3, $y3, $x5, $y5, $x4,$y4, $x6, $y6);
makelines($im, $n, $col_poly, $scalepx, $x4, $y4, $x2, $y2, $x6,$y6, $x7, $y7);
makelines($im, $n, $col_poly, $scalepx, $x4, $y4, $x6, $y6, $x2,$y2, $x7, $y7);

//Extracting the stickers of U, F and R faces:
$stickers_U=substr($stickers,0,($n)*($n));
$stickers_F=substr($stickers,$n*$n,($n)*($n));
$stickers_R=substr($stickers,$n*$n*2,($n)*($n));

//Calculate coordinates and fill up the U, F and R faces respectively:
calculate_coordinates($datax,$datay,$n, $x1,$y1,$x2,$y2,$x3,$y3,$x4,$y4);
fill_up($im, $n, $scalepx, $datax, $datay, $colors, $stickers_U);

calculate_coordinates($datax,$datay,$n, $x3,$y3,$x4,$y4,$x5,$y5,$x6,$y6);
fill_up($im, $n, $scalepx, $datax, $datay, $colors, $stickers_F);

calculate_coordinates($datax,$datay,$n, $x4,$y4,$x2,$y2,$x6,$y6,$x7,$y7);
fill_up($im, $n, $scalepx, $datax, $datay, $colors, $stickers_R);

// Resample image and make background transparent:
$interm=ImageCreateTrueColor($size,$size);
imagecopyresampled($interm,$im,0,0,0,0,$size,$size,$size*$scale,$size*$scale);
$output=ImageCreate($size,$size);
imagecopyresized($output,$interm,0,0,0,0,$size,$size,$size,$size);
$back = imagecolorallocate($output,221,221,221);
imagecolortransparent($output,$back);
imagefill($output,0,0,$back);

// Send image to client:
header("Content-type: image/png");
imagepng($output);
imagedestroy($im);
imagedestroy($output);
?>