PHP 3D Cube

<?php
/**
 * This script draws and outputs a Cube.
 *
 * The GD library is used to draw the cube and output it as a
 * PNG image.
 *
 * Developed by Leonel Machava <leonelmachava@gmail.com>
 * http://codentronix.com
 * http://codentronix.com/2011/06/06/how-to-draw-a-cube-using-php/
 *
 * This code is released under the "MIT License" available at
 * http://www.opensource.org/licenses/mit-license.php
 * http://codentronix.com/2011/06/06/how-to-draw-a-cube-using-php/
 */

/* Represents points in 3D space. */
class Point3D {
  public $x;
  public $y;
  public $z;

  public function __construct($x,$y,$z) {
    $this->x = $x;
    $this->y = $y;
    $this->z = $z;
  }

  public function rotateX($angle) {
    $rad = $angle * M_PI / 180;
    $cosa = cos($rad);
    $sina = sin($rad);
    $y = $this->y * $cosa - $this->z * $sina;
    $z = $this->y * $sina + $this->z * $cosa;
    return new Point3D($this->x, $y, $z);
  }

  public function rotateY($angle) {
    $rad = $angle * M_PI / 180;
    $cosa = cos($rad);
    $sina = sin($rad);
    $z = $this->z * $cosa - $this->x * $sina;
    $x = $this->z * $sina + $this->x * $cosa;
    return new Point3D($x, $this->y, $z);
  }

  public function rotateZ($angle) {
    $rad = $angle * M_PI / 180;
    $cosa = cos($rad);
    $sina = sin($rad);
    $x = $this->x * $cosa - $this->y * $sina;
    $y = $this->x * $sina + $this->y * $cosa;
    return new Point3D($x, $y, $this->z);
  }

  public function project($width,$height,$fov,$viewerDistance) {
    $factor = (float)($fov) / ($viewerDistance + $this->z);
    $x = $this->x * $factor + $width / 2;
    $y = -$this->y * $factor + $height / 2;
    return new Point3D($x,$y,$this->z);
  }
}
class Cube3DImage{
  public function __construct($width,$height,$depth){
        $this->width=$width;
        $this->height=$height;
        $this->depth=$depth;

        $this->rotate_x=0;
        $this->rotate_y=0;
        $this->rotate_z=0;

        $this->image_width=90;
        $this->image_height=90;
        $this->fov=256;
        $this->view_distance=4;

        $this->x_color=array(140,140,140);
        $this->y_color=array(192,192,192);
        $this->z_color=array(220,220,220);
        $this->bg_color=array(249, 249, 249);
    }
    function rotate($axis,$val){
        if($axis=='x'){$this->rotate_x=strtolower($val);}
        else if($axis=='y'){$this->rotate_y=strtolower($val);}
        else if($axis=='z'){$this->rotate_z=strtolower($val);}
    }
    function image(){
/*
                                        Z (+1z)
                                        .
g.  .  , h                              |
 :  f_ _._ e                            .
 ,  |    ,|                             |
c; ,| .  ;|<-d                          .
 ` ,|_ _ _|                             |
    b     a                             .
                                        |
                                        .
                                        |
                                        .
                                        |
                                        .
                                        |
                                        ,
                                 .   /  *  \   ,
                       ,    /                      ` .
                 /                                      `  \ .
         /   `                                                 `  \ .
(+1x) X                                                               Y (+1y)


*/
        $vertices = array(
            'a'=>new Point3D((abs($this->width/2)*(-1)), (abs($this->depth/2)), (abs($this->height/2)*(-1))),                   //a -> 0 = right, front, bottom
            'b'=>new Point3D((abs($this->width/2)),  (abs($this->depth/2)), (abs($this->height/2)*(-1))),                           //b -> 1 = left, front, bottom
            'c'=>new Point3D((abs($this->width/2)), (abs($this->depth/2)*(-1)),  (abs($this->height/2)*(-1))),              //c -> 2 = left, back, bottom
            'd'=>new Point3D((abs($this->width/2)*(-1)), (abs($this->depth/2)*(-1)),  (abs($this->height/2)*(-1))),     //d -> 3 = right, back, bottom
            'e'=>new Point3D((abs($this->width/2)*(-1)), (abs($this->depth/2)), (abs($this->height/2))),                            //e -> 4 = right, front, top
            'f'=>new Point3D((abs($this->width/2)), (abs($this->depth/2)), (abs($this->height/2))),                                     //f -> 5 = left, front, top
            'g'=>new Point3D((abs($this->width/2)), (abs($this->depth/2)*(-1)), (abs($this->height/2))),                            //g -> 6 = left, back, top
            'h'=>new Point3D((abs($this->width/2)*(-1)), (abs($this->depth/2)*(-1)), (abs($this->height/2)))                    //h -> 7 = right, back, top
        );
        $faces = array(
            'bottom'=>array('a', 'b', 'c', 'd'),// BOTTOM SIDE (a,b,c,d)
            'left'=>array('b', 'f', 'g', 'c'),// LEFT SIDE (b,f,g,c)
            'top'=>array('f', 'e', 'h', 'g'),// TOP SIDE (f,e,h,g)
            'right'=>array('e','a', 'd', 'h'),// RIGHT SIDE (e,a,d,h)
            'front'=>array('a', 'e', 'f', 'b'),// FRONT SIDE (a,e,f,b)
            'back'=>array( 'd', 'c', 'g', 'h') // BACK SIDE (d,c,g,h)
        );

        $im = imagecreatetruecolor($this->image_width, $this->image_height);
        imagefill($im , 0, 0, imagecolorallocate($im, $this->bg_color[0], $this->bg_color[1], $this->bg_color[2]));//background color
        $colors = array(
            'bottom'=>$this->z_color,
            'left'=>$this->x_color,
            'top'=>$this->z_color,
            'right'=>$this->x_color,
            'front'=>$this->y_color,
            'back'=>$this->y_color
        );
        foreach($colors as $k => $v){
            $im_colors[$k] = imagecolorallocate($im,$v[0],$v[1],$v[2]);
        }
        /* It will store transformed vertices. */
        $transform = array();
        foreach($vertices as $k => $v){
            $transform[$k] = $v->rotateX($this->rotate_x)->rotateY($this->rotate_y)->rotateZ($this->rotate_z)->project($this->image_width, $this->image_height, $this->fov, $this->view_distance);/* Transform all the vertices. */
        }
        $avgZ = array();
        /* Calculate the average Z value of each face. */
        //$faces['bottom'] $faces['left'] $faces['top'] $faces['right'] $faces['front'] $faces['back']
        foreach($faces as $k => $v){// as $k => $v
            $avgZ[$k] = ($transform[$v[0]]->z + $transform[$v[1]]->z + $transform[$v[2]]->z + $transform[$v[3]]->z) / $this->view_distance;//8/30/2011 ADJUSTED??!?
        }
        arsort($avgZ);

        foreach($avgZ as $k => $v){/* Draw the faces from back to front. */
            $_face = $faces[$k];//'bottom'=>, 'left'=>, 'top'=>, 'right'=>, 'front'=>, 'back'=>
            $points = array(
                $transform[$_face[0]]->x, $transform[$_face[0]]->y, // 0,1 => x1, y1
                $transform[$_face[1]]->x, $transform[$_face[1]]->y, // 2,3 => x2, y2
                $transform[$_face[2]]->x, $transform[$_face[2]]->y, // 4,5 => x3, y3
                $transform[$_face[3]]->x, $transform[$_face[3]]->y  // 6,7 => x4, y4
            );
            imagefilledpolygon($im,$points,4,$im_colors[$k]);
        }

        header("Content-Type: image/png");/* Tell the browser/client we are outputing a PNG image. */
        imagepng($im);/* Output the image. */
    }
}
$dim = array();
$dim['width']=14;//x cord
$dim['height']=14;//z cord
$dim['depth']=36;//y cord
$cubeOBJ=new Cube3DImage($dim['width'],$dim['height'],$dim['depth']);
$cubeOBJ->image_width=960;
$cubeOBJ->image_height=960;
$cubeOBJ->fov=256;
$cubeOBJ->view_distance=4;
if(@array_key_exists('fov',$_GET)){$cubeOBJ->fov=intVal($_GET['fov']);}
if(@array_key_exists('dist',$_GET)){$cubeOBJ->view_distance=intVal($_GET['dist']);}


/* Assign random values for the angles that describe the cube orientation. */
$angleX = 40;// up and down horizontally
$angleZ = 0;// side to side horizontally
$angleY = 20;// tilt (tip/roll)

$cubeOBJ->rotate('x', $angleX);
$cubeOBJ->rotate('y', $angleY);
$cubeOBJ->rotate('z', $angleZ);

$cubeOBJ->image();