Circle class

circle.php

<?php
    /*
    Lab 7
    circle.php
    Andre Lashley (andre.lashley@gmail.com)
    February 20, 2012
    4 hours estimated completion time
    4 hours actual completion time
    This program draws 6 different shapes.
    Visit http://deepblue.cs.camosun.bc.ca/~cst020/comp170/lab7/main.html to use it.
    This program uses source code found at http://ca.php.net/manual/en/function.imagecolorallocate.php in the comments
    to convert hex values passed into the function to RGB values.
    */
    
class Circle{

// create the properties of a circle and the canvas its drawn on
private $shapeSize;
private $location;
private $canvasHsize;
private $canvasVsize;
private $canvas;
private $fgcolor;
private $bgcolor;

// write a constructor to take the size of the shape, its location, the horizontal size of the canvas,
// and its vertical size
function __construct($inCanvasHsize, $inCanvasVsize, $inFgcolor, $inBgcolor, $inLocation, $inSize){
    $this->shapeSize = $inSize;
    $this->location = $inLocation;
    $this->canvasHsize = $inCanvasHsize;
    $this->canvasVsize = $inCanvasVsize;
    $this->fgcolor = $inFgcolor;
    $this->bgcolor = $inBgcolor;
    
    // Output the header telling the browser this is a png image.
	header ('Content-type: image/png');
    
    // create the empty canvas.
	$this->canvas = imagecreatetruecolor($this->canvasHsize, $this->canvasVsize) or die('Cannot Initialize new GD image stream');
    
    // convert the foreground and background colors to their associated hex values
    $this->bgcolor = $this->hex2rgb($this->bgcolor);
    $this->fgcolor = $this->hex2rgb($this->fgcolor);
    
    /* Define the foreground and background colours and fill the image with the background colour.
	The foreground colour is passed as a parameter, the background colour is white */
	$this->fgcolor = imagecolorallocate($this->canvas, $this->fgcolor[0], $this->fgcolor[1], $this->fgcolor[2]);
	$this->bgcolor = imagecolorallocate($this->canvas, $this->bgcolor[0], $this->bgcolor[1], $this->bgcolor[2]);
	imagefill($this->canvas, 0, 0, $this->bgcolor);
}

// make the shape bigger by some size
public function bigger(){
    $this->shapeSize += 10;
}

// make the shape smaller by some size
public function smaller(){
    $this->shapeSize -= 10;
}

// make the shape move up by some amount
public function moveUp(){
    $this->location[1] += 15;
}

// make the shape move down by some amount
public function moveDown(){
    $this->location[1] -= 15;
}

// make the shape move left by some amount
public function moveLeft(){
    $this->location[0] -= 15;
}

// move the shape right by some amount
public function moveRight(){
    $this->location[0] += 15;
}

// Draw a circle based on the location passed into the function.
public function draw(){
	imageellipse($this->canvas, $this->location[0], $this->canvasHsize - $this->location[1], $this->shapeSize, $this->shapeSize, $this->fgcolor);
}

// display what we've drawn on the canvas
public function display(){
    
    /* Write the image to standard out - in the case of the web server to the network to the browser
	and free up any memory used by the image */
	imagepng($this->canvas);
	imagedestroy($this->canvas);
}

// create a helper method to convert hex values to RGB
private function hex2rgb($rgb){
    /**
     * Convert color from hex in XXXXXX (eg. FFFFFF, 000000, FF0000) to array(R, G, B)
     * of integers (0-255).
     *
     * name: rgb2array
     * author: Yetty
     * @param $color hex in XXXXXX (eg. FFFFFF, 000000, FF0000)
     * @return string; array(R, G, B) of integers (0-255)
     */

    return array(
        base_convert(substr($rgb, 0, 2), 16, 10),
        base_convert(substr($rgb, 2, 2), 16, 10),
        base_convert(substr($rgb, 4, 2), 16, 10),
    );

}

}

// instantiate a circle object
$circle = new Circle(300, 300, "FFFFFF", "000000", array(75, 55), 50);
$circle->moveUp();
$circle->moveUp();
$circle->draw();
$circle->smaller();
$circle->smaller();
$circle->moveRight();
$circle->draw();
$circle->display();
?>