grafiek

<?php 
// grafiek class
// by PurpleMadness[PHP4Purple]
// requires gd2-library
// http://purplephp.nl, http://www.php4ever.net
class grafiek {
    // declareer variabelen
    var $steps = "";
    var $y = "";
    var $x = "";
    var $image = "";
    var $space = 20;
    var $gy;
    var $gx;
    var $startplekx;
    var $startpleky;
    // constructor
    function grafiek($steps, $x, $y, $text)
    {
        // set wat variabelen
        $this->steps = $steps;
        $this->y = $y;
        $this->x = $x;
        // achtergrondkleur
        $this->image = imagecreatetruecolor($x * 20 + $this->space + 20, $y * 20 + $this->space + 20);
        // zwarte kleur
        $black = imagecolorallocate($this->image, 255, 255, 255);
        // groene kleur
        $green = imagecolorallocate($this->image, 0, 255, 0);
        // 0 op de y-as
        $this->startpleky = $this->y * 20 + 20;
        // 0 op de x-as
        $this->startplekx = $this->space;
        // maak de titel
        $this->imagestringcentered($this->image, $this->space / 4, 1, $text, $green);
       //start wat functies
       $this->pngheader();
       $this->yas();
       $this->xas();
       $this->cijfers();
       imageantialias($this->image, 1);
    } 
    // function imagestringcentered, zorgt ervoor dat de imagestring horizontaal in het middden blijft.
    function imagestringcentered ($img, $y, $font, $text, $color)
    {
        while (strlen($text) * imagefontwidth($font) > imagesx($img)) {
            if ($font > 1) {
                $font--;
            } else {
                break;
            } 
        } 
        $cy = $y;
        imagestring($img, $font, imagesx($img) / 2 - strlen($text) * imagefontwidth($font) / 2, $cy, $text, $color);
    } 
    // teken de y-as
    function yas()
    {
        // witte kleur
        $white = imagecolorallocate($this->image, 255, 255, 255);
        // teken de lijn
        imageline($this->image, $this->space, $this->space, $this->space, $this->y * 20 + 20, $white);
    } 
    // teken de x-as
    function xas()
    {
  
        // witte kleur
        $white = imagecolorallocate($this->image, 255, 255, 255);
        // teken de lijn
        imageline($this->image, $this->space, $this->y * 20 + 20, $this->x * 20 + 20, $this->y * 20 + 20, $white);
    } 
    // teken de streepjes en de cijfers
    function cijfers()
    {
        // rode kleur (tekst kleur)
        $txtkleur = imagecolorallocate($this->image, 255, 0, 0);
        // blauwe kleur (lijn kleur)
        $streepkleur = imagecolorallocate($this->image, 255, 255, 255);
        // teken linksonder de 0
        imagestring($this->image, 4, $this->space-10, imagesy($this->image) - $this->space, "0", $txtkleur);
        $getaly = $this->y + 1; 
        // de horizontale lijntjes bij elke y as cijfer
        for($i = 1; $i <= $this->y; $i++) {
            imageline($this->image, $this->space-3, $i * 20, $this->space, $i * 20, $streepkleur);
            $getaly--;
            imagestring($this->image, 4, $this->space-10 * strlen($getaly * $this->steps), $i * 20-5, $getaly * $this->steps, $txtkleur);
        } 
        // de horizontale lijntjes bij elke x-as-cijfer
        for($i = 1; $i <= $this->x; $i++) {
            imageline($this->image, $this->space + $i * 20, $this->y * 20 + 20, $this->space + $i * 20, $this->y * 20 + 20 + 3, $streepkleur);
            imagestring($this->image, 4, $this->space + $i * 19, $this->y * 20 + 22, $i * $this->steps, $txtkleur);
        } 
    } 
    // trek strepen van $x naar $y
    function lineto($x, $y)
    { 
        $x = $x / $this->steps;
        $y = $y / $this->steps;
        if (!isset($this->gy, $this->gx)) {
            $lijnkleur = imagecolorallocate($this->image, 255, 0, 0);
            imageline($this->image, $this->startplekx, $this->startpleky, $x * 20 + 20, $this->y * 20 + 20 - $y * 20, $lijnkleur);
            $this->gx = $x * 20 + 20;
            $this->gy = $this->y * 20 + 20 - $y * 20;
        } else {
            $lijnkleur = imagecolorallocate($this->image, 255, 0, 0);
            imageline($this->image, $this->gx, $this->gy, $x * 20 + 20, $this->y * 20 + 20 - $y * 20, $lijnkleur);
            $this->gx = $x * 20 + 20;
            $this->gy = $this->y * 20 + 20 - $y * 20;
        } 
    } 
    // creëer de png
    function init()
    {
        imagepng($this->image);
    } 
    // maak de header
    function pngheader()
    {
        header("Content-type: image/png");
    } 
    // eind van het plaatje
    function destroy()
    {
        imagedestroy($this->image);
    } 
} 
// begin voorbeeld code
$grafiek = new grafiek(2, 7, 5, "php4purple grafiek");
$grafiek->lineto(1, 1);
$grafiek->lineto(2, 2.5);
$grafiek->lineto(3, 1);
$grafiek->lineto(4, 1.2);
$grafiek->lineto(5, 5);
$grafiek->lineto(6, 4.7);
$grafiek->lineto(7, 3.1);
$grafiek->init();
$grafiek->destroy();

?>