Script en PHP para generar el fractal Mandlebrot
El siguiente script permite generar el fractal de Mandlebrot. Descargado desde la pagina : http://khlo.co.uk/stuff/fractals/
<?php
set_time_limit(0);
function microtime_float() {
list($usec, $sec) = explode(" ", microtime());
return ((float)$usec + (float)$sec);
}
$time_start = microtime_float();
/* Lil Mandlebrot Set Fractal Generator */
define ('IMAGE_WIDTH', 100);
define ('IMAGE_HEIGHT', 100);
define ('X_MIN', -1.5);
define ('X_MAX', 0.5);
define ('Y_MIN', -1);
define ('Y_MAX', 1);
define ('MAX_ITERATIONS', 200); // if you change this to a number bigger than 200, make sure you create a new palette.png
header("Content-type: image/png");
$image = imagecreate(IMAGE_WIDTH, IMAGE_HEIGHT);
// Load the palette to find colours
$colours = array();
$colours['inside'] = imagecolorallocate($image, 0, 0, 0);
$palette = imagecreatefrompng("palette.png");
for ($i=0; $i<imagesx($palette); $i++) {
$rgb = imagecolorat($palette, $i, 0);
$colours[$i] = imagecolorallocate($image, ($rgb >> 16) & 0xFF, ($rgb >> 8) & 0xFF, $rgb & 0xFF);
}
for ($i=0; $i<IMAGE_WIDTH; $i++) {
for ($j=0; $j<IMAGE_HEIGHT; $j++) {
// What values of x and y does this pixel represent?
$x = X_MIN+$i*((X_MAX - X_MIN) / (IMAGE_WIDTH-1));
$y = Y_MIN+$j*((Y_MAX - Y_MIN) / (IMAGE_HEIGHT-1));
// C=x+yi
$iteration = 0;
$z = array(0,0); // The initial value of z is 0+0i
$magnitude = 0;
// Optimization: Store x^2 and y^2 so we don't have to keep
$x2 = 0;
$y2 = 0;
// If the |z| > 2 ever, then the sequence will tend to infinity so
while ($iteration <= MAX_ITERATIONS && $x2+y2 <= 4) {
// In order to get the next term in the sequence
// we need to square the previous number and then add
// the original complex number
//
// z(n+1) = z(n)^2+c
$k = $z;
// z is a complex number. When we square a complex number in the
// New real component: x^2-y^2
// New imaginary component: 2*real*imaginary
$z[0] = $x2 - $y2;
$z[1] = 2 * $k[0] * $k[1];
// Add Complex Number
$z[0] = $z[0] + $x;
$z[1] = $z[1] + $y;
$x2 = pow($z[0], 2);
$y2 = pow($z[1], 2);
++$iteration;
}
if ($iteration == MAX_ITERATIONS) {
imagesetpixel($image, $i, $j, $colors['inside']);
} else {
imagesetpixel($image, $i, $j, $colours[$iteration]);
}
}
}
$time_end = microtime_float();
header ("X-Exec-Time: ".($time_end - $time_start));
imagepng($image);
?>
Nota : se requiere la siguiente paleta de imagen que deberá ser guardada en la carpeta donde esta el script.
