image.php

gistfile1.aw

<?php
/**
 * image Generator -- see trac ticket #778 and #795
 *
 * Resizes an image
 *
 * For proper documentation see the phpdoc for the imageGenerator function.
 */

// If there isn't a directory for cached images, make one.
$cache_dir = '../../../var/cache/images';
if (!is_dir($cache_dir)) {
    mkdir($cache_dir, 0777, true);
}

$dst_w = (int)$_GET['w'];
$dst_h = (int)$_GET['h'];
$crop = (float)$_GET['crop'];
$stretch = (bool)$_GET['stretch'];
$filename = '../../images/' . basename($_GET['filename']);

if (!file_exists($filename)) {
    $filename = '../../images/1col.png';
}

// Find the current width and height of the image, also image_type for later.
list($width, $height, $image_type) = getimagesize($filename);

header("Content-type: " . image_type_to_mime_type($image_type));

$cached_filename = "{$cache_dir}/{$dst_w}-{$dst_h}-{$crop}-{$stretch}-" . basename($filename);

// DISABLE IMAGE CACHING DURING TESTING
// If the cached file already exists, spit it out...
if (file_exists($cached_filename)) {
    readfile($cached_filename);
    exit;
}

// So here is where we actually generate the image!
$generated_image = imagecreatetruecolor($dst_w, $dst_h);

switch ($image_type) {
    // If it's an image type we can't handle, it will end up being a blank rectangle
    case IMAGETYPE_PNG:
        $source_image = imagecreatefrompng($filename);
        $save_function_name = 'imagepng';
        //// I know it's a bit of a hack but it's quicker to code a variable function than running another switch
        break;
    case IMAGETYPE_GIF:
        $source_image = imagecreatefromgif($filename);
        $save_function_name = 'imagegif';
        break;
    case IMAGETYPE_JPEG:
        $source_image = imagecreatefromjpeg($filename);
        $save_function_name = 'imagejpeg';
        break;
}

// Work out rect co-ordinates to copy from source image into our destination image:
// The destination rect coordinates will ALWAYS be (0, 0, $dst_w, $dst_h)

if($stretch) {
    // stretches the image to fit. No Sigismund mad maths required (as ane fule kno.)
    $src_x = 0;
    $src_y = 0;
    $src_w = $width;
    $src_h = $height;
}
else {
    // Typically, I've left the toughest bit til last...
    $x_factor = $width / $dst_w; // x-axis scaling factor
    $y_factor = $height / $dst_h; // y-axis scaling factor
    if ($x_factor > $y_factor) { // destination image is narrower than source; crop horizontally
        // Because we're cropping horizontally, we need the entire vertical range.
        $src_y = 0;
        $src_h = $height;

        // How wide do we want?
        $src_w = $dst_w * $y_factor; // I think?

        // Then the crop parameter:
        $src_x = ($width - $src_w) * 0.5 * ($crop + 1);
    }
    else {
        // the same code except swapping x for y and w for h.
        $src_x = 0;
        $src_w = $width;
        $src_h = $dst_h * $x_factor;
        $src_y = ($height - $src_h) * 0.5 * ($crop + 1);
    }
}

// resize whole image, no matter what for first run...
imagecopyresampled($generated_image, $source_image, 0, 0, $src_x, $src_y, $dst_w, $dst_h, $src_w, $src_h);
$save_function_name($generated_image, $cached_filename);
imagedestroy($generated_image);
imagedestroy($source_image);

readfile($cached_filename);
?>