<?php

$mimetypes = array(
    'image/jpeg' => 'jpeg',
    'image/png' => 'png',
    'image/gif' => 'gif',
);

function createimage($filename, $mime) {
    global $mimetypes;
    $mime = trim($mime);

    if (isset($mimetypes[$mime])) {
        $imagecreate = 'imagecreatefrom' . $mimetypes[$mime];
        return $imagecreate($filename);
    }
}

function displayimage($image, $mime) {
    global $mimetypes;
    $mime = trim($mime);

    if (isset($mimetypes[$mime])) {
        header('Content-Type: ' . $mime);
        $img = 'image' . $mimetypes[$mime];
        return $img($image);
    }
}

function getpixelarray($image, $width, $height) {
    $pixels = array();
    for ($y = 0; $y < $height; $y++) {
        for ($x = 0; $x < $width; $x++) {
            array_push($pixels, imagecolorat($image, $x, $y));
        }
    }
    return $pixels;
}

function applypixels($image, $pixels, $x, $y, $width, $height, $opacity) {
    /**
     *  formula for finding posistion in pixel array
     *
     *  x + (y * width)
     */
    $trans = 256 - $opacity;
    for ($y1 = $y; $y1 < $height; $y1++) {
        for ($x1 = $x; $x1 < $width; $x1++) {
            $rgb = convertlong($pixels[$x1 + ($y1 * $width)]);
            if ($rgb['r'] == $rgb['g'] && $rgb['g'] == $rgb['b']) {

            } else {
                $imgcol = imagecolorat($image, $x1, $y1);
                $wcol = convertlong($pixels[$x1 + ($y1 * $width)]);

                $ir = ($imgcol >> 16 & 0xff) * $trans;
                $ig = ($imgcol >> 8 & 0xff) * $trans;
                $ib = ($imgcol & 0xff) * $trans;


                $color = (($wcol['r'] + $ir >> 8) << 16) + (($wcol['g'] + $ig >> 8) << 8)+ ($wcol['b'] + $ib >> 8);
                imagesetpixel($image, $x1, $y1, $color);
                //imagesetpixel($image, $x1, $y1, $pixels[$x1 + ($y1 * $width)]);
            }
        }
    }
}

function resizeimage($width, $height, $target) {
    if ($width > $height) {
        $percentage = ($target / $width);
    } else {
        $percentage = ($target / $height);
    }
    $width = round($width * $percentage);
    $height = round($height * $percentage);
    return 'width=' . $width . ' height=' . $height;
}

function convertlong($long) {
    return array(
        'r' => ($long >> 16) & 255,
        'g' =>($long >> 8) & 255,
        'b' => $long & 255
    );
}

function convertarray($array) {
    return ($array['r'] << 16) + ($array['g'] << 8) + $array['b'];
}

?>