Aprendiendo con Memes: Tenso | Learning with Memes: Tenso Image Generator | URL: http://www.michael-pratt.com/blog/9/Aprendiendo-con-Memes-Tenso/

Tenso.php

<?php
/**
 * Tenso.php
 *
 * @author Michael Pratt <pratt@hablarmierda.net>
 * @version 1.0
 * @link http://www.michael-pratt.com/blog/9/Aprendiendo-con-Memes-Tenso/
 * @demo http://www.michael-pratt.com/Lab/tenso/
 *
 * @License: MIT
 * Copyright (C) 2012 by Michael Pratt <pratt@hablarmierda.net>
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 * THE SOFTWARE.
 */

class Tenso
{
    protected $image, $output, $width, $height, $extension, $tmpfile;
    protected $font    = 'impact.ttf';
    protected $text    = '';
    protected $frames  = 4;
    protected $zoomFactor = 2;
    protected $center  = array();
    protected $start   = array();
    protected $destiny = array();
    protected $debug   = array();

    /**
     * Constructor
     *
     * @param string $image Location of the image
     * @return void
     */
    public function __construct($image)
    {
        $this->tmpfile = $image;
        list ($this->width, $this->height) = getimagesize($this->tmpfile);

        if (empty($this->width) ||empty($this->height))
            throw new Exception('Invalid Image');

        $this->extension = strtolower(pathinfo($image, PATHINFO_EXTENSION));
        switch ($this->extension)
        {
            case 'jpg':
                 $this->image = imagecreatefromjpeg($this->tmpfile);
                 break;

            case 'png':
                $this->image = imagecreatefrompng($this->tmpfile);
                break;

            case 'gif':
                $this->image = imagecreatefromgif($this->tmpfile);
                break;

            default:
                throw new Exception('Unknown extension');
        }

        // Get the center of the image!
        $this->center = array('x' => round($this->width/2), 'y' => round($this->height/2));
    }

    /**
     * Zooms the frame given the center coordinates.
     *
     * @param int $centerX X center coordinate of the frame
     * @param int $centerY Y center coordinate of the frame
     * @return resource The frame
     */
    protected function zoom($centerX, $centerY)
    {
        $zoom = intval($this->zoomFactor - 1);
        $topLeftX = $topLeftY = 0;
        while(true)
        {
            $zoom++;
            $width  = ceil($this->width/$zoom);
            $height = ceil($this->height/$zoom);

            // Get the top left coordinates of the zoom
            $topLeftX = round($centerX - ($width/2));
            $topLeftY = round($centerY - ($height/2));

            // Validate that X and Y are inside the range of the image!
            $validateX = ($topLeftY <= $this->width && ($topLeftX + $width) <= $this->width && $topLeftX >= 0);
            $validateY = ($topLeftY <= $this->height && ($topLeftY + $height) <= $this->height && $topLeftY >= 0);

            // Stop zooming if the coordinates are good OR if we have tried too many times.
            if (($validateX && $validateY) || $zoom >= 50)
                break;
        }

        $this->debug['zoom'][] = array('x' => $topLeftX,
                                       'y' => $topLeftY,
                                       'height' => $height,
                                       'width'  => $width,
                                       'factor' => $zoom);

        // Zoom the area
        $croppedImage = imagecreatetruecolor($width, $height);
        imagecopyresampled($croppedImage, $this->image, 0, 0, $topLeftX, $topLeftY, $this->width, $this->height, $this->width, $this->height);

        // Enhance it!
        $frame = imagecreatetruecolor($this->width, $this->height);
        imagecopyresampled($frame, $croppedImage, 0, 0, 0, 0, $this->width, $this->height, $width, $height);
        imagedestroy($croppedImage);

        return $frame;
    }

    /**
     * Generates the image
     *
     * @return void
     */
    public function create()
    {
        $this->debug['center'] = $this->center; $this->debug['destiny'] = $this->destiny;

        // If no starting point was defined, we use the center coordinates.
        if (!empty($this->start['x']) && !empty($this->start['y']))
        {
            $x = $this->start['x'];
            $y = $this->start['y'];
        }
        else
        {
            $x = $this->center['x'];
            $y = $this->center['y'];
        }

        $this->debug['starting_point'] = array('x' => $x, 'y' => $y);

        // The first frame is always the original file.
        $this->output = imagecreatetruecolor($this->width, ($this->height * $this->frames));
        imagealphablending($this->output, true);
        imagecopy($this->output, $this->image, 0, 0, 0, 0, $this->width, $this->height);

        // The remaining Frames
        $rFrames = ($this->frames-1);

        // Calculate the distance between the starting point and the destination, in relation to the number of frames
        $distanceX = round(($this->destiny['x'] - $x)/$rFrames);
        $distanceY = round(($this->destiny['y'] - $y)/$rFrames);

        // Start with 1 because we already have the first frame - Get the remaining ones!
        for ($i=1; $i<=$rFrames; $i++)
        {
            $x += $distanceX;
            $y += $distanceY;

            $frame = $this->zoom($x, $y);
            imagecopy($this->output, $frame, 0, ($this->height * $i), 0, 0, $this->width, $this->height);
            imagedestroy($frame);

            $this->debug['creation_points'][] = array('x' => $x, 'y' => $y);
        }

        $this->writeText();
    }

    /**
     * Writes text on the end of the image
     *
     * @return void
     */
    protected function writeText()
    {
        if (empty($this->text) || empty($this->font))
            return ;
        else if (!is_file($this->font))
            throw new Exception($this->font . ' was not found!');

        $white = imagecolorallocate($this->output, 255, 255, 255);
        $black = imagecolorallocate($this->output, 0, 0, 0);

        // centering text horizontally
        $x = (($this->width - (imagefontwidth(40) * strlen($this->text)))/2) - 40;
        imagettftext($this->output, 40, 0, ($x-1), (($this->height * $this->frames) - 20)-1, $black, $this->font, $this->text);
        imagettftext($this->output, 40, 0, ($x+1), (($this->height * $this->frames) - 20)+1, $black, $this->font, $this->text);
        imagettftext($this->output, 40, 0, $x, (($this->height * $this->frames) - 20), $white, $this->font, $this->text);
    }

    /**
     * Show the image in jpg format in the browser
     *
     * @return void
     */
    public function show()
    {
        header('Cache-Control: no-store, no-cache');
        header('Content-type: image/jpg');
        imagejpeg($this->output, null, 99);
    }

    /**
     * Returns important data for debugging
     *
     * @return array
     */
    public function debug() { return $this->debug; }

    /**
     * Setter Method
     *
     * @return void
     */
    public function set($key, $value)
    {
        if (property_exists($this, $key) && !in_array(strtolower($key), array('image', 'tmpfile')))
            $this->$key = $value;
    }

    /**
     * Clean the environment on object destruction
     *
     * @return void
     */
    public function __destruct() { imagedestroy($this->output); }
}

// Usage
$Tenso = new Tenso('lorito.jpg');
$Tenso->set('text', 'Tenso');
$Tenso->set('destiny', array('x' => 300, 'y' => 250);
$Tenso->create();
$Tenso->show();
?>

Text-Example.php

<?php
    // Coge la imágen
    list ($width, $height) = getimagesize('lorito.jpg');
    $image = imagecreatefromjpeg('lorito.jpg');

    // Texto y fuente
    $text = 'Hola';
    $font = 'impact.ttf';

    // Los colores para nuestro texto
    $white = imagecolorallocate($image, 255, 255, 255);
    $black = imagecolorallocate($image, 0, 0, 0);

    // Centramos el texto en el eje X
    $x = (($width - (imagefontwidth(40) * strlen($text)))/2) - 40;

    // Primero escribimos el texto en negro moviendolos un pixel a cada lado
    // De esta forma creamos el efecto de una márgen
    // El 20 es la distancia del texto al final de la imagen en el eje Y
    imagettftext($image, 40, 0, ($x-1), ($height - 20)-1, $black, $font, $text);
    imagettftext($image, 40, 0, ($x+1), ($height - 20)+1, $black, $font, $text);

    // Encima de la margen en negro escribimos el texto en blanco
    imagettftext($image, 40, 0, $x, ($height - 20), $white, $font, $text);


    if (file_exists('lorito-text.png'))
        unlink('lorito-text.png');

    // Guardamos la imágen
    imagepng($image, 'lorito-text.png');
?>

Zoom-Example.php

<?php
    // Datos de la imágen
    list ($width, $height) = getimagesize('lorito.jpg');
    $image = imagecreatefromjpeg('lorito.jpg');

    // Encontramos el centro de la imágen
    $centerX = ceil($width/2);
    $centerY = ceil($height/2);

    // Dividimos la imágen por el factor de zoom. En este caso 2X
    $zoomFactor = 2;
    $zoomWidth  = ceil($width/$zoomFactor);
    $zoomHeight = ceil($height/$zoomFactor);

    // Para la función imagecopyresampled necesitamos especificar la coordenada que se encuentra en
    // la parte superior izquierda. Ya tenemos la coordenada del centro, usemosla para nuestro objetivo.
    $topLeftX = round($centerX - ($zoomWidth/2));
    $topLeftY = round($centerY - ($zoomHeight/2));

    // Recortamos la imagen apartir de esa coordenada.
    $croppedImage = imagecreatetruecolor($zoomWidth, $zoomHeight);
    imagecopyresampled($croppedImage, $image, 0, 0, $topLeftX, $topLeftY, $width, $height, $width, $height);

    // La imagén recortada, la agrandamos al tamaño de la imágen original
    $zoomedImage = imagecreatetruecolor($width, $height);
    imagecopyresampled($zoomedImage, $croppedImage, 0, 0, 0, 0, $width, $height, $zoomWidth, $zoomHeight);
    imagedestroy($croppedImage);

    if (file_exists('lorito-zoomed.png'))
        unlink('lorito-zoomed.png');

    // Guardamos la imágen
    imagepng($zoomedImage, 'lorito-zoomed.png');
?>