Add autoloader.php as Composer alternative

README.md

@@ -28,14 +28,38 @@ In case you decide to contribute, please honor these things:
 
 
 
+---
+
+
+
 ## Installation
 
+### Composer (recommended)
+
 This package is available through Composer/Packagist:
 
 ```
 $ composer require jangobrick/php-svg
 ```
 
+### Manual
+
+[Download](https://github.com/JangoBrick/php-svg/zipball/master) this repo,
+or the [latest release](https://github.com/JangoBrick/php-svg/releases),
+and put it somewhere in your project. Then do:
+
+```php
+<?php
+require_once __DIR__.'/<path_where_you_put_it>/autoloader.php';
+```
+
+The rest works exactly the same as with Composer, just without things like nice
+version management.
+
+
+
+---
+
 
 
 ## Getting Started

autoloader.php

@@ -0,0 +1,34 @@
+<?php
+
+// PSR-4 autoloader implementation, taken from:
+// https://github.com/php-fig/fig-standards/blob/master/accepted/PSR-4-autoloader-examples.md
+// which is licensed under MIT.
+
+spl_autoload_register(function ($class) {
+
+    // project-specific namespace prefix
+    $prefix = 'JangoBrick\\SVG\\';
+
+    // base directory for the namespace prefix
+    $base_dir = __DIR__ . '/src/';
+
+    // does the class use the namespace prefix?
+    $len = strlen($prefix);
+    if (strncmp($prefix, $class, $len) !== 0) {
+        // no, move to the next registered autoloader
+        return;
+    }
+
+    // get the relative class name
+    $relative_class = substr($class, $len);
+
+    // replace the namespace prefix with the base directory, replace namespace
+    // separators with directory separators in the relative class name, append
+    // with .php
+    $file = $base_dir . str_replace('\\', '/', $relative_class) . '.php';
+
+    // if the file exists, require it
+    if (file_exists($file)) {
+        require $file;
+    }
+});