How do I keep whitespace formatting using PHP/HTML?

use the <pre> tag (pre formatted), that will use a mono spaced font (for your art) and keep all the white space

<pre>
text goes here and here 
             and here and here            Some out here
     ▄             ▄█▄ █▄       ▄
 ▄█▀█▓ ▄▓▀▀█▀ ▀▀▀█▓▀▀ ▀▀    ▄█▀█▓▀▀▀▀▀▓▄▀██▀▀
██  ██ ▀██▄▄ ▄█  ▀ ░▒ ░▒   ██  ██ ▄█▄ █▀ ██
█▓▄▀██  ▄ ▀█▌▓█    ▒▓ ▒▓   █▓▄▀██ ▓█ ▀▄  █▓
█▒  █▓ ██▄▓▀ ▀█▄▄█▄▓█ ▓█   █▒  █▓ ▒█  ▓█▄ ▒
    ▀▒           ▀  ▀ █▀       ▀▒  ▀  █▀  ░

</pre>  

You might have to convert any <‘s to &lt; ‘s