What is a workaround for colour coding in wordwrap() - php

Question

So Minecraft uses section signs (§) for colour coding so for example, light green is §a (a is the color code id for green). An important note to remember is that these are VISUALLY ignored in-game. I'm using wordwrap() to make text look centred however these section signs get in the way of that because they're visually not there yet still considered as characters by the function itself.
Here's my attempt: if you take a look, I tried to count the number of occurrences the section sign was found and multiplied it by two for the colour code character. I later then realized that this is inefficient because this affects the entire line of code and not just a specific bit. This basically means that this would make the length of other colour coded lines look odd since they have more or less colour coding in them. I also tried a rather dumb alternative where I'd use constants but I quickly realized that wasn't going to work. Let me know if anything is unclear. Thanks in advance.
$line = "§r§7This is the §eAuction House§7! In the §eAuction House§7, you can sell and purchase items from other Luriders who have auctioned their items. The §eAuction House §7is a great way to make some cash by simply selling items that other players might be interested in buying."
public static function itemLineOptimizer(string $line, int $width = 40)
{
$width += substr_count($line, '§') * 2;
return wordwrap($line, $width, "\n");
}
Console Output:
string(281) "§r§7This is the §eAuction House§7! In the §eAuction
House§7, you can sell and purchase items from other
Luriders who have auctioned their items. The §eAuction
House §7is a great way to make some cash by simply
selling items that other players might be interested in
buying."
In-Game Output:
In-Game Output

Answer 1

No where near as efficient as IMSoP's approach, but it is an alternative method I wanted to share. So what I did was I replaced section signs, removed them, wordwrapped, then added them back to their correct places. A bit complicated at first look but it's quite simple. Every line has its details commented.
function itemLineOptimizer(string $line, int $width = 40)
{
$line = str_replace("§", "&", $line); // Since section signs aren't just one-byte, we're going to make our lives easier and replace them with another one-byte symbol, I went with "&"
$colourCoding = array(); // Straightforward
$split = str_split($line); // Splitting the line into an array per character
foreach ($split as $key => $char){ // for every character has a $key (position) and the character itself: $char
if($char === "&") { // Check if it's a section sign / symbol chosen
array_push($colourCoding, [$key, $split[$key + 1]]); // add to $colourCoding an element which includes an array consisting of the position of the sign and the colour which the character at the position after
unset($split[$key]); // remove sign
unset($split[$key + 1]); // remove colour
}
}
// Now we've removed all colour coding from the line and saved it in $colourCoding
$bland = wordwrap(implode("", $split), $width, "\n"); // $bland is the now colourless wordwrapped line
foreach ($colourCoding as $array){ // Lastly we add the section signs back in their positions
$key = $array[0]; // position
$colour = $array[1]; // colour
$lineBreak = substr_count($bland, "§"); // Check for section signs already inside this line: they interfere with future loops since the correct position is different
$bland = substr_replace($bland, "§".$colour, $key + $lineBreak, 0); // Adding the colour coding back back to its correct position
}
return $bland; // Straightforward
}
$line = "§r§7This is the §eAuction House§7! In the §eAuction House§7, you can sell and purchase items from other Luriders who have auctioned their items. The §eAuction House §7is a great way to make some cash by simply selling items that other players might be interested in buying.";
var_dump(wordwrap($line, 40), itemLineOptimizer($line, 40));

Answer 2

One way to approach this which I though might be interesting is to take the internal implementation of wordwrap, and adapt it to our needs.
So I found the definition in the source, and in particular the special-case algorithm for handling a single-character line-break character which is all we need here, and saves us understanding all the other modes.
It works by copying the string, and then walking through it character by character, tracking when it last saw a space, and when it last saw or inserted a newline character. It then over-writes spaces with newline characters in place, without having to touch the rest of the string.
I first translated that literally into PHP (mostly a case of adding $ in front of each variable, and removing some special type handling macros), giving this:
function my_word_wrap($text, $linelength)
{
$newtext = $text;
$breakchar = "\n";
$laststart = $lastspace = 0;
$string_length = strlen($text);
for ($current = 0; $current < $string_length; $current++) {
if ( $text[$current] == $breakchar ) {
$laststart = $lastspace = $current + 1;
}
elseif ( $text[$current] == ' ' ) {
if ($current - $laststart >= $linelength) {
$newtext[$current] = $breakchar;
$laststart = $current + 1;
}
$lastspace = $current;
}
elseif ($current - $laststart >= $linelength && $laststart != $lastspace) {
$newtext[$lastspace] = $breakchar;
$laststart = $lastspace + 1;
}
}
return $newtext;
}
Two of those if statements include this condition which tracks how many characters we've seen since the last line break: $current - $laststart >= $linelength. What we could do is subtract from that the number of invisible characters we've seen, so they don't contribute to the "width" of lines: $current - $laststart - $invisibles >= $linelength.
Next, we need to detect section signs. My immediate guess was to use $text[$current] == '§', but that doesn't work because we're working in byte offsets, and § is not a single byte. Assuming UTF-8, it's specifically the pair of bytes which in hexadecimal are C2 A7, so we need to test the current and next character for that pair: $text[$current] == "\xC2" && $text[$current+1] == "\xA7".
Now we can detect the invisible characters, we can increment our $invisibles counter. Since § is two bytes, and the following character is also invisible, we want to increment the counter by three, and also move the $current pointer an extra two steps:
elseif ( $text[$current] == "\xC2" && $text[$current+1] == "\xA7" ) {
$invisibles += 3;
$current += 2;
}
Finally, we need to reset the $invisibles counter whenever we insert a newline, or see an existing one - in other words, everywhere we reset $laststart.
So, the final result looks like this:
function special_word_wrap($text, $linelength)
{
$newtext = $text;
$breakchar = "\n";
$laststart = $lastspace = $invisibles = 0;
$string_length = strlen($text);
for ($current = 0; $current < $string_length; $current++) {
if ( $text[$current] == $breakchar ) {
$laststart = $lastspace = $current + 1;
$invisibles = 0;
}
elseif ( $text[$current] == ' ' ) {
if ($current - $laststart - $invisibles >= $linelength) {
$newtext[$current] = $breakchar;
$laststart = $current + 1;
$invisibles = 0;
}
$lastspace = $current;
}
elseif ( $text[$current] == "\xC2" && $text[$current+1] == "\xA7" ) {
$invisibles += 3;
$current += 2;
}
elseif ($current - $laststart - $invisibles >= $linelength && $laststart != $lastspace) {
$newtext[$lastspace] = $breakchar;
$laststart = $lastspace + 1;
$invisibles = 0;
}
}
return $newtext;
}
Here's a live demo of it in action with your sample input.
Not the most elegant, and probably not the most efficient way to do it, but I enjoyed the exercise, even if it's not what you were hoping for. :)