Is there a simple way to manipulate bitwise enum in PHP? - php

Question

I'm creating a custom user profile for a game (osu!) and I'm trying to get which "mods" has been used in a "top play".
The API provides a decimal number containing each mods the player used in his play.
Ex: 72 for DoubleTime+Hidden mods, since DoubleTime is 64 and Hidden 8
$hidden = 8;
$doubletime = 64;
$hiddendoubletime = ($hidden|$doubletime);
I want to, from 72 for example, know that its 8 and 64.
or even from 88 that it's 8 and 16 and 64.
I was thinking about transform 88 for example in binary (01011000), then detect all "1" positions since each "1" gives a mod.
Here : 01011000 -
the first "1" at position 4 is the Hidden mod, the second "1" a position 5 is the Hardrock mod and finally, the "1" at position 7 is the DoubleTime mod.
Then enum is the following :
enum Mods
{
None = 0,
NoFail = 1,
Easy = 2,
TouchDevice = 4,
Hidden = 8,
HardRock = 16,
SuddenDeath = 32,
DoubleTime = 64,
Relax = 128,
HalfTime = 256,
Nightcore = 512, // Only set along with DoubleTime. i.e: NC only gives 576
Flashlight = 1024,
Autoplay = 2048,
SpunOut = 4096,
Relax2 = 8192, // Autopilot
Perfect = 16384, // Only set along with SuddenDeath. i.e: PF only gives 16416
Key4 = 32768,
Key5 = 65536,
Key6 = 131072,
Key7 = 262144,
Key8 = 524288,
FadeIn = 1048576,
Random = 2097152,
Cinema = 4194304,
Target = 8388608,
Key9 = 16777216,
KeyCoop = 33554432,
Key1 = 67108864,
Key3 = 134217728,
Key2 = 268435456,
ScoreV2 = 536870912,
LastMod = 1073741824,
}
As you can see, the list is pretty big, so I can't just try each mods combinations in if() condition.

Answer 1

I would do something like this....
<?php
$user_options = 88;
$no_options = array ( 'None' => 0 );
$game_options = array (
'NoFail' => 1,
'Easy' => 2,
'TouchDevice'=> 4,
'Hidden' => 8,
'HardRock' => 16,
'SuddenDeath' => 32,
'DoubleTime' => 64,
'Relax' => 128,
'HalfTime' => 256,
'Nightcore' => 512,
'Flashlight' => 1024,
'Autoplay' => 2048,
'SpunOut' => 4096,
'Relax2' => 8192,
'Perfect' => 16384,
'Key4' => 32768,
'Key5' => 65536,
'Key6' => 131072,
'Key7' => 262144,
'Key8' => 524288,
'FadeIn' => 1048576,
'Random' => 2097152,
'Cinema' => 4194304,
'Target' => 8388608,
'Key9' => 16777216,
'KeyCoop' => 33554432,
'Key1' => 67108864,
'Key3' => 134217728,
'Key2' => 268435456,
'ScoreV2' => 536870912,
'LastMod' => 1073741824
);
$filtered = array_filter ( $game_options, function ( $value ) use ( $user_options )
{
return ( $value & $user_options ) == $value ? $value : NULL;
});
if ( empty ( $filtered ) )
{
print_r ( $no_options );
}
else
{
print_r ( $filtered );
}
?>

Answer 2

I was thinking, it would be best to only cycle through the user(s) set options, that way you don't have to cycle through all the game_options when maybe only a few lower numbered bits are set...
<?php
$user_options = 344;
$game_options = array (
'NoFail' => 1,
'Easy' => 2,
'TouchDevice'=> 4,
'Hidden' => 8,
'HardRock' => 16,
'SuddenDeath' => 32,
'DoubleTime' => 64,
'Relax' => 128,
'HalfTime' => 256,
'Nightcore' => 512,
'Flashlight' => 1024,
'Autoplay' => 2048,
'SpunOut' => 4096,
'Relax2' => 8192,
'Perfect' => 16384,
'Key4' => 32768,
'Key5' => 65536,
'Key6' => 131072,
'Key7' => 262144,
'Key8' => 524288,
'FadeIn' => 1048576,
'Random' => 2097152,
'Cinema' => 4194304,
'Target' => 8388608,
'Key9' => 16777216,
'KeyCoop' => 33554432,
'Key1' => 67108864,
'Key3' => 134217728,
'Key2' => 268435456,
'ScoreV2' => 536870912,
'LastMod' => 1073741824
);
function get_options ( $game_options, $user_options )
{
/* if no options are set, return this */
$nil = array ( 'None' => 0 );
/* if option(s) are set, return the array of set option(s) */
$set = array ( );
/* only loop the $game_options up until the max set $user_options */
$stop = $user_options;
foreach ( $game_options AS $on => $ov )
{
if ( $ov > $stop )
{
break;
}
else if ( ( $ov & $user_options ) == $ov )
{
$set[$on] = $ov;
$stop -= $ov;
}
}
return empty ( $set ) ? $nil : $set;
}
print_r ( get_options ( $game_options, $user_options ) );
?>