pods::...oystick(3pm)

🎮 SDL::Joystick — the manual page, bestie edition 🎮

okay so this is pods::...oystick(3pm) from the User Contributed Perl Documentation crew — it's the SDL::Joystick page, aka SDL Bindings for the Joystick device. yes that's the NAME section, we're doing this properly 💅

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✨ CATEGORY ✨

Core, Joystick. that's it, that's the vibe. 👑

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✨ SYNOPSIS ✨

like, the whole thing in one go:

use SDL;
use SDL::Joystick;

SDL::init_sub_system(SDL_INIT_JOYSTICK);

die('no joystick found') unless(SDL::Joystick::num_joysticks());

my $joystick = SDL::Joystick->new(0);

literally that's the entire opening act 🎀

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🌸 METHODS 🌸

🦋 num_joysticks

int SDL::Joystick::num_joysticks( void );

counts up all the joysticks you got and returns how many there are. no cap. 🎮

🦋 name

string SDL::Joystick::name( index );

gets you the implementation dependent name of a joystick. the index param means "the N'th joystick on the system", iykyk.

my $num_joysticks = SDL::Joystick::num_joysticks();

printf("%d joysticks found\n", $num_joysticks);

for($i = 0; $i < $num_joysticks; $i++)
{
    printf("%s\n", SDL::Joystick::name($i));
}

look at her go, naming every single one 🫶

🦋 new

object SDL::Joystick->new( index );

opens a joystick for use within SDL. index is the N'th joystick in the system. super important: a joystick must be opened before it can be used, that's just the rules bestie 💀

# Initialize the joystick subsystem
SDL::init_sub_system(SDL_INIT_JOYSTICK);

# Check for joystick
if(SDL::Joystick::num_joysticks() > 0)
{
    # Open joystick
    my $joystick = SDL::Joystick->new(0);

    if($joystick)
    {
        printf("Opened Joystick 0\n");
        printf("Name: %s\n",              SDL::Joystick::name(0));
        printf("Number of Axes: %d\n",    SDL::Joystick::num_axes($joystick));
        printf("Number of Buttons: %d\n", SDL::Joystick::num_buttons($joystick));
        printf("Number of Balls: %d\n",   SDL::Joystick::num_balls($joystick));
    }
    else
    {
        printf("Couldn't open Joystick 0\n");
    }

    # Close if opened
    SDL::Joystick::close($joystick) if SDL::Joystick::opened(0);
}

the whole lifecycle in one block, we love a self-contained icon ✨

🦋 opened

int SDL::Joystick::opened( index );

figures out whether a joystick has already been opened within the application. index = the N'th joystick on the system.

returns 1 if it's been opened, or 0 if it hasn't. simple as 🍓

🦋 index

int SDL::Joystick::index( object );

returns the index of a given SDL_Joystick structure. check out SDL::Joystick::new if you need the backstory 👀

🦋 num_axes

int SDL::Joystick::num_axes( object );

returns the number of axes available from a previously opened joystick. see SDL::Joystick::new 🌈

🦋 num_balls

int SDL::Joystick::num_balls( object );

returns the number of trackballs available from a previously opened joystick. see SDL::Joystick::new 🌸

🦋 num_hats

int SDL::Joystick::num_hats( object );

gets the number of joystick hats from a previously opened joystick. see SDL::Joystick::new 🎩

🦋 num_buttons

int SDL::Joystick::num_buttons( object );

gets the number of joystick buttons from a previously opened joystick. see SDL::Joystick::new 💜

🦋 update

void SDL::Joystick::update();

updates the state (position, buttons, etc.) of all open joysticks. and here's the lil detail: if joystick events have been enabled with SDL::Joystick::event_state, then this gets called automatically in the event loop. so she's already on it 😎

🦋 get_axis

get_axis returns the current state of the given axis on the given joystick.

on most modern joysticks the X axis is usually represented by axis 0 and the Y axis by axis 1. the value returned by get_axis is a signed integer (-32768 to 32767) representing the current position of the axis — and ngl you may need to impose certain tolerances on these values to account for jitter. the jitter is real 😭

Note: some joysticks use axes 2 and 3 for extra buttons. plot twist.

returns a 16-bit signed integer representing the current position of the axis.

my $joystick = SDL::Joystick->new(0);

my $x_move   = SDL::Joystick::get_axis($joystick, 0);
my $y_move   = SDL::Joystick::get_axis($joystick, 1);

x and y, together, iconic 🫶

🦋 get_hat

int SDL::Joystick::get_hat( object, int );

get_hat returns the current state of the given hat on the given joystick.

the current state comes back as an OR'd combination of one or more of these:

• SDL_HAT_CENTERED
• SDL_HAT_UP
• SDL_HAT_RIGHT
• SDL_HAT_DOWN
• SDL_HAT_LEFT
• SDL_HAT_RIGHTUP
• SDL_HAT_RIGHTDOWN
• SDL_HAT_LEFTUP
• SDL_HAT_LEFTDOWN

dirs on dirs on dirs 📍

my $joystick = SDL::Joystick->new(0);

my $position = SDL::Joystick::get_hat($joystick, 0);

print("hat is in position UP\n") if $position & SDL_HAT_UP;

🦋 get_button

int SDL::Joystick::get_button( object, int );

get_button returns the current state of the given button on the given joystick.

returns 1 if the button is pressed. otherwise, 0. pressed or not pressed, no in-between bestie 💅

my $joystick    = SDL::Joystick->new(0);

my $num_buttons = SDL::Joystick::num_buttons($joystick);

for(my $i = 0; $i < $num_buttons; $i++)
{
    printf("button %d is %s\n", $i, SDL::Joystick::get_button($joystick, $i) ? 'pressed' : 'not pressed');
}

SDL::Joystick::close($joystick) if SDL::Joystick::opened(0);

🦋 get_ball

int SDL::Joystick::get_ball(SDL_Joystick $joystick, int $ball, int $dx, int $dy);

get the ball axis change 🎱

trackballs can only return relative motion since the last call to SDL::Joystick::get_ball — these motion deltas are placed into dx and dy.

returns 0 on success or -1 on failure.

my $delta_x  = 0;
my $delta_y  = 0;
my $joystick = SDL::Joystick->new(0);

SDL::Joystick::update();

printf("TrackBall Read Error!\n") if(SDL::JoystickGetBall($joystick, 0, $delta_x, $delta_y) == -1);
printf("Trackball Delta- X:%d, Y:%d\n", delta_x, delta_y);

🦋 close

void SDL::Joystick::close( object );

closes a previously opened joystick. see SDL::Joystick::new 🎀

SDL::Joystick::close($joystick) if SDL::Joystick::opened(0);

always close what you open, periodt 🔥

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👑 AUTHORS 👑

see AUTHORS in SDL. that's the whole section, she's brief and mysterious 🦋

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and that's the page babes 💖 written by the User Contributed Perl Documentation girlies, perl v5.42.0, dated 2024-05-01 — go forth and open a joystick, or like, at minimum check SDL::Joystick::num_joysticks() first 🙈✨