Expandfunction is_deck(){
	var os = os_get_info();
	var _is_deck = false;
	if (os_type == os_linux) {
		if (ds_exists(os, ds_type_map)) {
			var _renderer_info = os[? "gl_renderer_string"];
			if ((_renderer_info != undefined) and string_pos("valve", _renderer_info) > 1 and string_pos("neptune", _renderer_info) > 1) {
				_is_deck = true;
			}
		}
	}
	ds_map_destroy(os);
	return _is_deck;
}

Expand/// string_random_case(str);
//
//  Convert each letter in a string to either uppercase or lowercase, at random.
//
/// GMLscripts.com/license
function string_random_case(str) {
    var origstring = str;
    var stringarray = [];
    var finalstring = "";
    for(var i = 1; i < string_length(origstring); i++) {
        stringarray[i] = string_char_at(origstring,i);
        stringarray[i] = choose(string_upper(stringarray[i]),string_lower(stringarray[i]));
        finalstring += stringarray[i];
    }
    return finalstring;
}

Expand/// @func   get_unixtime()
/// @desc   Returns Unix timestamp.
function get_unixtime(){
    var timezone = date_get_timezone();
 
    date_set_timezone(timezone_utc);
    var epoch = floor(date_create_datetime(1970, 1, 1, 0, 0, 0));
    
    date_set_timezone(timezone);
    var datetime = date_current_datetime();
    
    var timestamp = floor(date_second_span(epoch, datetime));
 
    return timestamp;
}

/// @func   convert_unixtime(unix_timestamp)
/// @desc   Returns GameMaker datetime from Unix timestamp.
function convert_unixtime(timestamp){
    var timezone = date_get_timezone();
 
    date_set_timezone(timezone_utc);
    
    var epoch = date_create_datetime(1970, 1, 1, 0, 0, timestamp);
    var epH = date_get_hour(epoch);
    
    date_set_timezone(timezone);
    
    var cH = date_get_hour(date_current_datetime());
    
    var calcFuse = (cH - epH) * 3600;
    
    var datetime = date_create_datetime(1970, 1, 1, 0, 0, timestamp + calcFuse);
    return datetime;
}

Expandvar timestamp = get_unixtime();
draw_text(x,y,"Unix time: "+string(timestamp));

var datetime = convert_unixtime(timestamp);
draw_text(x,y+32,"Human time: "+string(date_datetime_string(datetime)));

Expand/// pick(val, case1, return1, case2, return2, ...)
//
// returns one of the values or undefined
//
//     val - value to compare with
//     case<x> - compare this to val
//     return<x> - return this if case<x> equals to val
//     
/// GMLscripts.com/license

function pick() {
	var val = argument[0];
	for(var i = 1; i < argument_count; i += 2) if argument[i] == val return argument[i+1];
	return undefined;
}

Expandenum e_TYPE { A, B, C, D }

type = e_TYPE.C;
var c = pick(type, e_TYPE.A, c_red, e_TYPE.B, c_lime, e_TYPE.C, c_orange, e_TYPE.D, c_aqua);
draw_set_color(c);

Expand/// drag_and_drop([button?])
//
//  Enables the object to be drag and dropped with the mouse around the room.
//
//      button?         Optional. Can be enabled if the sprite works as a button.
//                      ie. contains 2 images of a button being pressed.
//
/// GMLscripts.com/license
{
    var xx, yy, isbutton, hold, pressed, released;
    // Implement global vars
    if !variable_global_exists("cursor_dnd")
    {
        global.cursor_hover = noone;
        global.cursor_dnd = noone;
        global.cursor_xoffset = 0;
        global.cursor_yoffset = 0;
    }
    
    // variables
    xx = mouse_x;
    yy = mouse_y;
    isbutton = false;
    if(argument_count>0) isbutton = argument[0];
    if isbutton image_speed = 0;
    
    // inputs
    hold = mouse_check_button(mb_left);
    pressed = mouse_check_button_pressed(mb_left);
    released = mouse_check_button_released(mb_left);
    
    // mark as hover instance
    if position_meeting(xx, yy, id) && !instance_exists(global.cursor_hover)
    {
        global.cursor_hover = id;
    }
    if(global.cursor_hover == id)
    {
        if(!position_meeting(xx, yy, id))
            global.cursor_hover = noone;
    }
    
    // detect click
    if position_meeting(xx, yy, id) && pressed && !instance_exists(global.cursor_dnd)
    {
        global.cursor_dnd = id;
        global.cursor_xoffset = x-xx;
        global.cursor_yoffset = yy-y;
    }
    // dragging
    if(global.cursor_dnd == id)
    {
        x = xx+global.cursor_xoffset;
        y = yy-global.cursor_yoffset;
        if isbutton image_index = 1;
        if released
        {
            global.cursor_dnd = noone;
            if isbutton image_index = 0;
        }
    }
}

Expandarray_test = [10, 20, 70];
show_debug_message(array_sum(array_test));
// returns 10+20+70 = 100

Expandvar a = [1, 2, 3, 4, 5, 6];
array_shuffle(a);
show_debug_message(a); // for example: [ 5,2,1,4,3,6 ]

Expand/// @param {real} n number to check
/// @returns {bool}
function is_prime(n) {
    var a = [0, 2, 0, 4, 0, 2, 0, 2, 0, 2], p, m;
    if (n mod 2 == 0) return false;
    if (n mod 3 == 0) return false;
    p = 5;
    m = sqrt(n);
    while (p <= m) {
    if (n mod p == 0) return false;
        p += a[p mod 10];
    }
    return true;
}