Keyboard Input

GameMaker: Studio has a number of constants and functions related to the keyboard and how it can be used to make things happen in your games.

When dealing with the keyboard in GameMaker: Studio you have a variety of functions that can be used to recognise different keyboard states like pressed or released. There are also some that store all the keypresses as a string or that can tell you what the last key pressed was, as well as others that allow you to clear the keyboard state completely.

NOTE: These functions are designed for Windows/Mac/Ubuntu desktop platforms only. You may find some of the in-built variables and constants aren't valid on other platforms and many of the functions won't work on mobiles.

Now, each key is normally defined by a number, called the ascii code, and you can directly input this number into these functions and they will work fine... But, as it's a bit difficult to remember so many numbers and the relationship that they have with your keyboard, GameMaker: Studio has a series of constants for the most used keyboard special keys and a special function ord() to return the number from ordinary typed characters (either letters or numbers).

The following is a small example of how to use ord():

if keyboard_check(ord('A'))
   {
   hspeed = -5;
   }

So, the above will check the "A" key and if it's being pressed then it'll set the horizontal speed of the object to -5. Note, that the "A" is a capital "A", and that when using ord() the keyboard key to check must always be written in quotes and as a capital. Now, what if you want to use the arrow keys? Or if you want to modify an action using the "shift" key? Well, for that GameMaker: Studio has a series of vk_ constants (vk_ stands for virtual keyboard) that you can use in place of ord or the ascii code.

Here is a complete list of the vk_ constants:

The following constants can only be used with keyboard_check_direct():

The following is a small example of how to use the vk_ constants:

if keyboard_check_pressed(vk_tab)
   {
   instance_create(x,y,obj_Menu);
   }

The above code will detect if the "Tab" key is pressed and create an instance of object "obj_Menu" if it is.

For information on the available GameMaker: Studio keyboard functions, please see the following sections of the manual:

1. io_clear
   
2. keyboard_check
   
3. keyboard_check_pressed
   
4. keyboard_check_released
   
5. keyboard_check_direct
   
6. keyboard_clear
   
7. keyboard_key_press
   
8. keyboard_key_release
   
9. keyboard_key
   
10. keyboard_lastkey
    
11. keyboard_lastchar
    
12. keyboard_string
    
13. keyboard_set_map
    
14. keyboard_get_map
    
15. keyboard_unset_map
    
16. keyboard_get_numlock
    
17. keyboard_set_numlock
    

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