The main action sets are full of the most important actions that
you will need when working with GameMaker: Studio, and the
second set, marked "main2" in the object properties tab, deals with
timing, showing information, game control and resource control.
Set
Alarm
With this action you can set one of the twelve alarm clocks for the
instance. You select the number of steps and the alarm clock. After
the indicated number of steps, the instance will receive the
corresponding alarm event. You can also increase or decrease the
value by checking the Relative box. If you set the alarm
clock to a value less than or equal to 0 you switch it off, so the
event is not generated.
NOTE: An alarm with no actions in it will not run.
However, even with just a comment and no code, the alarm will count
down.
Set Time
Line
With this action you set the particular time line for an instance
of an object. You indicate the time line and the starting position
within the time line (0 is the beginning). Also you indicate
whether the time line should start immediately and whether it
should loop at the end.
Time
Line Position
With this action you can change the position in the current time
line (either absolute or relative). This can be used to skip
certain parts of the time line or to repeat certain parts.
Time
Line Speed
With this action you can change the speed of the time line (either
absolute or relative). A speed of 1 is the normal speed. When you
e.g. set it to 2 the actions will happen twice as fast and when you
set it to 0.5 twice as slow. You can also set a negative speed, in
which case the time line is played backwards.
Start
Time Line
This action starts the time line from its current position (if it
is paused or stopped).
Pause
Time Line
This action pauses the time line. Use the start action to let it
continue.
Stop Time
Line
This action stops the time line and sets the position back to
0.
Display
Message
With this action you can display a message in a dialog box. You
simply type in the message. If you use a # symbol in the message
text it will be interpreted as a new line character. (Use \# to get
the # symbol itself.) If the message text starts with a quote or
double quote symbol, it is interpreted as an expression. See below
for more information about expressions.
URL
Open
With this action you can tell your game to open a web page. You
need to specify the complete URL for this to work.
Restart
Game
With this action you restart the game from the beginning.
End
Game
With this action you end the game.
NOTE: If the target module for your game is HTML5, this
function will end the game but will not close the tab or
browser.
WARNING: If the target module for your game is iOS then
this action may block your device, and as such it is strongly
recommended that you do not use it for that platform except as a
dev tool. Your final game will also be rejected if this action is
used when submitting to the respective app store.
Save
Game
With this action you can save the current game status. You specify
the filename for saving (the file is created in the working
directory for the game). Later the game can be loaded with the next
action. (Please realize that only the basic game status is save.
Things that are for example not saved are the current sound that is
playing, and advanced aspects like the contents of data structures,
particles, etc.)
Load
Game
Load the game status from a file. You specify the file name. Make
sure the saved game is for the same game and created with the same
version of GameMaker. Otherwise an error will occur. (To be
precise, the game is loaded at the end of the current step. So some
actions after this one are still executed in the current game, not
the loaded one!)
Replace Sprite
This action can be used to replace a sprite from the contents of a
file. You indicate the sprite you want to replace, the filename and
the number of subimages in the sprite. Many different images file
formats are supported, e.g. .png, .jpg, .tif, and .gif. For a gif
file the number of subimages is automatically decided based on the
number of subimages in the gif file. Other settings for the sprite,
e.g. whether it is transparent or not, are not changed. You can use
this action to avoid storing all sprites in the program itself. For
example, at the beginning of a level you can replace sprites by the
actual character sprites you want to use. DON'T change a sprite
that is at that moment being used in an instance in the room. This
might give unwanted effects with collisions.
Replace
Sound
With this action you can replace a sound by the contents of a file
(.wav, .mid, or .mp3). You specify the sound and the filename. This
avoids having to store all the sounds in the game itself. For
example, you can use different pieces of background music and pick
the one you want to play. DON'T change a sound while it is
playing.
Replace Background
With this action you can replace a background by the contents of a
file. Many different images file formats are supported, e.g. .png,
.jpg, .tif, and .gif. You specify the background and the filename.
This avoids having to store all the backgrounds in the game itself.
DON'T change a background that is visible.