Designing Games with Game Maker - YoYo Games

sprite_add_from_surface(ind,id,x,y,w,h) Adds an area of the
surface id as a next subimage to the sprite with index ind.
sprite_delete(ind) Deletes the sprite from memory, freeing the memory
used.
The following routine exists to change the appearance of a sprite.
Sounds
sprite_set_alpha_from_sprite(ind,spr) Changes the alpha
(transparancy) values in the sprite with index ind using the intensity values in
the sprite spr. This cannot be undone.
The following routines can be used to create new sounds and to remove them.
sound_add(fname,kind,preload) Adds a sound resource to the game.
fname is the name of the sound file. kind indicates the kind of sound
(0=normal, 1=background, 2=3d, 3=mmplayer) preload indicates whether the
sound should immediately be stored in audio memory (true or false). The
function returns the index of the new sound, which can be used to play the
sound. (-1 if an error occurred, e.g. the file does not exist).
sound_replace(index,fname,kind,preload) Same as the previous
function but this time a new sound is not created but the existing sound index
is replaced, freeing the old sound. Returns whether correct.
sound_delete(index) Deletes the indicated sound, freeing all memory
associated with it. It can no longer be restored.
Backgrounds
The following routines can be used to create new backgrounds and to remove them.
background_duplicate(ind) Creates a duplicate of the background with
the given index. It returns the index of the new background. When an error
occurs -1 is returned.
background_assign(ind,back) Assigns the indicated background to
background ind. So this makes a copy of the background.
background_add(fname,transparent,smooth,preload) Adds the
image stored in the file fname to the set of background resources. Many