Designing Games with Game Maker - YoYo Games

does not matter.
background_create_from_surface(id,x,y,w,h,transparent,smoot
h,preload) Creates a background by copying the given area from the
surface with the given id. This makes it possible to create any background you
want. Draw the image on the surface using the drawing functions and next
create a background from it. Note that alpha values are maintained the
background.
background_delete(ind) Deletes the background from memory, freeing
the memory used.
The following routine exists to change the appearance of a background.
Fonts
background_set_alpha_from_background(ind,back) Changes the
alpha (transparancy) values in the background with index ind using the
intensity values in the background back. This cannot be undone.
It is possible to create, replace, and delete fonts during the game using the following
functions. (Don't replace a font that is set as the current font or at least set it again
afterwards.)
font_add(name,size,bold,italic,first,last) Adds a new font and
returns its index, indicating the name, size, whether it is bold or italic, and the
first and last character that must be created.
font_add_sprite(spr,first,prop,sep) Adds a new font and returns its
index. The font is created from a sprite. The sprite should contain a subimage
for each character. first indicate the index of the first character in the sprite.
For example, use ord('0') if your sprite only contains the digits. prop
indicates whether the font is proportional. In a proportional font, for each
character the width of the bounding box is used as the character width.
Finally, sep indicates the amount of white space that must separate the
characters horizontally. A typical value would lie between 2 and 8 depending
on the font size.
font_replace(ind,name,size,bold,italic,first,last) Replaces
the font ind with a new font, indicating the name, size, whether it is bold or
italic, and the first and last character that must be created.