The Animation Sequence Format

An animation is made up of a number of sprites and an .ani file which contains all the metadata.

The .ani file needs to specify the number of sprites using the @sprite_count attribute. Then different animation sequences can be defined.

Animation sequences are chains of sprites that can be replayed in-game. For example Cirno can either fly normally or flex while flying. In order for the game to understand which sprites need to be shown in what order and time delay you need to define a sequence for every action.

To define the action right of the player flying to the left for example, you write into the file

System Message: WARNING/2 (../doc/ANIMATION_FORMAT.rst, line 18)

Cannot analyze code. Pygments package not found.

.. code:: c

        right = d5 0 1 2 3

Every key in the .ani file not starting with @ corresponds to a sequence. The sequence specification itself is a list of frame indices. In the example above, the right sequence will cycle frames 0-3. Everything that is not a number like d5 in the example is a parameter:

d<n>: sets the frame delay to n. This means every sprite index given is shown for n ingame frames.
m: toggles the mirroring of the following frames.
m0,m1: set the absolute mirroring of the following frames.

All parameters are persistent within one sequence spec until you change them.

More examples:

System Message: WARNING/2 (../doc/ANIMATION_FORMAT.rst, line 39)

Cannot analyze code. Pygments package not found.

.. code:: c

        flap = d5 0 1 2 3 d2 4 5 6 7
        left = m d5 0 1 2 3
        alternateleftright = m d5 0 1 2 3 m 0 1 2 3

There are many possibilities to use d<n> to make animations look dynamic (or strange)

Some naming conventions

The resource code does not require you to choose any specific names for your sequences, but different parts of the game of course have to at some point. The most common convention is calling the standard sequence “main”. This is the least you need to do for anything using an aniplayer, because the aniplayer needs to know a valid starting animation.

If you have a sequence of the sprite going left or right, call it “left” and “right”. Player and fairy animations do this.

Look at existing files for more examples. Wriggle might be interesting for complicated delay and queue trickery. The documentation of the AniPlayer struct might also be interesting to learn more about the internals.