Sprite

Introduction

Most animated images you see in supertux are sprites. Sprite definitions are defined in individual files that end in “.sprite”, e.g. “data/images/creatures/snowball.sprite”, and follow S-expr syntax.

Example

 (supertux-sprite
   (action
     (name "left")
     (hitbox 2 4 31.8 31.8)
     (images "left-0.png"
             "left-1.png"
             "left-2.png")
   )
   (action
     (name "right")
     (hitbox 2 4 31.8 31.8)
     (mirror-action "left")
   )
   (action
     (name "squished-left")
     (hitbox 1 -19 31.8 31.8)
     (images "squished-left.png")
   )
   (action
     (name "squished-right")
     (hitbox 1 -19 31.8 31.8)
     (mirror-action "squished-left")
   )
 )

Format

Let's look at the sprite “snowball”:

A sprite consists of a set of actions. An action is simply an animation composed from several images. The engine can render a sprite and change it's currently displayed action. The snowball sprite, for example, contains 4 actions named “left”, “right”, “squished-left” and “squished-right”.

Additionally you can define animation speed (fps ) and a hitbox (hitbox ).

The hitbox offset indicates where the “origin” of the sprite is: If the engine draws a sprite at position 50,50 then will be substracted from the x coordinate and will be substraced from the y-coordinate. The hitbox size will get read by most sprites' gamecode to set the width and height of an imaginary rectangle that defines what parts of a sprite are solid.

(sprite) block

The sprite description file is S-expr based. A sprite description starts with a (sprite) list, It should then contain a name entry (name “myname”) and then several (action) entries (at least 1).

(action) block

The action block contains then the name of an action (name “myaction”) can optionally contain an (hitbox ) block. It's also possible to add an (fps number) block to define the number of frames played per second. Finnaly comes a list of (images) or the '(mirror-action “actionname”)'' keyword which will take an already defined action and flip all it's images vertically.

Adding Own Sprites / Testing

You can easily add your own sprites by creating a custom .sprite file and placing it somewhere appropriate, e.g. “data/creatures//.sprite” for badguys or “data/objects//.sprite” for game objects. Now you probably want to test your sprite. This is easily possible from the game Console (example for data/images/creatures/yeti/yeti.sprite):

  testsprite<-FloatingImage("images/creatures/yeti/yeti.sprite")
  testsprite.fade_in(1)
  testsprite.set_action("run-left")

To remove the sprite from your screen, use

  testsprite<-null

An alternative would be creating ScriptedObjects in the leveleditor and selecting your spritefile

Sprite Editor

A Python/GTK-based sprite editor, named GSprite, is currently under development. Such an editor will have a graphical interface, and be able to add, remove, and edit individual actions, but will require Python, GTK, and PyGTK libraries as dependencies.

Category:Game Engine Category:File Formats