Engine Requirements - JayhawkZombie/EECS581Project GitHub Wiki

##Engine Requirements

Requirements:
Feature: Level

  • The Level can be rendered with a tiled background
  • The background can be read from a file, with the following structure:
    ID: \<character\>  
    Path: \<path to texture file\>  
    (1 or more ID + Path specs)  
    Layout:  
    \<character\> \<character\> … \<character\>  
    …  
    \<character\> \<character\> … \<character\>
  • The in the file is a single character used to map the texture to the layout, for simpler file reading and reduced memory overhead.
  • The Background tiles are drawn to a single render texture before the level begins the “play” cycle to reduce runtime overhead for rendering
  • The Level contains additional “Layers”, to allow layered scenes
  • Each layer is rendered in a specified order, with the highest index in storage rendered last
  • The Level contains a collection of Actors that can manipulated, and a single Pawn that represents the Actor the player controls
  • The Level loading is done in separate thread(s) to avoid blocking the main thread
  • The Level does collision detection for every Actor and Volume and triggers events to occur based on those collisions

Feature: LevelObject

  • The LevelObject is a generic object that Level is completely aware of
    • Its public and private members can be seen by Level
    • It is specialized with:
    • Containing a ColliisonBox
    • Containing a set of textures used to render it
    • The CollisionBox member can be used to script actions when an interaction event is triggered
    • It contains Animations
    • The animations can be scripted/triggered to begin/stop/pause/speed up/slow down at any time using the CollisionBox or by manually doing so with a method call

Feature: Actor

  • The Actor is a generic Engine entity, derived from LevelObject
  • It is specialized in:
    • Maintaining a velocity and acceleration
    • Can interact with other LevelObjects
    • The entity accepts and responds to user keyboard input using the intrinsic EventHandler object present
    • Actor actions can be scripted using a node-based linear linking system or by triggering a specific event callback using CollisionVolumes

Feature: Animations

  • Animations are either sprite-based or spline-based
  • For Sprite-based Animations:
    • Animations use a sprite sheet, along with a set of IntRects to specify each frame of animations, which are specified in the animation file
    • Each frame is equally spaced along the duration timeline, so no single frame will be rendered longer than any other
    • Animations can have fade in/out transitions, the duration for which is specified in the animation file
    • The animation can loop forever If desired, and stopped/restarted/sped up/slowed down at any time
    • The file format is as follows:
    [Animation]  
    [\<key\>=\<value\>]  
    File=\<FilePath\>  
    Frames=\<number of frames in the animation\>    
    Duration=\<Duration for animation\>  
    Loop=\<true | false\>  
    TransitionIn= \<true + \<duration\> | false\>  
    TransitionOut= \<true + \<duration\> | false\>  
    FrameWidth= \<width, in px, of each frame in the sprite sheet\>      
    FrameHeight= \<height in px of each frame in the sprite sheet\>  

    Ex.
    File=sampleanimation.png   
    Frames=20  
    Duration=2  
    Loop=true  
    TransitionIn=true 0.5  
    TranstionOut=false  
    FrameWidth=50  
    FrameHeight=70
  • The “Engine::Util” namespace contains methods to be used for parsing this, as it has the same file structure as an ini file
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