prosperon/docs/game.md

= Yugine

The yugine essentially is made of a sequence of levels. Levels can be nested, they can be streamed in, or loaded one at a time. Levels are made of levels.

Different "modes" of using the engine has unique sequences of level loading orders. Each level has an associated script file. Level loading functions call the script file, as well as the level file. The level file can be considered to be a container of objects that the associated script file can access.

.Game start

• Engine scripts
• config.js
• game.lvl & game.js

.Editor

• Engine scripts
• config.js
• editor.js

.Editor play

• F5 debug.lvl ** Used for custom debug level testing. If doesn't exist, game.lvl is loaded.
• F6 game.lvl
• F7 Currently edited level

While playing ...

• F7 Stop

== Level model The game world is made up of objects. Levels are collections of objects. The topmost level is called "World". Objects are spawned into a specific level. If none are explicitly given, objects are spawned into World. Objects in turn are made up of components - sprites, colliders, and so on. Accessing an object might go like this:

World.level1.enemy1.sprite.path = "brick.png";

To set the image of enemy1 in level 1's sprite.

.Level functions ,=== name, description

levels, a list of all levels loaded in this one objects, a list of all objects belonging to this level (objects + levels) object_count, objects.length() spawn(type), creates an object from the supplied type in the level create(), creates an empty level inside of this one loadfile(file), loads file as a level inside of this one; returns it. Mainly for editor loadlevel(file), loads file as a level and does running required for gameplay load(level_json), clears this level and spawns all objects specified in the level_json clear(), kills all objects in this level kill(), cleans up the level and kills it

,===

.Objects Objects are things that exist in the game world.

,=== name, description level, the level this object belongs to pos, the global position relpos, the position relative to its level angle, the global angle relangle, angle relative to its level velocity, velocity of the object angularvelocity, angular velocity of the object alive, true if the object is valid varname, the variable name of the object (used for friendly naming) friction, physics attribnute elasticity, physics attribute flipx, true if the object is flipped on its x axis flipy, true if the object is mirrored on its y axis body, the internal gameobject id of the object controlled, true if the object is controlled by something phys, set to dynamic; kinematic; or static; explained below moi, the moment of inertia of the object mass, mass of the object visible, true if the object is visible. Set to false to disable all visible features belonging to it in_air(), true if the object is not on the ground on_ground(), !in_air() layer, collision layer for the physics engine draw_layer, draw order. higher numbers draw on top of lower ones scale, change to make the object larger or smaller from, the object this object was created from boundingbox, the boundingbox of this object in world dimensions push(vec), push this object each frame with vec velocity width, the boundingbox defined width height, the boundingbox defined height kill, destroy the object stop, ??? world2this(pos), return the pos in world coordinates to relative this object this2world(pos), return the pos in this coordinates relative to the world make(props, level), instantiate an object based on this, with additional props, in level ,===

.Editor related object features ,=== gizmo, path to an image to draw in editor mode ,===

.Functions for object control ,=== clone(name; ext), create a copy of this object and extend it with ext; does not spawn instadup(), create an exact duplicate of this object in the World revert(), remove everything that makes the object unique; make it exactly like what it was spawned from ,===

.Physics All objects belong to the physics engine, but may be totally ignored by it.

,=== static, does not and will not move dynamic, moves under the auspices of the physics engine kinematic, moves under the auspices of the player or other control mechanism ,===

Physics properties work as such ,=== mass, affects how much a given force will move an object elasticity, affects momentum loss on collisions; multiplicative between two objects for each collision; 1 for no loss; 0 for total stoppage; >1 for a chaotic increasing entropy simulation friction, affects momentum loss when rubbing against another surface; multiplicative between the two objects ,===

.Textures & images A sprite is a display of a specific texture in the game world. The underlying texture has values associated with it, like how it should be rendered: is it a sprite, is it a texture, does it have mipmaps, etc. Textures are all file based, and are only accessed through the explicit path to their associated image file.

.Finding & Addressing Objects

.Editor & Debugging Although intertwined, debugging functions and the editor are separate entities.

..Debugging Debugging functions are mapped to the F buttons, and are always available during gameplay in a debug build. Pressing the F button toggles the feature; pressing it with ALT shows a legend for that feature; pressing it with CTRL shows additional info

,=== F1, Draw physics info F3, Draw bounding boxes F12, Drawing gui debugging info ,===