Starward Rogue:XML - GameEntity Definitions

Overview

A lot of these things cross over between any type of entity, and some things are specific to only certain entity types (ships only, or shots only). So we're going to break it out like that, with specific notes for each section as relevant.

An example

<entity name="Goldbug"
display_name="Goldbug"
    	behavior="Stationary" category="Ship"
    	speed="0" turning_resistance="2.25"
    	max_health="50"
    	image_folder="Enemy_Stationary"    
	>
	<system type="Goldbug" offset="0,0" />
	<hitbox radius="32" />
    	<stacked_image src="Attachments/TarraCrawlerArm" size="60" offset="-20,20" />
	<modifier target="MyShots" type="RicochetsOffTerrain"/>
</entity>

Note that the above is all one xml node (entity) with a bunch of attributes, until you get down to the end carat (>). Then the next line has a self-terminating hitbox node (self terminating means it does <hitbox/> rather than having <hitbox></hitbox> -- you self-terminate nodes if they don’t have any sub-nodes). There’s then a stacked_image node, and a modifier node, all of which are sub-nodes of the entity.

Attributes

These are things that go directly on the entity node, in the format attribute=”value”. So in the code <entity name="Goldbug">, name is the attribute and Goldbug is the value for that attribute.

Most Important General

• name (string)
  • All entities must have a name. The name for an entity must be absolutely unique from any other entities in the game, no matter what file they are in.
  • The name is actually more of a “primary key” identifier, and it’s not something players would ever see.
    • “SDT#$S” is a perfectly valid name if you want, although it’s a super unhelpful one so please don’t do it.
  • By default, the image for any entity is based on its name. This can (and often should be) overridden, however -- the image_name property does that.
    • Ships:
      • By default they will use the image RuntimeData/Images/Ships/yournamehere
    • ItemPickups:
      • By default they will use the image RuntimeData/Images/Items/yournamehere
    • Shots:
      • By default they will use the image RuntimeData/Images/Shots/yournamehere
      • It’s unlikely you will ever define a shot, however. You’ll define bullet patterns and systems and ships, but all a shot is is a graphic and a collision box. You’ll reference those, but not define them.
        • The systems and bullet patterns denote how shots move, what their damage is, speed is, etc, etc, etc.
    • Obstacles:
      • It’s really complicated how these use the images, and tends to be very tileset-dependent, which is not something in the purview of what you’re really designing here. That’s more to do with environment than enemies/items.
• category (GameEntityCategory)
  • Oi! What is this thing? Depending on what you say, it will be parsed differently.
  • Ship: Player hulls or enemy ships.
  • Shot: An actual bullet (you won’t use this much, if at all).
  • ItemPickup: What it says on the tin.
  • Obstacle: Funky stuff you won’t use much, if at all.

Sub-Nodes

Until now, everything has been talking about attributes right on the entity node itself (so <entity attribute=”data”></entity>). Now we’re going to talk about sub-nodes that go inside the entity object, though.

An Example

From this example, there are four sub-nodes: one hitbox, two stacked_images, and one modifier.

<entity name="Goldbug"
display_name="Goldbug"
    	behavior="Stationary" category="Ship"
    	speed="0" turning_resistance="2.25"
    	max_health="50"
    	image_folder="Enemy_Stationary"    
	>
	<system type="Goldbug" offset="0,0" />
	<hitbox radius="32" />
 <stacked_image src="Attachments/TarraCrawlerArm" size="60" offset="-20,20" />    	
<stacked_image src="Attachments/TarraCrawlerArm" size="60" offset="20,20"/>
	<modifier target="MyShots" type="RicochetsOffTerrain"/>
</entity>

A key thing to note about all of these sub-nodes is that they in turn also have attributes of their own. Another key thing to note is that you can have as many copies of these kinds of sub-nodes inside an entity as you want. Aka, you can have 1 hitbox or 10, as needed.

system (default schema)

Overall premise: a system attached to this ship, that can actually do something like shoot or trigger a player ability or whatever. These have locations inside the sim, but cannot collide with anything, have no concept of health, etc.

Example:

<system type="Minigun" offset="20,10" />

Attributes

• type (EntitySystem name)
  • This tells it what system node to pull from the EntitySystem xml
• offset (int,int)
  • This is the x,y offset of the center of the system from the center of the entity. Particularly useful when you have many systems on a single enemy.

system (alternate schema for when you want random variation in enemies)

Example:

<system offset="20,10">
	<possibility type="Minigun" chance="3" />
	<possibility type="TestWeapon" chance="1" />
</system>

possibility Attributes

• chance (int)
  • the relative chance of that system being picked for that spot for each entity of this type being spawned
  • So in this example, it has a 3-out-of-4 chance of picking minigun, and a 1-out-of-4 chance of picking TestWeapon
  • Don't use on player hulls or familiars, or it will reroll every time you enter a new room

hitbox

Overall premise: this is a circular space that a ship can be shot in, or that a shot occupies and thus collides with ships via. It’s the part of the ship/shot/whatever that is “solid,” in most respects.

Attributes

• radius (int)
  • This defines the radius of the red circle of the hitbox (hit F7 to see that).
• offset (int,int)
  • This is the x,y offset of the center of the hitbox from the center of the entity. Particularly useful when you have many hitboxes on a single enemy.
  • Note that the pessimistic blue bounding box for hitting walls will encompass all the hitboxes you define.
• incoming_damage_multiplier (float)
  • a shot hitting this particular hitbox will have its damage multiplied by this before it's applied to the entity
• set to zero for immunity to damage
  • negative numbers act like zero; they don't cause healing
• on_hit_triggers_systems_of_type (system)
  • a shot hitting this particular hitbox will authorize this system to fire (only matters if it's got firing_timing=Never)

stacked_image

Overall premise: sometimes we want to show multiple images on top of the base image of the ship or shot or what have you. This lets us build up larger ships than we’d otherwise have, and it lets us take off pieces when we move to “later stage” copies of the ship (just remove the stacked_image entries and hitbox entries of relevance when doing that.)

Attributes

• src (string)
  • This looks in the same folder that the base image of the entity is in, whatever that is. Generally speaking it’s nice to put the attachments in some sort of subfolder, and you can specify that all in this one field (as noted in the example above).
• size (int)
  • What is the width (and height) of this square image? I’m honestly not positive why we care, but do set it accurately just in case.
• offset (int,int)
  • This is the x,y offset of the center of the stacked image from the center of the entity. You’re presumably always going to want to set this to something.
• rotation (int)
  • The number of degrees (0 to 364) that the image should be rotated from the basic orientation of the entity it is stacked on. Default 0.
• flipX (bool)
  • Should we flip this horizontally? This is different from doing a rotation of 180, since this will keep it upright and mirrored rather than being upside-down.
• flipY (bool)
  • Same as flipX, but in the vertical axis instead.

room

Only used for bosses, basically for boss rooms rather than picking a room of that type and then populating it, it picks a boss of the appropriate type (miniboss or boss) and then tries to pick a room that will fit the boss. The rooms that will fit are specified as room sub-nodes on the boss's entity record, like this:

Example:

<room src="Boss/CMP_BossNoWindows" buddies="SmallEnemy,SmallEnemy" />

Attributes

• src (string)
  • the name of the room script to use, relative to RuntimeData/Rooms/ , and without the .txt extension.
  • the room script must contain a B to seed the boss at, or it will throw an error during seeding
• buddies (list of GameEntity names, optional)
  • the names of other monsters to seed with this specific setup (you can have more than one room node with the same src, and different buddy lists), at the 'U' tiles in the room script
    • if the room script's number of 'U' tiles is not exactly equal to the number of buddies specified here, it will throw an error during seeding

periodic_movement_mode

This is a large enough subject that it is defined here in its own section: Starward_Rogue:XML - PeriodicMovementModeType Definitions

Starward Rogue XML Documentation Main