JarCastingAgrotera
Zero-overhead anti-boilerplate strategies for Artemis Entity System Framework.
Nota Bene: RIP agrotera
Agrotera probably won't see much future development; a lot of the functionality provided by agrotera is now present in artemis-odb. Refer to this post for more details.
Features
- Compile-time class engineering: no reflection overhead, no extra classes, no additional runtime dependencies, works with Android.
- @ArtemisSystem for EntitySystems and @ArtemisManager for Managers.
- Injects
Aspectin constructor, unless already defined (only applies to EntitySystems). - Declares fields for referenced component mappers, managers and systems (only tested with Eclipse and maven).
- Wires up referenced classes in
initialize(), prepending to the method if already defined. - Generate Component Dependency Matrices via maven plugin (example).
- Injects
- @Profile EntitySystems
- Injects conditional profiler call at start of
begin()and before any exit point inend(). - User-specified profiler class - adhering to ArtemisProfiler.
- Injects conditional profiler call at start of
- Inject abitrary classes with @ArtemisInjected.
- Creates an
initialize(World)method on the annotated class.
- Creates an
Installation
- Preparing Eclipse IDE: Add lombok-pg and agrotera-lombok to
eclipse.ini. - Eclipse project setup: Add lombok-pg to classpath and
agrotera-asmas a project builder. Not necessary when using Eclipse+Maven. - Maven project setup: Configure
agrotera-maven-plugin. Also applies to Eclipse+Maven.
Minimal example
###What you type:
@Profile(using=Profiler.class, enabled=true)
@ArtemisSystem(
requires={Renderable.class, Velocity.class},
excludes={Cullable.class, AssetReference.class},
managers={TagManager.class, GroupManager.class},
systems=VelocitySystem.class)
public class TestSystem extends IntervalEntityProcessingSystem
{
public TestSystem()
{
super(null, 0.05f);
}
@Override
protected void process(Entity e)
{
// process system
}
}
###What the JVM gets:
@WovenByTheHuntress // marker annotation; don't process class when present
@Profile(using=Profiler.class, enabled=true)
@ArtemisSystem(
requires={Renderable.class, Velocity.class},
excludes={Cullable.class, AssetReference.class},
managers={TagManager.class, GroupManager.class},
systems=VelocitySystem.class)
public class TestSystem extends IntervalEntityProcessingSystem
{
private final Profiler $profiler;
private ComponentMapper<Renderable> renderableMapper;
private ComponentMapper<Velocity> velocityMapper;
private VelocitySystem velocitySystem;
private TagManager tagManager;
private GroupManager groupManager;
public TestSystem()
{
super(Aspect.getAspectForAll(Renderable.class, Velocity.class)
.exclude(Cullable.class, AssetReference.class), 0.05f);
$profiler = new Profiler();
$profiler.setTag(getClass());
}
@Override
protected void initialize()
{
renderableMapper = world.getMapper(Renderable.class);
velocityMapper = world.getMapper(Velocity.class);
tagManager = world.getManager(TagManager.class);
groupManager = world.getManager(GroupManager.class);
velocitySystem = world.getSystem(VelocitySystem.class);
}
@Override
protected void begin()
{
$profiler.start();
}
@Override
protected void end()
{
$profiler.stop();
}
@Override
protected void process(Entity e)
{
// process system
}
}
Behind the veil
Agrotera consists of two intermingling parts.
agrotera-lombok
Responsible for declaring the fields, inferred from annotations, ensuring that the IDE doesn't complain about unresolved fields.
Provides @Profiler, @ArtemisSystem, @ArtemisManager and @ArtemisInjected, processed alongside lombok-pg (you know, that fork of Project Lombok - because I couldn't get type resolution working under vanilla lombok).
agrotera-asm
Transforms the entity systems and managers; wiring up dependencies and injecting profiler calls. Conceived as a post-compile step run via the agrotera-maven-plugin or with an eclipse builder.
Artemis Maven dependency / Shameless self-promotion
Our fork of Artemis:
<dependency>
<groupId>net.onedaybeard.artemis</groupId>
<artifactId>artemis-odb</artifactId>
<version>0.5.0</version>
</dependency>
Contact
junkdog at onedaybeard dot net - twitter: @junkdogAP