Entities ahoy!

Jussi Lepistö — Sat, 28 Jun 2008 01:27:14 +0000

Entity system

Today I've continued work under the hood, on the entity system. Both components and entity types are now loaded using the plugin / entry point system of setuptools, which means custom components and units will be really easy to create and distribute. And much easier for me to load. I have a habit of making too many sweeping changes to code at once, and this is no exception. On the other hand, this does result in massive improvements to the entity system and especially creation of entity type files, so it's all for the greater good.

No screenshots to show for my efforts, but see the end of the post for examples of what entity type files currently look like. This might change before these changes are completed.

Entity editor

I'll probably have to start working on an entity editor at some point, since I recon unit and other entity creation will get quite complicated when multiple linked entities, collision shapes, etc. etc. get involved. I'm no big fan of GUI programming, especially since Python's GUI libraries all seem kind of shoddy (though that seems to apply to other languages too, at least C# and Java). Anyway, I'll probably use wxPython for it. Making it in-game would be cool, but too much effort at the moment.

Trac

I tried installing Trac (again) today since they just released version 0.11, and couldn't get it working (again). After getting over a few hurdles, I was finally stumped when trac-admin hanged while trying to create the environment. Every time. I really want to like Trac, since it's excellent when it works, but I've had nothing but problems trying to get it working myself. It seems I'll have to let it go and find some other issue tracker when I really start needing one. I'd like it to integrate with Mylyn, but the (free) options there are a bit limited. We'll see...

Entity types files

Here's what a unit type file currently looks like. The interface for this is not fully implemented yet, but I hope I'll get that finished during this weekend.

from artillerybrawl import component, entity
from artillerybrawl.entity import Entity

Unit = entity.get_class("unit")

class Howitzer(Unit):
name = "howitzer"

def __init__(self):
Unit.__init__(self)

self.mass = None
self.material = None
self.hitpoints = None
self.resistances = None

# Body
self.body_width = None
self.body_height = None
self.body_texture = None

self.collision_meshes = None

# Turret
self.turret_offset = None

self.turret_width = None
self.turret_height = None
self.turret_texture = None

self.turret_min_angle = None
self.turret_max_angle = None
self.turret_max_power = None

def create(self):
entity = Unit.create(self)

# Body
body_sprite = component.create("sprite",
self.body_width, self.body_height, self.body_texture)
body_physics = component.create("physics",
self.mass, self.collision_meshes, self.material)
body_damage = component.create("damage", self.hitpoints)

body = Entity(self.name, (body_sprite, body_physics, body_damage))

# Turret
turret_transform = component.create("transform", parent=body)
turret_sprite = component.create("sprite",
self.turret_width, self.turret_height, self.turret_texture)
turret_component = component.create("turret",
self.turret_min_angle, self.turret_max_angle, self.turret_max_power)

turret = Entity("%s_turret" % self.name,
(turret_transform, turret_sprite, turret_component))

return body

And an actual unit base on the unit type above.

from artillerybrawl import entity

Howitzer = entity.get_class("howitzer")

class A1(Howitzer):
name = "A1"

def __init__(self):
Howitzer.__init__(self)

self.mass = 1000.0
self.material = "metal"

self.hitpoints = 100
self.resistances = {
"kinetic": 50.0,
}

# Body
self.body_width = 5.0
self.body_height = 2.5
self.body_texture = "a1"

self.collision_meshes = [
[(0.0, 0.0), (1.0, 1.0), (0.0, 1.0), (1.0, 0.0)],
[(0.0, 0.0), (1.0, 1.0), (0.0, 1.0), (1.0, 0.0)],
]

# Turret
self.turret_offset = (2.5, 2.5)

self.turret_width = 5.0
self.turret_height = 1.0
self.turret_texture = "a1_turret"

self.turret_min_angle = -5.0
self.turret_max_angle = 85.0
self.turret_max_power = 100.0

Busy and exhausted

Jussi Lepistö — Sat, 08 Dec 2007 16:16:34 +0000

Three days of training capoeira behind, one left (tomorrow). It's starting to feel quite exhausting, but has been really fun too! That's also the reason I haven't updated in a while, and haven't made much progress either. But I've done a bit...

The plugin system and layout is hopefully more or less final (for) now and the renderer is starting to get together again. I want to get the renderer plugin done and do some changes to resource management, then start working on scene management again. When that's sufficiently done, I can finally start working on the actual game. I'm not going to work on the engine any more than the game requires. I also released a simple tool for counting Python lines of code a couple of days ago.