I wrote Ittyon <https://github.com/weavejester/ittyon> a little while ago, which is a database partially inspired by the entity-component model, but uses a more clojurey architecture.
There are also experiments with trying to make rule systems like Clara fast enough to use in games. On 16 August 2017 at 02:05, Jeaye <cont...@jeaye.com> wrote: > Alex Kehayias gave a talk about designing a functional game engine in > ClojureScript, using components, here: https://www.youtube.com/watch? > v=TW1ie0pIO_E I thought it was a superb talk. > > There's also Arcadia, here: https://github.com/arcadia-unity/Arcadia > which wrap's Unity3D in Clojure, but Unity takes about the most imperative > approach to components as possible. > > In general, and as Alex shows, the entity-component approach can work very > well with game engines. The issues of coupling can either be tackled with > explicit dependency declaration or by a more flexible async > notification/inbox system. I haven't yet built something like this, though > I'd like to, but, if/when I do, my design would be very much along the > lines of Alex's. > > J > > On Tue, Aug 15, 2017 at 05:52:38PM -0700, Didier wrote: > > I recently stumbled upon the entity-component-system design pattern which > > is popular in game engine > > design: https://en.wikipedia.org/wiki/Entity%E2%80%93component%E2% > 80%93system, > > and really liked what I saw, thought it could be a good fit for Clojure. > > > > Basically, it has three concepts: > > > > 1) Components are pure data grouped together as per a given domain. In a > > game engine that would be for example the 3D positional data related to > > positioning of objects in the 3D scene. So one component would be > > PositionComponent and it would have :X, :Y. > > > > 2) Entities are collections of Components with a unique ID. > > > > 3) Systems are processing functions that take an entity, transforming > their > > components' data, or performing side effects from them. > > > > Generally, in games, they inverse the entities, so instead of having > > entities contain components, they have components stored in an array with > > the index being the entity ID, and another array which contains the set > of > > components for the entity at that index. All of this is kept track of by > a > > world container. > > > > (def world > > {:entities [] > > :comp1 [] > > :comp2 [] > > ...}) > > > > > > So say you want to create an entity which is composed of comp1 and comp2, > > you would just add to the world :entities at index 0 a set #{:comp1 > > :comp2}, and to the world :comp1 and :comp2 vectors at index 0 an initial > > component1 and component2 data structure. In games, for performance, they > > use a bitmask instead of a set for the entry of :entities. > > > > > > I'm not sure this structure is necessary if trying to use the pattern not > > for game, but it doesn't hurt either I think. > > > > What I like about this, is I'm thinking its possible to use it to do > > data-driven functional object modeling in Clojure. A problem I face, and > I > > feel other faces in Clojure, is how do you model entities without OOP? I > > find this creates a kind of OO that is functional and data driven. > > > > You would spec a bunch of component, they're pure data. Then you'd define > > systems (aka functions) which take an entity, and operate on the entity's > > components (aka its data). At first glance, this appears to just be OOP, > > but there's no inheritance here, and functions that operate or related > data > > are decoupled from the data. Systems are implicitly mapped to components, > > based on what they work on. So you can extend all entities with more > > functionality easily. You can also create entities from components on the > > fly. > > > > On second glance, I wonder what's different about this from just > functions > > operating over data. I think its just a more rigid means to do so when > you > > need the concept of entities. In a way, entities act as a class, in that > > they're a template of data. A system works over that template. > > > > Has anyone experimented with this in Clojure? > > > > -- > > You received this message because you are subscribed to the Google > > Groups "Clojure" group. > > To post to this group, send email to clojure@googlegroups.com > > Note that posts from new members are moderated - please be patient with > your first post. > > To unsubscribe from this group, send email to > > clojure+unsubscr...@googlegroups.com > > For more options, visit this group at > > http://groups.google.com/group/clojure?hl=en > > --- > > You received this message because you are subscribed to the Google > Groups "Clojure" group. > > To unsubscribe from this group and stop receiving emails from it, send > an email to clojure+unsubscr...@googlegroups.com. > > For more options, visit https://groups.google.com/d/optout. > > -- > You received this message because you are subscribed to the Google > Groups "Clojure" group. > To post to this group, send email to clojure@googlegroups.com > Note that posts from new members are moderated - please be patient with > your first post. > To unsubscribe from this group, send email to > clojure+unsubscr...@googlegroups.com > For more options, visit this group at > http://groups.google.com/group/clojure?hl=en > --- > You received this message because you are subscribed to the Google Groups > "Clojure" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to clojure+unsubscr...@googlegroups.com. > For more options, visit https://groups.google.com/d/optout. > -- James Reeves booleanknot.com -- You received this message because you are subscribed to the Google Groups "Clojure" group. To post to this group, send email to clojure@googlegroups.com Note that posts from new members are moderated - please be patient with your first post. To unsubscribe from this group, send email to clojure+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/clojure?hl=en --- You received this message because you are subscribed to the Google Groups "Clojure" group. To unsubscribe from this group and stop receiving emails from it, send an email to clojure+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/d/optout.
