Collision group on polygons

schteppe / p2.js

JavaScript 2D physics library

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Collision group on polygons #191

Open jstoeffler opened 8 years ago

jstoeffler commented 8 years ago

Hi,

I'd like to create polygons belonging to collision group.

I found two different approaches:

creating the polygon shape myself (creating a new "Body.fromPolygon" method)
looping through the body shapes after calling "Body.fromPolygon"

And they don't seem consistent with the API, it feels some decoupling is needed. Did I miss something, or is it an improvement that could be done?

jstoeffler commented 8 years ago

Just saw that it's probably the same idea than #172 Feel free to close the issue if it is.

schteppe commented 8 years ago

It probably is. I see two possible ways to solve it. Either keep it as it is, and the collision groups/masks can be added to each convex shape created by body.fromPolygon. Or, make a Polygon shape that holds all the convex shapes and add some special treatment for collision groups/masks for each subshape... Both ways are sort of inconsistent with the API :(

jstoeffler commented 8 years ago

Thanks for the answer. Some thoughts:

fromPolygon could take more options then (like collision groups)
Perhaps the part of fromPolygon that creates the convex shapes from the path could be extracted? I've seen there's quite more happening there, and I'm not familiar with the library yet, so perhaps that's candid :)

schteppe commented 8 years ago

Both options are good! But I think the latter would be the best. It would make build sizes smaller if the poly-decomp library could be moved away from the Body class.