How to use AutoGeometry

[slembcke]

Oh shoot. That's right. There was an annoying rescale step in there that I wanted to fix in the next version... There is a thread where I answered exactly that question and I can't find it now.

[slembcke]

Aha!
http://chipmunk-physics.net/forum/viewt ... f=1&t=2598

[csoul]

Sorry, but I read through that whole thread and did not see an answer to the problem.

What I'm asking is this. I can create a convex shape like this:

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ChipmunkPolyline *hull = [[line simplifyCurves:1.0] toConvexHull:1.0];
self.shape = [hull asChipmunkPolyShapeWithBody:self.physicsBody offset:cpvneg(sprite.anchorPointInPoints)];

To create a shape that may have concave areas, I have to do this apparently

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ChipmunkPolylineSet *hull = [[line simplifyCurves:1.0] toConvexHulls_BETA:1.0];
self.shape = ________ ??

I need to know what goes in the blank. There is no asChipmunkPolyShapeWithBody method for ChipmunkPolylineSet.

[slembcke]

Did you see the github branch in the post with the screenshot? It implements exactly what you are looking for in the GeometryNode.m file. I posted a link specifically to the diff of those changes as well.

[csoul]

Those links just lead to more frustration for me unfortunately. Going to send an email.

[slembcke]

Ok. So I made a brand new example that modifies the code from Gemeralds to do I think exactly what you are looking for:
https://github.com/slembcke/ConcaveSprite

It sets up the physics stuff in the CCSprite designated initializer so it basically "just works".

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	ConcaveSprite *sprite = [ConcaveSprite spriteWithFile:image];
	sprite.position = point;
	sprite.elasticity = 1.0;
	[self addChild:sprite];
	[_space add:sprite];

[csoul]

ConcaveSprite is working well, but how should I go about setting collisionType on an instance or subclass? Typically I would do this in the initializer:

self.shape.collisionType = [MyClass class];

But I'm not sure where that would fit in the ConcaveSprite workflow.

[slembcke]

Well, I threw that example together pretty quickly when you asked for it. The only property it exposed was elasticity and had a note in it about how to expose more of them.

I went ahead and added more of them though if you pull.

[csoul]

Thanks, but I'm not seeing any new commits in the repo. The last commit I see is 0b3463c on 4/22.

[slembcke]

Hmm. It shows up on Github as of an hour ago: https://github.com/slembcke/ConcaveSprite