A fast, easy to use, free, and community supported 2D game engine
Oscar
Member
Hello,
I am using chipmunk in my cocos2d game, and I am using as the shape data a Sprite, this all works perfectly fine and my shape and Sprite are in sync. However my Sprite is constantly rotating and shrinking, but of course my Polygon Shape is not. Is there a way I can have my shape rotate and shrink in sync with my Sprite?. Could someone please point me to some documentation for this?.
Oscar
Member
Thank you for your quick reply leocck, I will look into that. I am right know initializing my shape like this:
int num = 4;
CGPoint verts[] = {
ccp(-10,-34),
ccp(-10, 34),
ccp( 10, 34),
ccp( 10,-34),
};
cpBody *body = cpBodyNew(1.0f, cpMomentForPoly(1.0f, num, verts, CGPointZero));
body->p = ccp(x, y);
cpSpaceAddBody(space, body);
cpShape* shape = cpPolyShapeNew(body, num, verts, CGPointZero);
shape->e = 0.5f; shape->u = 0.5f;
shape->data = sprite;
cpSpaceAddShape(space, shape);
You'd probably want to override setRotation and setScale on your Sprite class. Inside setRotation you'd want to do what leocck said, however scale is a bit harder. You'd have to remember the original vertices and then in setScale you'd want multiply each vertex by the scale and call cpPolySetVerts with the new vertices... sounds like a good time!
Oscar
Member
Yes after some more research looks like that is precisely what I will have to do. Unfortunately there isn't a cppolysetverts at least with the chimpmunk version I am using, is this available for later versions?. What I found here http://www.slembcke.net/forums/viewtopic.php?f=1&t=371&p=1717 is that you actually have to recreate your cppoly with the new vertices every time.
That method definitely exists in the newer versions... not sure when it was introduced. It may have been in the "unsafe" chipmunk file that used to exist for a little while there.
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