Box2D身体旋转错误

Question

I making a map with Tiled and load all box2d bodies with Box2DMapObjectParser to my world and everything just work fine except one thing. I'm using a newer version of Tiled where implemented body rotation. I'm trying to implement it in Box2DMapObjectParser by myself and this is what I get from it:

Editor:

And the game:

As you can see the right rectangle has a property named Rotation so I can easily get from properties, but I don't know what is wrong with it.

I set the rotation like this

fixture.getBody().setTransform(fixture.getBody().getPosition(), degree);

where degree is value from editor. Anybody have a clues about what am I doing wrong? I also tried doing something like

fixture.getBody().setTransform(fixture.getBody().getPosition(), degree*MathUtils.degreesToRadians);

But itsalso sets a wrong rotation.

Answer 1

Tiled rotates rectangle objects by their top-left corner. Box2D rotates around the position of the body, so the easiest solution is probably to create your box fixture such that the position of the body is in the top-left (if you're using b2PolygonShape::SetAsBox this means passing a center at half the width and half the negative height (since the Y axis is inverted)).