JBox2D is a java physics engine often used in games an other physics simulations, and is a port/extension of the C++ physics engine, Box2D.

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Rotating towards a point in Box2D

I'm using Box2d as my physics engine and I'm trying to solve what would normally be a simple problem but what has become a nightmare for me and preventing me from finishing my app. (6 months work) ...
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In JBox2d when dragging a Body, why is the direction is flipped vertically?

Why is it when I drag a JBox2d Body with the mouse, the vertical component is flipped? e.g. If I drag down-right, the Body moves up-right. Is this expected behaviour, a bug in JBox2D, a Mac ...
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Why do my Box2D bodies occasionally get stuck and separate forcibly?

I'm making a space game with LibGDX and Box2D. I made a video here to illustrate the issue. Verbal description: When objects collide, they sometimes get stuck together and are then suddenly separated ...
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Mouse click coordinates not mapping to Box2d world

I'm using Box2d in Java with OpenGL, trying to detect if a mouse has clicked on a Body. But having trouble mapping mouse coordinates to Box2d world. I have a Body positioned at 20.0f, 30.0f in the ...
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Box2DLight position seems to Floor

I am creating a top down game and i'm using raycasted lights from Box2Dlights, My light is all set up and working. its attached to the player's Body, and when the player moves, the sprite I attached ...
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Using debugdraw in jbox2d

I've created a class which implements org.jbox2d.callbacks.DebugDraw. And implemented the abstract methods too. DebugDrawHandler extends org.jbox2d.callbacks.DebugDraw I've instanciated it with: ...
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Correctly identifying a Fixture from an extended class in Box2D's ContactListener

Sorry for the confusing title, I dont know how to resume it that much. Im making a game, and I have a simple class Mob which is extended by Warrior and Enemy. A Mob has a Body, and that body usually ...
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Drawing jbox2d shapes in slick2d

How would be the best way to go about drawing polygons in slick after forces where applied to them via jbox2d? There seems to be no way to get the vertices of a body defined in jbox2d...
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Box2D and randomly generated tilemaps

I am making a 2D Terraria-style sidescrolling game. I want to use box2d for the physics. However, I am using tilemaps for the maps, and I do not know of a processor-efficient way to use Box2D bodies ...
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How can I avoid duplication of jBox2D physics attributes?

I'm using jBox2D for physics and collision detection in a game engine with an entity-component system. It works, but I'm unsure how to structure my code with respect to the values represented in the ...
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GWT problem with Box2D WheelJoint

I am using the below libgdx java code for a wheel joint and rear axle using Box2D. This works fine for android, Desktop, but when I attempt to run through GWT I get the following error. at ...
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Apply impulse to ball to a fixed height Jbox2D android

I have to hit a ball to a fixed height repeatedly as shown in the following image. This game is similar to 1983 Hitit The difference is the hitting y axis will be variable. I wanted to hit the ...
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Relative movement in Box2D (keep object from falling off planet)

I'm creating a game with planets orbiting around a sun, like this: The brown square is the earth, rotating around its center and around the sun. The yellow square is the sun, which doesn't move. Now ...