### Complete Box2D Hello World Example in Java

Source: https://context7.com/libgdx/gdx-box2d/llms.txt

This Java example provides a full demonstration of initializing Box2D, creating a physics world with gravity, setting up static and dynamic bodies with shapes, running a simulation loop, and performing cleanup. It covers essential Box2D functionalities for a basic physics simulation.

```java
import com.badlogic.gdx.box2d.Box2d;
import com.badlogic.gdx.box2d.structs.*;
import com.badlogic.gdx.box2d.enums.*;
import static com.badlogic.gdx.box2d.Box2d.*;

public class Box2dHelloWorld {
    public static void main(String[] args) {
        // Initialize Box2D
        Box2d.initialize();

        // Create world with gravity
        b2WorldDef worldDef = b2DefaultWorldDef();
        worldDef.gravity().x(0.0f);
        worldDef.gravity().y(-10.0f);
        b2WorldId worldId = b2CreateWorld(worldDef.asPointer());

        // Create static ground body
        b2BodyDef groundBodyDef = b2DefaultBodyDef();
        groundBodyDef.position().x(0.0f);
        groundBodyDef.position().y(-10.0f);
        b2BodyId groundId = b2CreateBody(worldId, groundBodyDef.asPointer());

        // Add ground shape
        b2Polygon groundBox = b2MakeBox(50.0f, 10.0f);
        b2ShapeDef groundShapeDef = b2DefaultShapeDef();
        b2CreatePolygonShape(groundId, groundShapeDef.asPointer(), groundBox.asPointer());

        // Create dynamic body
        b2BodyDef bodyDef = b2DefaultBodyDef();
        bodyDef.type(b2BodyType.b2_dynamicBody);
        bodyDef.position().x(0.0f);
        bodyDef.position().y(4.0f);
        b2BodyId bodyId = b2CreateBody(worldId, bodyDef.asPointer());

        // Add dynamic shape
        b2Polygon dynamicBox = b2MakeBox(1.0f, 1.0f);
        b2ShapeDef shapeDef = b2DefaultShapeDef();
        shapeDef.density(1.0f);
        shapeDef.material().friction(0.3f);
        b2CreatePolygonShape(bodyId, shapeDef.asPointer(), dynamicBox.asPointer());

        // Simulation loop
        float timeStep = 1.0f / 60.0f;
        int subStepCount = 4;

        for (int i = 0; i < 90; i++) {
            b2World_Step(worldId, timeStep, subStepCount);

            b2Vec2 position = b2Body_GetPosition(bodyId);
            b2Rot rotation = b2Body_GetRotation(bodyId);
            float angle = b2Rot_GetAngle(rotation);

            System.out.printf("Step %d: x=%.2f y=%.2f angle=%.2f\n",
                i, position.x(), position.y(), angle);
        }

        // Cleanup
        b2DestroyWorld(worldId);
        System.out.println("Simulation complete!");
    }
}

```

--------------------------------

### Initialize Box2D Native Library (Java)

Source: https://context7.com/libgdx/gdx-box2d/llms.txt

Initializes the Box2D native library and sets up JNI bindings. This must be called once before using any Box2D functionality. It loads the shared library, sets up FFI types, and installs a custom assertion handler.

```java
import com.badlogic.gdx.box2d.Box2d;

public class MyGame {
    public void create() {
        // Initialize Box2D - required before any other Box2D calls
        Box2d.initialize();

        // Now Box2D is ready to use
        System.out.println("Box2D initialized successfully");
    }
}
```

--------------------------------

### Setup Multithreaded Box2D Physics Simulation in Java

Source: https://context7.com/libgdx/gdx-box2d/llms.txt

Configures and manages a multithreaded Box2D physics world using Box2dWorldTaskSystem. This utility handles thread management and synchronization for parallel physics simulation. Requires Box2D, libGDX core, and Box2dWorldTaskSystem.

```java
import static com.badlogic.gdx.box2d.Box2d.*;
import com.badlogic.gdx.box2d.structs.*;
import com.badlogic.gdx.box2d.utils.Box2dWorldTaskSystem;

public class MultithreadedPhysics {
    private b2WorldId worldId;
    private Box2dWorldTaskSystem taskSystem;

    public void create() {
        Box2d.initialize();

        b2WorldDef worldDef = b2DefaultWorldDef();
        worldDef.gravity().y(-10.0f);
        worldDef.enableSleep(false);

        // Create task system with 4 worker threads
        Thread mainThread = Thread.currentThread();
        taskSystem = Box2dWorldTaskSystem.createForWorld(
            worldDef,
            4,                          // Number of workers
            mainThread::interrupt,      // Death handler
            true                        // Enable pooling for performance
        );

        worldId = b2CreateWorld(worldDef.asPointer());
    }

    public void update() {
        float timeStep = 1.0f / 60.0f;
        int subStepCount = 4;

        b2World_Step(worldId, timeStep, subStepCount);

        // IMPORTANT: Must call after every step
        taskSystem.afterStep();
    }

    public void dispose() {
        b2DestroyWorld(worldId);
        taskSystem.dispose();  // Clean up threads and resources
    }
}

```

--------------------------------

### Install gdx-box2d Dependencies (Gradle)

Source: https://context7.com/libgdx/gdx-box2d/llms.txt

Add gdx-box2d dependencies to your Gradle project. This includes the core library, platform-specific native artifacts, and optional utility classes for common functionality like debug rendering.

```groovy
// build.gradle.kts
dependencies {
    implementation("com.badlogicgames.gdx:gdx-box2d:3.1.1-1")
    implementation("com.badlogicgames.gdx:gdx-box2d-platform:3.1.1-1:natives-desktop")
    // Optional utility classes
    implementation("com.badlogicgames.gdx:gdx-box2d-utils:3.1.1-1")
}
```

--------------------------------

### Body Operations API

Source: https://context7.com/libgdx/gdx-box2d/llms.txt

Provides methods to query and modify the state of rigid bodies within the physics simulation. This includes getting and setting position, velocity, applying forces and impulses, and controlling body activation.

```APIDOC
## Body Operations

### Description
Provides methods to query and modify body state during simulation. Get/set position, velocity, apply forces and impulses, and control body behavior.

### Method
Various methods like `b2Body_GetPosition`, `b2Body_ApplyForceToCenter`, `b2Body_SetTransform`, etc.

### Endpoint
N/A (These are function calls operating on `b2BodyId`)

### Parameters
#### Path Parameters
None

#### Query Parameters
None

#### Request Body
None

### Request Example
```java
import static com.badlogic.gdx.box2d.Box2d.*;
import com.badlogic.gdx.box2d.structs.*;

public void bodyOperations(b2BodyId bodyId) {
    // Query body state
    b2Vec2 position = b2Body_GetPosition(bodyId);
    b2Rot rotation = b2Body_GetRotation(bodyId);
    b2Vec2 linearVelocity = b2Body_GetLinearVelocity(bodyId);
    float angularVelocity = b2Body_GetAngularVelocity(bodyId);
    float mass = b2Body_GetMass(bodyId);

    // Apply forces (accumulated over time step)
    b2Vec2 force = new b2Vec2();
    force.x(100.0f);
    force.y(0.0f);
    b2Body_ApplyForceToCenter(bodyId, force, true);  // wake=true

    // Apply impulse (immediate velocity change)
    b2Vec2 impulse = new b2Vec2();
    impulse.x(10.0f);
    impulse.y(0.0f);
    b2Body_ApplyLinearImpulseToCenter(bodyId, impulse, true);

    // Apply torque
    b2Body_ApplyTorque(bodyId, 50.0f, true);

    // Set velocity directly
    b2Vec2 newVelocity = new b2Vec2();
    newVelocity.x(5.0f);
    newVelocity.y(0.0f);
    b2Body_SetLinearVelocity(bodyId, newVelocity);
    b2Body_SetAngularVelocity(bodyId, 1.0f);

    // Teleport body (use sparingly)
    b2Vec2 newPosition = new b2Vec2();
    newPosition.x(10.0f);
    newPosition.y(5.0f);
    b2Rot newRotation = b2MakeRot(0.0f);
    b2Body_SetTransform(bodyId, newPosition, newRotation);

    // Enable/disable body
    b2Body_Disable(bodyId);
    b2Body_Enable(bodyId);

    // Check body state
    boolean isAwake = b2Body_IsAwake(bodyId);
    boolean isEnabled = b2Body_IsEnabled(bodyId);
}
```

### Response
#### Success Response (200)
These operations modify the simulation state directly. Return values are typically booleans or void, indicating success or providing queried data.

#### Response Example
```json
{
  "isAwake": true,
  "isEnabled": true,
  "position": {"x": 10.0, "y": 5.0},
  "linearVelocity": {"x": 5.0, "y": 0.0}
}
```
```

--------------------------------

### Create Rigid Bodies in Box2D World (Java)

Source: https://context7.com/libgdx/gdx-box2d/llms.txt

Demonstrates how to create static, dynamic, and kinematic rigid bodies in a Box2D world using `b2DefaultBodyDef()` and `b2CreateBody()`. It shows configuration of position, type, damping, and other body properties.

```java
import static com.badlogic.gdx.box2d.Box2d.*;
import com.badlogic.gdx.box2d.structs.*;
import com.badlogic.gdx.box2d.enums.*;

public void createBodies(b2WorldId worldId) {
    // Create a static ground body
    b2BodyDef groundDef = b2DefaultBodyDef();
    groundDef.position().x(0.0f);
    groundDef.position().y(-10.0f);
    // type defaults to b2_staticBody

    b2BodyId groundId = b2CreateBody(worldId, groundDef.asPointer());

    // Create a dynamic body (affected by physics)
    b2BodyDef dynamicDef = b2DefaultBodyDef();
    dynamicDef.type(b2BodyType.b2_dynamicBody);
    dynamicDef.position().x(0.0f);
    dynamicDef.position().y(4.0f);
    dynamicDef.linearDamping(0.1f);      // Air resistance
    dynamicDef.angularDamping(0.1f);     // Rotational damping
    dynamicDef.gravityScale(1.0f);       // Full gravity
    dynamicDef.fixedRotation(false);     // Allow rotation
    dynamicDef.isBullet(false);          // Enable CCD for fast objects

    b2BodyId dynamicId = b2CreateBody(worldId, dynamicDef.asPointer());

    // Create a kinematic body (controlled velocity, no physics response)
    b2BodyDef kinematicDef = b2DefaultBodyDef();
    kinematicDef.type(b2BodyType.b2_kinematicBody);
    kinematicDef.position().x(5.0f);
    kinematicDef.position().y(2.0f);
    kinematicDef.linearVelocity().x(1.0f);  // Moving platform
    kinematicDef.linearVelocity().y(0.0f);

    b2BodyId kinematicId = b2CreateBody(worldId, kinematicDef.asPointer());
}
```

--------------------------------

### Managing VoidPointer Context and User Data in Java

Source: https://github.com/libgdx/gdx-box2d/blob/master/README.md

This Java code demonstrates a factory pattern for managing context or user data associated with VoidPointers in Box2D. It allows storing and retrieving Java objects using long pointers, ensuring thread-safe operations. The factory handles ID generation and mapping between IDs and objects, with options for automatic or manual memory management.

```java
public class Box2DIDFactory<T> {

    private long id = 0;
    private LongMap<T> map = new LongMap<>();

    public VoidPointer putData(T obj) {
        synchronized (this) {
            id += 1;
            map.put(id, obj);
            return new VoidPointer(id, false);
        }
    }

    public void putData(T obj, VoidPointer pointer) {
        synchronized (this) {
            id += 1;
            map.put(id, obj);
            pointer.setPointer(id);
        }
    }

    public long putDataRaw(T obj) {
        synchronized (this) {
            id += 1;
            map.put(id, obj);
            return id;
        }
    }

    public T obtainData(VoidPointer pointer) {
        synchronized (this) {
            return map.get(pointer.getPointer());
        }
    }

    public T obtainDataRaw(long pointer) {
        synchronized (this) {
            return map.get(pointer);
        }
    }
}
```

--------------------------------

### Create Physics World with Custom Settings (Java)

Source: https://context7.com/libgdx/gdx-box2d/llms.txt

Creates a physics world with customizable settings using `b2DefaultWorldDef()` and `b2CreateWorld()`. Configure gravity, restitution threshold, hit event threshold, and enable/disable sleeping and continuous collision detection.

```java
import static com.badlogic.gdx.box2d.Box2d.*;
import com.badlogic.gdx.box2d.structs.*;

public b2WorldId createPhysicsWorld() {
    // Get default world definition
    b2WorldDef worldDef = b2DefaultWorldDef();

    // Configure gravity (x=0, y=-10 for standard downward gravity)
    worldDef.gravity().x(0.0f);
    worldDef.gravity().y(-10.0f);

    // Optional: Configure physics parameters
    worldDef.restitutionThreshold(1.0f);    // Bounce threshold in m/s
    worldDef.hitEventThreshold(1.0f);        // Hit event threshold
    worldDef.enableSleep(true);              // Allow bodies to sleep
    worldDef.enableContinuous(true);         // Enable CCD

    // Create the world
    b2WorldId worldId = b2CreateWorld(worldDef.asPointer());

    // Validate world was created
    if (b2World_IsValid(worldId)) {
        System.out.println("World created successfully");
    }

    return worldId;
}
```

--------------------------------

### Advance Physics Simulation with b2World_Step

Source: https://context7.com/libgdx/gdx-box2d/llms.txt

Advances the physics simulation by one time step. This function should be called every frame with a fixed time step for stable simulation. The subStepCount parameter controls simulation quality, impacting accuracy and performance.

```java
import static com.badlogic.gdx.box2d.Box2d.*;
import com.badlogic.gdx.box2d.structs.*;

public class PhysicsSimulation {
    private b2WorldId worldId;
    private final float timeStep = 1.0f / 60.0f;  // 60 Hz
    private final int subStepCount = 4;           // Quality setting

    public void update() {
        // Step the physics simulation
        b2World_Step(worldId, timeStep, subStepCount);
    }

    public void render(b2BodyId bodyId) {
        // Get body position after simulation step
        b2Vec2 position = b2Body_GetPosition(bodyId);
        b2Rot rotation = b2Body_GetRotation(bodyId);
        float angle = b2Rot_GetAngle(rotation);

        System.out.printf("Position: (%.2f, %.2f), Angle: %.2f rad%n",
            position.x(), position.y(), angle);
    }
}
```

--------------------------------

### Thread-Safe User Data Management with VoidPointer in Java

Source: https://context7.com/libgdx/gdx-box2d/llms.txt

This Java code demonstrates a thread-safe factory pattern for associating arbitrary Java objects with Box2D physics entities using void pointers. It utilizes a LongMap to store object references, keyed by unique IDs generated by the factory, ensuring safe data retrieval and management across threads.

```java
import com.badlogic.gdx.jnigen.runtime.pointer.VoidPointer;
import com.badlogic.gdx.utils.LongMap;

public class Box2DIDFactory<T> {
    private long id = 0;
    private LongMap<T> map = new LongMap<>();

    public VoidPointer putData(T obj) {
        synchronized (this) {
            id += 1;
            map.put(id, obj);
            return new VoidPointer(id, false);
        }
    }

    public T obtainData(VoidPointer pointer) {
        synchronized (this) {
            return map.get(pointer.getPointer());
        }
    }

    public void removeData(VoidPointer pointer) {
        synchronized (this) {
            map.remove(pointer.getPointer());
        }
    }
}

// Usage example
public class GameEntity {
    public String name;
    public int health;
}

// Assuming Box2d and worldId are initialized elsewhere
// Box2DIDFactory<GameEntity> entityFactory = new Box2DIDFactory<>();

// When creating a body
// GameEntity entity = new GameEntity();
// entity.name = "Player";
// entity.health = 100;

// b2BodyDef bodyDef = b2DefaultBodyDef();
// bodyDef.userData(entityFactory.putData(entity));
// b2BodyId bodyId = b2CreateBody(worldId, bodyDef.asPointer());

// Later, retrieve the entity
// VoidPointer userData = b2Body_GetUserData(bodyId);
// GameEntity retrieved = entityFactory.obtainData(userData);
// System.out.println("Entity: " + retrieved.name);

```

--------------------------------

### b2World_Step()

Source: https://context7.com/libgdx/gdx-box2d/llms.txt

Advances the physics simulation by one time step. It's recommended to call this every frame with a fixed time step for stable simulation. The subStepCount parameter affects accuracy and performance.

```APIDOC
## b2World_Step()

### Description
Advances the physics simulation by one time step. Call this every frame with a fixed time step (typically 1/60 second) for stable simulation. The subStepCount parameter controls simulation quality - higher values provide more accurate results at the cost of performance.

### Method
`b2World_Step`

### Parameters
#### Path Parameters
None

#### Query Parameters
None

#### Request Body
None

### Request Example
```java
import static com.badlogic.gdx.box2d.Box2d.*;
import com.badlogic.gdx.box2d.structs.*;

public class PhysicsSimulation {
    private b2WorldId worldId;
    private final float timeStep = 1.0f / 60.0f;  // 60 Hz
    private final int subStepCount = 4;           // Quality setting

    public void update() {
        // Step the physics simulation
        b2World_Step(worldId, timeStep, subStepCount);
    }

    public void render(b2BodyId bodyId) {
        // Get body position after simulation step
        b2Vec2 position = b2Body_GetPosition(bodyId);
        b2Rot rotation = b2Body_GetRotation(bodyId);
        float angle = b2Rot_GetAngle(rotation);

        System.out.printf("Position: (%.2f, %.2f), Angle: %.2f rad\n",
            position.x(), position.y(), angle);
    }
}
```

### Response
#### Success Response (200)
No specific response body is defined for this function, as it modifies the simulation state.

#### Response Example
N/A
```

--------------------------------

### Create and Destroy Joints Between Bodies

Source: https://context7.com/libgdx/gdx-box2d/llms.txt

Demonstrates the creation of various joints (revolute, distance) between bodies and the destruction of joints. Joints are used to create constraints, simulating connections like hinges or springs.

```java
import static com.badlogic.gdx.box2d.Box2d.*;
import com.badlogic.gdx.box2d.structs.*;

public void createJoints(b2WorldId worldId, b2BodyId bodyA, b2BodyId bodyB) {
    // Create a revolute (hinge) joint
    b2RevoluteJointDef revoluteDef = b2DefaultRevoluteJointDef();
    revoluteDef.bodyIdA(bodyA);
    revoluteDef.bodyIdB(bodyB);
    revoluteDef.localAnchorA().x(1.0f);
    revoluteDef.localAnchorA().y(0.0f);
    revoluteDef.localAnchorB().x(-1.0f);
    revoluteDef.localAnchorB().y(0.0f);
    revoluteDef.enableLimit(true);
    revoluteDef.lowerAngle(-0.5f * 3.14159f);
    revoluteDef.upperAngle(0.5f * 3.14159f);
    revoluteDef.enableMotor(true);
    revoluteDef.motorSpeed(1.0f);
    revoluteDef.maxMotorTorque(100.0f);

    b2JointId revoluteJoint = b2CreateRevoluteJoint(worldId, revoluteDef.asPointer());

    // Create a distance (spring) joint
    b2DistanceJointDef distanceDef = b2DefaultDistanceJointDef();
    distanceDef.bodyIdA(bodyA);
    distanceDef.bodyIdB(bodyB);
    distanceDef.localAnchorA().x(0.0f);
    distanceDef.localAnchorA().y(0.0f);
    distanceDef.localAnchorB().x(0.0f);
    distanceDef.localAnchorB().y(0.0f);
    distanceDef.length(5.0f);           // Rest length
    distanceDef.enableSpring(true);
    distanceDef.hertz(2.0f);            // Oscillation frequency
    distanceDef.dampingRatio(0.5f);     // Damping

    b2JointId distanceJoint = b2CreateDistanceJoint(worldId, distanceDef.asPointer());

    // Destroy a joint
    b2DestroyJoint(revoluteJoint);
}
```

--------------------------------

### Create Collision Shapes in Box2D (Java)

Source: https://context7.com/libgdx/gdx-box2d/llms.txt

Explains how to create and attach various collision shapes to Box2D bodies using `b2DefaultShapeDef()` and shape creation functions like `b2MakeBox()`, `b2CreatePolygonShape()`, `b2CreateCircleShape()`, and `b2CreateCapsuleShape()`. It covers setting density, friction, restitution, and sensor properties.

```java
import static com.badlogic.gdx.box2d.Box2d.*;
import com.badlogic.gdx.box2d.structs.*;

public void createShapes(b2BodyId groundId, b2BodyId dynamicId) {
    // Create shape definition with material properties
    b2ShapeDef shapeDef = b2DefaultShapeDef();
    shapeDef.density(1.0f);                    // kg/m^2
    shapeDef.material().friction(0.3f);        // Friction coefficient
    shapeDef.material().restitution(0.5f);     // Bounciness (0-1)

    // Create a box shape (ground)
    b2Polygon groundBox = b2MakeBox(50.0f, 10.0f);  // half-width, half-height
    b2CreatePolygonShape(groundId, shapeDef.asPointer(), groundBox.asPointer());

    // Create a smaller box for dynamic body
    b2Polygon dynamicBox = b2MakeBox(1.0f, 1.0f);
    b2CreatePolygonShape(dynamicId, shapeDef.asPointer(), dynamicBox.asPointer());

    // Create a rounded box
    b2Polygon roundedBox = b2MakeRoundedBox(0.45f, 0.45f, 0.05f);
    b2CreatePolygonShape(dynamicId, shapeDef.asPointer(), roundedBox.asPointer());

    // Create a circle shape
    b2Circle circle = new b2Circle();
    circle.center().x(0.0f);
    circle.center().y(0.0f);
    circle.radius(0.5f);
    b2CreateCircleShape(dynamicId, shapeDef.asPointer(), circle.asPointer());

    // Create a capsule shape
    b2Capsule capsule = new b2Capsule();
    capsule.center1().x(0.0f);
    capsule.center1().y(-0.5f);
    capsule.center2().x(0.0f);
    capsule.center2().y(0.5f);
    capsule.radius(0.25f);
    b2CreateCapsuleShape(dynamicId, shapeDef.asPointer(), capsule.asPointer());

    // Create a sensor shape (detects overlaps, no collision response)
    b2ShapeDef sensorDef = b2DefaultShapeDef();
    sensorDef.isSensor(true);
    sensorDef.enableSensorEvents(true);
    b2Polygon sensorBox = b2MakeBox(2.0f, 2.0f);
    b2CreatePolygonShape(dynamicId, sensorDef.asPointer(), sensorBox.asPointer());
}
```

--------------------------------

### Manage Body State and Apply Forces/Impulses

Source: https://context7.com/libgdx/gdx-box2d/llms.txt

Provides methods to query and modify body state during simulation, including getting/setting position and velocity, and applying forces and impulses. It also covers enabling/disabling bodies and checking their awake status.

```java
import static com.badlogic.gdx.box2d.Box2d.*;
import com.badlogic.gdx.box2d.structs.*;

public void bodyOperations(b2BodyId bodyId) {
    // Query body state
    b2Vec2 position = b2Body_GetPosition(bodyId);
    b2Rot rotation = b2Body_GetRotation(bodyId);
    b2Vec2 linearVelocity = b2Body_GetLinearVelocity(bodyId);
    float angularVelocity = b2Body_GetAngularVelocity(bodyId);
    float mass = b2Body_GetMass(bodyId);

    // Apply forces (accumulated over time step)
    b2Vec2 force = new b2Vec2();
    force.x(100.0f);
    force.y(0.0f);
    b2Body_ApplyForceToCenter(bodyId, force, true);  // wake=true

    // Apply impulse (immediate velocity change)
    b2Vec2 impulse = new b2Vec2();
    impulse.x(10.0f);
    impulse.y(0.0f);
    b2Body_ApplyLinearImpulseToCenter(bodyId, impulse, true);

    // Apply torque
    b2Body_ApplyTorque(bodyId, 50.0f, true);

    // Set velocity directly
    b2Vec2 newVelocity = new b2Vec2();
    newVelocity.x(5.0f);
    newVelocity.y(0.0f);
    b2Body_SetLinearVelocity(bodyId, newVelocity);
    b2Body_SetAngularVelocity(bodyId, 1.0f);

    // Teleport body (use sparingly)
    b2Vec2 newPosition = new b2Vec2();
    newPosition.x(10.0f);
    newPosition.y(5.0f);
    b2Rot newRotation = b2MakeRot(0.0f);
    b2Body_SetTransform(bodyId, newPosition, newRotation);

    // Enable/disable body
    b2Body_Disable(bodyId);
    b2Body_Enable(bodyId);

    // Check body state
    boolean isAwake = b2Body_IsAwake(bodyId);
    boolean isEnabled = b2Body_IsEnabled(bodyId);
}
```

--------------------------------

### Joint Creation API

Source: https://context7.com/libgdx/gdx-box2d/llms.txt

Enables the creation of various types of joints to constrain the relative motion between two rigid bodies. Supported joint types include revolute, distance, prismatic, weld, wheel, and motor joints.

```APIDOC
## Joint Creation

### Description
Creates constraints between bodies. Box2D supports various joint types: revolute (rotation), distance (spring), prismatic (sliding), weld, wheel, and motor joints.

### Method
`b2CreateRevoluteJoint`, `b2CreateDistanceJoint`, `b2DestroyJoint`, etc.

### Endpoint
N/A (These are function calls operating on `b2WorldId` and `b2BodyId`)

### Parameters
#### Path Parameters
None

#### Query Parameters
None

#### Request Body
None

### Request Example
```java
import static com.badlogic.gdx.box2d.Box2d.*;
import com.badlogic.gdx.box2d.structs.*;

public void createJoints(b2WorldId worldId, b2BodyId bodyA, b2BodyId bodyB) {
    // Create a revolute (hinge) joint
    b2RevoluteJointDef revoluteDef = b2DefaultRevoluteJointDef();
    revoluteDef.bodyIdA(bodyA);
    revoluteDef.bodyIdB(bodyB);
    revoluteDef.localAnchorA().x(1.0f);
    revoluteDef.localAnchorA().y(0.0f);
    revoluteDef.localAnchorB().x(-1.0f);
    revoluteDef.localAnchorB().y(0.0f);
    revoluteDef.enableLimit(true);
    revoluteDef.lowerAngle(-0.5f * 3.14159f);
    revoluteDef.upperAngle(0.5f * 3.14159f);
    revoluteDef.enableMotor(true);
    revoluteDef.motorSpeed(1.0f);
    revoluteDef.maxMotorTorque(100.0f);

    b2JointId revoluteJoint = b2CreateRevoluteJoint(worldId, revoluteDef.asPointer());

    // Create a distance (spring) joint
    b2DistanceJointDef distanceDef = b2DefaultDistanceJointDef();
    distanceDef.bodyIdA(bodyA);
    distanceDef.bodyIdB(bodyB);
    distanceDef.localAnchorA().x(0.0f);
    distanceDef.localAnchorA().y(0.0f);
    distanceDef.localAnchorB().x(0.0f);
    distanceDef.localAnchorB().y(0.0f);
    distanceDef.length(5.0f);           // Rest length
    distanceDef.enableSpring(true);
    distanceDef.hertz(2.0f);            // Oscillation frequency
    distanceDef.dampingRatio(0.5f);     // Damping

    b2JointId distanceJoint = b2CreateDistanceJoint(worldId, distanceDef.asPointer());

    // Destroy a joint
    b2DestroyJoint(revoluteJoint);
}
```

### Response
#### Success Response (200)
Joint creation functions typically return a `b2JointId` upon successful creation. Joint destruction functions return void.

#### Response Example
```json
{
  "jointId": "some_unique_joint_identifier",
  "status": "created"
}
```
```

--------------------------------

### Process Box2D Physics Events in Java

Source: https://context7.com/libgdx/gdx-box2d/llms.txt

Handles various Box2D physics events such as contact begin/end, sensor overlap, and high-speed impacts. Events are transient and only valid for the current simulation step. Requires Box2D and libGDX core libraries.

```java
import static com.badlogic.gdx.box2d.Box2d.*;
import com.badlogic.gdx.box2d.structs.*;

public void processEvents(b2WorldId worldId) {
    // Get contact events
    b2ContactEvents contactEvents = b2World_GetContactEvents(worldId);

    // Process begin touch events
    int beginCount = contactEvents.beginCount();
    b2ContactBeginTouchEvent.b2ContactBeginTouchEventPointer beginEvents = contactEvents.beginEvents();
    for (int i = 0; i < beginCount; i++) {
        b2ContactBeginTouchEvent event = beginEvents.getStackElement(i);
        b2ShapeId shapeA = event.shapeIdA();
        b2ShapeId shapeB = event.shapeIdB();
        System.out.println("Contact began between two shapes");
    }

    // Process end touch events
    int endCount = contactEvents.endCount();
    b2ContactEndTouchEvent.b2ContactEndTouchEventPointer endEvents = contactEvents.endEvents();
    for (int i = 0; i < endCount; i++) {
        b2ContactEndTouchEvent event = endEvents.getStackElement(i);
        System.out.println("Contact ended");
    }

    // Process hit events (high-speed impacts)
    int hitCount = contactEvents.hitCount();
    b2ContactHitEvent.b2ContactHitEventPointer hitEvents = contactEvents.hitEvents();
    for (int i = 0; i < hitCount; i++) {
        b2ContactHitEvent event = hitEvents.getStackElement(i);
        float approachSpeed = event.approachSpeed();
        System.out.printf("Hit event with speed: %.2f%n", approachSpeed);
    }

    // Get sensor events
    b2SensorEvents sensorEvents = b2World_GetSensorEvents(worldId);

    int sensorBeginCount = sensorEvents.beginCount();
    b2SensorBeginTouchEvent.b2SensorBeginTouchEventPointer sensorBegin = sensorEvents.beginEvents();
    for (int i = 0; i < sensorBeginCount; i++) {
        b2SensorBeginTouchEvent event = sensorBegin.getStackElement(i);
        System.out.println("Object entered sensor");
    }
}

```

--------------------------------

### Render Box2D Physics Debug Information with libGDX in Java

Source: https://context7.com/libgdx/gdx-box2d/llms.txt

Utilizes Box2dDebugRenderer to visualize Box2D physics objects within a libGDX application. It renders shapes, joints, and other physics-related elements for debugging purposes. Requires Box2D, libGDX core, and Box2dDebugRenderer.

```java
import com.badlogic.gdx.box2d.utils.Box2dDebugRenderer;
import com.badlogic.gdx.box2d.structs.*;
import com.badlogic.gdx.graphics.OrthographicCamera;
import com.badlogic.gdx.math.Matrix4;

public class DebugRendering {
    private Box2dDebugRenderer debugRenderer;
    private b2WorldId worldId;
    private OrthographicCamera camera;

    public void create() {
        debugRenderer = new Box2dDebugRenderer();
        camera = new OrthographicCamera(20, 15);

        // Configure what to draw
        b2DebugDraw debugDraw = debugRenderer.getB2DebugDraw();
        debugDraw.drawShapes(true);
        debugDraw.drawJoints(true);
        debugDraw.drawAABBs(false);
        debugDraw.drawMass(false);
        debugDraw.drawContacts(false);
    }

    public void render() {
        camera.update();

        // Render physics debug visualization
        debugRenderer.render(worldId, camera.combined);
    }

    public void dispose() {
        debugRenderer.dispose();
    }
}

```

=== COMPLETE CONTENT === This response contains all available snippets from this library. No additional content exists. Do not make further requests.