[AlexisDrogoul]

The goal of this PR is to introduce joints in the physics engine, step by step,

[AlexisDrogoul]

@copilot resolve the merge conflicts in this pull request

[Copilot]

🟡 Changes recommended

The GAML models currently fail parsing/operator resolution, and joint typing, coordinates, and JBullet lifecycle contain correctness issues.

7 open findings

• Model name contains unsupported spaces · New
• Model declaration uses an invalid space-separated name · New
• Instance operators require an unlisted physical-world receiver · New
• Agent removal leaves constraints attached to deleted bodies · New
• Slider axis omits Box2D Y-axis conversion · New
• GAML string getter returns a JointType enum · New
• Feature list advertises unsupported joint types and actions · New

What changed in this PR

Adds cross-engine joint support to the physics extension, exposing hinge, slider, and ball-and-socket joints to GAML.

Changes:

• Adds generic joint definitions and GAML-facing wrappers/operators.
• Implements joints for Box2D, JBullet, and native Bullet.
• Adds articulated-joint example models.

File	Description
NativeBulletPhysicalWorld.java	Implements native Bullet joints.
BulletPhysicalWorld.java	Implements JBullet constraints.
GamlJointType.java	Registers the GAML joint type.
PhysicalSimulationAgent.java	Exposes joint creation operators.
GamaJoint.java	Wraps joints and motor controls.
IPhysicalWorld.java	Adds the joint creation contract.
IJointDefinition.java	Defines engine-independent joint configuration.
Box2DPhysicalWorld.java	Implements Box2D joints.
Jointed Snake.gaml	Demonstrates a motorized chain.
Box2D Articulated Arm.gaml	Demonstrates a motorized arm.

🧠 Review effort: Balanced

---

Give feedback about Copilot approvals in this survey to enter a drawing for a $150 gift card.

[Copilot]

@copilot resolve the merge conflicts in this pull request

Resolved the conflict while merging main in ee9e28b; the joint additions are adapted to the merged APIs, and the full reactor compile passes.

[Copilot]

🟡 Changes recommended

The GAML operators have incompatible instance signatures, and body updates can leave joints attached to obsolete physics bodies.

6 open findings

• Pass the created base agent to joint creation · New
• Destroy joints when updating backend bodies · New
• Agent removal leaves constraints attached to deleted bodies
• Instance operators require an unlisted physical-world receiver
• Start extension type IDs at the custom-type range · New
• Use valid GAML joint declaration syntax · New

5 resolved since last review

• Model declaration uses an invalid space-separated name
• Model name contains unsupported spaces
• GAML string getter returns a JointType enum
• Slider axis omits Box2D Y-axis conversion
• Feature list advertises unsupported joint types and actions

🧠 Review effort: Balanced