Add barycentric coordinates to ray vs. triangle collision results

[Copilot]

Ray-triangle collision results (CollisionResult) had no way to retrieve barycentric coordinates of the contact point, making texture-coord interpolation and surface-parameter lookups impossible without redundant re-computation.

Changes

• CollisionResult: Added contactBaryCoords (Vector2f) field with getter/setter. Convention: (u, v) where u = weight of v1, v = weight of v2, 1-u-v = weight of v0.

• CollisionResults: Added requiresBaryCoords boolean flag (default false) with setRequiresBaryCoords(boolean) / isRequiresBaryCoords(). Barycentric coordinates are only computed and stored when this flag is enabled, avoiding unnecessary allocation and math for callers that don't need them.

• Ray: Added intersects(Vector3f v0, Vector3f v1, Vector3f v2, Vector2f baryCoords) overload that computes barycentric coordinates alongside the hit distance in a single pass. Updated collideWith(AbstractTriangle) to populate contactBaryCoords on the result only when the flag is set.

• BIHNode: Updated intersectWhere() leaf loop (mesh collision path) to use the new overload and store barycentric coords on each CollisionResult only when the flag is set.

Usage

CollisionResults results = new CollisionResults();
results.setRequiresBaryCoords(true); // opt in to barycentric computation
ray.collideWith(geometry, results);

CollisionResult hit = results.getClosestCollision();
Vector2f bary = hit.getContactBaryCoords(); // (u, v); w0 = 1 - u - v

// Interpolate a vertex attribute (e.g. texture coords) at the hit point
Vector2f texCoord = texCoord0.mult(1 - bary.x - bary.y)
                 .add(texCoord1.mult(bary.x))
                 .add(texCoord2.mult(bary.y));

getContactBaryCoords() returns null when the flag is disabled (default) or for collision types that don't involve a triangle (e.g. bounding volume hits).

---

✨ Let Copilot coding agent set things up for you — coding agent works faster and does higher quality work when set up for your repo.

[riccardobl]

Can you add a boolean flag to CollisionResults to enable barycentric coordinate computation? So that it is done only when the developer need them? @copilot

[Copilot]

Can you add a boolean flag to CollisionResults to enable barycentric coordinate computation? So that it is done only when the developer need them? @copilot

Done in commit 16a97ce. Added requiresBaryCoords boolean flag (default false) to CollisionResults. Barycentric coordinates are only computed and stored when results.setRequiresBaryCoords(true) is called before the collision query. No Vector2f is allocated and no extra math is done when the flag is off.