Extend BulletBodyNode::add_shapes_from_collision_solids() to accept a TransformState

Code is much the same as original, so adapt original function to use the expanded one. This is useful for example when the collision node is rotated, is not centered to origin, or has several parent transforms applied on it.

panda/src/bullet/bulletBodyNode.cxx

@@ -799,10 +799,21 @@ set_ccd_motion_threshold(PN_stdfloat threshold) {
 }
 
 /**
- *
+ * Add shapes from the specified collision node to this body.
  */
 void BulletBodyNode::
 add_shapes_from_collision_solids(CollisionNode *cnode) {
+  add_shapes_from_collision_solids(cnode, TransformState::make_identity());
+}
+
+/**
+ * Add shapes from the specified collision node to this body. Also apply the
+ * given transform state to all solids. This is useful for example when the
+ * collision node is rotated, is not centered to origin, or has several parent
+ * transforms applied on it.
+ */
+void BulletBodyNode::
+add_shapes_from_collision_solids(CollisionNode *cnode, const TransformState *relative_transform) {
   LightMutexHolder holder(BulletWorld::get_global_lock());
 
   PT(BulletTriangleMesh) mesh = nullptr;
@@ -816,7 +827,7 @@ add_shapes_from_collision_solids(CollisionNode *cnode) {
       CPT(CollisionSphere) sphere = DCAST(CollisionSphere, solid);
       CPT(TransformState) ts = TransformState::make_pos(sphere->get_center());
 
-      do_add_shape(BulletSphereShape::make_from_solid(sphere), ts);
+      do_add_shape(BulletSphereShape::make_from_solid(sphere), relative_transform->compose(ts));
     }
 
     // CollisionBox
@@ -824,7 +835,7 @@ add_shapes_from_collision_solids(CollisionNode *cnode) {
       CPT(CollisionBox) box = DCAST(CollisionBox, solid);
       CPT(TransformState) ts = TransformState::make_pos(box->get_center());
 
-      do_add_shape(BulletBoxShape::make_from_solid(box), ts);
+      do_add_shape(BulletBoxShape::make_from_solid(box), relative_transform->compose(ts));
     }
 
     // CollisionCapsule
@@ -832,14 +843,14 @@ add_shapes_from_collision_solids(CollisionNode *cnode) {
       CPT(CollisionCapsule) capsule = DCAST(CollisionCapsule, solid);
       CPT(TransformState) ts = TransformState::make_pos((capsule->get_point_b() + capsule->get_point_a()) / 2.0);
 
-      do_add_shape(BulletCapsuleShape::make_from_solid(capsule), ts);
+      do_add_shape(BulletCapsuleShape::make_from_solid(capsule), relative_transform->compose(ts));
     }
 
     // CollisionPlane
     else if (CollisionPlane::get_class_type() == type) {
       CPT(CollisionPlane) plane = DCAST(CollisionPlane, solid);
 
-      do_add_shape(BulletPlaneShape::make_from_solid(plane));
+      do_add_shape(BulletPlaneShape::make_from_solid(plane), relative_transform);
     }
 
     // CollisionGeom
@@ -861,7 +872,7 @@ add_shapes_from_collision_solids(CollisionNode *cnode) {
   }
 
   if (mesh && mesh->do_get_num_triangles() > 0) {
-    do_add_shape(new BulletTriangleMeshShape(mesh, true));
+    do_add_shape(new BulletTriangleMeshShape(mesh, true), relative_transform);
   }
 }
 

panda/src/bullet/bulletBodyNode.h

@@ -52,6 +52,7 @@ PUBLISHED:
   BoundingSphere get_shape_bounds() const;
 
   void add_shapes_from_collision_solids(CollisionNode *cnode);
+  void add_shapes_from_collision_solids(CollisionNode *cnode, const TransformState *relative_transform);
 
   // Static and kinematic
   bool is_static() const;