chore: remove redundant active_set_offset field

Author: sebcrozet

src/dynamics/island_manager/island.rs

@@ -77,7 +77,6 @@ impl IslandManager {
             );
             rb.ids.active_island_id = new_island_id;
             rb.ids.active_set_id = id;
-            rb.ids.active_set_offset = id as u32;
 
             new_island.additional_solver_iterations = new_island
                 .additional_solver_iterations
@@ -87,7 +86,6 @@ impl IslandManager {
             if let Some(moved_handle) = source_island.bodies.get(id_to_remove).copied() {
                 let moved_rb = bodies.index_mut_internal(moved_handle);
                 moved_rb.ids.active_set_id = id_to_remove;
-                moved_rb.ids.active_set_offset = id_to_remove as u32;
             }
         }
 
@@ -147,7 +145,6 @@ impl IslandManager {
             rb.wake_up(false);
             rb.ids.active_island_id = to_keep;
             rb.ids.active_set_id = target_island.bodies.len();
-            rb.ids.active_set_offset = (target_island.bodies.len()) as u32;
             target_island.bodies.push(*handle);
             target_island.additional_solver_iterations = target_island
                 .additional_solver_iterations

src/dynamics/island_manager/manager.rs

@@ -67,16 +67,13 @@ impl IslandManager {
         };
 
         let swapped_handle = island.bodies.last().copied().unwrap_or(removed_handle);
-        island
-            .bodies
-            .swap_remove(removed_ids.active_set_offset as usize);
+        island.bodies.swap_remove(removed_ids.active_set_id);
 
         // Remap the active_set_id of the body we moved with the `swap_remove`.
         if swapped_handle != removed_handle {
             let swapped_body = bodies
                 .get_mut(swapped_handle)
                 .expect("Internal error: bodies must be removed from islands on at a times");
-            swapped_body.ids.active_set_offset = removed_ids.active_set_offset;
             swapped_body.ids.active_set_id = removed_ids.active_set_id;
         }
 
@@ -187,7 +184,6 @@ impl IslandManager {
 
                 rb.ids.active_island_id = id;
                 rb.ids.active_set_id = target_island.bodies.len();
-                rb.ids.active_set_offset = target_island.bodies.len() as u32;
                 target_island.bodies.push(handle);
             } else {
                 let mut new_island = Island::singleton(handle, rb);
@@ -201,7 +197,6 @@ impl IslandManager {
                 self.islands.insert(id, new_island);
                 rb.ids.active_island_id = id;
                 rb.ids.active_set_id = 0;
-                rb.ids.active_set_offset = 0;
             }
         }
 

src/dynamics/island_manager/validation.rs

@@ -26,8 +26,7 @@ impl IslandManager {
                     assert_eq!(rb.is_sleeping(), island.is_sleeping());
                     // The body’s island id must match the island id.
                     assert_eq!(rb.ids.active_island_id, island_id);
-                    // The body’s offset must match its handle’s position in island.bodies.
-                    assert_eq!(body_id, rb.ids.active_set_offset as usize);
+                    // The body’s active set id must match its handle’s position in island.bodies.
                     assert_eq!(body_id, rb.ids.active_set_id);
                 }
             }

src/dynamics/rigid_body.rs

@@ -665,7 +665,7 @@ impl RigidBody {
     //       to all the fixed bodies active set offsets?
     pub fn effective_active_set_offset(&self) -> u32 {
         if self.is_dynamic_or_kinematic() {
-            self.ids.active_set_offset
+            self.ids.active_set_id as u32
         } else {
             u32::MAX
         }

src/dynamics/rigid_body_components.rs

@@ -1029,7 +1029,6 @@ impl RigidBodyCcd {
 pub struct RigidBodyIds {
     pub(crate) active_island_id: usize,
     pub(crate) active_set_id: usize,
-    pub(crate) active_set_offset: u32,
     pub(crate) active_set_timestamp: u32,
 }
 
@@ -1038,7 +1037,6 @@ impl Default for RigidBodyIds {
         Self {
             active_island_id: usize::MAX,
             active_set_id: usize::MAX,
-            active_set_offset: u32::MAX,
             active_set_timestamp: 0,
         }
     }

src/dynamics/solver/contact_constraint/contact_with_coulomb_friction.rs

@@ -52,15 +52,15 @@ impl ContactWithCoulombFrictionBuilder {
             && manifold_id[ii] != usize::MAX
         {
             let handle = manifolds[ii].data.rigid_body1.unwrap(); // Can unwrap thanks to the dominance check.
-            bodies[handle].ids.active_set_offset
+            bodies[handle].ids.active_set_id as u32
         } else {
             u32::MAX
         }];
         let ids2: [u32; SIMD_WIDTH] = array![|ii| if manifolds[ii].data.relative_dominance >= 0
             && manifold_id[ii] != usize::MAX
         {
             let handle = manifolds[ii].data.rigid_body2.unwrap(); // Can unwrap thanks to the dominance check.
-            bodies[handle].ids.active_set_offset
+            bodies[handle].ids.active_set_id as u32
         } else {
             u32::MAX
         }];

src/dynamics/solver/contact_constraint/contact_with_twist_friction.rs

@@ -59,15 +59,15 @@ impl ContactWithTwistFrictionBuilder {
             && manifold_id[ii] != usize::MAX
         {
             let handle = manifolds[ii].data.rigid_body1.unwrap(); // Can unwrap thanks to the dominance check.
-            bodies[handle].ids.active_set_offset
+            bodies[handle].ids.active_set_id as u32
         } else {
             u32::MAX
         }];
         let ids2: [u32; SIMD_WIDTH] = array![|ii| if manifolds[ii].data.relative_dominance >= 0
             && manifold_id[ii] != usize::MAX
         {
             let handle = manifolds[ii].data.rigid_body2.unwrap(); // Can unwrap thanks to the dominance check.
-            bodies[handle].ids.active_set_offset
+            bodies[handle].ids.active_set_id as u32
         } else {
             u32::MAX
         }];

src/dynamics/solver/contact_constraint/generic_contact_constraint.rs

@@ -68,15 +68,15 @@ impl GenericContactConstraintBuilder {
             multibody1
                 .map(|mb| mb.0.solver_id)
                 .unwrap_or(if type1.is_dynamic_or_kinematic() {
-                    rb1.ids.active_set_offset
+                    rb1.ids.active_set_id as u32
                 } else {
                     u32::MAX
                 });
         let solver_vel2 =
             multibody2
                 .map(|mb| mb.0.solver_id)
                 .unwrap_or(if type2.is_dynamic_or_kinematic() {
-                    rb2.ids.active_set_offset
+                    rb2.ids.active_set_id as u32
                 } else {
                     u32::MAX
                 });

src/dynamics/solver/interaction_groups.rs

@@ -117,26 +117,26 @@ impl ParallelInteractionGroups {
                 (false, false) => {
                     let rb1 = &bodies[body_pair.0.unwrap()];
                     let rb2 = &bodies[body_pair.1.unwrap()];
-                    let color_mask = bcolors[rb1.ids.active_set_offset as usize]
-                        | bcolors[rb2.ids.active_set_offset as usize];
+                    let color_mask =
+                        bcolors[rb1.ids.active_set_id] | bcolors[rb2.ids.active_set_id];
                     *color = (!color_mask).trailing_zeros() as usize;
                     color_len[*color] += 1;
-                    bcolors[rb1.ids.active_set_offset as usize] |= 1 << *color;
-                    bcolors[rb2.ids.active_set_offset as usize] |= 1 << *color;
+                    bcolors[rb1.ids.active_set_id] |= 1 << *color;
+                    bcolors[rb2.ids.active_set_id] |= 1 << *color;
                 }
                 (true, false) => {
                     let rb2 = &bodies[body_pair.1.unwrap()];
-                    let color_mask = bcolors[rb2.ids.active_set_offset as usize];
+                    let color_mask = bcolors[rb2.ids.active_set_id];
                     *color = 127 - (!color_mask).leading_zeros() as usize;
                     color_len[*color] += 1;
-                    bcolors[rb2.ids.active_set_offset as usize] |= 1 << *color;
+                    bcolors[rb2.ids.active_set_id] |= 1 << *color;
                 }
                 (false, true) => {
                     let rb1 = &bodies[body_pair.0.unwrap()];
-                    let color_mask = bcolors[rb1.ids.active_set_offset as usize];
+                    let color_mask = bcolors[rb1.ids.active_set_id];
                     *color = 127 - (!color_mask).leading_zeros() as usize;
                     color_len[*color] += 1;
-                    bcolors[rb1.ids.active_set_offset as usize] |= 1 << *color;
+                    bcolors[rb1.ids.active_set_id] |= 1 << *color;
                 }
                 (true, true) => unreachable!(),
             }
@@ -270,18 +270,10 @@ impl InteractionGroups {
             }
 
             let ijoint = interaction.data.locked_axes.bits() as usize;
-            let i1 = rb1.ids.active_set_offset;
-            let i2 = rb2.ids.active_set_offset;
-            let conflicts = self
-                .body_masks
-                .get(i1 as usize)
-                .copied()
-                .unwrap_or_default()
-                | self
-                    .body_masks
-                    .get(i2 as usize)
-                    .copied()
-                    .unwrap_or_default()
+            let i1 = rb1.ids.active_set_id;
+            let i2 = rb2.ids.active_set_id;
+            let conflicts = self.body_masks.get(i1).copied().unwrap_or_default()
+                | self.body_masks.get(i2).copied().unwrap_or_default()
                 | joint_type_conflicts[ijoint];
             let conflictfree_targets = !(conflicts & occupied_mask); // The & is because we consider empty buckets as free of conflicts.
             let conflictfree_occupied_targets = conflictfree_targets & occupied_mask;
@@ -420,17 +412,15 @@ impl InteractionGroups {
                     continue;
                 }
 
-                let (status1, active_set_offset1) = if let Some(rb1) = interaction.data.rigid_body1
-                {
+                let (status1, active_set_id1) = if let Some(rb1) = interaction.data.rigid_body1 {
                     let rb1 = &bodies[rb1];
-                    (rb1.body_type, rb1.ids.active_set_offset)
+                    (rb1.body_type, rb1.ids.active_set_id as u32)
                 } else {
                     (RigidBodyType::Fixed, u32::MAX)
                 };
-                let (status2, active_set_offset2) = if let Some(rb2) = interaction.data.rigid_body2
-                {
+                let (status2, active_set_id2) = if let Some(rb2) = interaction.data.rigid_body2 {
                     let rb2 = &bodies[rb2];
-                    (rb2.body_type, rb2.ids.active_set_offset)
+                    (rb2.body_type, rb2.ids.active_set_id as u32)
                 } else {
                     (RigidBodyType::Fixed, u32::MAX)
                 };
@@ -443,8 +433,8 @@ impl InteractionGroups {
                     continue;
                 }
 
-                let i1 = active_set_offset1;
-                let i2 = active_set_offset2;
+                let i1 = active_set_id1;
+                let i2 = active_set_id2;
                 let mask1 = if !is_fixed1 {
                     self.body_masks[i1 as usize]
                 } else {

src/dynamics/solver/joint_constraint/joint_constraint_builder.rs

@@ -119,12 +119,12 @@ impl JointConstraintBuilderSimd {
         let rb2 = array![|ii| &bodies[joint[ii].body2]];
 
         let body1 = array![|ii| if rb1[ii].is_dynamic_or_kinematic() {
-            rb1[ii].ids.active_set_offset
+            rb1[ii].ids.active_set_id as u32
         } else {
             u32::MAX
         }];
         let body2 = array![|ii| if rb2[ii].is_dynamic_or_kinematic() {
-            rb2[ii].ids.active_set_offset
+            rb2[ii].ids.active_set_id as u32
         } else {
             u32::MAX
         }];