disable collision between bullet shooter & bullet

src/app.c

@@ -267,7 +267,6 @@ void app_entry_point(void)
         arena_temp_end(temp);
     }
 
-
     logf_info("Program exited normally");
     scratch_end(scratch);
 }

src/entity.c

@@ -78,7 +78,7 @@ void entity_store_copy_replace(struct entity_store *dest, struct entity_store *s
 }
 
 /* ========================== *
- * Allocation
+ * Entity allocation
  * ========================== */
 
 INTERNAL struct entity *entity_alloc_internal(struct entity_store *store)
@@ -132,7 +132,7 @@ INTERNAL void entity_release_internal(struct entity_store *store, struct entity
 void entity_release(struct entity_store *store, struct entity *ent)
 {
     if (ent->parent.gen) {
-        entity_unlink_parent(ent);
+        entity_unlink_from_parent(ent);
     }
     entity_release_internal(store, ent);
 }
@@ -352,7 +352,7 @@ void entity_link_parent(struct entity *ent, struct entity *parent)
 
     if (ent->parent.gen) {
         /* Unlink from current parent */
-        entity_unlink_parent(ent);
+        entity_unlink_from_parent(ent);
     }
 
     struct entity_handle handle = ent->handle;
@@ -370,11 +370,16 @@ void entity_link_parent(struct entity *ent, struct entity *parent)
     }
     parent->last = handle;
 
-    ent->is_top = parent->is_root;
+    if (parent->is_root) {
+        ent->is_top = true;
+        ent->top = handle;
+    } else {
+        ent->top = parent->top;
+    }
 }
 
 /* NOTE: Entity will be dangling after calling this, should re-link to root entity. */
-void entity_unlink_parent(struct entity *ent)
+void entity_unlink_from_parent(struct entity *ent)
 {
     struct entity_store *store = entity_get_store(ent);
 

src/entity.h

@@ -91,6 +91,9 @@ struct entity {
     /* Is entity a child of the root entity */
     b32 is_top;
 
+    /* The handle of the top level parent of the entity */
+    struct entity_handle top;
+
     /* Tree */
     struct entity_handle parent;
     struct entity_handle next;
@@ -353,7 +356,7 @@ struct entity *entity_find_first_match_all(struct entity_store *store, struct en
 
 /* Tree */
 void entity_link_parent(struct entity *parent, struct entity *child);
-void entity_unlink_parent(struct entity *ent);
+void entity_unlink_from_parent(struct entity *ent);
 
 /* Lookup */
 struct entity_lookup entity_lookup_alloc(u64 num_buckets);

src/game.c

@@ -335,6 +335,7 @@ INTERNAL PHYS_COLLISION_CALLBACK_FUNC_DEF(on_collision, array)
     for (u64 i = 0; i < array.count; ++i) {
         struct phys_collision_data *data = &array.a[i];
 
+        struct phys_contact_constraint *constraint = data->constraint;
         struct entity *e0 = entity_from_handle(store, data->e0);
         struct entity *e1 = entity_from_handle(store, data->e1);
 
@@ -343,8 +344,16 @@ INTERNAL PHYS_COLLISION_CALLBACK_FUNC_DEF(on_collision, array)
             if (entity_has_prop(e0, ENTITY_PROP_BULLET) || entity_has_prop(e1, ENTITY_PROP_BULLET)) {
                 struct entity *bullet = entity_has_prop(e0, ENTITY_PROP_BULLET) ? e0 : e1;
                 struct entity *target = e0 == bullet ? e1 : e0;
+                struct entity *src = entity_from_handle(store, bullet->bullet_src);
                 (UNUSED)bullet;
                 (UNUSED)target;
+                (UNUSED)src;
+
+                if (entity_handle_eq(src->top, target->top)) {
+                    /* Ignore collision if weapon and target share same top level parent */
+                    constraint->skip_solve = true;
+                    continue;
+                }
 
                 /* Disable bullet */
                 entity_enable_prop(bullet, ENTITY_PROP_RELEASE_BEFORE_PUBLISH);

src/phys.c

@@ -119,10 +119,27 @@ struct phys_collision_data_array phys_create_contacts(struct arena *arena, struc
             struct phys_contact_constraint *constraint = NULL;
             if (collider_res.num_points > 0) {
                 if (!entity_is_valid_and_active(constraint_ent)) {
+                    /* Create constraint */
+                    {
+                        constraint_ent = entity_alloc(root);
+                        constraint_ent->contact_constraint_data.e1 = e1->handle;
+                        constraint_ent->contact_constraint_data.e0 = e0->handle;
+                        constraint_ent->contact_constraint_data.skip_solve = entity_has_prop(e0, ENTITY_PROP_SENSOR) || entity_has_prop(e1, ENTITY_PROP_SENSOR)
+                            || !(entity_has_prop(e0, ENTITY_PROP_PHYSICAL_DYNAMIC) || entity_has_prop(e1, ENTITY_PROP_PHYSICAL_DYNAMIC));
+                        entity_enable_prop(constraint_ent, ENTITY_PROP_ACTIVE);
+
+                        /* TODO: Should we recalculate normal as more contact points are added? */
+                        entity_enable_prop(constraint_ent, ENTITY_PROP_CONTACT_CONSTRAINT);
+                        entity_activate(constraint_ent, tick_id);
+                        ASSERT(!entry);  /* Existing entry should never be present here */
+                        entity_lookup_set(contact_lookup, key, constraint_ent->handle);
+                    }
+
                     /* Push collision data */
                     if (ctx->pre_solve_callback || ctx->post_solve_callback) {
                         struct phys_collision_data *data = arena_push_zero(arena, struct phys_collision_data);
                         ++res.count;
+                        data->constraint = &constraint_ent->contact_constraint_data;
                         data->e0 = e0->handle;
                         data->e1 = e1->handle;
                         data->normal = collider_res.normal;
@@ -150,22 +167,6 @@ struct phys_collision_data_array phys_create_contacts(struct arena *arena, struc
                         }
                         data->vrel = vrel;
                     }
-
-                    /* Create constraint */
-                    {
-                        constraint_ent = entity_alloc(root);
-                        constraint_ent->contact_constraint_data.e1 = e1->handle;
-                        constraint_ent->contact_constraint_data.e0 = e0->handle;
-                        constraint_ent->contact_constraint_data.skip_solve = entity_has_prop(e0, ENTITY_PROP_SENSOR) || entity_has_prop(e1, ENTITY_PROP_SENSOR)
-                            || !(entity_has_prop(e0, ENTITY_PROP_PHYSICAL_DYNAMIC) || entity_has_prop(e1, ENTITY_PROP_PHYSICAL_DYNAMIC));
-                        entity_enable_prop(constraint_ent, ENTITY_PROP_ACTIVE);
-
-                        /* TODO: Should we recalculate normal as more contact points are added? */
-                        entity_enable_prop(constraint_ent, ENTITY_PROP_CONTACT_CONSTRAINT);
-                        entity_activate(constraint_ent, tick_id);
-                        ASSERT(!entry);  /* Existing entry should never be present here */
-                        entity_lookup_set(contact_lookup, key, constraint_ent->handle);
-                    }
                 }
                 constraint = &constraint_ent->contact_constraint_data;
                 constraint->normal = collider_res.normal;
@@ -1127,7 +1128,7 @@ void phys_step(struct phys_ctx *ctx, f32 timestep)
 
     f32 remaining_dt = timestep;
     while (remaining_dt > 0) {
-        __profscope(step);
+        __profscope(step_part);
         struct temp_arena scratch = scratch_begin_no_conflict();
         /* TOI */
         f32 step_dt = remaining_dt;
@@ -1160,22 +1161,27 @@ void phys_step(struct phys_ctx *ctx, f32 timestep)
         f32 substep_dt = step_dt / GAME_PHYSICS_SUBSTEPS;
         for (u32 i = 0; i < GAME_PHYSICS_SUBSTEPS; ++i) {
             __profscope(substep);
+
+            /* Warm start */
 #if GAME_PHYSICS_ENABLE_WARM_STARTING
             phys_warm_start_contacts(ctx);
             phys_warm_start_motor_joints(ctx);
             phys_warm_start_mouse_joints(ctx);
 #endif
 
+            /* Solve */
 #if GAME_PHYSICS_ENABLE_COLLISION
             phys_solve_contacts(ctx, substep_dt, true);
 #endif
             phys_solve_motor_joints(ctx, substep_dt);
             phys_solve_mouse_joints(ctx, substep_dt);
 
+            /* Integrate */
             phys_integrate_velocities(ctx, substep_dt);
 
+            /* Relaxation solve */
 #if GAME_PHYSICS_ENABLE_COLLISION && GAME_PHYSICS_ENABLE_RELAXATION
-            phys_solve_contacts(ctx, substep_dt, false);  /* Relaxation */
+            phys_solve_contacts(ctx, substep_dt, false);
 #endif
         }
 

src/phys.h

@@ -7,8 +7,9 @@
 struct entity_store;
 struct entity_lookup;
 
+struct phys_contact_constraint;
 struct phys_collision_data {
-    struct entity_handle constraint_ent;
+    struct phys_contact_constraint *constraint;
     struct entity_handle e0;
     struct entity_handle e1;
     struct v2 point;