bullet emitter

3 files changed, 68 insertions, 40 deletions

diff --git a/src/sim/entity/mod.rs b/src/sim/entity/mod.rs
index 2a046c5..a86a51f 100644
--- a/src/sim/entity/mod.rs
+++ b/src/sim/entity/mod.rs
@@ -49,6 +49,7 @@ impl Marchable for EntityCells {
 }
 
 pub trait EntityBehaviour {
+    // TODO merge ctxs?
     fn update(&mut self, _update_ctx: &mut EntityUpdateCtx, _ctx: &mut SimCtx, _delta_time: f32) {}
     fn physics_update(
         &mut self,
@@ -67,6 +68,23 @@ pub struct EntityDef {
 }
 
 impl EntityDef {
+    pub fn from_cells_and_rb(
+        cells: EntityCells,
+        rb: RigidBody,
+        behaviour: Option<Box<dyn EntityBehaviour>>,
+    ) -> Self {
+        let collider = RbManager::convex_hull_collider_from_marchable(&cells, Some(10))
+            .mass(mass_from_cells(&cells.cells))
+            .build();
+
+        EntityDef {
+            rb: Some(rb),
+            collider: Some(collider),
+            cells: Some(cells),
+            behaviour,
+        }
+    }
+
     pub fn from_cells(
         position: Vec2,
         cells: EntityCells,
diff --git a/src/sim/sim_manager/mod.rs b/src/sim/sim_manager/mod.rs
index be75eeb..89ae528 100644
--- a/src/sim/sim_manager/mod.rs
+++ b/src/sim/sim_manager/mod.rs
@@ -7,10 +7,12 @@ use crate::{
     config::{PHYSICS_DELTA_TIME, PHYSICS_FPS, SIM_FPS},
     sim::{
         cell_manager::manager::CellManager,
-        entity::{Entity, EntityDef, EntityId},
+        entity::{Entity, EntityDef, EntityId, EntityUpdateResult},
         particle_manager::ParticleManager,
         rb_manager::RbManager,
-        sim_manager::utils::{read_back_entities_from_world, write_entities_to_world},
+        sim_manager::utils::{
+            process_entity_update_result, read_back_entities_from_world, write_entities_to_world,
+        },
     },
 };
 
@@ -112,10 +114,7 @@ impl SimManager {
             if let Some(entity) = entity
                 && let Some(result) = entity.update(&mut ctx, delta_time)
             {
-                // process entity update results
-                for d in result.deferred_destructions {
-                    self.destroy_entity(d);
-                }
+                process_entity_update_result(self, result);
             }
         }
 
@@ -136,9 +135,7 @@ impl SimManager {
             if let Some(entity) = entity
                 && let Some(result) = entity.physics_update(&mut ctx, delta_time)
             {
-                for d in result.deferred_destructions {
-                    self.destroy_entity(d);
-                }
+                process_entity_update_result(self, result);
             }
         }
         // before we move the rigidbodies, upsert the current terrain state
diff --git a/src/sim/sim_manager/utils.rs b/src/sim/sim_manager/utils.rs
index 506844c..e77f30a 100644
--- a/src/sim/sim_manager/utils.rs
+++ b/src/sim/sim_manager/utils.rs
@@ -2,7 +2,11 @@ use glam::IVec2;
 
 use crate::{
     content::materials::MaterialId,
-    sim::{cell::Cell, entity::EntityId, sim_manager::SimManager},
+    sim::{
+        cell::Cell,
+        entity::{EntityId, EntityUpdateResult},
+        sim_manager::SimManager,
+    },
 };
 
 fn write_entity_to_world(sim: &mut SimManager, entity_id: EntityId) -> Vec<(u8, u8, i32, i32)> {
@@ -82,46 +86,55 @@ pub fn read_back_entities_from_world(
     cells_written_by_entity: Vec<(EntityId, Vec<(u8, u8, i32, i32)>)>,
 ) {
     for (entity_id, cells_written) in cells_written_by_entity {
-        if let Some(entity) = sim.entities.get_mut(&entity_id) {
-            let entity_cells = entity.data.cells.as_mut().unwrap();
-            let mut should_update_entity = false;
+        let mut entity = sim.entities.get_mut(&entity_id);
+        let mut should_update_entity = false;
 
-            for (lx, ly, x, y) in cells_written {
-                // update the entity
-                // TODO optimize
-                let new_local_cell = sim.cell_manager.get_cell_from_game_position(x, y).unwrap();
-                if !new_local_cell.entity_integrated() {
-                    // this means that the entity changed in some way, so we should recompute its shape
-                    // TODO wait N frames to debounce this
-                    should_update_entity = true;
-                }
+        for (lx, ly, x, y) in cells_written {
+            // update the entity
+            // TODO optimize
+            let new_local_cell = sim.cell_manager.get_cell_from_game_position(x, y).unwrap();
+            if !new_local_cell.entity_integrated() {
+                // this means that the entity changed in some way, so we should recompute its shape
+                // TODO wait N frames to debounce this
+                should_update_entity = true;
+            }
+            if let Some(entity) = &mut entity {
+                let entity_cells = entity.data.cells.as_mut().unwrap();
                 // we do this unconditionally because it's cheaper than checking if it actually needs to be updated
                 // and because we don't have a good way to track changes to cell state
                 entity_cells
                     .set_cell_at_local_position(IVec2::new(lx as i32, ly as i32), new_local_cell);
-
-                // update the world
-                // TODO optimize
-                sim.cell_manager
-                    .set_cell_from_game_position(x, y, Cell::void(), false);
             }
 
-            if should_update_entity {
-                if let Some(new_collider) = entity.compute_collider() {
-                    sim.rb_manager
-                        .physics_manager
-                        .world
-                        .remove_collider(entity.data.collider_h.unwrap());
+            // update the world
+            // TODO optimize
+            sim.cell_manager
+                .set_cell_from_game_position(x, y, Cell::void(), false);
+        }
 
-                    let new_handle = sim
-                        .rb_manager
-                        .physics_manager
-                        .world
-                        .insert_collider(new_collider, Some(entity.data.rb_h.unwrap()));
+        if let Some(entity) = &mut entity
+            && should_update_entity
+        {
+            if let Some(new_collider) = entity.compute_collider() {
+                sim.rb_manager
+                    .physics_manager
+                    .world
+                    .remove_collider(entity.data.collider_h.unwrap());
 
-                    entity.data.collider_h = Some(new_handle);
-                }
+                let new_handle = sim
+                    .rb_manager
+                    .physics_manager
+                    .world
+                    .insert_collider(new_collider, Some(entity.data.rb_h.unwrap()));
+
+                entity.data.collider_h = Some(new_handle);
             }
         }
     }
 }
+
+pub fn process_entity_update_result(sim: &mut SimManager, result: EntityUpdateResult) {
+    for d in result.deferred_destructions {
+        sim.destroy_entity(d);
+    }
+}