automatic chunk marching

1 files changed, 40 insertions, 17 deletions

diff --git a/src/sim/rb_sim/mod.rs b/src/sim/rb_sim/mod.rs
index 0192555..b79de86 100644
--- a/src/sim/rb_sim/mod.rs
+++ b/src/sim/rb_sim/mod.rs
@@ -5,7 +5,7 @@ use fxhash::FxHashMap;
 use glam::Vec2;
 use rapier2d::{
     dynamics::{self},
-    geometry,
+    geometry::{self, ColliderHandle},
     glamx::vec2,
     math, prelude,
 };
@@ -70,8 +70,10 @@ impl PhysicsManager {
 }
 
 pub struct RbSimManager {
-    physics_manager: PhysicsManager,
+    chunk_colliders: FxHashMap<(i32, i32), ColliderHandle>,
     pub rb_entities: FxHashMap<u32, RbEntity>,
+
+    physics_manager: PhysicsManager,
     next_id: u32,
     debug_line_buffer: DebugLineBuffer,
 }
@@ -165,25 +167,44 @@ impl RbSimManager {
     }
 
     fn collider_from_chunk(&self, position: Vec2, chunk: &Chunk) -> geometry::Collider {
-        let mut paths = marching_squares_vertex_trace(chunk, CHUNK_SIZE, CHUNK_SIZE);
-        let mut path: Vec<Vec2> = paths
-            // NAIVE, using the second and assuming it's the outer path
-            .swap_remove(0)
-            .iter()
-            .map(|v| v / PIXELS_TO_METRES)
-            .collect();
-        // close the loop
-        let first = (*path.first().unwrap()).clone();
-        path.push(first);
+        let polys = marching_squares_vertex_trace(chunk, CHUNK_SIZE, CHUNK_SIZE);
+        let mut vertices = Vec::new();
+        let mut indices = Vec::new();
 
-        geometry::ColliderBuilder::polyline(path, None)
+        for poly in polys {
+            let v = vertices.len() as u32;
+            let p = poly.len() as u32;
+            if p < 3 {
+                continue;
+            }
+            for i in 0..p {
+                vertices.push(poly[i as usize] / PIXELS_TO_METRES);
+                indices.push([v + i, v + (i + 1) % p]);
+            }
+        }
+
+        geometry::ColliderBuilder::polyline(vertices, Some(indices))
             .translation(position / PIXELS_TO_METRES)
             .build()
     }
 
-    pub fn test_add_collider_from_chunk(&mut self, position: Vec2, chunk: &Chunk) {
-        let collider = self.collider_from_chunk(position, chunk);
-        self.physics_manager.collider_set.insert(collider);
+    pub fn upsert_chunk_collider(&mut self, cx: i32, cy: i32, chunk: &Chunk) {
+        let collider = self.collider_from_chunk(
+            Vec2::new((cx * CHUNK_SIZE) as f32, (cy * CHUNK_SIZE) as f32),
+            chunk,
+        );
+
+        if let Some(handle) = self.chunk_colliders.remove(&(cx, cy)) {
+            self.physics_manager.collider_set.remove(
+                handle,
+                &mut self.physics_manager.island_manager,
+                &mut self.physics_manager.rigid_body_set,
+                false,
+            );
+        }
+
+        let handle = self.physics_manager.collider_set.insert(collider);
+        self.chunk_colliders.insert((cx, cy), handle);
     }
 
     pub fn test(&mut self) {
@@ -231,8 +252,10 @@ impl RbSimManager {
 
     pub fn new() -> Self {
         RbSimManager {
-            physics_manager: PhysicsManager::new(),
             rb_entities: FxHashMap::default(),
+            chunk_colliders: FxHashMap::default(),
+
+            physics_manager: PhysicsManager::new(),
             next_id: 0,
             debug_line_buffer: DebugLineBuffer::default(),
         }