1 files changed, 89 insertions, 0 deletions
diff --git a/import/src/physics.rs b/import/src/physics.rs
new file mode 100644
index 0000000..3beb49b
--- /dev/null
+++ b/import/src/physics.rs
@@ -0,0 +1,89 @@
+/*
+    wearechat - generic multiplayer game with voip
+    Copyright (C) 2025 metamuffin
+
+    This program is free software: you can redistribute it and/or modify
+    it under the terms of the GNU Affero General Public License as published by
+    the Free Software Foundation, version 3 of the License only.
+
+    This program is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU Affero General Public License for more details.
+
+    You should have received a copy of the GNU Affero General Public License
+    along with this program.  If not, see <https://www.gnu.org/licenses/>.
+*/
+use anyhow::{Result, anyhow};
+use gltf::{Gltf, Node, buffer::Data, json::Value};
+use log::{debug, info};
+use weareshared::{
+    Affine3A, packets::Resource, resources::CollisionPart, store::ResourceStore, vec3a,
+};
+
+pub fn import_physics(
+    gltf: &Gltf,
+    trans: Affine3A,
+    node: &Node,
+    store: &ResourceStore,
+    buffers: &[Data],
+) -> Result<Vec<(Affine3A, Resource<CollisionPart>)>> {
+    let mut collision = Vec::new();
+    if let Some(physics) = node
+        .extensions()
+        .and_then(|e| e.get("KHR_physics_rigid_bodies"))
+    {
+        debug!("--- COLLISION ---");
+        if let Some(collider) = physics.get("collider") {
+            if let Some(geometry) = collider.get("geometry") {
+                if let Some(&Value::Bool(chull)) = geometry.get("convexHull") {
+                    let node = geometry
+                        .get("node")
+                        .and_then(|n| n.as_u64())
+                        .ok_or(anyhow!("coll geom node missing"))?;
+                    let node = gltf
+                        .nodes()
+                        .nth(node as usize)
+                        .ok_or(anyhow!("coll geom node reference invalid"))?;
+                    let mesh = node.mesh().ok_or(anyhow!("coll geom node has no mesh"))?;
+                    for p in mesh.primitives() {
+                        let reader = p.reader(|buf| Some(&buffers[buf.index()]));
+
+                        let index = reader
+                            .read_indices()
+                            .ok_or(anyhow!("coll geom no index buffer"))?
+                            .into_u32()
+                            .array_chunks::<3>()
+                            .collect::<Vec<_>>();
+                        let position = reader
+                            .read_positions()
+                            .ok_or(anyhow!("coll geom no positions"))?
+                            .map(|[x, y, z]| vec3a(x, y, z))
+                            .collect::<Vec<_>>();
+
+                        let mut collpart = CollisionPart {
+                            name: node.name().map(|s| s.to_string()),
+                            ..Default::default()
+                        };
+
+                        if chull {
+                            debug!("convex hull has {} positions", position.len());
+                            collpart.sh_convex_hull = Some(store.set(&position)?);
+                        } else {
+                            debug!(
+                                "mesh has {} indecies and {} positions",
+                                index.len(),
+                                position.len()
+                            );
+                            collpart.sh_mesh = Some((store.set(&index)?, store.set(&position)?));
+                        }
+
+                        info!("added collision {:?}", node.name().unwrap_or_default());
+                        collision.push((trans, store.set(&collpart)?));
+                    }
+                }
+            }
+        }
+    }
+    Ok(collision)
+}