1 files changed, 73 insertions, 0 deletions
diff --git a/world/src/physics.rs b/world/src/physics.rs
new file mode 100644
index 0000000..82bb28f
--- /dev/null
+++ b/world/src/physics.rs
@@ -0,0 +1,73 @@
+use anyhow::{Result, anyhow};
+use gltf::{Gltf, Node, buffer::Data, json::Value};
+use log::info;
+use weareshared::{
+    resources::{CollisionPart, Prefab},
+    store::ResourceStore,
+    vec3a,
+};
+
+use crate::mesh::node_transform_to_affine;
+
+pub fn import_physics(
+    gltf: &Gltf,
+    node: &Node,
+    prefab: &mut Prefab,
+    store: &ResourceStore,
+    buffers: &[Data],
+) -> Result<()> {
+    if let Some(physics) = node
+        .extensions()
+        .map(|e| e.get("KHR_physics_rigid_bodies"))
+        .flatten()
+    {
+        info!("--- COLLISION ---");
+        if let Some(collider) = physics.get("collider") {
+            if let Some(geometry) = collider.get("geometry") {
+                if geometry.get("convexHull") == Some(&Value::Bool(true)) {
+                    let node = geometry
+                        .get("node")
+                        .map(|n| n.as_u64())
+                        .flatten()
+                        .ok_or(anyhow!("convexHull node missing"))?;
+                    let node = gltf
+                        .nodes()
+                        .nth(node as usize)
+                        .ok_or(anyhow!("convexHull node reference invalid"))?;
+                    let mesh = node.mesh().ok_or(anyhow!("convexHull 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!("convexHull no index buffer"))?
+                            .into_u32()
+                            .map(|e| e as u16)
+                            .array_chunks::<3>()
+                            .collect::<Vec<_>>();
+                        let position = reader
+                            .read_positions()
+                            .ok_or(anyhow!("convexHull no positions"))?
+                            .map(|[x, y, z]| vec3a(x, y, z))
+                            .collect::<Vec<_>>();
+
+                        info!(
+                            "convex hull has {} indecies and {} positions",
+                            index.len(),
+                            position.len()
+                        );
+
+                        prefab.collision.push((
+                            node_transform_to_affine(&node),
+                            store.set(&CollisionPart {
+                                sh_mesh: Some((store.set(&index)?, store.set(&position)?)),
+                                ..Default::default()
+                            })?,
+                        ));
+                    }
+                }
+            }
+        }
+    }
+    Ok(())
+}