porting mistake

Cargo.lock

@@ -3904,6 +3904,7 @@ dependencies = [
  "arrayvec",
  "glam",
  "id",
+ "mlua",
  "strafesnet_common",
 ]
 

engine/physics/Cargo.toml

@@ -7,6 +7,7 @@ edition = "2024"
 arrayvec = "0.7.6"
 glam = "0.30.0"
 id = { version = "0.1.0", registry = "strafesnet" }
+mlua = { version = "0.11.5", features = ["luau"] }
 strafesnet_common = { path = "../../lib/common", registry = "strafesnet" }
 
 [lints]

engine/physics/src/lib.rs

@@ -3,6 +3,7 @@ mod face_crawler;
 mod model;
 mod push_solve;
 mod minimum_difference;
+mod minimum_difference_lua;
 
 pub mod physics;
 

engine/physics/src/minimum_difference.rs

@@ -10,13 +10,20 @@ use crate::model::{MinkowskiMesh,MinkowskiVert};
 // written by Trey Reynolds in 2021
 
 type Simplex<const N:usize,Vert>=[Vert;N];
-#[derive(Clone,Copy)]
+#[derive(Clone,Copy,Debug)]
 enum Simplex1_3<Vert>{
 	Simplex1(Simplex<1,Vert>),
 	Simplex2(Simplex<2,Vert>),
 	Simplex3(Simplex<3,Vert>),
 }
 impl<Vert> Simplex1_3<Vert>{
+	fn len(&self)->usize{
+		match self{
+			Simplex1_3::Simplex1(_)=>1,
+			Simplex1_3::Simplex2(_)=>2,
+			Simplex1_3::Simplex3(_)=>3,
+		}
+	}
 	fn push_front(self,v:Vert)->Simplex2_4<Vert>{
 		match self{
 			Simplex1_3::Simplex1([v0])=>Simplex2_4::Simplex2([v,v0]),
@@ -136,12 +143,15 @@ fn reduce1<M:MeshQuery>(
 	mesh:&M,
 	point:Planar64Vec3,
 )->Reduced<M::Vert>{
+	println!("reduce1");
 	// --debug.profilebegin("reduceSimplex0")
 	// local a = a1 - a0
 	let p0=mesh.vert(v0);
 
+	println!("p0={p0}");
 	// local p = -a
 	let p=-(p0+point);
+	println!("p={p}");
 
 	// local direction = p
 	let mut dir=p;
@@ -165,6 +175,7 @@ fn reduce2<M:MeshQuery>(
 	mesh:&M,
 	point:Planar64Vec3,
 )->Reduced<M::Vert>{
+	println!("reduce2");
 	// --debug.profilebegin("reduceSimplex1")
 	// local a = a1 - a0
 	// local b = b1 - b0
@@ -222,6 +233,7 @@ fn reduce3<M:MeshQuery>(
 	mesh:&M,
 	point:Planar64Vec3,
 )->Reduced<M::Vert>{
+	println!("reduce3");
 	// --debug.profilebegin("reduceSimplex2")
 	// local a = a1 - a0
 	// local b = b1 - b0
@@ -236,6 +248,7 @@ fn reduce3<M:MeshQuery>(
 	let p=-(p0+point);
 	let mut u=p1-p0;
 	let v=p2-p0;
+	println!("p={p} u={u} v={v}");
 
 	// local uv = u:Cross(v)
 	// local up = u:Cross(p)
@@ -259,6 +272,7 @@ fn reduce3<M:MeshQuery>(
 		}else{
 			uv
 		};
+		println!("and we got here?? direction={direction:?}");
 
 		// return direction, a0, a1, b0, b1, c0, c1
 		return Reduced{
@@ -331,6 +345,7 @@ fn reduce4<M:MeshQuery>(
 	mesh:&M,
 	point:Planar64Vec3,
 )->Reduce<M::Vert>{
+	println!("reduce4");
 	// --debug.profilebegin("reduceSimplex3")
 	// local a = a1 - a0
 	// local b = b1 - b0
@@ -366,9 +381,11 @@ fn reduce4<M:MeshQuery>(
 	let uv_p=uv.dot(p);
 
 	// if pvw/uvw >= 0 and upw/uvw >= 0 and uvp/uvw >= 0 then
-	if !pv_w.div_sign(uv_w).is_negative()
-	 ||!up_w.div_sign(uv_w).is_negative()
-	 ||!uv_p.div_sign(uv_w).is_negative(){
+	let a=!pv_w.div_sign(uv_w).is_negative();
+	let b=!up_w.div_sign(uv_w).is_negative();
+	let c=!uv_p.div_sign(uv_w).is_negative();
+	println!("a={a} b={b} c={c}");
+	if a&&b&&c{
 		// origin is contained, this is a positive detection
 		// local direction = Vector3.new(0, 0, 0)
 		// return direction, a0, a1, b0, b1, c0, c1, d0, d1
@@ -751,13 +768,22 @@ fn crawl_to_closest_fev<'a>(mesh:&MinkowskiMesh<'a>,simplex:Simplex<3,MinkowskiV
 		},
 	}
 }
-
 pub fn closest_fev_not_inside<'a>(mesh:&MinkowskiMesh<'a>,point:Planar64Vec3)->Option<FEV<MinkowskiMesh<'a>>>{
+	println!("=== LUA ===");
+	let (hits,_details)=crate::minimum_difference_lua::minimum_difference_details(mesh,point).unwrap();
+	println!("=== RUST ===");
+	let closest_fev_not_inside=closest_fev_not_inside_inner(mesh,point);
+	assert_eq!(hits,closest_fev_not_inside.is_none(),"algorithms disagree");
+	closest_fev_not_inside
+}
+
+fn closest_fev_not_inside_inner<'a>(mesh:&MinkowskiMesh<'a>,point:Planar64Vec3)->Option<FEV<MinkowskiMesh<'a>>>{
 	const ENABLE_FAST_FAIL:bool=false;
 	// TODO: remove mesh negation
 	minimum_difference::<ENABLE_FAST_FAIL,_,_>(&-mesh,point,
 		// on_exact
 		|is_intersecting,simplex|{
+			println!("on_exact simplex={simplex:?}");
 			if is_intersecting{
 				return None;
 			}
@@ -821,6 +847,7 @@ fn minimum_difference<const ENABLE_FAST_FAIL:bool,T,M:MeshQuery>(
 	if initial_axis==vec3::zero(){
 		initial_axis=choose_any_direction();
 	}
+	println!("initial_axis={initial_axis}");
 	let last_point=mesh.farthest_vert(-initial_axis);
 	// this represents the 'a' value in the commented code
 	let mut last_pos=mesh.vert(last_point);
@@ -829,6 +856,8 @@ fn minimum_difference<const ENABLE_FAST_FAIL:bool,T,M:MeshQuery>(
 	// exitRadius = testIntersection and 0 or exitRadius or 1/0
 	// for _ = 1, 100 do
 	loop{
+		println!("arity={} direction={direction}",simplex_small.len());
+
 		// new_point_p = queryP(-direction)
 		// new_point_q = queryQ(direction)
 		// local next_point = new_point_q - new_point_p
@@ -836,7 +865,11 @@ fn minimum_difference<const ENABLE_FAST_FAIL:bool,T,M:MeshQuery>(
 		let next_pos=mesh.vert(next_point);
 
 		// if -direction:Dot(next_point) > (exitRadius + radiusP + radiusQ)*direction.magnitude then
-		if ENABLE_FAST_FAIL&&direction.dot(next_pos+point).is_negative(){
+		let d=direction.dot(next_pos+point);
+		let fast_fail=d.is_negative();
+		println!("ENABLE_FAST_FAIL={ENABLE_FAST_FAIL} fast_fail={fast_fail} next_point={} dot={d}",next_pos+point);
+		if ENABLE_FAST_FAIL&&fast_fail{
+			println!("on_fast_fail");
 			return on_fast_fail();
 		}
 
@@ -845,8 +878,11 @@ fn minimum_difference<const ENABLE_FAST_FAIL:bool,T,M:MeshQuery>(
 		// if
 		// 	direction:Dot(next_point - a) <= 0 or
 		// 	absDet(next_point, a, b, c) < 1e-6
-		if !direction.dot(next_pos-last_pos).is_positive()
-		||simplex_big.det_is_zero(mesh){
+		let cond1=!direction.dot(next_pos-last_pos).is_positive();
+		let cond2=simplex_big.det_is_zero(mesh);
+		println!("cond1={cond1} cond2={cond2}");
+		if cond1||cond2{
+			println!("on_exact");
 			// Found enough information to compute the exact closest point.
 			// local norm = direction.unit
 			// local dist = a:Dot(norm)
@@ -859,6 +895,7 @@ fn minimum_difference<const ENABLE_FAST_FAIL:bool,T,M:MeshQuery>(
 		match simplex_big.reduce(mesh,point){
 			// if a and b and c and d then
 			Reduce::Escape(simplex)=>{
+				println!("on_escape");
 				// Enough information to conclude that the meshes are intersecting.
 				// Topology information is computed if needed.
 				return on_escape(simplex);

engine/physics/src/minimum_difference_lua.rs

@@ -0,0 +1,173 @@
+use mlua::{Lua,FromLuaMulti,IntoLuaMulti,Function,Result as LuaResult,Vector};
+use strafesnet_common::integer::{Planar64,Planar64Vec3,FixedFromFloatError};
+
+use crate::model::{MeshQuery,MinkowskiMesh};
+
+pub fn contains_point(
+	mesh:&MinkowskiMesh,
+	point:Planar64Vec3,
+)->LuaResult<bool>{
+	Ok(minimum_difference(mesh,point,true)?.hits)
+}
+pub fn minimum_difference_details(
+	mesh:&MinkowskiMesh,
+	point:Planar64Vec3,
+)->LuaResult<(bool,Option<Details>)>{
+	let md=minimum_difference(mesh,point,false)?;
+	Ok((md.hits,md.details))
+}
+fn p64v3(v:Vector)->Result<Planar64Vec3,FixedFromFloatError>{
+	Ok(Planar64Vec3::new([
+		v.x().try_into()?,
+		v.y().try_into()?,
+		v.z().try_into()?,
+	]))
+}
+fn vec(v:Planar64Vec3)->Vector{
+	Vector::new(v.x.into(),v.y.into(),v.z.into())
+}
+struct MinimumDifference{
+	hits:bool,
+	details:Option<Details>
+}
+pub struct Details{
+	pub distance:Planar64,
+	pub p_pos:Planar64Vec3,
+	pub p_norm:Planar64Vec3,
+	pub q_pos:Planar64Vec3,
+	pub q_norm:Planar64Vec3,
+}
+impl FromLuaMulti for MinimumDifference{
+	fn from_lua_multi(mut values:mlua::MultiValue,_lua:&Lua)->LuaResult<Self>{
+		match values.make_contiguous(){
+			&mut [
+				mlua::Value::Boolean(hits),
+				mlua::Value::Nil,
+				mlua::Value::Nil,
+				mlua::Value::Nil,
+				mlua::Value::Nil,
+				mlua::Value::Nil,
+			]=>Ok(Self{hits,details:None}),
+			&mut [
+				mlua::Value::Boolean(hits),
+				mlua::Value::Number(distance),
+				mlua::Value::Vector(p_pos),
+				mlua::Value::Vector(p_norm),
+				mlua::Value::Vector(q_pos),
+				mlua::Value::Vector(q_norm),
+			]=>Ok(Self{
+				hits,
+				details:Some(Details{
+					distance:distance.try_into().unwrap(),
+					p_pos:p64v3(p_pos).unwrap(),
+					p_norm:p64v3(p_norm).unwrap(),
+					q_pos:p64v3(q_pos).unwrap(),
+					q_norm:p64v3(q_norm).unwrap(),
+				}),
+			}),
+			&mut [
+				mlua::Value::Boolean(hits),
+				mlua::Value::Integer(distance),
+				mlua::Value::Vector(p_pos),
+				mlua::Value::Vector(p_norm),
+				mlua::Value::Vector(q_pos),
+				mlua::Value::Vector(q_norm),
+			]=>Ok(Self{
+				hits,
+				details:Some(Details{
+					distance:distance.into(),
+					p_pos:p64v3(p_pos).unwrap(),
+					p_norm:p64v3(p_norm).unwrap(),
+					q_pos:p64v3(q_pos).unwrap(),
+					q_norm:p64v3(q_norm).unwrap(),
+				}),
+			}),
+			values=>Err(mlua::Error::runtime(format!("Invalid return values: {values:?}"))),
+		}
+	}
+}
+
+struct Args{
+	query_p:Function,
+	radius_p:f64,
+	query_q:Function,
+	radius_q:f64,
+	test_intersection:bool,
+}
+impl Args{
+	fn new(
+		lua:&Lua,
+		mesh:&'static MinkowskiMesh<'static>,
+		point:Planar64Vec3,
+		test_intersection:bool,
+	)->LuaResult<Self>{
+		let radius_p=0.0;
+		let radius_q=0.0;
+		// Query the farthest point on the mesh in the given direction.
+		let query_p=lua.create_function(move|_,dir:Option<Vector>|{
+			let Some(dir)=dir else{
+				return Ok(vec(mesh.mesh0.hint_point()));
+			};
+			let dir=p64v3(dir).unwrap();
+			let vert_id=mesh.mesh0.farthest_vert(dir);
+			let dir=mesh.mesh0.vert(vert_id);
+			Ok(vec(dir))
+		})?;
+		// query_q is different since it includes the test point offset.
+		let query_q=lua.create_function(move|_,dir:Option<Vector>|{
+			let Some(dir)=dir else{
+				return Ok(vec(mesh.mesh1.hint_point()+point));
+			};
+			let dir=p64v3(dir).unwrap();
+			let vert_id=mesh.mesh1.farthest_vert(dir);
+			let dir=mesh.mesh1.vert(vert_id)+point;
+			Ok(vec(dir))
+		})?;
+		Ok(Args{
+			query_p,
+			radius_p,
+			query_q,
+			radius_q,
+			test_intersection,
+		})
+	}
+}
+impl IntoLuaMulti for Args{
+	fn into_lua_multi(self,lua:&Lua)->LuaResult<mlua::MultiValue>{
+		use mlua::IntoLua;
+		Ok(mlua::MultiValue::from_vec(vec![
+			self.query_p.into_lua(lua)?,
+			self.radius_p.into_lua(lua)?,
+			self.query_q.into_lua(lua)?,
+			self.radius_q.into_lua(lua)?,
+			mlua::Value::Nil,
+			self.test_intersection.into_lua(lua)?,
+		]))
+	}
+}
+
+fn minimum_difference(
+	mesh:&MinkowskiMesh,
+	point:Planar64Vec3,
+	test_intersection:bool,
+)->LuaResult<MinimumDifference>{
+	let ctx=init_lua()?;
+	// SAFETY: mesh lifetime must outlive args usages
+	let mesh=unsafe{core::mem::transmute(mesh)};
+	let args=Args::new(&ctx.lua,mesh,point,test_intersection)?;
+	ctx.f.call(args)
+}
+
+struct Ctx{
+	lua:Lua,
+	f:Function,
+}
+fn init_lua()->LuaResult<Ctx>{
+	static SOURCE:std::sync::LazyLock<String>=std::sync::LazyLock::new(||std::fs::read_to_string("Trey-MinimumDifference.lua").unwrap());
+	let lua=Lua::new();
+	lua.sandbox(true)?;
+	let lib_f=lua.load(SOURCE.as_str()).set_name("Trey-MinimumDifference").into_function()?;
+	let lib:mlua::Table=lib_f.call(())?;
+	let f=lib.raw_get("difference")?;
+	Ok(Ctx{lua,f})
+}

engine/physics/src/model.rs

@@ -91,7 +91,6 @@ pub trait MeshQuery{
 		(self.vert(v1)-self.vert(v0))*((directed_edge_id.parity() as i64)*2-1)
 	}
 	/// This must return a point inside the mesh.
-	#[expect(dead_code)]
 	fn hint_point(&self)->Planar64Vec3;
 	fn farthest_vert(&self,dir:Planar64Vec3)->Self::Vert;
 	fn vert(&self,vert_id:Self::Vert)->Planar64Vec3;
@@ -646,8 +645,8 @@ pub enum MinkowskiFace{
 
 #[derive(Debug)]
 pub struct MinkowskiMesh<'a>{
-	mesh0:TransformedMesh<'a>,
-	mesh1:TransformedMesh<'a>,
+	pub mesh0:TransformedMesh<'a>,
+	pub mesh1:TransformedMesh<'a>,
 }
 
 pub type GigaTime=Ratio<Fixed<4,128>,Fixed<4,128>>;

integration-testing/src/test_scenes.rs

@@ -115,3 +115,48 @@ fn bug_3(){
 	assert_eq!(body.acceleration,vec3::int(0,0,0));
 	assert_eq!(body.time,Time::from_secs(2));
 }
+
+fn test_scene_cylinder()->PhysicsData{
+	let mut builder=TestSceneBuilder::new();
+	let cube_face_description=CubeFaceDescription::new(Default::default(),RenderConfigId::new(0));
+	let mesh=builder.push_mesh(strafesnet_rbx_loader::primitives::unit_cylinder(cube_face_description));
+	// place one 5x5x5 cylinder.
+	// log cylinder
+	// transform=PhysicsMeshTransform { vertex: Planar64Affine3 { matrix3: Matrix { array: [[-0.00000469, 20.41880000, -0.00001730], [-3.71969533, -0.00000d38, -11.c3c43095], [-11.c3c41e7d, 0.00000000, 3.719690ac]] }, translation: Vector { array: [-908.de600000, 28f.e5240000, 24c.c4d80000] } }, normal: Matrix { array: [[-0.00002d857e4861a0, 147.71af629e398c1d05, -0.0000ead3c8730458], [-6f.147da83887600000, -0.0001ab1b4486f8fc, -23d.04a89b8def680000], [-23d.04aae32fa55a8280, 0.0000018177694d73, 6f.147e3a4136524bf8]] }, det: 2942.07be40fdd83c96df87d34320 }
+	// wedge part
+	// transform=PhysicsMeshTransform { vertex: Planar64Affine3 { matrix3: Matrix { array: [[-4.9ba5b000, 0.00000000, 0.00000000], [0.00000000, 3.85509c00, 0.00000000], [0.00000000, 0.00000000, -4.9ba5b000]] }, translation: Vector { array: [-781.30380000, 35b.dab40000, 11c.a4160000] } }, normal: Matrix { array: [[-10.3941970ff7400000, 0.0000000000000000, 0.0000000000000000], [0.0000000000000000, 15.3bcf8e5c59000000, 0.0000000000000000], [0.0000000000000000, 0.0000000000000000, -10.3941970ff7400000]] }, det: 4a.c2312159fcd9163c00000000 }
+	builder.push_mesh_instance(mesh,Planar64Affine3::new(
+		mat3::Matrix3::from_cols([vec3::raw_array([-0x4_9ba5b000, 0x0_00000000, 0x0_00000000]), vec3::raw_array([0x0_00000000, 0x3_85509c00, 0x0_00000000]), vec3::raw_array([0x0_00000000, 0x0_00000000, -0x4_9ba5b000])]),
+		vec3::raw_array([-0x781_30380000, 0x35b_dab40000, 0x11c_a4160000])
+	));
+	builder.build()
+}
+
+#[test]
+fn test_minimum_difference(){
+	let physics_data=test_scene_cylinder();
+	// log cylinder
+	// H p(-2329.436, 694.175, 587.190) v(0.000, -5.714, 0.000) a(0.000, -100.000, 0.000) t(56s+880000000ns)
+	// wedge part
+	// H p(-1920.041, 867.905, 284.639) v(0.000, -4.695, 0.000) a(0.000, -100.000, 0.000) t(119s+260000000ns)
+	let body=strafesnet_physics::physics::Body::new(
+		vec3::try_from_f32_array([-1920.041, 867.905, 284.639]).unwrap(),
+		vec3::try_from_f32_array([0.000, -4.695, 0.000]).unwrap(),
+		vec3::int(0,-100,0),
+		Time::ZERO,
+	);
+	let mut physics=PhysicsState::new_with_body(body);
+	physics.style_mut().gravity=vec3::zero();
+	let mut phys_iter=PhysicsContext::iter_internal(&mut physics,&physics_data,Time::from_secs(3))
+		.filter(|ins|!matches!(ins.instruction,InternalInstruction::StrafeTick));
+	// touch side of part at 0,0,0
+	assert_eq!(phys_iter.next().unwrap().time,Time::from_secs(1));
+	// touch top of part at 5,-5,0
+	assert_eq!(phys_iter.next().unwrap().time,Time::from_secs(2));
+	assert!(phys_iter.next().is_none());
+	let body=physics.body();
+	assert_eq!(body.position,vec3::int(5+2,0,0)>>1);
+	assert_eq!(body.velocity,vec3::int(0,0,0));
+	assert_eq!(body.acceleration,vec3::int(0,0,0));
+	assert_eq!(body.time,Time::from_secs(2));
+}