negative everything

Cargo.lock

@@ -1974,9 +1974,9 @@ dependencies = [
 
 [[package]]
 name = "luau0-src"
-version = "0.15.11+luau697"
+version = "0.17.0+luau701"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "bdbf698d77af7b846fab212ca666c5d597b9ff445ef1a647e181d3392e13dfdf"
+checksum = "ed8f8edd8aba9654a9eeb62b2fe7461589f2faf2d0a1bc04bd64c0123319b3fc"
 dependencies = [
  "cc",
 ]
@@ -2149,12 +2149,13 @@ dependencies = [
 
 [[package]]
 name = "mlua"
-version = "0.11.4"
+version = "0.11.5"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "9be1c2bfc684b8a228fbaebf954af7a47a98ec27721986654a4cc2c40a20cc7e"
+checksum = "935ac67539907efcd7198137eb7358e052555f77fe1b2916600a2249351f2b33"
 dependencies = [
  "bstr",
  "either",
+ "libc",
  "mlua-sys",
  "num-traits",
  "parking_lot",
@@ -2164,9 +2165,9 @@ dependencies = [
 
 [[package]]
 name = "mlua-sys"
-version = "0.8.3"
+version = "0.9.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "3d4dc9cfc5a7698899802e97480617d9726f7da78c910db989d4d0fd4991d900"
+checksum = "8c968af21bf6b19fc9ca8e7b85ee16f86e4c9e3d0591de101a5608086bda0ad8"
 dependencies = [
  "cc",
  "cfg-if",
@@ -3814,6 +3815,7 @@ 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

@@ -1,7 +1,9 @@
 mod body;
-mod push_solve;
 mod face_crawler;
 mod model;
+mod push_solve;
+mod minimum_difference;
+mod minimum_difference_lua;
 
 pub mod physics;
 

engine/physics/src/minimum_difference.rs

@@ -0,0 +1,648 @@
+use strafesnet_common::integer::vec3;
+use strafesnet_common::integer::vec3::Vector3;
+use strafesnet_common::integer::{Fixed,Planar64Vec3};
+
+use crate::model::{MeshQuery,MinkowskiMesh,MinkowskiVert};
+
+// This algorithm is based on Lua code
+// written by Trey Reynolds in 2021
+
+type Simplex<const N:usize>=[MinkowskiVert;N];
+enum Simplex1_3{
+	Simplex1(Simplex<1>),
+	Simplex2(Simplex<2>),
+	Simplex3(Simplex<3>),
+}
+impl Simplex1_3{
+	fn push_front(self,v:MinkowskiVert)->Simplex2_4{
+		match self{
+			Simplex1_3::Simplex1([v0])=>Simplex2_4::Simplex2([v,v0]),
+			Simplex1_3::Simplex2([v0,v1])=>Simplex2_4::Simplex3([v,v0,v1]),
+			Simplex1_3::Simplex3([v0,v1,v2])=>Simplex2_4::Simplex4([v,v0,v1,v2]),
+		}
+	}
+}
+enum Simplex2_4{
+	Simplex2(Simplex<2>),
+	Simplex3(Simplex<3>),
+	Simplex4(Simplex<4>),
+}
+
+/*
+local function absDet(r, u, v, w)
+	if w then
+		return math.abs((u - r):Cross(v - r):Dot(w - r))
+	elseif v then
+		return (u - r):Cross(v - r).magnitude
+	elseif u then
+		return (u - r).magnitude
+	else
+		return 1
+	end
+end
+*/
+impl Simplex2_4{
+	fn det_is_zero(&self,mesh:&MinkowskiMesh)->bool{
+		match self{
+			&Self::Simplex4([p0,p1,p2,p3])=>{
+				let p0=mesh.vert(p0);
+				let p1=mesh.vert(p1);
+				let p2=mesh.vert(p2);
+				let p3=mesh.vert(p3);
+				(p1-p0).cross(p2-p0).dot(p3-p0)==Fixed::ZERO
+			},
+			&Self::Simplex3([p0,p1,p2])=>{
+				let p0=mesh.vert(p0);
+				let p1=mesh.vert(p1);
+				let p2=mesh.vert(p2);
+				(p1-p0).cross(p2-p0)==vec3::zero()
+			},
+			&Self::Simplex2([p0,p1])=>{
+				let p0=mesh.vert(p0);
+				let p1=mesh.vert(p1);
+				p1-p0==vec3::zero()
+			}
+		}
+	}
+}
+
+/*
+local function choosePerpendicularDirection(d)
+	local x, y, z = d.x, d.y, d.z
+	local best = math.min(x*x, y*y, z*z)
+	if x*x == best then
+		return Vector3.new(y*y + z*z, -x*y, -x*z)
+	elseif y*y == best then
+		return Vector3.new(-x*y, x*x + z*z, -y*z)
+	else
+		return Vector3.new(-x*z, -y*z, x*x + y*y)
+	end
+end
+*/
+fn choose_perpendicular_direction(d:Planar64Vec3)->Planar64Vec3{
+	let x=d.x.abs();
+	let y=d.y.abs();
+	let z=d.z.abs();
+	if x<y&&x<z{
+		Vector3::new([Fixed::ZERO,-d.z,d.y])
+	}else if y<z{
+		Vector3::new([d.z,Fixed::ZERO,-d.x])
+	}else{
+		Vector3::new([-d.y,d.x,Fixed::ZERO])
+	}
+}
+
+const fn choose_any_direction()->Planar64Vec3{
+	vec3::X
+}
+
+fn reduce1(
+	[v0]:Simplex<1>,
+	mesh:&MinkowskiMesh,
+	point:Planar64Vec3,
+)->Reduced{
+	// --debug.profilebegin("reduceSimplex0")
+	// local a = a1 - a0
+	let p0=-mesh.vert(v0);
+
+	// local p = -a
+	let p=-(p0+point);
+
+	// local direction = p
+	let mut dir=p;
+
+	// if direction.magnitude == 0 then
+	// 	direction = chooseAnyDirection()
+	if dir==vec3::zero(){
+		dir=choose_any_direction();
+	}
+
+	// return direction, a0, a1
+	Reduced{
+		dir,
+		simplex:Simplex1_3::Simplex1([v0]),
+	}
+}
+
+// local function reduceSimplex1(a0, a1, b0, b1)
+fn reduce2(
+	[v0,v1]:Simplex<2>,
+	mesh:&MinkowskiMesh,
+	point:Planar64Vec3,
+)->Reduced{
+	// --debug.profilebegin("reduceSimplex1")
+	// local a = a1 - a0
+	// local b = b1 - b0
+	let p0=-mesh.vert(v0);
+	let p1=-mesh.vert(v1);
+
+	// local p = -a
+	// local u = b - a
+	let p=-(p0+point);
+	let u=p1-p0;
+
+	// -- modify to take into account the radiuses
+	// local p_u = p:Dot(u)
+	let p_u=p.dot(u);
+
+	// if p_u >= 0 then
+	if !p_u.is_negative(){
+		// local direction = u:Cross(p):Cross(u)
+		let direction=u.cross(p).cross(u);
+
+		// if direction.magnitude == 0 then
+		if direction==vec3::zero(){
+			return Reduced{
+				dir:choose_perpendicular_direction(u),
+				simplex:Simplex1_3::Simplex2([v0,v1]),
+			};
+		}
+
+		// -- modify the direction to take into account a0R and b0R
+		// return direction, a0, a1, b0, b1
+		return Reduced{
+			dir:direction.narrow_1().unwrap(),
+			simplex:Simplex1_3::Simplex2([v0,v1]),
+		};
+	}
+
+	// local direction = p
+	let mut dir=p;
+
+	// if direction.magnitude == 0 then
+	if dir==vec3::zero(){
+		dir=choose_perpendicular_direction(u);
+	}
+
+	// return direction, a0, a1
+	Reduced{
+		dir,
+		simplex:Simplex1_3::Simplex1([v0]),
+	}
+}
+
+// local function reduceSimplex2(a0, a1, b0, b1, c0, c1)
+fn reduce3(
+	[v0,mut v1,v2]:Simplex<3>,
+	mesh:&MinkowskiMesh,
+	point:Planar64Vec3,
+)->Reduced{
+	// --debug.profilebegin("reduceSimplex2")
+	// local a = a1 - a0
+	// local b = b1 - b0
+	// local c = c1 - c0
+	let p0=-mesh.vert(v0);
+	let p1=-mesh.vert(v1);
+	let p2=-mesh.vert(v2);
+
+	// local p = -a
+	// local u = b - a
+	// local v = c - a
+	let p=-(p0+point);
+	let mut u=p1-p0;
+	let v=p2-p0;
+
+	// local uv = u:Cross(v)
+	// local up = u:Cross(p)
+	// local pv = p:Cross(v)
+	// local uv_up = uv:Dot(up)
+	// local uv_pv = uv:Dot(pv)
+	let mut uv=u.cross(v);
+	let mut up=u.cross(p);
+	let pv=p.cross(v);
+	let uv_up=uv.dot(up);
+	let uv_pv=uv.dot(pv);
+
+	// if uv_up >= 0 and uv_pv >= 0 then
+	if !uv_up.is_negative()&&!uv_pv.is_negative(){
+		// local uvp = uv:Dot(p)
+		let uvp=uv.dot(p);
+
+		// local direction = uvp < 0 and -uv or uv
+		let direction=if uvp.is_negative(){
+			-uv
+		}else{
+			uv
+		};
+
+		// return direction, a0, a1, b0, b1, c0, c1
+		return Reduced{
+			dir:direction.narrow_1().unwrap(),
+			simplex:Simplex1_3::Simplex3([v0,v1,v2]),
+		};
+	}
+
+	// local u_u = u:Dot(u)
+	// local v_v = v:Dot(v)
+	// local uDist = uv_up/(u_u*v.magnitude)
+	// local vDist = uv_pv/(v_v*u.magnitude)
+	// local minDist2 = math.min(uDist, vDist)
+	let u_dist=uv_up*v.length();
+	let v_dist=uv_pv*u.length();
+
+	// if vDist == minDist2 then
+	if v_dist<u_dist{
+		u=v;
+		up=-pv;
+		uv=-uv;
+		// b0 = c0
+		// b1 = c1
+		v1=v2;
+	}
+
+	// local p_u = p:Dot(u)
+	let p_u=p.dot(u);
+
+	// if p_u >= 0 then
+	if !p_u.is_negative(){
+		// local direction = up:Cross(u)
+		let direction=up.cross(u);
+		// if direction.magnitude == 0 then
+		if direction==vec3::zero(){
+			// direction = uv
+			return Reduced{
+				dir:uv.narrow_1().unwrap(),
+				simplex:Simplex1_3::Simplex2([v0,v1]),
+			};
+		}
+
+		// return direction, a0, a1, b0, b1
+		return Reduced{
+			dir:direction.narrow_1().unwrap(),
+			simplex:Simplex1_3::Simplex2([v0,v1]),
+		};
+	}
+
+	// local direction = p
+	let dir=p;
+	// if direction.magnitude == 0 then
+	if dir==vec3::zero(){
+		// direction = uv
+		return Reduced{
+			dir:uv.narrow_1().unwrap(),
+			simplex:Simplex1_3::Simplex1([v0]),
+		};
+	}
+	// return direction, a0, a0
+	Reduced{
+		dir,
+		simplex:Simplex1_3::Simplex1([v0]),
+	}
+}
+
+// local function reduceSimplex3(a0, a1, b0, b1, c0, c1, d0, d1)
+fn reduce4(
+	[v0,mut v1,mut v2,v3]:Simplex<4>,
+	mesh:&MinkowskiMesh,
+	point:Planar64Vec3,
+)->Reduce{
+	// --debug.profilebegin("reduceSimplex3")
+	// local a = a1 - a0
+	// local b = b1 - b0
+	// local c = c1 - c0
+	// local d = d1 - d0
+	let p0=-mesh.vert(v0);
+	let p1=-mesh.vert(v1);
+	let p2=-mesh.vert(v2);
+	let p3=-mesh.vert(v3);
+
+	// local p = -a
+	// local u = b - a
+	// local v = c - a
+	// local w = d - a
+	let p=-(p0+point);
+	let mut u=p1-p0;
+	let mut v=p2-p0;
+	let w=p3-p0;
+
+	// local uv = u:Cross(v)
+	// local vw = v:Cross(w)
+	// local wu = w:Cross(u)
+	// local uvw = uv:Dot(w)
+	// local pvw = vw:Dot(p)
+	// local upw = wu:Dot(p)
+	// local uvp = uv:Dot(p)
+	let mut uv=u.cross(v);
+	let vw=v.cross(w);
+	let wu=w.cross(u);
+	let uv_w=uv.dot(w);
+	let pv_w=vw.dot(p);
+	let up_w=wu.dot(p);
+	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(){
+		// 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
+		return Reduce::Escape([v0,v1,v2,v3]);
+	}
+
+	// local uvwSign = uvw < 0 and -1 or uvw > 0 and 1 or 0
+	// local uvDist = uvp*uvwSign/uv.magnitude
+	// local vwDist = pvw*uvwSign/vw.magnitude
+	// local wuDist = upw*uvwSign/wu.magnitude
+	// local minDist3 = math.min(uvDist, vwDist, wuDist)
+	let uv_dist=uv_p.mul_sign(uv_w);
+	let vw_dist=pv_w.mul_sign(uv_w);
+	let wu_dist=up_w.mul_sign(uv_w);
+	let wu_len=wu.length();
+	let uv_len=uv.length();
+	let vw_len=vw.length();
+
+	if vw_dist*wu_len<wu_dist*vw_len{
+		// if vwDist == minDist3 then
+		if vw_dist*uv_len<uv_dist*vw_len{
+			(u,v)=(v,w);
+			uv=vw;
+			// uv_p=pv_w; // unused
+			// b0, c0 = c0, d0
+			// b1, c1 = c1, d1
+			(v1,v2)=(v2,v3);
+		}else{
+			v2=v3;
+		}
+	}else{
+		// elseif wuDist == minDist3 then
+		if wu_dist*uv_len<uv_dist*wu_len{
+			(u,v)=(w,u);
+			uv=wu;
+			// uv_p=up_w; // unused
+			// b0, c0 = d0, b0
+			// b1, c1 = d1, b1
+			// before [a,b,c,d]
+			(v1,v2)=(v3,v1);
+			// after [a,d,b]
+		}else{
+			v2=v3;
+		}
+	}
+
+	// local up = u:Cross(p)
+	// local pv = p:Cross(v)
+	// local uv_up = uv:Dot(up)
+	// local uv_pv = uv:Dot(pv)
+	let mut up=u.cross(p);
+	let pv=p.cross(v);
+	let uv_up=uv.dot(up);
+	let uv_pv=uv.dot(pv);
+
+	// if uv_up >= 0 and uv_pv >= 0 then
+	if !uv_up.is_negative()&&!uv_pv.is_negative(){
+		// local direction = uvw < 0 and uv or -uv
+		// return direction, a0, a1, b0, b1, c0, c1
+		if uv_w.is_negative(){
+			return Reduce::Reduced(Reduced{
+				dir:uv.narrow_1().unwrap(),
+				simplex:Simplex1_3::Simplex3([v0,v1,v2]),
+			});
+		}else{
+			return Reduce::Reduced(Reduced{
+				dir:-uv.narrow_1().unwrap(),
+				simplex:Simplex1_3::Simplex3([v0,v1,v2]),
+			});
+		}
+	}
+
+	// local u_u = u:Dot(u)
+	// local v_v = v:Dot(v)
+	// local uDist = uv_up/(u_u*v.magnitude)
+	// local vDist = uv_pv/(v_v*u.magnitude)
+	// local minDist2 = math.min(uDist, vDist)
+	let u_dist=uv_up*v.length();
+	let v_dist=uv_pv*u.length();
+
+	// if vDist == minDist2 then
+	if v_dist<u_dist{
+		u=v;
+		up=-pv;
+		uv=-uv;
+		// b0 = c0
+		// b1 = c1
+		v1=v2;
+	}
+
+	// local p_u = p:Dot(u)
+	let p_u=p.dot(u);
+
+	// if p_u >= 0 then
+	if !p_u.is_negative(){
+		// local direction = up:Cross(u)
+		let direction=up.cross(u);
+		// if direction.magnitude == 0 then
+		if direction==vec3::zero(){
+			// direction = uvw < 0 and uv or -uv
+			// return direction, a0, a1, b0, b1
+			if uv_w.is_negative(){
+				return Reduce::Reduced(Reduced{
+					dir:uv.narrow_1().unwrap(),
+					simplex:Simplex1_3::Simplex2([v0,v1]),
+				});
+			}else{
+				return Reduce::Reduced(Reduced{
+					dir:-uv.narrow_1().unwrap(),
+					simplex:Simplex1_3::Simplex2([v0,v1]),
+				});
+			}
+		}
+
+		// return direction, a0, a1, b0, b1
+		return Reduce::Reduced(Reduced{
+			dir:direction.narrow_1().unwrap(),
+			simplex:Simplex1_3::Simplex2([v0,v1]),
+		});
+	}
+
+	// local direction = p
+	let dir=p;
+	// if direction.magnitude == 0 then
+	if dir==vec3::zero(){
+		// direction = uvw < 0 and uv or -uv
+		if uv_w.is_negative(){
+			return Reduce::Reduced(Reduced{
+				dir:uv.narrow_1().unwrap(),
+				simplex:Simplex1_3::Simplex1([v0]),
+			});
+		}else{
+			return Reduce::Reduced(Reduced{
+				dir:-uv.narrow_1().unwrap(),
+				simplex:Simplex1_3::Simplex1([v0]),
+			});
+		}
+	}
+
+	// return direction, a0, a1
+	Reduce::Reduced(Reduced{
+		dir,
+		simplex:Simplex1_3::Simplex1([v0]),
+	})
+}
+
+struct Reduced{
+	dir:Planar64Vec3,
+	simplex:Simplex1_3,
+}
+
+enum Reduce{
+	Escape(Simplex<4>),
+	Reduced(Reduced),
+}
+
+impl Simplex2_4{
+	fn reduce(self,mesh:&MinkowskiMesh,point:Planar64Vec3)->Reduce{
+		match self{
+			Self::Simplex2(simplex)=>Reduce::Reduced(reduce2(simplex,mesh,point)),
+			Self::Simplex3(simplex)=>Reduce::Reduced(reduce3(simplex,mesh,point)),
+			Self::Simplex4(simplex)=>reduce4(simplex,mesh,point),
+		}
+	}
+}
+
+// local function expand(
+// 	queryP, queryQ,
+// 	vertA0, vertA1,
+// 	vertB0, vertB1,
+// 	vertC0, vertC1,
+// 	vertD0, vertD1,
+// 	accuracy
+// )
+fn refine_to_exact(mesh:&MinkowskiMesh,simplex:Simplex<4>)->Simplex2_4{
+	unimplemented!()
+}
+
+/// Intermediate data structure containing a partially complete calculation.
+/// Sometimes you only care about the topology, and not about the
+/// exact point of intersection details.
+pub struct Topology{
+	simplex:Simplex2_4,
+}
+impl Topology{
+	/// Returns None if the point is intersecting the mesh.
+	pub fn closest_point_details(self,mesh:&MinkowskiMesh)->Option<Details>{
+		// NOTE: if hits is true, this if statement necessarily evaluates to true.
+		// i.e. hits implies this statement
+		// if -dist <= exitRadius + radiusP + radiusQ then
+		// 	local posP, posQ = decompose(-point, a0, a1, b0, b1, c0, c1)
+		// 	return hits, -dist - radiusP - radiusQ,
+		// 		posP - radiusP*norm, -norm,
+		// 		posQ + radiusQ*norm, norm
+		// end
+		// return false
+		unimplemented!()
+	}
+}
+pub struct Details{
+	// distance:Planar64,
+	// p_pos:Planar64Vec3,
+	// p_norm:Planar64Vec3,
+	// q_pos:Planar64Vec3,
+	// q_norm:Planar64Vec3,
+}
+
+pub fn contains_point(mesh:&MinkowskiMesh,point:Planar64Vec3)->bool{
+	const ENABLE_FAST_FAIL:bool=true;
+	minimum_difference::<ENABLE_FAST_FAIL,_>(mesh,point,
+		// on_exact
+		|last_pos,direction|{
+			// local norm = direction.unit
+			// local dist = a:Dot(norm)
+			// local hits = -dist < radiusP + radiusQ
+			// return hits
+			(last_pos+point).dot(direction).is_positive()
+		},
+		// on_escape
+		|_simplex|{
+			// intersection is guaranteed at this point
+			true
+		},
+		// fast_fail value
+		||false
+	)
+}
+pub fn closest_fev(mesh:&MinkowskiMesh,point:Planar64Vec3)->Topology{
+	const ENABLE_FAST_FAIL:bool=false;
+	minimum_difference::<ENABLE_FAST_FAIL,_>(mesh,point,
+		// on_exact
+		|_last_pos,_direction|unimplemented!(),
+		// on_escape
+		|simplex|{
+			// local norm, dist, u0, u1, v0, v1, w0, w1 = expand(queryP, queryQ, a0, a1, b0, b1, c0, c1, d0, d1, 1e-5)
+			let simplex=refine_to_exact(mesh,simplex);
+			Topology{simplex}
+		},
+		// fast_fail value is irrelevant and will never be returned!
+		||unreachable!()
+	)
+}
+
+// local function minimumDifference(
+// 	queryP, radiusP,
+// 	queryQ, radiusQ,
+// 	exitRadius, testIntersection
+// )
+fn minimum_difference<const ENABLE_FAST_FAIL:bool,T>(
+	mesh:&MinkowskiMesh,
+	point:Planar64Vec3,
+	on_exact:impl FnOnce(Planar64Vec3,Planar64Vec3)->T,
+	on_escape:impl FnOnce(Simplex<4>)->T,
+	on_fast_fail:impl FnOnce()->T,
+)->T{
+	// local initialAxis = queryQ() - queryP()
+	// local new_point_p = queryP(initialAxis)
+	// local new_point_q = queryQ(-initialAxis)
+	// local direction, a0, a1, b0, b1, c0, c1, d0, d1
+	let mut initial_axis=-mesh.hint_point()+point;
+	// degenerate case
+	if initial_axis==vec3::zero(){
+		initial_axis=choose_any_direction();
+	}
+	let last_point=mesh.farthest_vert(direction);
+	// this represents the 'a' value in the commented code
+	let mut last_pos=-mesh.vert(last_point);
+	let Reduced{dir:mut direction,simplex:mut simplex_small}=reduce1([last_point],mesh,point);
+
+	// exitRadius = testIntersection and 0 or exitRadius or 1/0
+	// for _ = 1, 100 do
+	loop{
+		// new_point_p = queryP(-direction)
+		// new_point_q = queryQ(direction)
+		// local next_point = new_point_q - new_point_p
+		let next_point=mesh.farthest_vert(-direction);
+		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(){
+			return on_fast_fail();
+		}
+
+		let simplex_big=simplex_small.push_front(next_point);
+
+		// 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){
+			// Found enough information to compute the exact closest point.
+			return on_exact(last_pos,direction);
+		}
+
+		// direction, a0, a1, b0, b1, c0, c1, d0, d1 = reduceSimplex(new_point_p, new_point_q, a0, a1, b0, b1, c0, c1)
+		match simplex_big.reduce(mesh,point){
+			// if a and b and c and d then
+			Reduce::Escape(simplex)=>{
+				// Enough information to conclude that the meshes are intersecting.
+				// Topology information is computed if needed.
+				return on_escape(simplex);
+			},
+			Reduce::Reduced(reduced)=>{
+				direction=reduced.dir;
+				simplex_small=reduced.simplex;
+			},
+		}
+
+		// next loop this will be a
+		last_pos=next_pos;
+	}
+}

engine/physics/src/minimum_difference_lua.rs

@@ -0,0 +1,159 @@
+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,Details)>{
+	let md=minimum_difference(mesh,point,false)?;
+	Ok((md.hits,md.details.unwrap()))
+}
+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(),
+				}),
+			}),
+			values=>Err(mlua::Error::runtime(format!("Invalid return values: {values:?}"))),
+		}
+	}
+}
+
+struct Args{
+	query_p:Function,
+	radius_p:f64,
+	query_q:Function,
+	radius_q:f64,
+	exit_radius: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;
+		let exit_radius=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,
+			exit_radius,
+			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)?,
+			self.exit_radius.into_lua(lua)?,
+			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("/home/quat/strafesnet/game/src/ReplicatedStorage/Shared/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

@@ -509,7 +509,7 @@ impl TransformedMesh<'_>{
 	pub fn verts<'a>(&'a self)->impl Iterator<Item=Vector3<Fixed<2,64>>>+'a{
 		self.view.data.verts.iter().map(|&Vert(pos)|self.transform.vertex.transform_point3(pos))
 	}
-	fn farthest_vert(&self,dir:Planar64Vec3)->SubmeshVertId{
+	pub fn farthest_vert(&self,dir:Planar64Vec3)->SubmeshVertId{
 		//this happens to be well-defined.  there are no virtual virtices
 		SubmeshVertId::new(
 			self.view.topology.verts.iter()
@@ -567,7 +567,7 @@ impl MeshQuery for TransformedMesh<'_>{
 //(face,vertex)
 //(edge,edge)
 //(vertex,face)
-#[derive(Clone,Copy,Debug)]
+#[derive(Clone,Copy,Debug,Eq,PartialEq)]
 pub enum MinkowskiVert{
 	VertVert(SubmeshVertId,SubmeshVertId),
 }
@@ -586,7 +586,7 @@ impl UndirectedEdge for MinkowskiEdge{
 		}
 	}
 }
-#[derive(Clone,Copy,Debug)]
+#[derive(Clone,Copy,Debug,Eq,PartialEq)]
 pub enum MinkowskiDirectedEdge{
 	VertEdge(SubmeshVertId,SubmeshDirectedEdgeId),
 	EdgeVert(SubmeshDirectedEdgeId,SubmeshVertId),
@@ -619,8 +619,8 @@ pub enum MinkowskiFace{
 
 #[derive(Debug)]
 pub struct MinkowskiMesh<'a>{
-	mesh0:TransformedMesh<'a>,
-	mesh1:TransformedMesh<'a>,
+	pub mesh0:TransformedMesh<'a>,
+	pub mesh1:TransformedMesh<'a>,
 }
 
 //infinity fev algorithm state transition
@@ -647,7 +647,7 @@ impl MinkowskiMesh<'_>{
 			mesh1,
 		}
 	}
-	fn farthest_vert(&self,dir:Planar64Vec3)->MinkowskiVert{
+	pub fn farthest_vert(&self,dir:Planar64Vec3)->MinkowskiVert{
 		MinkowskiVert::VertVert(self.mesh0.farthest_vert(dir),self.mesh1.farthest_vert(-dir))
 	}
 	fn next_transition_vert(&self,vert_id:MinkowskiVert,best_distance_squared:&mut Fixed<2,64>,infinity_dir:Planar64Vec3,point:Planar64Vec3)->Transition{
@@ -810,20 +810,11 @@ impl MinkowskiMesh<'_>{
 		}
 		best_edge
 	}
-	fn infinity_in(&self,infinity_body:Body)->Option<(MinkowskiFace,GigaTime)>{
-		let infinity_fev=self.infinity_fev(-infinity_body.velocity,infinity_body.position);
-		// Bound::Included means that the surface of the mesh is included in the mesh
-		infinity_fev.crawl(self,&infinity_body,Bound::Unbounded,Bound::Included(&infinity_body.time)).hit()
-	}
-	pub fn is_point_in_mesh(&self,point:Planar64Vec3)->bool{
-		let infinity_body=Body::new(point,vec3::Y,vec3::zero(),Time::ZERO);
-		//movement must escape the mesh forwards and backwards in time,
-		//otherwise the point is not inside the mesh
-		self.infinity_in(infinity_body)
-    	.is_some_and(|_|
-			self.infinity_in(-infinity_body)
-    		.is_some()
-     	)
+	pub fn contains_point(&self,point:Planar64Vec3)->bool{
+		let contains_point_lua=crate::minimum_difference_lua::contains_point(self,point).unwrap();
+		let contains_point=crate::minimum_difference::contains_point(self,point);
+		println!("contains_point={contains_point} contains_point_lua={contains_point_lua}");
+		contains_point
 	}
 }
 impl MeshQuery for MinkowskiMesh<'_>{
@@ -863,8 +854,7 @@ impl MeshQuery for MinkowskiMesh<'_>{
 		}
 	}
 	fn hint_point(&self)->Planar64Vec3{
-		self.mesh1.transform.vertex.translation-
-		self.mesh0.transform.vertex.translation
+		self.mesh0.transform.vertex.translation-self.mesh1.transform.vertex.translation
 	}
 	fn face_edges(&self,face_id:MinkowskiFace)->impl AsRef<[MinkowskiDirectedEdge]>{
 		match face_id{

engine/physics/src/physics.rs

@@ -1277,7 +1277,7 @@ fn recalculate_touching(
 		//no checks are needed because of the time limits.
 		let model_mesh=models.mesh(convex_mesh_id);
 		let minkowski=model_physics::MinkowskiMesh::minkowski_sum(model_mesh,hitbox_mesh.transformed_mesh());
-		if minkowski.is_point_in_mesh(body.position){
+		if minkowski.contains_point(body.position){
 			match convex_mesh_id.model_id{
 				//being inside of contact objects is an invalid physics state
 				//but the physics isn't advanced enough to do anything about it yet