use super::{
AnyVelocityConstraint, DeltaVel, VelocityConstraintElement, VelocityConstraintNormalPart,
};
use crate::data::ComponentSet;
use crate::dynamics::{IntegrationParameters, RigidBodyIds, RigidBodyMassProps, RigidBodyVelocity};
use crate::geometry::{ContactManifold, ContactManifoldIndex};
use crate::math::{
AngVector, AngularInertia, Point, Real, SimdReal, Vector, DIM, MAX_MANIFOLD_POINTS, SIMD_WIDTH,
};
#[cfg(feature = "dim2")]
use crate::utils::WBasis;
use crate::utils::{WAngularInertia, WCross, WDot};
use num::Zero;
use simba::simd::{SimdPartialOrd, SimdValue};
#[derive(Copy, Clone, Debug)]
pub(crate) struct WVelocityConstraint {
pub dir1: Vector<SimdReal>, #[cfg(feature = "dim3")]
pub tangent1: Vector<SimdReal>, pub elements: [VelocityConstraintElement<SimdReal>; MAX_MANIFOLD_POINTS],
pub num_contacts: u8,
pub im1: Vector<SimdReal>,
pub im2: Vector<SimdReal>,
pub limit: SimdReal,
pub mj_lambda1: [usize; SIMD_WIDTH],
pub mj_lambda2: [usize; SIMD_WIDTH],
pub manifold_id: [ContactManifoldIndex; SIMD_WIDTH],
pub manifold_contact_id: [[u8; SIMD_WIDTH]; MAX_MANIFOLD_POINTS],
}
impl WVelocityConstraint {
pub fn generate<Bodies>(
params: &IntegrationParameters,
manifold_id: [ContactManifoldIndex; SIMD_WIDTH],
manifolds: [&ContactManifold; SIMD_WIDTH],
bodies: &Bodies,
out_constraints: &mut Vec<AnyVelocityConstraint>,
push: bool,
) where
Bodies: ComponentSet<RigidBodyIds>
+ ComponentSet<RigidBodyVelocity>
+ ComponentSet<RigidBodyMassProps>,
{
for ii in 0..SIMD_WIDTH {
assert_eq!(manifolds[ii].data.relative_dominance, 0);
}
let inv_dt = SimdReal::splat(params.inv_dt());
let velocity_solve_fraction = SimdReal::splat(params.velocity_solve_fraction);
let erp_inv_dt = SimdReal::splat(params.erp_inv_dt());
let delassus_inv_factor = SimdReal::splat(params.delassus_inv_factor);
let allowed_lin_err = SimdReal::splat(params.allowed_linear_error);
let handles1 = gather![|ii| manifolds[ii].data.rigid_body1.unwrap()];
let handles2 = gather![|ii| manifolds[ii].data.rigid_body2.unwrap()];
let vels1: [&RigidBodyVelocity; SIMD_WIDTH] = gather![|ii| bodies.index(handles1[ii].0)];
let vels2: [&RigidBodyVelocity; SIMD_WIDTH] = gather![|ii| bodies.index(handles2[ii].0)];
let ids1: [&RigidBodyIds; SIMD_WIDTH] = gather![|ii| bodies.index(handles1[ii].0)];
let ids2: [&RigidBodyIds; SIMD_WIDTH] = gather![|ii| bodies.index(handles2[ii].0)];
let mprops1: [&RigidBodyMassProps; SIMD_WIDTH] = gather![|ii| bodies.index(handles1[ii].0)];
let mprops2: [&RigidBodyMassProps; SIMD_WIDTH] = gather![|ii| bodies.index(handles2[ii].0)];
let world_com1 = Point::from(gather![|ii| mprops1[ii].world_com]);
let im1 = Vector::from(gather![|ii| mprops1[ii].effective_inv_mass]);
let ii1: AngularInertia<SimdReal> =
AngularInertia::from(gather![|ii| mprops1[ii].effective_world_inv_inertia_sqrt]);
let linvel1 = Vector::from(gather![|ii| vels1[ii].linvel]);
let angvel1 = AngVector::<SimdReal>::from(gather![|ii| vels1[ii].angvel]);
let world_com2 = Point::from(gather![|ii| mprops2[ii].world_com]);
let im2 = Vector::from(gather![|ii| mprops2[ii].effective_inv_mass]);
let ii2: AngularInertia<SimdReal> =
AngularInertia::from(gather![|ii| mprops2[ii].effective_world_inv_inertia_sqrt]);
let linvel2 = Vector::from(gather![|ii| vels2[ii].linvel]);
let angvel2 = AngVector::<SimdReal>::from(gather![|ii| vels2[ii].angvel]);
let force_dir1 = -Vector::from(gather![|ii| manifolds[ii].data.normal]);
let mj_lambda1 = gather![|ii| ids1[ii].active_set_offset];
let mj_lambda2 = gather![|ii| ids2[ii].active_set_offset];
let num_active_contacts = manifolds[0].data.num_active_contacts();
#[cfg(feature = "dim2")]
let tangents1 = force_dir1.orthonormal_basis();
#[cfg(feature = "dim3")]
let tangents1 = super::compute_tangent_contact_directions(&force_dir1, &linvel1, &linvel2);
for l in (0..num_active_contacts).step_by(MAX_MANIFOLD_POINTS) {
let manifold_points =
gather![|ii| &manifolds[ii].data.solver_contacts[l..num_active_contacts]];
let num_points = manifold_points[0].len().min(MAX_MANIFOLD_POINTS);
let mut constraint = WVelocityConstraint {
dir1: force_dir1,
#[cfg(feature = "dim3")]
tangent1: tangents1[0],
elements: [VelocityConstraintElement::zero(); MAX_MANIFOLD_POINTS],
im1,
im2,
limit: SimdReal::splat(0.0),
mj_lambda1,
mj_lambda2,
manifold_id,
manifold_contact_id: [[0; SIMD_WIDTH]; MAX_MANIFOLD_POINTS],
num_contacts: num_points as u8,
};
for k in 0..num_points {
let friction = SimdReal::from(gather![|ii| manifold_points[ii][k].friction]);
let restitution = SimdReal::from(gather![|ii| manifold_points[ii][k].restitution]);
let is_bouncy = SimdReal::from(gather![
|ii| manifold_points[ii][k].is_bouncy() as u32 as Real
]);
let is_resting = SimdReal::splat(1.0) - is_bouncy;
let point = Point::from(gather![|ii| manifold_points[ii][k].point]);
let dist = SimdReal::from(gather![|ii| manifold_points[ii][k].dist]);
let tangent_velocity =
Vector::from(gather![|ii| manifold_points[ii][k].tangent_velocity]);
let dp1 = point - world_com1;
let dp2 = point - world_com2;
let vel1 = linvel1 + angvel1.gcross(dp1);
let vel2 = linvel2 + angvel2.gcross(dp2);
constraint.limit = friction;
constraint.manifold_contact_id[k] = gather![|ii| manifold_points[ii][k].contact_id];
{
let gcross1 = ii1.transform_vector(dp1.gcross(force_dir1));
let gcross2 = ii2.transform_vector(dp2.gcross(-force_dir1));
let imsum = im1 + im2;
let r = delassus_inv_factor
/ (force_dir1.dot(&imsum.component_mul(&force_dir1))
+ gcross1.gdot(gcross1)
+ gcross2.gdot(gcross2));
let projected_velocity = (vel1 - vel2).dot(&force_dir1);
let mut rhs_wo_bias =
(SimdReal::splat(1.0) + is_bouncy * restitution) * projected_velocity;
rhs_wo_bias += dist.simd_max(SimdReal::zero()) * inv_dt;
rhs_wo_bias *= is_bouncy + is_resting * velocity_solve_fraction;
let rhs_bias = (dist + allowed_lin_err).simd_min(SimdReal::zero())
* (erp_inv_dt);
constraint.elements[k].normal_part = VelocityConstraintNormalPart {
gcross1,
gcross2,
rhs: rhs_wo_bias + rhs_bias,
rhs_wo_bias,
impulse: na::zero(),
r,
};
}
constraint.elements[k].tangent_part.impulse = na::zero();
for j in 0..DIM - 1 {
let gcross1 = ii1.transform_vector(dp1.gcross(tangents1[j]));
let gcross2 = ii2.transform_vector(dp2.gcross(-tangents1[j]));
let imsum = im1 + im2;
let r = tangents1[j].dot(&imsum.component_mul(&tangents1[j]))
+ gcross1.gdot(gcross1)
+ gcross2.gdot(gcross2);
let rhs = (vel1 - vel2 + tangent_velocity).dot(&tangents1[j]);
constraint.elements[k].tangent_part.gcross1[j] = gcross1;
constraint.elements[k].tangent_part.gcross2[j] = gcross2;
constraint.elements[k].tangent_part.rhs[j] = rhs;
constraint.elements[k].tangent_part.r[j] = if cfg!(feature = "dim2") {
SimdReal::splat(1.0) / r
} else {
r
};
}
#[cfg(feature = "dim3")]
{
constraint.elements[k].tangent_part.r[2] = SimdReal::splat(2.0)
* (constraint.elements[k].tangent_part.gcross1[0]
.gdot(constraint.elements[k].tangent_part.gcross1[1])
+ constraint.elements[k].tangent_part.gcross2[0]
.gdot(constraint.elements[k].tangent_part.gcross2[1]));
}
}
if push {
out_constraints.push(AnyVelocityConstraint::Grouped(constraint));
} else {
out_constraints[manifolds[0].data.constraint_index + l / MAX_MANIFOLD_POINTS] =
AnyVelocityConstraint::Grouped(constraint);
}
}
}
pub fn solve(
&mut self,
mj_lambdas: &mut [DeltaVel<Real>],
solve_normal: bool,
solve_friction: bool,
) {
let mut mj_lambda1 = DeltaVel {
linear: Vector::from(gather![|ii| mj_lambdas[self.mj_lambda1[ii] as usize].linear]),
angular: AngVector::from(gather![
|ii| mj_lambdas[self.mj_lambda1[ii] as usize].angular
]),
};
let mut mj_lambda2 = DeltaVel {
linear: Vector::from(gather![|ii| mj_lambdas[self.mj_lambda2[ii] as usize].linear]),
angular: AngVector::from(gather![
|ii| mj_lambdas[self.mj_lambda2[ii] as usize].angular
]),
};
VelocityConstraintElement::solve_group(
&mut self.elements[..self.num_contacts as usize],
&self.dir1,
#[cfg(feature = "dim3")]
&self.tangent1,
&self.im1,
&self.im2,
self.limit,
&mut mj_lambda1,
&mut mj_lambda2,
solve_normal,
solve_friction,
);
for ii in 0..SIMD_WIDTH {
mj_lambdas[self.mj_lambda1[ii] as usize].linear = mj_lambda1.linear.extract(ii);
mj_lambdas[self.mj_lambda1[ii] as usize].angular = mj_lambda1.angular.extract(ii);
}
for ii in 0..SIMD_WIDTH {
mj_lambdas[self.mj_lambda2[ii] as usize].linear = mj_lambda2.linear.extract(ii);
mj_lambdas[self.mj_lambda2[ii] as usize].angular = mj_lambda2.angular.extract(ii);
}
}
pub fn writeback_impulses(&self, manifolds_all: &mut [&mut ContactManifold]) {
for k in 0..self.num_contacts as usize {
let impulses: [_; SIMD_WIDTH] = self.elements[k].normal_part.impulse.into();
#[cfg(feature = "dim2")]
let tangent_impulses: [_; SIMD_WIDTH] = self.elements[k].tangent_part.impulse[0].into();
#[cfg(feature = "dim3")]
let tangent_impulses = self.elements[k].tangent_part.impulse;
for ii in 0..SIMD_WIDTH {
let manifold = &mut manifolds_all[self.manifold_id[ii]];
let contact_id = self.manifold_contact_id[k][ii];
let active_contact = &mut manifold.points[contact_id as usize];
active_contact.data.impulse = impulses[ii];
#[cfg(feature = "dim2")]
{
active_contact.data.tangent_impulse = tangent_impulses[ii];
}
#[cfg(feature = "dim3")]
{
active_contact.data.tangent_impulse = tangent_impulses.extract(ii);
}
}
}
}
pub fn remove_bias_from_rhs(&mut self) {
for elt in &mut self.elements {
elt.normal_part.rhs = elt.normal_part.rhs_wo_bias;
}
}
}