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use na::{RealField, Unit};
use ncollide::query::ContactKinematic;
use crate::math::Vector;
use crate::object::{BodyHandle, BodyPartHandle, BodySet, ColliderHandle};
use crate::solver::IntegrationParameters;
/// A generic non-linear position constraint.
pub struct GenericNonlinearConstraint<N: RealField + Copy, Handle: BodyHandle> {
/// The first body affected by the constraint.
pub body1: BodyPartHandle<Handle>,
/// The second body affected by the constraint.
pub body2: Option<BodyPartHandle<Handle>>,
/// Whether this constraint affects the bodies translation or orientation.
pub is_angular: bool,
// FIXME: rename ndofs1?
/// Number of degree of freedom of the first body.
pub dim1: usize,
/// Number of degree of freedom of the second body.
pub dim2: usize,
/// Index of the first entry of the constraint jacobian multiplied by the inverse mass of the first body.
pub wj_id1: usize,
/// Index of the first entry of the constraint jacobian multiplied by the inverse mass of the second body.
pub wj_id2: usize,
/// The target position change this constraint must apply.
pub rhs: N,
/// The scaling parameter of the SOR-prox method.
pub r: N,
}
impl<N: RealField + Copy, Handle: BodyHandle> GenericNonlinearConstraint<N, Handle> {
/// Initialize a new nonlinear constraint.
pub fn new(
body1: BodyPartHandle<Handle>,
body2: Option<BodyPartHandle<Handle>>,
is_angular: bool,
dim1: usize,
dim2: usize,
wj_id1: usize,
wj_id2: usize,
rhs: N,
r: N,
) -> Self {
GenericNonlinearConstraint {
body1,
body2,
is_angular,
dim1,
dim2,
wj_id1,
wj_id2,
rhs,
r,
}
}
}
/// Implemented by structures that generate non-linear constraints.
pub trait NonlinearConstraintGenerator<N: RealField + Copy, Handle: BodyHandle> {
/// Maximum of non-linear position constraint this generator needs to output.
fn num_position_constraints(&self, bodies: &dyn BodySet<N, Handle = Handle>) -> usize;
/// Generate the `i`-th position constraint of this generator.
fn position_constraint(
&self,
parameters: &IntegrationParameters<N>,
i: usize,
bodies: &mut dyn BodySet<N, Handle = Handle>,
jacobians: &mut [N],
) -> Option<GenericNonlinearConstraint<N, Handle>>;
}
/// A non-linear position-based non-penetration constraint.
#[derive(Debug)]
pub struct NonlinearUnilateralConstraint<
N: RealField + Copy,
Handle: BodyHandle,
CollHandle: ColliderHandle,
> {
/// The scaling parameter of the SOR-prox method.
pub r: N,
/// The target position change this constraint must apply.
pub rhs: N,
/// Number of degree of freedom of the first body.
pub ndofs1: usize,
/// The first body affected by the constraint.
pub body1: BodyPartHandle<Handle>,
/// The first collider affected by the constraint.
pub collider1: CollHandle,
/// Number of degree of freedom of the second body.
pub ndofs2: usize,
/// The second body affected by the constraint.
pub body2: BodyPartHandle<Handle>,
/// The second collider affected by the constraint.
pub collider2: CollHandle,
/// The kinematic information used to update the contact location.
pub kinematic: ContactKinematic<N>,
/// The contact normal on the local space of `self.body1`.
pub normal1: Unit<Vector<N>>,
/// The contact normal on the local space of `self.body2`.
pub normal2: Unit<Vector<N>>,
}
impl<N: RealField + Copy, Handle: BodyHandle, CollHandle: ColliderHandle>
NonlinearUnilateralConstraint<N, Handle, CollHandle>
{
/// Create a new nonlinear position-based non-penetration constraint.
pub fn new(
body1: BodyPartHandle<Handle>,
collider1: CollHandle,
ndofs1: usize,
body2: BodyPartHandle<Handle>,
collider2: CollHandle,
ndofs2: usize,
normal1: Unit<Vector<N>>,
normal2: Unit<Vector<N>>,
kinematic: ContactKinematic<N>,
) -> Self {
let r = N::zero();
let rhs = N::zero();
NonlinearUnilateralConstraint {
r,
rhs,
ndofs1,
body1,
collider1,
ndofs2,
body2,
collider2,
kinematic,
normal1,
normal2,
}
}
}
/// A non-linear position constraint generator to enforce multibody joint limits.
pub struct MultibodyJointLimitsNonlinearConstraintGenerator;
impl MultibodyJointLimitsNonlinearConstraintGenerator {
/// Creates the constraint generator from the given multibody link.
pub fn new() -> Self {
MultibodyJointLimitsNonlinearConstraintGenerator
}
}
impl<N: RealField + Copy, Handle: BodyHandle> NonlinearConstraintGenerator<N, Handle>
for MultibodyJointLimitsNonlinearConstraintGenerator
{
fn num_position_constraints(&self, _: &dyn BodySet<N, Handle = Handle>) -> usize {
0
}
fn position_constraint(
&self,
_: &IntegrationParameters<N>,
_: usize,
_: &mut dyn BodySet<N, Handle = Handle>,
_: &mut [N],
) -> Option<GenericNonlinearConstraint<N, Handle>> {
None
}
}