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use super::{AnyJointVelocityConstraint, AnyVelocityConstraint, DeltaVel, ThreadContext};
use crate::dynamics::solver::{
AnyJointPositionConstraint, AnyPositionConstraint, ParallelSolverConstraints,
};
use crate::dynamics::{IntegrationParameters, JointGraphEdge};
use crate::geometry::ContactManifold;
use crate::math::Real;
use std::sync::atomic::Ordering;
pub(crate) struct ParallelVelocitySolver {}
impl ParallelVelocitySolver {
pub fn solve(
thread: &ThreadContext,
params: &IntegrationParameters,
manifolds_all: &mut [&mut ContactManifold],
joints_all: &mut [JointGraphEdge],
mj_lambdas: &mut [DeltaVel<Real>],
contact_constraints: &mut ParallelSolverConstraints<
AnyVelocityConstraint,
AnyPositionConstraint,
>,
joint_constraints: &mut ParallelSolverConstraints<
AnyJointVelocityConstraint,
AnyJointPositionConstraint,
>,
) {
if contact_constraints.constraint_descs.is_empty()
&& joint_constraints.constraint_descs.is_empty()
{
return;
}
/*
* Warmstart constraints.
*/
{
// Each thread will concurrently grab thread.batch_size constraint desc to
// solve. If the batch size is large enough for to cross the boundary of
// a parallel_desc_group, we have to wait util the current group is finished
// before starting the next one.
let mut target_num_desc = 0;
let mut start_index = thread
.warmstart_contact_index
.fetch_add(thread.batch_size, Ordering::SeqCst);
let mut batch_size = thread.batch_size;
let mut shift = 0;
macro_rules! warmstart(
($part: expr) => {
for group in $part.parallel_desc_groups.windows(2) {
let num_descs_in_group = group[1] - group[0];
target_num_desc += num_descs_in_group;
while start_index < group[1] {
let end_index = (start_index + batch_size).min(group[1]);
let constraints = if end_index == $part.constraint_descs.len() {
&mut $part.velocity_constraints[$part.constraint_descs[start_index].0..]
} else {
&mut $part.velocity_constraints[$part.constraint_descs[start_index].0..$part.constraint_descs[end_index].0]
};
for constraint in constraints {
constraint.warmstart(mj_lambdas);
}
let num_solved = end_index - start_index;
batch_size -= num_solved;
thread
.num_warmstarted_contacts
.fetch_add(num_solved, Ordering::SeqCst);
if batch_size == 0 {
start_index = thread
.warmstart_contact_index
.fetch_add(thread.batch_size, Ordering::SeqCst);
start_index -= shift;
batch_size = thread.batch_size;
} else {
start_index += num_solved;
}
}
ThreadContext::lock_until_ge(&thread.num_warmstarted_contacts, target_num_desc);
}
}
);
warmstart!(joint_constraints);
shift = joint_constraints.constraint_descs.len();
start_index -= shift;
warmstart!(contact_constraints);
}
/*
* Solve constraints.
*/
{
// Each thread will concurrently grab thread.batch_size constraint desc to
// solve. If the batch size is large enough for to cross the boundary of
// a parallel_desc_group, we have to wait util the current group is finished
// before starting the next one.
let mut start_index = thread
.solve_interaction_index
.fetch_add(thread.batch_size, Ordering::SeqCst);
let mut batch_size = thread.batch_size;
let contact_descs = &contact_constraints.constraint_descs[..];
let joint_descs = &joint_constraints.constraint_descs[..];
let mut target_num_desc = 0;
let mut shift = 0;
for _ in 0..params.max_velocity_iterations {
macro_rules! solve {
($part: expr) => {
// Joint groups.
for group in $part.parallel_desc_groups.windows(2) {
let num_descs_in_group = group[1] - group[0];
target_num_desc += num_descs_in_group;
while start_index < group[1] {
let end_index = (start_index + batch_size).min(group[1]);
let constraints = if end_index == $part.constraint_descs.len() {
&mut $part.velocity_constraints
[$part.constraint_descs[start_index].0..]
} else {
&mut $part.velocity_constraints[$part.constraint_descs
[start_index]
.0
..$part.constraint_descs[end_index].0]
};
// println!(
// "Solving a constraint {:?}.",
// rayon::current_thread_index()
// );
for constraint in constraints {
constraint.solve(mj_lambdas);
}
let num_solved = end_index - start_index;
batch_size -= num_solved;
thread
.num_solved_interactions
.fetch_add(num_solved, Ordering::SeqCst);
if batch_size == 0 {
start_index = thread
.solve_interaction_index
.fetch_add(thread.batch_size, Ordering::SeqCst);
start_index -= shift;
batch_size = thread.batch_size;
} else {
start_index += num_solved;
}
}
ThreadContext::lock_until_ge(
&thread.num_solved_interactions,
target_num_desc,
);
}
};
}
solve!(joint_constraints);
shift += joint_descs.len();
start_index -= joint_descs.len();
solve!(contact_constraints);
shift += contact_descs.len();
start_index -= contact_descs.len();
}
}
/*
* Writeback impulses.
*/
let joint_constraints = &joint_constraints.velocity_constraints;
let contact_constraints = &contact_constraints.velocity_constraints;
crate::concurrent_loop! {
let batch_size = thread.batch_size;
for constraint in joint_constraints[thread.joint_writeback_index] {
constraint.writeback_impulses(joints_all);
}
}
crate::concurrent_loop! {
let batch_size = thread.batch_size;
for constraint in contact_constraints[thread.impulse_writeback_index] {
constraint.writeback_impulses(manifolds_all);
}
}
}
}