feat: implement new "small-steps" solver + joint improvements

1 files changed, 0 insertions, 378 deletions

diff --git a/src/dynamics/solver/generic_velocity_constraint.rs b/src/dynamics/solver/generic_velocity_constraint.rs
deleted file mode 100644
index ed8c569..0000000
--- a/src/dynamics/solver/generic_velocity_constraint.rs
+++ /dev/null
@@ -1,378 +0,0 @@
-use crate::dynamics::solver::{GenericRhs, VelocityConstraint};
-use crate::dynamics::{IntegrationParameters, MultibodyJointSet, RigidBodySet};
-use crate::geometry::{ContactManifold, ContactManifoldIndex};
-use crate::math::{Real, DIM, MAX_MANIFOLD_POINTS};
-use crate::utils::{WAngularInertia, WCross, WDot};
-
-use super::{
-    AnyVelocityConstraint, DeltaVel, VelocityConstraintElement, VelocityConstraintNormalPart,
-};
-#[cfg(feature = "dim2")]
-use crate::utils::WBasis;
-use na::DVector;
-
-#[derive(Copy, Clone, Debug)]
-pub(crate) struct GenericVelocityConstraint {
-    // We just build the generic constraint on top of the velocity constraint,
-    // adding some information we can use in the generic case.
-    pub velocity_constraint: VelocityConstraint,
-    pub j_id: usize,
-    pub ndofs1: usize,
-    pub ndofs2: usize,
-    pub generic_constraint_mask: u8,
-}
-
-impl GenericVelocityConstraint {
-    pub fn generate(
-        params: &IntegrationParameters,
-        manifold_id: ContactManifoldIndex,
-        manifold: &ContactManifold,
-        bodies: &RigidBodySet,
-        multibodies: &MultibodyJointSet,
-        out_constraints: &mut Vec<AnyVelocityConstraint>,
-        jacobians: &mut DVector<Real>,
-        jacobian_id: &mut usize,
-        insert_at: Option<usize>,
-    ) {
-        let cfm_factor = params.cfm_factor();
-        let inv_dt = params.inv_dt();
-        let erp_inv_dt = params.erp_inv_dt();
-
-        let handle1 = manifold.data.rigid_body1.unwrap();
-        let handle2 = manifold.data.rigid_body2.unwrap();
-
-        let rb1 = &bodies[handle1];
-        let rb2 = &bodies[handle2];
-
-        let (vels1, mprops1, type1) = (&rb1.vels, &rb1.mprops, &rb1.body_type);
-        let (vels2, mprops2, type2) = (&rb2.vels, &rb2.mprops, &rb2.body_type);
-        let ccd_thickness = rb1.ccd.ccd_thickness + rb2.ccd.ccd_thickness;
-
-        let multibody1 = multibodies
-            .rigid_body_link(handle1)
-            .map(|m| (&multibodies[m.multibody], m.id));
-        let multibody2 = multibodies
-            .rigid_body_link(handle2)
-            .map(|m| (&multibodies[m.multibody], m.id));
-        let mj_lambda1 = multibody1
-            .map(|mb| mb.0.solver_id)
-            .unwrap_or(if type1.is_dynamic() {
-                rb1.ids.active_set_offset
-            } else {
-                0
-            });
-        let mj_lambda2 = multibody2
-            .map(|mb| mb.0.solver_id)
-            .unwrap_or(if type2.is_dynamic() {
-                rb2.ids.active_set_offset
-            } else {
-                0
-            });
-        let force_dir1 = -manifold.data.normal;
-
-        #[cfg(feature = "dim2")]
-        let tangents1 = force_dir1.orthonormal_basis();
-        #[cfg(feature = "dim3")]
-        let tangents1 =
-            super::compute_tangent_contact_directions(&force_dir1, &vels1.linvel, &vels2.linvel);
-
-        let multibodies_ndof = multibody1.map(|m| m.0.ndofs()).unwrap_or(0)
-            + multibody2.map(|m| m.0.ndofs()).unwrap_or(0);
-        // For each solver contact we generate DIM constraints, and each constraints appends
-        // the multibodies jacobian and weighted jacobians
-        let required_jacobian_len =
-            *jacobian_id + manifold.data.solver_contacts.len() * multibodies_ndof * 2 * DIM;
-
-        if jacobians.nrows() < required_jacobian_len && !cfg!(feature = "parallel") {
-            jacobians.resize_vertically_mut(required_jacobian_len, 0.0);
-        }
-
-        for (_l, manifold_points) in manifold
-            .data
-            .solver_contacts
-            .chunks(MAX_MANIFOLD_POINTS)
-            .enumerate()
-        {
-            let chunk_j_id = *jacobian_id;
-            let mut is_fast_contact = false;
-            let mut constraint = VelocityConstraint {
-                dir1: force_dir1,
-                #[cfg(feature = "dim3")]
-                tangent1: tangents1[0],
-                elements: [VelocityConstraintElement::zero(); MAX_MANIFOLD_POINTS],
-                im1: if type1.is_dynamic() {
-                    mprops1.effective_inv_mass
-                } else {
-                    na::zero()
-                },
-                im2: if type2.is_dynamic() {
-                    mprops2.effective_inv_mass
-                } else {
-                    na::zero()
-                },
-                cfm_factor,
-                limit: 0.0,
-                mj_lambda1,
-                mj_lambda2,
-                manifold_id,
-                manifold_contact_id: [0; MAX_MANIFOLD_POINTS],
-                num_contacts: manifold_points.len() as u8,
-            };
-
-            for k in 0..manifold_points.len() {
-                let manifold_point = &manifold_points[k];
-                let dp1 = manifold_point.point - mprops1.world_com;
-                let dp2 = manifold_point.point - mprops2.world_com;
-
-                let vel1 = vels1.linvel + vels1.angvel.gcross(dp1);
-                let vel2 = vels2.linvel + vels2.angvel.gcross(dp2);
-
-                constraint.limit = manifold_point.friction;
-                constraint.manifold_contact_id[k] = manifold_point.contact_id;
-
-                // Normal part.
-                {
-                    let torque_dir1 = dp1.gcross(force_dir1);
-                    let torque_dir2 = dp2.gcross(-force_dir1);
-
-                    let gcross1 = if type1.is_dynamic() {
-                        mprops1
-                            .effective_world_inv_inertia_sqrt
-                            .transform_vector(torque_dir1)
-                    } else {
-                        na::zero()
-                    };
-                    let gcross2 = if type2.is_dynamic() {
-                        mprops2
-                            .effective_world_inv_inertia_sqrt
-                            .transform_vector(torque_dir2)
-                    } else {
-                        na::zero()
-                    };
-
-                    let inv_r1 = if let Some((mb1, link_id1)) = multibody1.as_ref() {
-                        mb1.fill_jacobians(
-                            *link_id1,
-                            force_dir1,
-                            #[cfg(feature = "dim2")]
-                            na::vector!(torque_dir1),
-                            #[cfg(feature = "dim3")]
-                            torque_dir1,
-                            jacobian_id,
-                            jacobians,
-                        )
-                        .0
-                    } else if type1.is_dynamic() {
-                        force_dir1.dot(&mprops1.effective_inv_mass.component_mul(&force_dir1))
-                            + gcross1.gdot(gcross1)
-                    } else {
-                        0.0
-                    };
-
-                    let inv_r2 = if let Some((mb2, link_id2)) = multibody2.as_ref() {
-                        mb2.fill_jacobians(
-                            *link_id2,
-                            -force_dir1,
-                            #[cfg(feature = "dim2")]
-                            na::vector!(torque_dir2),
-                            #[cfg(feature = "dim3")]
-                            torque_dir2,
-                            jacobian_id,
-                            jacobians,
-                        )
-                        .0
-                    } else if type2.is_dynamic() {
-                        force_dir1.dot(&mprops2.effective_inv_mass.component_mul(&force_dir1))
-                            + gcross2.gdot(gcross2)
-                    } else {
-                        0.0
-                    };
-
-                    let r = crate::utils::inv(inv_r1 + inv_r2);
-
-                    let is_bouncy = manifold_point.is_bouncy() as u32 as Real;
-                    let is_resting = 1.0 - is_bouncy;
-
-                    let mut rhs_wo_bias = (1.0 + is_bouncy * manifold_point.restitution)
-                        * (vel1 - vel2).dot(&force_dir1);
-                    rhs_wo_bias += manifold_point.dist.max(0.0) * inv_dt;
-                    rhs_wo_bias *= is_bouncy + is_resting;
-                    let rhs_bias =
-                        /* is_resting * */ erp_inv_dt * manifold_point.dist.clamp(-params.max_penetration_correction, 0.0);
-
-                    let rhs = rhs_wo_bias + rhs_bias;
-                    is_fast_contact = is_fast_contact || (-rhs * params.dt > ccd_thickness * 0.5);
-
-                    constraint.elements[k].normal_part = VelocityConstraintNormalPart {
-                        gcross1,
-                        gcross2,
-                        rhs,
-                        rhs_wo_bias,
-                        impulse: na::zero(),
-                        r,
-                    };
-                }
-
-                // Tangent parts.
-                {
-                    constraint.elements[k].tangent_part.impulse = na::zero();
-
-                    for j in 0..DIM - 1 {
-                        let torque_dir1 = dp1.gcross(tangents1[j]);
-                        let gcross1 = if type1.is_dynamic() {
-                            mprops1
-                                .effective_world_inv_inertia_sqrt
-                                .transform_vector(torque_dir1)
-                        } else {
-                            na::zero()
-                        };
-                        constraint.elements[k].tangent_part.gcross1[j] = gcross1;
-
-                        let torque_dir2 = dp2.gcross(-tangents1[j]);
-                        let gcross2 = if type2.is_dynamic() {
-                            mprops2
-                                .effective_world_inv_inertia_sqrt
-                                .transform_vector(torque_dir2)
-                        } else {
-                            na::zero()
-                        };
-                        constraint.elements[k].tangent_part.gcross2[j] = gcross2;
-
-                        let inv_r1 = if let Some((mb1, link_id1)) = multibody1.as_ref() {
-                            mb1.fill_jacobians(
-                                *link_id1,
-                                tangents1[j],
-                                #[cfg(feature = "dim2")]
-                                na::vector![torque_dir1],
-                                #[cfg(feature = "dim3")]
-                                torque_dir1,
-                                jacobian_id,
-                                jacobians,
-                            )
-                            .0
-                        } else if type1.is_dynamic() {
-                            force_dir1.dot(&mprops1.effective_inv_mass.component_mul(&force_dir1))
-                                + gcross1.gdot(gcross1)
-                        } else {
-                            0.0
-                        };
-
-                        let inv_r2 = if let Some((mb2, link_id2)) = multibody2.as_ref() {
-                            mb2.fill_jacobians(
-                                *link_id2,
-                                -tangents1[j],
-                                #[cfg(feature = "dim2")]
-                                na::vector![torque_dir2],
-                                #[cfg(feature = "dim3")]
-                                torque_dir2,
-                                jacobian_id,
-                                jacobians,
-                            )
-                            .0
-                        } else if type2.is_dynamic() {
-                            force_dir1.dot(&mprops2.effective_inv_mass.component_mul(&force_dir1))
-                                + gcross2.gdot(gcross2)
-                        } else {
-                            0.0
-                        };
-
-                        let r = crate::utils::inv(inv_r1 + inv_r2);
-
-                        let rhs =
-                            (vel1 - vel2 + manifold_point.tangent_velocity).dot(&tangents1[j]);
-
-                        constraint.elements[k].tangent_part.rhs[j] = rhs;
-                        // FIXME: in 3D, we should take into account gcross[0].dot(gcross[1])
-                        // in lhs. See the corresponding code on the `velocity_constraint.rs`
-                        // file.
-                        constraint.elements[k].tangent_part.r[j] = r;
-                    }
-                }
-            }
-
-            constraint.cfm_factor = if is_fast_contact { 1.0 } else { cfm_factor };
-
-            let ndofs1 = multibody1.map(|mb| mb.0.ndofs()).unwrap_or(0);
-            let ndofs2 = multibody2.map(|mb| mb.0.ndofs()).unwrap_or(0);
-            // NOTE: we use the generic constraint for non-dynamic bodies because this will
-            //       reduce all ops to nothing because its ndofs will be zero.
-            let generic_constraint_mask = (multibody1.is_some() as u8)
-                | ((multibody2.is_some() as u8) << 1)
-                | (!type1.is_dynamic() as u8)
-                | ((!type2.is_dynamic() as u8) << 1);
-
-            let constraint = GenericVelocityConstraint {
-                velocity_constraint: constraint,
-                j_id: chunk_j_id,
-                ndofs1,
-                ndofs2,
-                generic_constraint_mask,
-            };
-
-            if let Some(at) = insert_at {
-                out_constraints[at + _l] = AnyVelocityConstraint::NongroupedGeneric(constraint);
-            } else {
-                out_constraints.push(AnyVelocityConstraint::NongroupedGeneric(constraint));
-            }
-        }
-    }
-
-    pub fn solve(
-        &mut self,
-        jacobians: &DVector<Real>,
-        mj_lambdas: &mut [DeltaVel<Real>],
-        generic_mj_lambdas: &mut DVector<Real>,
-        solve_restitution: bool,
-        solve_friction: bool,
-    ) {
-        let mut mj_lambda1 = if self.generic_constraint_mask & 0b01 == 0 {
-            GenericRhs::DeltaVel(mj_lambdas[self.velocity_constraint.mj_lambda1 as usize])
-        } else {
-            GenericRhs::GenericId(self.velocity_constraint.mj_lambda1 as usize)
-        };
-
-        let mut mj_lambda2 = if self.generic_constraint_mask & 0b10 == 0 {
-            GenericRhs::DeltaVel(mj_lambdas[self.velocity_constraint.mj_lambda2 as usize])
-        } else {
-            GenericRhs::GenericId(self.velocity_constraint.mj_lambda2 as usize)
-        };
-
-        let elements = &mut self.velocity_constraint.elements
-            [..self.velocity_constraint.num_contacts as usize];
-        VelocityConstraintElement::generic_solve_group(
-            self.velocity_constraint.cfm_factor,
-            elements,
-            jacobians,
-            &self.velocity_constraint.dir1,
-            #[cfg(feature = "dim3")]
-            &self.velocity_constraint.tangent1,
-            &self.velocity_constraint.im1,
-            &self.velocity_constraint.im2,
-            self.velocity_constraint.limit,
-            self.ndofs1,
-            self.ndofs2,
-            self.j_id,
-            &mut mj_lambda1,
-            &mut mj_lambda2,
-            generic_mj_lambdas,
-            solve_restitution,
-            solve_friction,
-        );
-
-        if let GenericRhs::DeltaVel(mj_lambda1) = mj_lambda1 {
-            mj_lambdas[self.velocity_constraint.mj_lambda1 as usize] = mj_lambda1;
-        }
-
-        if let GenericRhs::DeltaVel(mj_lambda2) = mj_lambda2 {
-            mj_lambdas[self.velocity_constraint.mj_lambda2 as usize] = mj_lambda2;
-        }
-    }
-
-    pub fn writeback_impulses(&self, manifolds_all: &mut [&mut ContactManifold]) {
-        self.velocity_constraint.writeback_impulses(manifolds_all);
-    }
-
-    pub fn remove_cfm_and_bias_from_rhs(&mut self) {
-        self.velocity_constraint.remove_cfm_and_bias_from_rhs();
-    }
-}