First public release of Rapier.

src/dynamics/solver/position_ground_constraint_wide.rs

@@ -0,0 +1,199 @@
+use super::AnyPositionConstraint;
+use crate::dynamics::{IntegrationParameters, RigidBodySet};
+use crate::geometry::{ContactManifold, KinematicsCategory};
+use crate::math::{
+    AngularInertia, Isometry, Point, Rotation, SimdFloat, Translation, Vector, MAX_MANIFOLD_POINTS,
+    SIMD_WIDTH,
+};
+use crate::utils::{WAngularInertia, WCross, WDot};
+
+use num::Zero;
+use simba::simd::{SimdBool as _, SimdComplexField, SimdPartialOrd, SimdValue};
+
+pub(crate) struct WPositionGroundConstraint {
+    pub rb2: [usize; SIMD_WIDTH],
+    // NOTE: the points are relative to the center of masses.
+    pub p1: [Point<SimdFloat>; MAX_MANIFOLD_POINTS],
+    pub local_p2: [Point<SimdFloat>; MAX_MANIFOLD_POINTS],
+    pub n1: Vector<SimdFloat>,
+    pub radius: SimdFloat,
+    pub im2: SimdFloat,
+    pub ii2: AngularInertia<SimdFloat>,
+    pub erp: SimdFloat,
+    pub max_linear_correction: SimdFloat,
+    pub num_contacts: u8,
+}
+
+impl WPositionGroundConstraint {
+    pub fn generate(
+        params: &IntegrationParameters,
+        manifolds: [&ContactManifold; SIMD_WIDTH],
+        bodies: &RigidBodySet,
+        out_constraints: &mut Vec<AnyPositionConstraint>,
+        push: bool,
+    ) {
+        let mut rbs1 = array![|ii| bodies.get(manifolds[ii].body_pair.body1).unwrap(); SIMD_WIDTH];
+        let mut rbs2 = array![|ii| bodies.get(manifolds[ii].body_pair.body2).unwrap(); SIMD_WIDTH];
+        let mut flipped = [false; SIMD_WIDTH];
+
+        for ii in 0..SIMD_WIDTH {
+            if !rbs2[ii].is_dynamic() {
+                flipped[ii] = true;
+                std::mem::swap(&mut rbs1[ii], &mut rbs2[ii]);
+            }
+        }
+
+        let im2 = SimdFloat::from(array![|ii| rbs2[ii].mass_properties.inv_mass; SIMD_WIDTH]);
+        let sqrt_ii2: AngularInertia<SimdFloat> =
+            AngularInertia::from(array![|ii| rbs2[ii].world_inv_inertia_sqrt; SIMD_WIDTH]);
+
+        let local_n1 = Vector::from(
+            array![|ii| if flipped[ii] { manifolds[ii].local_n2 } else { manifolds[ii].local_n1 }; SIMD_WIDTH],
+        );
+        let local_n2 = Vector::from(
+            array![|ii| if flipped[ii] { manifolds[ii].local_n1 } else { manifolds[ii].local_n2 }; SIMD_WIDTH],
+        );
+
+        let radius1 = SimdFloat::from(array![|ii| manifolds[ii].kinematics.radius1; SIMD_WIDTH]);
+        let radius2 = SimdFloat::from(array![|ii| manifolds[ii].kinematics.radius2; SIMD_WIDTH]);
+
+        let position1 = Isometry::from(array![|ii| rbs1[ii].predicted_position; SIMD_WIDTH]);
+
+        let rb2 = array![|ii| rbs2[ii].active_set_offset; SIMD_WIDTH];
+
+        let radius = radius1 + radius2 /*- SimdFloat::splat(params.allowed_linear_error)*/;
+
+        let n1 = position1 * local_n1;
+
+        for l in (0..manifolds[0].num_active_contacts()).step_by(MAX_MANIFOLD_POINTS) {
+            let manifold_points = array![|ii| &manifolds[ii].active_contacts()[l..]; SIMD_WIDTH];
+            let num_points = manifold_points[0].len().min(MAX_MANIFOLD_POINTS);
+
+            let mut constraint = WPositionGroundConstraint {
+                rb2,
+                p1: [Point::origin(); MAX_MANIFOLD_POINTS],
+                local_p2: [Point::origin(); MAX_MANIFOLD_POINTS],
+                n1,
+                radius,
+                im2,
+                ii2: sqrt_ii2.squared(),
+                erp: SimdFloat::splat(params.erp),
+                max_linear_correction: SimdFloat::splat(params.max_linear_correction),
+                num_contacts: num_points as u8,
+            };
+
+            for i in 0..num_points {
+                let local_p1 = Point::from(
+                    array![|ii| if flipped[ii] { manifold_points[ii][i].local_p2 } else { manifold_points[ii][i].local_p1 }; SIMD_WIDTH],
+                );
+                let local_p2 = Point::from(
+                    array![|ii| if flipped[ii] { manifold_points[ii][i].local_p1 } else { manifold_points[ii][i].local_p2 }; SIMD_WIDTH],
+                );
+
+                constraint.p1[i] = position1 * local_p1 - n1 * radius1;
+                constraint.local_p2[i] = local_p2 - local_n2 * radius2;
+            }
+
+            if push {
+                if manifolds[0].kinematics.category == KinematicsCategory::PointPoint {
+                    out_constraints
+                        .push(AnyPositionConstraint::GroupedPointPointGround(constraint));
+                } else {
+                    out_constraints
+                        .push(AnyPositionConstraint::GroupedPlanePointGround(constraint));
+                }
+            } else {
+                if manifolds[0].kinematics.category == KinematicsCategory::PointPoint {
+                    out_constraints[manifolds[0].constraint_index + l / MAX_MANIFOLD_POINTS] =
+                        AnyPositionConstraint::GroupedPointPointGround(constraint);
+                } else {
+                    out_constraints[manifolds[0].constraint_index + l / MAX_MANIFOLD_POINTS] =
+                        AnyPositionConstraint::GroupedPlanePointGround(constraint);
+                }
+            }
+        }
+    }
+    pub fn solve_point_point(
+        &self,
+        params: &IntegrationParameters,
+        positions: &mut [Isometry<f32>],
+    ) {
+        // FIXME: can we avoid most of the multiplications by pos1/pos2?
+        // Compute jacobians.
+        let mut pos2 = Isometry::from(array![|ii| positions[self.rb2[ii]]; SIMD_WIDTH]);
+        let allowed_err = SimdFloat::splat(params.allowed_linear_error);
+        let target_dist = self.radius - allowed_err;
+
+        for k in 0..self.num_contacts as usize {
+            let p1 = self.p1[k];
+            let p2 = pos2 * self.local_p2[k];
+
+            let dpos = p2 - p1;
+            let sqdist = dpos.norm_squared();
+
+            if sqdist.simd_lt(target_dist * target_dist).any() {
+                let dist = sqdist.simd_sqrt();
+                let n = dpos / dist;
+                let err = ((dist - target_dist) * self.erp)
+                    .simd_clamp(-self.max_linear_correction, SimdFloat::zero());
+                let dp2 = p2.coords - pos2.translation.vector;
+                let gcross2 = -dp2.gcross(n);
+                let ii_gcross2 = self.ii2.transform_vector(gcross2);
+
+                // Compute impulse.
+                let inv_r = self.im2 + gcross2.gdot(ii_gcross2);
+                let impulse = err / inv_r;
+
+                // Apply impulse.
+                pos2.translation = Translation::from(n * (-impulse * self.im2)) * pos2.translation;
+                pos2.rotation = Rotation::new(ii_gcross2 * impulse) * pos2.rotation;
+            }
+        }
+
+        for ii in 0..SIMD_WIDTH {
+            positions[self.rb2[ii]] = pos2.extract(ii);
+        }
+    }
+
+    pub fn solve_plane_point(
+        &self,
+        params: &IntegrationParameters,
+        positions: &mut [Isometry<f32>],
+    ) {
+        // FIXME: can we avoid most of the multiplications by pos1/pos2?
+        // Compute jacobians.
+        let mut pos2 = Isometry::from(array![|ii| positions[self.rb2[ii]]; SIMD_WIDTH]);
+        let allowed_err = SimdFloat::splat(params.allowed_linear_error);
+        let target_dist = self.radius - allowed_err;
+
+        for k in 0..self.num_contacts as usize {
+            let n1 = self.n1;
+            let p1 = self.p1[k];
+            let p2 = pos2 * self.local_p2[k];
+            let dpos = p2 - p1;
+            let dist = dpos.dot(&n1);
+
+            // NOTE: this condition does not seem to be useful perfomancewise?
+            if dist.simd_lt(target_dist).any() {
+                let err = ((dist - target_dist) * self.erp)
+                    .simd_clamp(-self.max_linear_correction, SimdFloat::zero());
+                let dp2 = p2.coords - pos2.translation.vector;
+
+                let gcross2 = -dp2.gcross(n1);
+                let ii_gcross2 = self.ii2.transform_vector(gcross2);
+
+                // Compute impulse.
+                let inv_r = self.im2 + gcross2.gdot(ii_gcross2);
+                let impulse = err / inv_r;
+
+                // Apply impulse.
+                pos2.translation = Translation::from(n1 * (-impulse * self.im2)) * pos2.translation;
+                pos2.rotation = Rotation::new(ii_gcross2 * impulse) * pos2.rotation;
+            }
+        }
+
+        for ii in 0..SIMD_WIDTH {
+            positions[self.rb2[ii]] = pos2.extract(ii);
+        }
+    }
+}