box3d_rust/joint/
types.rs

1// Port of the joint data model from box3d-cpp-reference/src/joint.h.
2// Lifecycle and plumbing from joint.c; per-type solve in sibling modules.
3//
4// SPDX-FileCopyrightText: 2025 Erin Catto
5// SPDX-License-Identifier: MIT
6
7use crate::core::NULL_INDEX;
8use crate::math_functions::{
9    Matrix3, Quat, Transform, Vec2, Vec3, MAT3_ZERO, QUAT_IDENTITY, TRANSFORM_IDENTITY, VEC2_ZERO,
10    VEC3_ZERO,
11};
12use crate::solver::Softness;
13
14/// Joint type enumeration. (types.h: b3JointType)
15#[derive(Debug, Clone, Copy, PartialEq, Eq, Default)]
16#[repr(i32)]
17pub enum JointType {
18    #[default]
19    Parallel = 0,
20    Distance = 1,
21    Filter = 2,
22    Motor = 3,
23    Prismatic = 4,
24    Revolute = 5,
25    Spherical = 6,
26    Weld = 7,
27    Wheel = 8,
28}
29
30/// A joint edge connects bodies and joints in a joint graph. (b3JointEdge)
31#[derive(Debug, Clone, Copy, PartialEq, Eq)]
32pub struct JointEdge {
33    pub body_id: i32,
34    pub prev_key: i32,
35    pub next_key: i32,
36}
37
38impl Default for JointEdge {
39    fn default() -> Self {
40        JointEdge {
41            body_id: NULL_INDEX,
42            prev_key: NULL_INDEX,
43            next_key: NULL_INDEX,
44        }
45    }
46}
47
48/// Map from JointId to joint data in the solver sets. (b3Joint)
49#[derive(Debug, Clone)]
50pub struct Joint {
51    pub user_data: u64,
52
53    /// Index of simulation set stored in World. NULL_INDEX when slot is free.
54    pub set_index: i32,
55
56    /// Index into the constraint graph color array; may be NULL_INDEX for
57    /// sleeping/disabled joints. NULL_INDEX when slot is free.
58    pub color_index: i32,
59
60    /// Joint index within set or graph color. NULL_INDEX when slot is free.
61    pub local_index: i32,
62
63    pub edges: [JointEdge; 2],
64
65    pub joint_id: i32,
66    pub island_id: i32,
67
68    /// Index into the island's joints array for O(1) swap-removal.
69    /// NULL_INDEX when not in an island.
70    pub island_index: i32,
71
72    pub draw_scale: f32,
73
74    pub type_: JointType,
75
76    /// Monotonically advanced when a joint is allocated in this slot.
77    pub generation: u16,
78
79    pub collide_connected: bool,
80}
81
82impl Default for Joint {
83    fn default() -> Self {
84        Joint {
85            user_data: 0,
86            set_index: NULL_INDEX,
87            color_index: NULL_INDEX,
88            local_index: NULL_INDEX,
89            edges: [JointEdge::default(); 2],
90            joint_id: NULL_INDEX,
91            island_id: NULL_INDEX,
92            island_index: NULL_INDEX,
93            draw_scale: 1.0,
94            type_: JointType::Distance,
95            generation: 0,
96            collide_connected: false,
97        }
98    }
99}
100
101/// (b3DistanceJoint)
102#[derive(Debug, Clone, Copy, PartialEq, Default)]
103pub struct DistanceJoint {
104    pub length: f32,
105    pub hertz: f32,
106    pub damping_ratio: f32,
107    pub lower_spring_force: f32,
108    pub upper_spring_force: f32,
109    pub min_length: f32,
110    pub max_length: f32,
111
112    pub max_motor_force: f32,
113    pub motor_speed: f32,
114
115    pub impulse: f32,
116    pub lower_impulse: f32,
117    pub upper_impulse: f32,
118    pub motor_impulse: f32,
119
120    pub index_a: i32,
121    pub index_b: i32,
122    pub anchor_a: Vec3,
123    pub anchor_b: Vec3,
124    pub delta_center: Vec3,
125    pub distance_softness: Softness,
126    pub axial_mass: f32,
127
128    pub enable_spring: bool,
129    pub enable_limit: bool,
130    pub enable_motor: bool,
131}
132
133/// (b3MotorJoint)
134#[derive(Debug, Clone, Copy, PartialEq)]
135pub struct MotorJoint {
136    pub linear_velocity: Vec3,
137    pub angular_velocity: Vec3,
138    pub max_velocity_force: f32,
139    pub max_velocity_torque: f32,
140    pub linear_hertz: f32,
141    pub linear_damping_ratio: f32,
142    pub max_spring_force: f32,
143    pub angular_hertz: f32,
144    pub angular_damping_ratio: f32,
145    pub max_spring_torque: f32,
146
147    pub linear_velocity_impulse: Vec3,
148    pub angular_velocity_impulse: Vec3,
149    pub linear_spring_impulse: Vec3,
150    pub angular_spring_impulse: Vec3,
151
152    pub linear_spring: Softness,
153    pub angular_spring: Softness,
154
155    pub index_a: i32,
156    pub index_b: i32,
157    pub frame_a: Transform,
158    pub frame_b: Transform,
159    pub delta_center: Vec3,
160    pub angular_mass: Matrix3,
161}
162
163impl Default for MotorJoint {
164    fn default() -> Self {
165        MotorJoint {
166            linear_velocity: VEC3_ZERO,
167            angular_velocity: VEC3_ZERO,
168            max_velocity_force: 0.0,
169            max_velocity_torque: 0.0,
170            linear_hertz: 0.0,
171            linear_damping_ratio: 0.0,
172            max_spring_force: 0.0,
173            angular_hertz: 0.0,
174            angular_damping_ratio: 0.0,
175            max_spring_torque: 0.0,
176            linear_velocity_impulse: VEC3_ZERO,
177            angular_velocity_impulse: VEC3_ZERO,
178            linear_spring_impulse: VEC3_ZERO,
179            angular_spring_impulse: VEC3_ZERO,
180            linear_spring: Softness::default(),
181            angular_spring: Softness::default(),
182            index_a: NULL_INDEX,
183            index_b: NULL_INDEX,
184            frame_a: TRANSFORM_IDENTITY,
185            frame_b: TRANSFORM_IDENTITY,
186            delta_center: VEC3_ZERO,
187            angular_mass: MAT3_ZERO,
188        }
189    }
190}
191
192/// (b3ParallelJoint)
193#[derive(Debug, Clone, Copy, PartialEq)]
194pub struct ParallelJoint {
195    pub hertz: f32,
196    pub damping_ratio: f32,
197    pub max_torque: f32,
198
199    pub perp_impulse: Vec2,
200    pub perp_axis_x: Vec3,
201    pub perp_axis_y: Vec3,
202
203    pub quat_a: Quat,
204    pub quat_b: Quat,
205    pub index_a: i32,
206    pub index_b: i32,
207    pub softness: Softness,
208}
209
210impl Default for ParallelJoint {
211    fn default() -> Self {
212        ParallelJoint {
213            hertz: 0.0,
214            damping_ratio: 0.0,
215            max_torque: 0.0,
216            perp_impulse: VEC2_ZERO,
217            perp_axis_x: VEC3_ZERO,
218            perp_axis_y: VEC3_ZERO,
219            quat_a: QUAT_IDENTITY,
220            quat_b: QUAT_IDENTITY,
221            index_a: NULL_INDEX,
222            index_b: NULL_INDEX,
223            softness: Softness::default(),
224        }
225    }
226}
227
228/// (b3PrismaticJoint)
229#[derive(Debug, Clone, Copy, PartialEq)]
230pub struct PrismaticJoint {
231    pub perp_impulse: Vec2,
232    pub angular_impulse: Vec3,
233    pub spring_impulse: f32,
234    pub motor_impulse: f32,
235    pub lower_impulse: f32,
236    pub upper_impulse: f32,
237    pub hertz: f32,
238    pub damping_ratio: f32,
239    pub max_motor_force: f32,
240    pub motor_speed: f32,
241    pub target_translation: f32,
242    pub lower_translation: f32,
243    pub upper_translation: f32,
244
245    pub index_a: i32,
246    pub index_b: i32,
247    pub frame_a: Transform,
248    pub frame_b: Transform,
249    pub joint_axis: Vec3,
250    pub perp_axis_y: Vec3,
251    pub perp_axis_z: Vec3,
252    pub delta_center: Vec3,
253    pub delta_angle: f32,
254    pub rotation_mass: Matrix3,
255    pub spring_softness: Softness,
256
257    pub enable_spring: bool,
258    pub enable_limit: bool,
259    pub enable_motor: bool,
260}
261
262impl Default for PrismaticJoint {
263    fn default() -> Self {
264        PrismaticJoint {
265            perp_impulse: VEC2_ZERO,
266            angular_impulse: VEC3_ZERO,
267            spring_impulse: 0.0,
268            motor_impulse: 0.0,
269            lower_impulse: 0.0,
270            upper_impulse: 0.0,
271            hertz: 0.0,
272            damping_ratio: 0.0,
273            max_motor_force: 0.0,
274            motor_speed: 0.0,
275            target_translation: 0.0,
276            lower_translation: 0.0,
277            upper_translation: 0.0,
278            index_a: NULL_INDEX,
279            index_b: NULL_INDEX,
280            frame_a: TRANSFORM_IDENTITY,
281            frame_b: TRANSFORM_IDENTITY,
282            joint_axis: VEC3_ZERO,
283            perp_axis_y: VEC3_ZERO,
284            perp_axis_z: VEC3_ZERO,
285            delta_center: VEC3_ZERO,
286            delta_angle: 0.0,
287            rotation_mass: MAT3_ZERO,
288            spring_softness: Softness::default(),
289            enable_spring: false,
290            enable_limit: false,
291            enable_motor: false,
292        }
293    }
294}
295
296/// (b3RevoluteJoint)
297#[derive(Debug, Clone, Copy, PartialEq)]
298pub struct RevoluteJoint {
299    pub linear_impulse: Vec3,
300    pub perp_impulse: Vec2,
301    pub spring_impulse: f32,
302    pub motor_impulse: f32,
303    pub lower_impulse: f32,
304    pub upper_impulse: f32,
305    pub hertz: f32,
306    pub damping_ratio: f32,
307    pub max_motor_torque: f32,
308    pub motor_speed: f32,
309    pub target_angle: f32,
310    pub lower_angle: f32,
311    pub upper_angle: f32,
312
313    pub index_a: i32,
314    pub index_b: i32,
315    pub frame_a: Transform,
316    pub frame_b: Transform,
317    pub rotation_axis_z: Vec3,
318    pub perp_axis_x: Vec3,
319    pub perp_axis_y: Vec3,
320    pub delta_center: Vec3,
321    pub delta_angle: f32,
322    pub axial_mass: f32,
323    pub spring_softness: Softness,
324
325    pub enable_spring: bool,
326    pub enable_motor: bool,
327    pub enable_limit: bool,
328}
329
330impl Default for RevoluteJoint {
331    fn default() -> Self {
332        RevoluteJoint {
333            linear_impulse: VEC3_ZERO,
334            perp_impulse: VEC2_ZERO,
335            spring_impulse: 0.0,
336            motor_impulse: 0.0,
337            lower_impulse: 0.0,
338            upper_impulse: 0.0,
339            hertz: 0.0,
340            damping_ratio: 0.0,
341            max_motor_torque: 0.0,
342            motor_speed: 0.0,
343            target_angle: 0.0,
344            lower_angle: 0.0,
345            upper_angle: 0.0,
346            index_a: NULL_INDEX,
347            index_b: NULL_INDEX,
348            frame_a: TRANSFORM_IDENTITY,
349            frame_b: TRANSFORM_IDENTITY,
350            rotation_axis_z: VEC3_ZERO,
351            perp_axis_x: VEC3_ZERO,
352            perp_axis_y: VEC3_ZERO,
353            delta_center: VEC3_ZERO,
354            delta_angle: 0.0,
355            axial_mass: 0.0,
356            spring_softness: Softness::default(),
357            enable_spring: false,
358            enable_motor: false,
359            enable_limit: false,
360        }
361    }
362}
363
364/// (b3SphericalJoint)
365#[derive(Debug, Clone, Copy, PartialEq)]
366pub struct SphericalJoint {
367    pub linear_impulse: Vec3,
368    pub spring_impulse: Vec3,
369    pub motor_impulse: Vec3,
370    pub lower_twist_impulse: f32,
371    pub upper_twist_impulse: f32,
372    pub swing_impulse: f32,
373    pub hertz: f32,
374    pub damping_ratio: f32,
375    pub max_motor_torque: f32,
376    pub motor_velocity: Vec3,
377    pub lower_twist_angle: f32,
378    pub upper_twist_angle: f32,
379    pub cone_angle: f32,
380    pub target_rotation: Quat,
381
382    pub index_a: i32,
383    pub index_b: i32,
384    pub frame_a: Transform,
385    pub frame_b: Transform,
386    pub delta_center: Vec3,
387    pub swing_axis: Vec3,
388    pub twist_jacobian: Vec3,
389
390    pub rotation_mass: Matrix3,
391    pub swing_mass: f32,
392    pub twist_mass: f32,
393    pub spring_softness: Softness,
394
395    pub enable_spring: bool,
396    pub enable_motor: bool,
397    pub enable_cone_limit: bool,
398    pub enable_twist_limit: bool,
399}
400
401impl Default for SphericalJoint {
402    fn default() -> Self {
403        SphericalJoint {
404            linear_impulse: VEC3_ZERO,
405            spring_impulse: VEC3_ZERO,
406            motor_impulse: VEC3_ZERO,
407            lower_twist_impulse: 0.0,
408            upper_twist_impulse: 0.0,
409            swing_impulse: 0.0,
410            hertz: 0.0,
411            damping_ratio: 0.0,
412            max_motor_torque: 0.0,
413            motor_velocity: VEC3_ZERO,
414            lower_twist_angle: 0.0,
415            upper_twist_angle: 0.0,
416            cone_angle: 0.0,
417            target_rotation: QUAT_IDENTITY,
418            index_a: NULL_INDEX,
419            index_b: NULL_INDEX,
420            frame_a: TRANSFORM_IDENTITY,
421            frame_b: TRANSFORM_IDENTITY,
422            delta_center: VEC3_ZERO,
423            swing_axis: VEC3_ZERO,
424            twist_jacobian: VEC3_ZERO,
425            rotation_mass: MAT3_ZERO,
426            swing_mass: 0.0,
427            twist_mass: 0.0,
428            spring_softness: Softness::default(),
429            enable_spring: false,
430            enable_motor: false,
431            enable_cone_limit: false,
432            enable_twist_limit: false,
433        }
434    }
435}
436
437/// (b3WeldJoint)
438#[derive(Debug, Clone, Copy, PartialEq)]
439pub struct WeldJoint {
440    pub linear_hertz: f32,
441    pub linear_damping_ratio: f32,
442    pub angular_hertz: f32,
443    pub angular_damping_ratio: f32,
444
445    pub linear_spring: Softness,
446    pub angular_spring: Softness,
447    pub linear_impulse: Vec3,
448    pub angular_impulse: Vec3,
449
450    pub index_a: i32,
451    pub index_b: i32,
452    pub frame_a: Transform,
453    pub frame_b: Transform,
454    pub delta_center: Vec3,
455
456    pub angular_mass: Matrix3,
457}
458
459impl Default for WeldJoint {
460    fn default() -> Self {
461        WeldJoint {
462            linear_hertz: 0.0,
463            linear_damping_ratio: 0.0,
464            angular_hertz: 0.0,
465            angular_damping_ratio: 0.0,
466            linear_spring: Softness::default(),
467            angular_spring: Softness::default(),
468            linear_impulse: VEC3_ZERO,
469            angular_impulse: VEC3_ZERO,
470            index_a: NULL_INDEX,
471            index_b: NULL_INDEX,
472            frame_a: TRANSFORM_IDENTITY,
473            frame_b: TRANSFORM_IDENTITY,
474            delta_center: VEC3_ZERO,
475            angular_mass: MAT3_ZERO,
476        }
477    }
478}
479
480/// (b3WheelJoint)
481#[derive(Debug, Clone, Copy, PartialEq)]
482pub struct WheelJoint {
483    pub linear_impulse: Vec2,
484    pub angular_impulse: Vec2,
485    pub spin_impulse: f32,
486    pub max_spin_torque: f32,
487    pub spin_speed: f32,
488    pub suspension_spring_impulse: f32,
489    pub lower_suspension_impulse: f32,
490    pub upper_suspension_impulse: f32,
491    pub lower_suspension_limit: f32,
492    pub upper_suspension_limit: f32,
493    pub suspension_hertz: f32,
494    pub suspension_damping_ratio: f32,
495    pub steering_spring_impulse: f32,
496    pub lower_steering_impulse: f32,
497    pub upper_steering_impulse: f32,
498    pub lower_steering_limit: f32,
499    pub upper_steering_limit: f32,
500    pub target_steering_angle: f32,
501    pub max_steering_torque: f32,
502    pub steering_hertz: f32,
503    pub steering_damping_ratio: f32,
504
505    pub index_a: i32,
506    pub index_b: i32,
507    pub frame_a: Transform,
508    pub frame_b: Transform,
509    pub delta_center: Vec3,
510    pub spin_mass: f32,
511    pub suspension_mass: f32,
512    pub steering_mass: f32,
513    pub suspension_softness: Softness,
514    pub steering_softness: Softness,
515
516    pub enable_spin_motor: bool,
517    pub enable_suspension_spring: bool,
518    pub enable_suspension_limit: bool,
519    pub enable_steering: bool,
520    pub enable_steering_limit: bool,
521    pub enable_steering_motor: bool,
522}
523
524impl Default for WheelJoint {
525    fn default() -> Self {
526        WheelJoint {
527            linear_impulse: VEC2_ZERO,
528            angular_impulse: VEC2_ZERO,
529            spin_impulse: 0.0,
530            max_spin_torque: 0.0,
531            spin_speed: 0.0,
532            suspension_spring_impulse: 0.0,
533            lower_suspension_impulse: 0.0,
534            upper_suspension_impulse: 0.0,
535            lower_suspension_limit: 0.0,
536            upper_suspension_limit: 0.0,
537            suspension_hertz: 0.0,
538            suspension_damping_ratio: 0.0,
539            steering_spring_impulse: 0.0,
540            lower_steering_impulse: 0.0,
541            upper_steering_impulse: 0.0,
542            lower_steering_limit: 0.0,
543            upper_steering_limit: 0.0,
544            target_steering_angle: 0.0,
545            max_steering_torque: 0.0,
546            steering_hertz: 0.0,
547            steering_damping_ratio: 0.0,
548            index_a: NULL_INDEX,
549            index_b: NULL_INDEX,
550            frame_a: TRANSFORM_IDENTITY,
551            frame_b: TRANSFORM_IDENTITY,
552            delta_center: VEC3_ZERO,
553            spin_mass: 0.0,
554            suspension_mass: 0.0,
555            steering_mass: 0.0,
556            suspension_softness: Softness::default(),
557            steering_softness: Softness::default(),
558            enable_spin_motor: false,
559            enable_suspension_spring: false,
560            enable_suspension_limit: false,
561            enable_steering: false,
562            enable_steering_limit: false,
563            enable_steering_motor: false,
564        }
565    }
566}
567
568/// Joint-specific simulation union. (C anonymous union in b3JointSim)
569/// Filter joints have no simulation payload.
570#[derive(Debug, Clone, Copy, PartialEq)]
571pub enum JointUnion {
572    Distance(DistanceJoint),
573    Filter,
574    Motor(MotorJoint),
575    Parallel(ParallelJoint),
576    Revolute(RevoluteJoint),
577    Spherical(SphericalJoint),
578    Prismatic(PrismaticJoint),
579    Weld(WeldJoint),
580    Wheel(WheelJoint),
581}
582
583impl JointUnion {
584    /// Empty payload for the given type (C memset of the union).
585    pub fn empty(joint_type: JointType) -> Self {
586        match joint_type {
587            JointType::Distance => JointUnion::Distance(DistanceJoint::default()),
588            JointType::Filter => JointUnion::Filter,
589            JointType::Motor => JointUnion::Motor(MotorJoint::default()),
590            JointType::Parallel => JointUnion::Parallel(ParallelJoint::default()),
591            JointType::Prismatic => JointUnion::Prismatic(PrismaticJoint::default()),
592            JointType::Revolute => JointUnion::Revolute(RevoluteJoint::default()),
593            JointType::Spherical => JointUnion::Spherical(SphericalJoint::default()),
594            JointType::Weld => JointUnion::Weld(WeldJoint::default()),
595            JointType::Wheel => JointUnion::Wheel(WheelJoint::default()),
596        }
597    }
598}
599
600impl Default for JointUnion {
601    fn default() -> Self {
602        JointUnion::Distance(DistanceJoint::default())
603    }
604}
605
606impl JointSim {
607    /// (C: &base->distanceJoint)
608    pub fn distance(&self) -> &DistanceJoint {
609        match &self.union_ {
610            JointUnion::Distance(joint) => joint,
611            _ => unreachable!("joint union is not a distance joint"),
612        }
613    }
614
615    pub fn distance_mut(&mut self) -> &mut DistanceJoint {
616        match &mut self.union_ {
617            JointUnion::Distance(joint) => joint,
618            _ => unreachable!("joint union is not a distance joint"),
619        }
620    }
621
622    /// (C: &base->parallelJoint)
623    pub fn parallel(&self) -> &ParallelJoint {
624        match &self.union_ {
625            JointUnion::Parallel(joint) => joint,
626            _ => unreachable!("joint union is not a parallel joint"),
627        }
628    }
629
630    pub fn parallel_mut(&mut self) -> &mut ParallelJoint {
631        match &mut self.union_ {
632            JointUnion::Parallel(joint) => joint,
633            _ => unreachable!("joint union is not a parallel joint"),
634        }
635    }
636
637    /// (C: &base->weldJoint)
638    pub fn weld(&self) -> &WeldJoint {
639        match &self.union_ {
640            JointUnion::Weld(joint) => joint,
641            _ => unreachable!("joint union is not a weld joint"),
642        }
643    }
644
645    pub fn weld_mut(&mut self) -> &mut WeldJoint {
646        match &mut self.union_ {
647            JointUnion::Weld(joint) => joint,
648            _ => unreachable!("joint union is not a weld joint"),
649        }
650    }
651
652    /// (C: &base->revoluteJoint)
653    pub fn revolute(&self) -> &RevoluteJoint {
654        match &self.union_ {
655            JointUnion::Revolute(joint) => joint,
656            _ => unreachable!("joint union is not a revolute joint"),
657        }
658    }
659
660    pub fn revolute_mut(&mut self) -> &mut RevoluteJoint {
661        match &mut self.union_ {
662            JointUnion::Revolute(joint) => joint,
663            _ => unreachable!("joint union is not a revolute joint"),
664        }
665    }
666
667    /// (C: &base->prismaticJoint)
668    pub fn prismatic(&self) -> &PrismaticJoint {
669        match &self.union_ {
670            JointUnion::Prismatic(joint) => joint,
671            _ => unreachable!("joint union is not a prismatic joint"),
672        }
673    }
674
675    pub fn prismatic_mut(&mut self) -> &mut PrismaticJoint {
676        match &mut self.union_ {
677            JointUnion::Prismatic(joint) => joint,
678            _ => unreachable!("joint union is not a prismatic joint"),
679        }
680    }
681
682    /// (C: &base->motorJoint)
683    pub fn motor(&self) -> &MotorJoint {
684        match &self.union_ {
685            JointUnion::Motor(joint) => joint,
686            _ => unreachable!("joint union is not a motor joint"),
687        }
688    }
689
690    pub fn motor_mut(&mut self) -> &mut MotorJoint {
691        match &mut self.union_ {
692            JointUnion::Motor(joint) => joint,
693            _ => unreachable!("joint union is not a motor joint"),
694        }
695    }
696
697    /// (C: &base->sphericalJoint)
698    pub fn spherical(&self) -> &SphericalJoint {
699        match &self.union_ {
700            JointUnion::Spherical(joint) => joint,
701            _ => unreachable!("joint union is not a spherical joint"),
702        }
703    }
704
705    pub fn spherical_mut(&mut self) -> &mut SphericalJoint {
706        match &mut self.union_ {
707            JointUnion::Spherical(joint) => joint,
708            _ => unreachable!("joint union is not a spherical joint"),
709        }
710    }
711
712    /// (C: &base->wheelJoint)
713    pub fn wheel(&self) -> &WheelJoint {
714        match &self.union_ {
715            JointUnion::Wheel(joint) => joint,
716            _ => unreachable!("joint union is not a wheel joint"),
717        }
718    }
719
720    pub fn wheel_mut(&mut self) -> &mut WheelJoint {
721        match &mut self.union_ {
722            JointUnion::Wheel(joint) => joint,
723            _ => unreachable!("joint union is not a wheel joint"),
724        }
725    }
726}
727
728/// The base joint simulation class. (b3JointSim)
729#[derive(Debug, Clone, Copy, PartialEq)]
730pub struct JointSim {
731    pub joint_id: i32,
732
733    pub body_id_a: i32,
734    pub body_id_b: i32,
735
736    pub type_: JointType,
737
738    /// Joint frames local to body origin
739    pub local_frame_a: Transform,
740    pub local_frame_b: Transform,
741
742    pub inv_mass_a: f32,
743    pub inv_mass_b: f32,
744    pub inv_i_a: Matrix3,
745    pub inv_i_b: Matrix3,
746
747    pub constraint_hertz: f32,
748    pub constraint_damping_ratio: f32,
749
750    pub constraint_softness: Softness,
751
752    pub force_threshold: f32,
753    pub torque_threshold: f32,
754
755    pub fixed_rotation: bool,
756
757    pub union_: JointUnion,
758}
759
760impl Default for JointSim {
761    fn default() -> Self {
762        JointSim {
763            joint_id: NULL_INDEX,
764            body_id_a: NULL_INDEX,
765            body_id_b: NULL_INDEX,
766            type_: JointType::Distance,
767            local_frame_a: TRANSFORM_IDENTITY,
768            local_frame_b: TRANSFORM_IDENTITY,
769            inv_mass_a: 0.0,
770            inv_mass_b: 0.0,
771            inv_i_a: MAT3_ZERO,
772            inv_i_b: MAT3_ZERO,
773            constraint_hertz: 0.0,
774            constraint_damping_ratio: 0.0,
775            constraint_softness: Softness::default(),
776            force_threshold: 0.0,
777            torque_threshold: 0.0,
778            fixed_rotation: false,
779            union_: JointUnion::default(),
780        }
781    }
782}
box3d_rust/joint/types.rs

box3d_rust/joint/
types.rs
