checkpoint; wheel_forces skeleton fn

src/action/systems.rs

@@ -129,52 +129,16 @@ pub(super) fn falling_cat(
     }
 }
 
-/// Apply forces to the cyberbike as a result of input.
-pub(super) fn input_forces(
-    settings: Res<MovementSettings>,
-    input: Res<InputState>,
-    mut braking_query: Query<&mut MultibodyJoint, (Without<CyberSteering>, With<CyberWheel>)>,
-    mut body_query: Query<(&Transform, &mut ExternalForce), With<CyberBikeBody>>,
-    mut steering_query: Query<&mut MultibodyJoint, With<CyberSteering>>,
-) {
-    let (xform, mut forces) = body_query.single_mut();
-
-    // thrust
-    let thrust = xform.forward() * input.throttle * settings.accel;
-    let point = xform.translation + *xform.back();
-    let force = ExternalForce::at_point(thrust, point, xform.translation);
-    *forces += force;
-
-    // brake + thrust
-    // for mut motor in braking_query.iter_mut() {
-    //     let factor = if input.brake {
-    //         500.00
-    //     } else {
-    //         input.throttle * settings.accel
-    //     };
-    //     let speed = if input.brake { 0.0 } else { -70.0 };
-    //     motor.data = (*motor
-    //         .data
-    //         .as_revolute_mut()
-    //         .unwrap()
-    //         .set_motor_max_force(factor)
-    //         .set_motor_velocity(speed, factor))
-    //     .into();
-    // }
-
-    // steering
-    let angle = yaw_to_angle(input.yaw);
-    let mut steering = steering_query.single_mut();
-    steering.data = (*steering
-        .data
-        .as_revolute_mut()
-        .unwrap()
-        .set_motor_position(-angle, 100.0, 0.5))
-    .into();
-}
-
 pub(super) fn wheel_forces(
-    mut wheels_query: Query<(&Transform, &Velocity, &mut PreviousVelocity), With<CyberWheel>>,
+    mut wheels_query: Query<
+        (
+            &Transform,
+            &Velocity,
+            &mut PreviousVelocity,
+            Option<&CyberSteering>,
+        ),
+        With<CyberWheel>,
+    >,
     mut body_query: Query<
         (
             &Transform,
@@ -184,47 +148,58 @@ pub(super) fn wheel_forces(
         ),
         With<CyberBikeBody>,
     >,
-    config: Res<WheelConfig>,
+    wheel_config: Res<WheelConfig>,
+    rapier_config: Res<RapierConfiguration>,
     context: Res<RapierContext>,
+    settings: Res<MovementSettings>,
+    input: Res<InputState>,
 ) {
     let (body_xform, body_vel, mut body_pvel, body_mass) = body_query.single_mut();
 
-    for (xform, vel, mut pvel) in wheels_query.iter_mut() {
+    let gvec = rapier_config.gravity;
-        //
+
+    // body kinematics
+    let body_lin_accel = body_vel.linvel - body_pvel.0.linvel;
+    let body_ang_accel = body_vel.angvel - body_pvel.0.angvel;
+    let mut body_forward = body_vel
+        .linvel
+        .try_normalize()
+        .unwrap_or_else(|| body_xform.forward().normalize());
+    // we're just projecting onto the ground, so nuke the Y.
+    body_forward.y = 0.0;
+    let body_half_mass = body_mass.mass * 0.5;
+    let g = gvec * settings.gravity * body_half_mass;
+
+    // inputs
+    let steering_angle = yaw_to_angle(input.yaw);
+    let throttle = input.throttle * settings.accel;
+
+    for (xform, vel, mut pvel, steering) in wheels_query.iter_mut() {
+        if let Some((_, projected)) =
+            context.project_point(xform.translation, true, QueryFilter::only_fixed())
+        {
+            let normal = -(projected.point - xform.translation);
+            let len = normal.length();
+            let normal = normal.normalize();
+            if len < wheel_config.radius {
+                // we're in contact
+
+                // do gravity's share
+
+                // do linear acceleration's share
+
+                // do friction's share
+
+                // do thrust's share
+
+                // do steering's share
+            }
+        }
     }
 
     body_pvel.0 = *body_vel;
 }
 
-/// Don't let the wheels get stuck underneat the planet
-pub(super) fn surface_fix(
-    mut wheel_query: Query<(Entity, &Transform, &mut CollisionGroups), With<CyberWheel>>,
-    span_query: Query<&Transform, With<CyberWheel>>,
-    config: Res<WheelConfig>,
-    context: Res<RapierContext>,
-) {
-    let mut wheels = Vec::new();
-    for xform in span_query.iter() {
-        wheels.push(xform);
-    }
-    let span = (wheels[1].translation - wheels[0].translation).normalize();
-
-    for (entity, xform, mut cgroups) in wheel_query.iter_mut() {
-        //let ray_dir = xform.translation.normalize();
-        let ray_dir = Vec3::NEG_Y; //xform.right().cross(span).normalize();
-        if let Some(hit) = context.cast_ray_and_get_normal(
-            xform.translation,
-            ray_dir,
-            config.radius,
-            false,
-            QueryFilter::only_fixed(),
-        ) {
-            //cgroups.memberships = Group::NONE;
-            //cgroups.filters = Group::NONE;
-        }
-    }
-}
-
 /// General velocity-based drag-force calculation; does not take orientation
 /// into account.
 pub(super) fn drag(mut query: Query<(&Velocity, &mut ExternalForce), With<CyberBikeBody>>) {

src/bike/wheels.rs

@@ -87,8 +87,7 @@ pub(crate) fn spawn_wheels(
             .id();
 
         let axel_parent_entity = if let Some(steering) = steering {
-            let neck_builder =
+            let neck_builder = FixedJointBuilder::new().local_anchor1(Vec3::new(0.0, 0.0, 0.1)); // this adds another 0.1m of trail
-                RevoluteJointBuilder::new(rake_vec).local_anchor1(Vec3::new(0.0, 0.0, 0.1)); // this adds another 0.1m of trail
             let neck_joint = MultibodyJoint::new(fork_rb_entity, neck_builder);
             let neck = commands
                 .spawn(RigidBody::Dynamic)
@@ -101,17 +100,13 @@ pub(crate) fn spawn_wheels(
             fork_rb_entity
         };
 
-        let axel_builder = FixedJointBuilder::new(); //RevoluteJointBuilder::new(Vec3::X);
+        let axel_builder = FixedJointBuilder::new();
         let axel_joint = MultibodyJoint::new(axel_parent_entity, axel_builder);
-        let wheel_damping = Damping {
-            //linear_damping: 0.8,
-            ..Default::default()
-        };
 
         commands.spawn(pbr_bundle).insert((
             collider,
             mass_props,
-            wheel_damping,
+            //wheel_damping,
             ccd,
             not_sleeping,
             axel_joint,