Add joint softness per joint (#901)

examples2d/pin_slot_joint2.rs

@@ -1,5 +1,8 @@
-use rapier2d::prelude::*;
+use crate::utils::character;
+use crate::utils::character::CharacterControlMode;
 use rapier_testbed2d::Testbed;
+use rapier2d::control::{KinematicCharacterController, PidController};
+use rapier2d::prelude::*;
 
 pub fn init_world(testbed: &mut Testbed) {
     /*
@@ -77,10 +80,29 @@ pub fn init_world(testbed: &mut Testbed) {
         .build();
     impulse_joints.insert(character_handle, cube_handle, pin_slot_joint, true);
 
+    /*
+     * Callback to update the character based on user inputs.
+     */
+    let mut control_mode = CharacterControlMode::Kinematic(0.1);
+    let mut controller = KinematicCharacterController::default();
+    let mut pid = PidController::default();
+
+    testbed.add_callback(move |graphics, physics, _, _| {
+        if let Some(graphics) = graphics {
+            character::update_character(
+                graphics,
+                physics,
+                &mut control_mode,
+                &mut controller,
+                &mut pid,
+                character_handle,
+            );
+        }
+    });
+
     /*
      * Set up the testbed.
      */
     testbed.set_world(bodies, colliders, impulse_joints, multibody_joints);
-    testbed.set_character_body(character_handle);
     testbed.look_at(point![0.0, 1.0], 100.0);
 }