IntegrationParameters: deprectate dt() and inv_dt() methods

src_testbed/box2d_backend.rs

@@ -211,7 +211,7 @@ impl Box2dWorld {
 
         counters.step_started();
         self.world.step(
-            params.dt(),
+            params.dt,
             params.max_velocity_iterations as i32,
             params.max_position_iterations as i32,
         );

src_testbed/harness/mod.rs

@@ -238,7 +238,7 @@ impl Harness {
 
         self.events.poll_all();
 
-        self.state.time += self.physics.integration_parameters.dt();
+        self.state.time += self.physics.integration_parameters.dt;
         self.state.timestep_id += 1;
     }
 

src_testbed/nphysics_backend.rs

@@ -143,7 +143,7 @@ impl NPhysicsWorld {
             .max_velocity_iterations = params.max_velocity_iterations;
         self.mechanical_world
             .integration_parameters
-            .set_dt(params.dt());
+            .set_dt(params.dt);
 
         counters.step_started();
         self.mechanical_world.step(

src_testbed/physx_backend.rs

@@ -396,7 +396,7 @@ impl PhysxWorld {
 
     pub fn step(&mut self, counters: &mut Counters, params: &IntegrationParameters) {
         counters.step_started();
-        self.scene.step(params.dt(), true);
+        self.scene.step(params.dt, true);
         counters.step_completed();
     }