specs-physics

commit 3219ceccd2c0648d93542a28ad08766e906ca76f
parent bab0ab3ccb599c700ca47642a9eeb742ac603dc2
Author: bamlin <b.amling@tarent.de>
Date:   Sat,  1 Jun 2019 15:06:14 +0200

only update timestep when values differ; also added another convenience function for registering systems to a given dispatcher builder

Diffstat:
M
Cargo.toml
 | 
2
+-
M
examples/basic.rs
 | 
4
++--
M
examples/hierarchy.rs
 | 
6
++++--
M
examples/positions.rs
 | 
4
++--
M
src/lib.rs
 | 
19
++++++++++++++-----
M
src/systems/physics_stepper.rs
 | 
11
++++++++++-

6 files changed, 33 insertions(+), 13 deletions(-)
diff --git a/Cargo.toml b/Cargo.toml
@@ -1,6 +1,6 @@
 [package]
 name = "specs-physics"
-version = "0.1.0"
+version = "0.1.1"
 authors = ["Benjamin Amling <benjamin@amling.net>"]
 repository = "https://github.com/bamling/specs-physics.git"
 homepage = "https://github.com/bamling/specs-physics.git"
diff --git a/examples/basic.rs b/examples/basic.rs
@@ -4,7 +4,7 @@ extern crate simple_logger;
 use specs::{world::Builder, Component, DenseVecStorage, FlaggedStorage, World};
 use specs_physics::{
     body::{BodyStatus, Position},
-    dispatcher,
+    physics_dispatcher,
     PhysicsBodyBuilder,
     PhysicsColliderBuilder,
     Shape,
@@ -43,7 +43,7 @@ fn main() {
 
     // create the dispatcher containing all relevant Systems; alternatively to using
     // the convenience function you can add all required Systems by hand
-    let mut dispatcher = dispatcher::<f32, Pos>();
+    let mut dispatcher = physics_dispatcher::<f32, Pos>();
     dispatcher.setup(&mut world.res);
 
     // create an Entity containing the required Components
diff --git a/examples/hierarchy.rs b/examples/hierarchy.rs
@@ -4,9 +4,10 @@ extern crate simple_logger;
 use specs::{world::Builder, Component, DenseVecStorage, FlaggedStorage, World};
 use specs_physics::{
     body::{BodyStatus, Position},
-    dispatcher,
+    physics_dispatcher,
     PhysicsBodyBuilder,
     PhysicsColliderBuilder,
+    PhysicsParent,
     Shape,
 };
 
@@ -43,7 +44,7 @@ fn main() {
 
     // create the dispatcher containing all relevant Systems; alternatively to using
     // the convenience function you can add all required Systems by hand
-    let mut dispatcher = dispatcher::<f32, Pos>();
+    let mut dispatcher = physics_dispatcher::<f32, Pos>();
     dispatcher.setup(&mut world.res);
 
     // create an Entity containing the required Components; this Entity will be the
@@ -75,6 +76,7 @@ fn main() {
                 .sensor(true)
                 .build(),
         )
+        .with(PhysicsParent { entity: parent })
         .build();
 
     // execute the dispatcher
diff --git a/examples/positions.rs b/examples/positions.rs
@@ -6,7 +6,7 @@ use nalgebra::Vector3;
 use specs::{world::Builder, Component, DenseVecStorage, FlaggedStorage, World};
 use specs_physics::{
     body::{BodyStatus, Position},
-    dispatcher,
+    physics_dispatcher,
     PhysicsBodyBuilder,
     PhysicsColliderBuilder,
     Shape,
@@ -45,7 +45,7 @@ fn main() {
 
     // create the dispatcher containing all relevant Systems; alternatively to using
     // the convenience function you can add all required Systems by hand
-    let mut dispatcher = dispatcher::<f32, Pos>();
+    let mut dispatcher = physics_dispatcher::<f32, Pos>();
     dispatcher.setup(&mut world.res);
 
     // create an Entity containing the required Components; for this examples sake
diff --git a/src/lib.rs b/src/lib.rs
@@ -89,15 +89,26 @@ impl Parent for PhysicsParent {
 }
 
 /// Convenience function for configuring and building a `Dispatcher` with all
-/// required physics related `System`s. This also serves as a blueprint on how
-/// to properly set up the `System`s and have them depend on each other.
-pub fn dispatcher<'a, 'b, N, P>() -> Dispatcher<'a, 'b>
+/// required physics related `System`s.
+pub fn physics_dispatcher<'a, 'b, N, P>() -> Dispatcher<'a, 'b>
 where
     N: RealField,
     P: Component<Storage = FlaggedStorage<P, DenseVecStorage<P>>> + Position<N> + Send + Sync,
 {
     let mut dispatcher_builder = DispatcherBuilder::new();
+    register_physics_systems::<N, P>(&mut dispatcher_builder);
 
+    dispatcher_builder.build()
+}
+
+/// Convenience function for registering all required physics related `System`s
+/// to the given `DispatcherBuilder`. This also serves as a blueprint on how
+///// to properly set up the `System`s and have them depend on each other.
+pub fn register_physics_systems<N, P>(dispatcher_builder: &mut DispatcherBuilder)
+where
+    N: RealField,
+    P: Component<Storage = FlaggedStorage<P, DenseVecStorage<P>>> + Position<N> + Send + Sync,
+{
     // add SyncBodiesToPhysicsSystem first since we have to start with bodies;
     // colliders can exist without a body but in most cases have a body parent
     dispatcher_builder.add(
@@ -144,6 +155,4 @@ where
         "sync_positions_from_physics_system",
         &["physics_stepper_system"],
     );
-
-    dispatcher_builder.build()
 }
diff --git a/src/systems/physics_stepper.rs b/src/systems/physics_stepper.rs
@@ -19,7 +19,16 @@ impl<'s, N: RealField> System<'s> for PhysicsStepperSystem<N> {
         // accordingly; this should not be required if the Systems are executed in a
         // fixed interval
         if let Some(time_step) = time_step {
-            physics.world.set_timestep(time_step.0);
+            // only update timestep if it actually differs from the current nphysics World
+            // one; keep in mind that changing the Resource will destabilize the simulation
+            if physics.world.timestep() != time_step.0 {
+                warn!(
+                    "TimeStep and world.timestep() differ, changing worlds timestep from {} to: {:?}",
+                    physics.world.timestep(),
+                    time_step.0
+                );
+                physics.world.set_timestep(time_step.0);
+            }
         }
 
         physics.world.step();