Let physics run for a while to prevent bugs

Game.cpp

@@ -185,6 +185,7 @@ class App : public OgreBites::ApplicationContext {
 		ECS::Vector2 mouse{ 0, 0 };
 		float wheel_y;
 		bool mouse_moved = false, wheel_moved = false;
+		float mInitDelay;
 
 	public:
 		Ogre::Timer fps_timer;
@@ -195,6 +196,7 @@ class App : public OgreBites::ApplicationContext {
 			, mApp(app)
 			, fast(false)
 			, control(0)
+			, mInitDelay(1.0)
 		{
 		}
 		bool isGuiEnabled()
@@ -322,6 +324,8 @@ class App : public OgreBites::ApplicationContext {
 			}
 			if (!isGuiEnabled()) {
 				mApp->updateWorld(evt.timeSinceLastFrame);
+				if (mInitDelay >= 0.0f)
+					mInitDelay -= evt.timeSinceLastFrame;
 			}
 			if (!isGuiEnabled() && ECS::get().has<ECS::Input>()) {
 				ECS::Input &input =

src/gamedata/CharacterModule.cpp

@@ -24,6 +24,8 @@ CharacterModule::CharacterModule(flecs::world &ecs)
 		.kind(flecs::OnUpdate)
 		.each([this](EngineData &eng, CharacterBase &ch) {
 			ch.mTimer += eng.delta;
+			if (eng.startupDelay >= 0.0f)
+				eng.startupDelay -= eng.delta;
 		});
 	ecs.system<Input, Camera>("HandleInput")
 		.kind(flecs::OnUpdate)
@@ -179,11 +181,12 @@ CharacterModule::CharacterModule(flecs::world &ecs)
 				return;
 			ch.mBoneMotion = ch.mRootBone->getPosition();
 		});
-	ecs.system<CharacterBase, CharacterBody, AnimationControl>(
-		   "HandleRootMotion")
+	ecs.system<const EngineData, CharacterBase, CharacterBody,
+		   AnimationControl>("HandleRootMotion")
 		.kind(flecs::OnUpdate)
-		.each([this](flecs::entity e, CharacterBase &ch,
-			     CharacterBody &body, AnimationControl &anim) {
+		.each([this](flecs::entity e, const EngineData &eng,
+			     CharacterBase &ch, CharacterBody &body,
+			     AnimationControl &anim) {
 			float delta = e.world().delta_time();
 			if (!ch.mBodyNode)
 				return;
@@ -218,26 +221,29 @@ CharacterModule::CharacterModule(flecs::world &ecs)
 					body.gvelocity.y, -2.5f, 2.5f);
 			} else
 				body.gvelocity += gravity * delta;
-			body.gvelocity *= 0.99;
-			velocity += body.gvelocity;
-			Ogre::Vector3 rotMotion = velocity * delta;
-			btVector3 currentPosition =
-				body.mGhostObject->getWorldTransform()
-					.getOrigin();
-			is_on_floor = body.mController->isOnFloor();
-			penetration = body.mController->isPenetrating();
-			if (is_on_floor)
-				body.gvelocity =
-					Ogre::Vector3(0.0f, 0.0f, 0.0f);
+			if (eng.startupDelay < 0.0f) {
+				body.gvelocity *= 0.99;
+				velocity += body.gvelocity;
+				Ogre::Vector3 rotMotion = velocity * delta;
+				btVector3 currentPosition =
+					body.mGhostObject->getWorldTransform()
+						.getOrigin();
+				is_on_floor = body.mController->isOnFloor();
+				penetration = body.mController->isPenetrating();
+				if (is_on_floor)
+					body.gvelocity =
+						Ogre::Vector3(0.0f, 0.0f, 0.0f);
 
-			btTransform from(
-				Ogre::Bullet::convert(
-					ch.mBodyNode->getOrientation()),
-				Ogre::Bullet::convert(
-					ch.mBodyNode->getPosition()));
-			ch.mBodyNode->setPosition(ch.mBodyNode->getPosition() +
-						  rotMotion);
-			ch.mBoneMotion = Ogre::Vector3(0, 0, 0);
+				btTransform from(
+					Ogre::Bullet::convert(
+						ch.mBodyNode->getOrientation()),
+					Ogre::Bullet::convert(
+						ch.mBodyNode->getPosition()));
+				ch.mBodyNode->setPosition(
+					ch.mBodyNode->getPosition() +
+					rotMotion);
+				ch.mBoneMotion = Ogre::Vector3(0, 0, 0);
+			}
 		});
 	ecs.system<const Input, AnimationControl>("HandlePlayerAnimations")
 		.kind(flecs::OnUpdate)

src/gamedata/Components.h

@@ -17,6 +17,7 @@ struct EngineData {
 	Ogre::SceneManager *mScnMgr;
 	Ogre::Bullet::DynamicsWorld *mWorld;
 	float delta;
+	float startupDelay;
 };
 struct Vector3 {
 	float x;

src/gamedata/GameData.cpp

@@ -31,7 +31,7 @@ void setup(Ogre::SceneManager *scnMgr, Ogre::Bullet::DynamicsWorld *world,
 		.each([](EngineData &eng) {
 			eng.delta = ECS::get().delta_time();
 		});
-	ecs.set<EngineData>({ scnMgr, world, 0.0f });
+	ecs.set<EngineData>({ scnMgr, world, 0.0f, 0.0f });
 	ecs.set<Camera>({ cameraNode, camera, false });
 	ecs.add<GameData>();
 	ecs.add<Input>();