Fixed Timestep Interpolation (3D)

Adds 3D fixed timestep interpolation to the rendering server.
This does not yet include support for multimeshes or particles.

Co-authored-by: lawnjelly <lawnjelly@gmail.com>

2 files changed, 9 insertions, 16 deletions

diff --git a/main/main.cpp b/main/main.cpp
index 060b3fe2f6..7d17ec8ab8 100644
--- a/main/main.cpp
+++ b/main/main.cpp
@@ -2380,6 +2380,7 @@ Error Main::setup(const char *execpath, int argc, char *argv[], bool p_second_ph
 	GLOBAL_DEF("debug/settings/stdout/print_fps", false);
 	GLOBAL_DEF("debug/settings/stdout/print_gpu_profile", false);
 	GLOBAL_DEF("debug/settings/stdout/verbose_stdout", false);
+	GLOBAL_DEF("debug/settings/physics_interpolation/enable_warnings", true);
 
 	if (!OS::get_singleton()->_verbose_stdout) { // Not manually overridden.
 		OS::get_singleton()->_verbose_stdout = GLOBAL_GET("debug/settings/stdout/verbose_stdout");
@@ -4047,16 +4048,16 @@ bool Main::iteration() {
 
 		uint64_t physics_begin = OS::get_singleton()->get_ticks_usec();
 
-#ifndef _3D_DISABLED
-		PhysicsServer3D::get_singleton()->sync();
-		PhysicsServer3D::get_singleton()->flush_queries();
-#endif // _3D_DISABLED
-
 		// Prepare the fixed timestep interpolated nodes BEFORE they are updated
 		// by the physics server, otherwise the current and previous transforms
 		// may be the same, and no interpolation takes place.
 		OS::get_singleton()->get_main_loop()->iteration_prepare();
 
+#ifndef _3D_DISABLED
+		PhysicsServer3D::get_singleton()->sync();
+		PhysicsServer3D::get_singleton()->flush_queries();
+#endif // _3D_DISABLED
+
 		PhysicsServer2D::get_singleton()->sync();
 		PhysicsServer2D::get_singleton()->flush_queries();
 
@@ -4066,6 +4067,7 @@ bool Main::iteration() {
 #endif // _3D_DISABLED
 			PhysicsServer2D::get_singleton()->end_sync();
 
+			Engine::get_singleton()->_in_physics = false;
 			exit = true;
 			break;
 		}
@@ -4089,6 +4091,8 @@ bool Main::iteration() {
 
 		message_queue->flush();
 
+		OS::get_singleton()->get_main_loop()->iteration_end();
+
 		physics_process_ticks = MAX(physics_process_ticks, OS::get_singleton()->get_ticks_usec() - physics_begin); // keep the largest one for reference
 		physics_process_max = MAX(OS::get_singleton()->get_ticks_usec() - physics_begin, physics_process_max);
 
diff --git a/main/main_timer_sync.cpp b/main/main_timer_sync.cpp
index d358d9fa93..569930d427 100644
--- a/main/main_timer_sync.cpp
+++ b/main/main_timer_sync.cpp
@@ -299,17 +299,6 @@ int64_t MainTimerSync::DeltaSmoother::smooth_delta(int64_t p_delta) {
 // before advance_core considers changing the physics_steps return from
 // the typical values as defined by typical_physics_steps
 double MainTimerSync::get_physics_jitter_fix() {
-	// Turn off jitter fix when using fixed timestep interpolation.
-	// Note this shouldn't be on UNTIL 3d interpolation is implemented,
-	// otherwise we will get people making 3d games with the physics_interpolation
-	// set to on getting jitter fix disabled unexpectedly.
-#if 0
-	if (Engine::get_singleton()->is_physics_interpolation_enabled()) {
-		// Would be better to write a simple bypass for jitter fix but this will do to get started.
-		return 0.0;
-	}
-#endif
-
 	return Engine::get_singleton()->get_physics_jitter_fix();
 }