Refresh rate driven rendering tick logic (#3375)

* Implement sync interval and refresh rate API for RenderViewportWidget Signed-off-by: nvsickle <nvsickle@amazon.com> * Measure actual frame timings in the viewport info overlay. Takes the median of the sum of (frame end - frame begin) to provide more a more representative view of when frames begin and end. Note: Until VSync is internally supported by the event loop, this will produce nearly identical frame timings as the frame will spend as much time as needed synchronously waiting on a vblank. Signed-off-by: nvsickle <nvsickle@amazon.com> * Make frame timing per-pipeline, wire up refresh rate info to ViewportContext Signed-off-by: nvsickle <nvsickle@amazon.com> * POC: Frame limit pipeline rendering Signed-off-by: nvsickle <nvsickle@amazon.com> * Switch Editor tick to every 0ms to allow better tick accumulation behavior Signed-off-by: nvsickle <nvsickle@amazon.com> * Move RPISystemComponent to the tick bus, remove tick accumulation logic Signed-off-by: nvsickle <nvsickle@amazon.com> * Add `AddToRenderTickAtInterval` to RenderPipeline API This allows a pipeline to update at a set cadence, instead of rendering every frame or being directly told when to tick. Signed-off-by: nvsickle <nvsickle@amazon.com> * Make ViewportContext enforce a target framerate -Adds GetFpsLimit/SetFpsLimit for actively limiting FPS -Calculates a render tick interval based on vsync and the vps limit and updates the current pipeline Signed-off-by: nvsickle <nvsickle@amazon.com> * Add r_fps_limit and ed_inactive_viewport_fps_limit cvars Signed-off-by: nvsickle <nvsickle@amazon.com> * Quick null check from a crash I bumped into Signed-off-by: nvsickle <nvsickle@amazon.com> * Fix off-by-one on FPS calculation (shouldn't include the not-yet-rendered frame) Signed-off-by: nvsickle <nvsickle@amazon.com> * Clarify frame time begin initialization Signed-off-by: nvsickle <nvsickle@amazon.com> * Fix TrackView export. Signed-off-by: nvsickle <nvsickle@amazon.com> * Address some reviewer feedback, revert RPISystem API change, fix CPU profiler. Signed-off-by: nvsickle <nvsickle@amazon.com> * Add g_simulation_tick_rate Signed-off-by: nvsickle <nvsickle@amazon.com> * Address review feedback, make frame limit updates event driven Signed-off-by: nvsickle <nvsickle@amazon.com> * Remove timestamp update from ComponentApplication::Tick Signed-off-by: nvsickle <nvsickle@amazon.com>
2021-09-13 17:57:42 -07:00
parent b2963f2bc1
commit db63dcbcd9
26 changed files with 633 additions and 124 deletions
@@ -74,6 +74,8 @@
 #include <AzCore/Module/Environment.h>
 #include <AzCore/std/string/conversions.h>

+AZ_CVAR(float, g_simulation_tick_rate, 0, nullptr, AZ::ConsoleFunctorFlags::Null, "The rate at which the game simulation tick loop runs, or 0 for as fast as possible");
+
 static void PrintEntityName(const AZ::ConsoleCommandContainer& arguments)
 {
    if (arguments.empty())
@@ -1392,6 +1394,23 @@ namespace AZ
                AZ_PROFILE_SCOPE(AzCore, "ComponentApplication::Tick:OnTick");
                EBUS_EVENT(TickBus, OnTick, m_deltaTime, ScriptTimePoint(now));
            }
+
+            // If tick rate limiting is on, ensure (1 / g_simulation_tick_rate) ms has elapsed since the last frame,
+            // sleeping if there's still time remaining.
+            if (g_simulation_tick_rate > 0.f)
+            {
+                now = AZStd::chrono::system_clock::now();
+
+                // Work in microsecond durations here as that's the native measurement time for time_point
+                constexpr float microsecondsPerSecond = 1000.f * 1000.f;
+                const AZStd::chrono::microseconds timeBudgetPerTick(static_cast<int>(microsecondsPerSecond / g_simulation_tick_rate));
+                AZStd::chrono::microseconds timeUntilNextTick = m_currentTime + timeBudgetPerTick - now;
+
+                if (timeUntilNextTick.count() > 0)
+                {
+                    AZStd::this_thread::sleep_for(timeUntilNextTick);
+                }
+            }
        }
    }

@@ -46,6 +46,8 @@ namespace AZ

        TICK_PRE_RENDER     = 750,     ///< Suggested tick handler position to update render-related data.

+        TICK_RENDER         = 800,     ///< Suggested tick handler position for rendering.
+
        TICK_DEFAULT        = 1000,    ///< Default tick handler position when the handler is constructed.

        TICK_UI             = 2000,    ///< Suggested tick handler position for UI components.