[development] minor Profiler gem fixes (#5473)

Fixed incorrect frame boundary guess when loading a profile capture
Added some missing default initializers
Removed implicit dependency on Atom timing marker constants
Fixed issue with small visualizer viewport bounds when loading a saved capture

Signed-off-by: AMZN-ScottR 24445312+AMZN-ScottR@users.noreply.github.com

Code/Framework/AzCore/AzCore/Statistics/StatisticalProfilerProxy.h

@@ -157,6 +157,22 @@ namespace AZ::Statistics
             }
         }
 
+        void GetAllStatistics(AZStd::vector<NamedRunningStatistic*>& stats)
+        {
+            for (auto& iter : m_profilers)
+            {
+                iter.second.m_profiler.GetStatsManager().GetAllStatistics(stats);
+            }
+        }
+
+        void GetAllStatisticsOfUnits(AZStd::vector<NamedRunningStatistic*>& stats, const char* units)
+        {
+            for (auto& iter : m_profilers)
+            {
+                iter.second.m_profiler.GetStatsManager().GetAllStatisticsOfUnits(stats, units);
+            }
+        }
+
     private:
         struct ProfilerInfo
         {

Code/Framework/AzCore/AzCore/Statistics/StatisticsManager.h

@@ -56,13 +56,25 @@ namespace AZ
 
             void GetAllStatistics(AZStd::vector<NamedRunningStatistic*>& vector)
             {
-                for (auto const& it : m_statistics)
+                for (const auto& it : m_statistics)
                 {
                     NamedRunningStatistic* stat = it.second;
                     vector.push_back(stat);
                 }
             }
 
+            void GetAllStatisticsOfUnits(AZStd::vector<NamedRunningStatistic*>& vector, const char* units)
+            {
+                for (const auto& it : m_statistics)
+                {
+                    NamedRunningStatistic* stat = it.second;
+                    if (stat->GetUnits() == units)
+                    {
+                        vector.push_back(stat);
+                    }
+                }
+            }
+
             //! Helper method to apply units to statistics with empty units string.
             AZ::u32 ApplyUnits(const AZStd::string& units)
             {

Gems/Profiler/Code/Source/CpuProfilerImpl.h

@@ -150,7 +150,7 @@ namespace Profiler
 
         AZStd::mutex m_continuousCaptureEndingMutex;
 
-        AZStd::atomic_bool m_continuousCaptureInProgress;
+        AZStd::atomic_bool m_continuousCaptureInProgress = false;
 
         // Stores multiple frames of profiling data, size is controlled by MaxFramesToSave. Flushed when EndContinuousCapture is called.
         // Ring buffer so that we can have fast append of new data + removal of old profiling data with good cache locality.

Gems/Profiler/Code/Source/ImGuiCpuProfiler.cpp

@@ -23,9 +23,13 @@
 #include <AzCore/std/sort.h>
 #include <AzCore/std/string/conversions.h>
 #include <AzCore/std/time.h>
+#include <AzCore/Time/ITime.h>
 
 namespace Profiler
 {
+    constexpr AZStd::sys_time_t ProfilerViewEdgePadding = 5000;
+    constexpr size_t InitialCpuTimingStatsAllocation = 8;
+
     namespace CpuProfilerImGuiHelper
     {
         float TicksToMs(double ticks)
@@ -435,6 +439,11 @@ namespace Profiler
         m_tableData.clear();
         m_groupRegionMap.clear();
 
+        // Since we don't serialize the frame boundaries, we will use "Component application simulation tick" from
+        // ComponentApplication::Tick as a heuristic.
+        static const AZ::Name::Hash frameBoundaryHash = AZ::Name("Component application simulation tick").GetHash();
+
+        AZStd::sys_time_t frameTime = 0;
         for (const auto& entry : deserializedData)
         {
             const auto [groupNameItr, wasGroupNameInserted] = m_deserializedStringPool.emplace(entry.m_groupName.GetCStr());
@@ -445,10 +454,12 @@ namespace Profiler
             const CachedTimeRegion newRegion(*groupRegionNameItr, entry.m_stackDepth, entry.m_startTick, entry.m_endTick);
             m_savedData[entry.m_threadId].push_back(newRegion);
 
-            // Since we don't serialize the frame boundaries, we need to use the RPI's OnSystemTick event as a heuristic.
-            const static AZ::Name frameBoundaryName = AZ::Name("RPISystem: OnSystemTick");
-            if (entry.m_regionName == frameBoundaryName)
+            if (entry.m_regionName.GetHash() == frameBoundaryHash)
             {
+                if (!m_frameEndTicks.empty())
+                {
+                    frameTime = entry.m_endTick - m_frameEndTicks.back();
+                }
                 m_frameEndTicks.push_back(entry.m_endTick);
             }
 
@@ -462,9 +473,9 @@ namespace Profiler
             m_groupRegionMap[*groupNameItr][*regionNameItr].RecordRegion(newRegion, entry.m_threadId);
         }
 
-        // Update viewport bounds with some added UX fudge factor
-        m_viewportStartTick = deserializedData.back().m_startTick - 1000;
-        m_viewportEndTick = deserializedData.back().m_endTick + 1000;
+        // Update viewport bounds to the estimated final frame time with some padding
+        m_viewportStartTick = m_frameEndTicks.back() - frameTime - ProfilerViewEdgePadding;
+        m_viewportEndTick = m_frameEndTicks.back() + ProfilerViewEdgePadding;
 
         // Invariant: each vector in m_savedData must be sorted so that we can efficiently cull region data.
         for (auto& [threadId, singleThreadData] : m_savedData)
@@ -642,21 +653,13 @@ namespace Profiler
         m_cpuTimingStatisticsWhenPause.clear();
         if (auto statsProfiler = AZ::Interface<StatisticalProfilerProxy>::Get(); statsProfiler)
         {
-            auto& rhiMetrics = statsProfiler->GetProfiler(AZ_CRC_CE("RHI"));
-
-            const NamedRunningStatistic* frameTimeMetric = rhiMetrics.GetStatistic(AZ_CRC_CE("Frame to Frame Time"));
-            if (frameTimeMetric)
-            {
-                m_frameToFrameTime = static_cast<AZStd::sys_time_t>(frameTimeMetric->GetMostRecentSample());
-            }
-
             AZStd::vector<NamedRunningStatistic*> statistics;
-            rhiMetrics.GetStatsManager().GetAllStatistics(statistics);
+            statistics.reserve(InitialCpuTimingStatsAllocation);
 
+            statsProfiler->GetAllStatisticsOfUnits(statistics, "clocks");
             for (NamedRunningStatistic* stat : statistics)
             {
                 m_cpuTimingStatisticsWhenPause.push_back({ stat->GetName(), stat->GetMostRecentSample() });
-                stat->Reset();
             }
         }
     }
@@ -731,7 +734,11 @@ namespace Profiler
 
     void ImGuiCpuProfiler::CullFrameData()
     {
-        const AZStd::sys_time_t deleteBeforeTick = AZStd::GetTimeNowTicks() - m_frameToFrameTime * m_framesToCollect;
+        const AZ::TimeUs delta = AZ::GetRealTickDeltaTimeUs();
+        const float deltaTimeInSeconds = AZ::TimeUsToSeconds(delta);
+        const AZStd::sys_time_t frameToFrameTime = static_cast<AZStd::sys_time_t>(deltaTimeInSeconds * AZStd::GetTimeTicksPerSecond());
+
+        const AZStd::sys_time_t deleteBeforeTick = AZStd::GetTimeNowTicks() - frameToFrameTime * m_framesToCollect;
 
         // Remove old frame boundary data
         auto firstBoundaryToKeepItr = AZStd::upper_bound(m_frameEndTicks.begin(), m_frameEndTicks.end(), deleteBeforeTick);

Gems/Profiler/Code/Source/ImGuiCpuProfiler.h

@@ -89,7 +89,7 @@ namespace Profiler
         struct CpuTimingEntry
         {
             const AZStd::string& m_name;
-            double m_executeDuration;
+            double m_executeDuration = 0;
         };
 
         ImGuiCpuProfiler() = default;
@@ -175,8 +175,8 @@ namespace Profiler
         AZ::u64 m_savedRegionCount = 0;
 
         // Viewport tick bounds, these are used to convert tick space -> screen space and cull so we only draw onscreen objects
-        AZStd::sys_time_t m_viewportStartTick;
-        AZStd::sys_time_t m_viewportEndTick;
+        AZStd::sys_time_t m_viewportStartTick = 0;
+        AZStd::sys_time_t m_viewportEndTick = 0;
 
         // Map to store each thread's TimeRegions, individual vectors are sorted by start tick
         // note: we use size_t as a proxy for thread_id because native_thread_id_type differs differs from
@@ -215,7 +215,6 @@ namespace Profiler
 
         // Last captured CPU timing statistics
         AZStd::vector<CpuTimingEntry> m_cpuTimingStatisticsWhenPause;
-        AZStd::sys_time_t m_frameToFrameTime{};
 
         AZ::IO::FixedMaxPath m_lastCapturedFilePath;