Fix for Issue 226. Updated gather commands to match PMC.

Author: markgalvan-intel

IntelPresentMon/PresentMonMiddleware/source/FrameEventQuery.cpp

@@ -28,6 +28,17 @@ namespace pmon::mid
 
 namespace
 {
+	double TimestampDeltaToMilliSeconds(uint64_t timestampDelta, double performanceCounterPeriodMs)
+	{
+		return performanceCounterPeriodMs * double(timestampDelta);
+	}
+
+	double TimestampDeltaToUnsignedMilliSeconds(uint64_t timestampFrom, uint64_t timestampTo, double performanceCounterPeriodMs)
+	{
+		return timestampFrom == 0 || timestampTo <= timestampFrom ? 0.0 : 
+			TimestampDeltaToMilliSeconds(timestampTo - timestampFrom, performanceCounterPeriodMs);
+	}
+
 	template<auto pMember>
 	constexpr auto GetSubstructurePointer()
 	{
@@ -156,8 +167,8 @@ namespace
 				reinterpret_cast<double&>(pDestBlob[outputOffset_]) = val;
 			}
 			else {
-				const auto qpcDuration = ctx.pSourceFrameData->present_event.*pEnd - start;
-				const auto val = ctx.performanceCounterPeriodMs * double(qpcDuration);
+				const auto val = TimestampDeltaToUnsignedMilliSeconds(start,
+					ctx.pSourceFrameData->present_event.*pEnd, ctx.performanceCounterPeriodMs);
 				reinterpret_cast<double&>(pDestBlob[outputOffset_]) = val;
 			}
 		}
@@ -272,8 +283,8 @@ namespace
 					return;
 				}
 			}
-			const auto qpcDuration = ctx.pSourceFrameData->present_event.*pEnd - ctx.cpuFrameQpc;
-			const auto val = ctx.performanceCounterPeriodMs * double(qpcDuration);
+			const auto val = TimestampDeltaToUnsignedMilliSeconds(ctx.cpuFrameQpc, 
+				ctx.pSourceFrameData->present_event.*pEnd, ctx.performanceCounterPeriodMs);
 			reinterpret_cast<double&>(pDestBlob[outputOffset_]) = val;
 		}
 		uint32_t GetBeginOffset() const override
@@ -310,8 +321,8 @@ namespace
 					return;
 				}
 			}
-			const auto qpcDuration = ctx.nextDisplayedQpc - ctx.pSourceFrameData->present_event.*pStart;
-			const auto val = ctx.performanceCounterPeriodMs * double(qpcDuration);
+			const auto val = TimestampDeltaToUnsignedMilliSeconds(ctx.pSourceFrameData->present_event.*pStart,
+				ctx.nextDisplayedQpc, ctx.performanceCounterPeriodMs);
 			reinterpret_cast<double&>(pDestBlob[outputOffset_]) = val;
 		}
 		uint32_t GetBeginOffset() const override
@@ -362,9 +373,11 @@ namespace
 		GpuWaitGatherCommand_(size_t nextAvailableByteOffset) : outputOffset_{ (uint32_t)nextAvailableByteOffset } {}
 		void Gather(const Context& ctx, uint8_t* pDestBlob) const override
 		{
-			const auto qpcDuration = (ctx.pSourceFrameData->present_event.ReadyTime - ctx.pSourceFrameData->present_event.GPUStartTime) -
-				ctx.pSourceFrameData->present_event.GPUDuration;
-			const auto val = std::max(0., ctx.performanceCounterPeriodMs * double(qpcDuration));
+			const auto gpuDuration = TimestampDeltaToUnsignedMilliSeconds(ctx.pSourceFrameData->present_event.GPUStartTime,
+				ctx.pSourceFrameData->present_event.ReadyTime, ctx.performanceCounterPeriodMs);
+			const auto gpuBusy = TimestampDeltaToMilliSeconds(ctx.pSourceFrameData->present_event.GPUDuration,
+				ctx.performanceCounterPeriodMs);
+			const auto val = std::max(0., gpuDuration - gpuBusy);
 			reinterpret_cast<double&>(pDestBlob[outputOffset_]) = val;
 		}
 		uint32_t GetBeginOffset() const override
@@ -540,7 +553,7 @@ std::unique_ptr<mid::GatherCommand_> PM_FRAME_QUERY::MapQueryElementToGatherComm
 	case PM_METRIC_CPU_WAIT:
 		return std::make_unique<QpcDurationGatherCommand_<&Pre::TimeInPresent>>(pos);
 	case PM_METRIC_GPU_TIME:
-		return std::make_unique<QpcDifferenceGatherCommand_<&Pre::GPUStartTime, &Pre::ReadyTime, 1, 0, 1, 0>>(pos);
+		return std::make_unique<QpcDifferenceGatherCommand_<&Pre::GPUStartTime, &Pre::ReadyTime, 0, 0, 0, 0>>(pos);
 	case PM_METRIC_GPU_WAIT:
 		return std::make_unique<GpuWaitGatherCommand_>(pos);
 	case PM_METRIC_DISPLAYED_TIME: