Port and refactor virtual_workgroup.hlsl

Author: kpentaris

include/nbl/builtin/hlsl/scan/virtual_workgroup.hlsl

@@ -0,0 +1,91 @@
+#ifndef _NBL_HLSL_SCAN_VIRTUAL_WORKGROUP_INCLUDED_
+#define _NBL_HLSL_SCAN_VIRTUAL_WORKGROUP_INCLUDED_
+
+// TODO (PentaKon): Decide if these are needed once we have a clearer picture of the refactor
+#include <nbl/builtin/hlsl/limits/numeric.hlsl>
+#include <nbl/builtin/hlsl/math/typeless_arithmetic.hlsl>
+#include <nbl/builtin/hlsl/workgroup/arithmetic.hlsl> // This is where all the nbl_glsl_workgroupOPs are defined
+#include <nbl/builtin/hlsl/scan/declarations.hlsl>
+
+#include <nbl/builtin/hlsl/binops.hlsl>
+
+const uint gl_LocalInvocationIndex: SV_GroupIndex;
+
+namespace nbl
+{
+namespace hlsl
+{
+namespace scan
+{
+	template<class Binop, class Storage_t>
+	void virtualWorkgroup(in uint treeLevel, in uint localWorkgroupIndex)
+	{
+		Binop binop;
+		const Parameters_t params = getParameters();
+		const uint levelInvocationIndex = localWorkgroupIndex * _NBL_HLSL_WORKGROUP_SIZE_ + gl_LocalInvocationIndex;
+		const bool lastInvocationInGroup = gl_LocalInvocationIndex == (_NBL_HLSL_WORKGROUP_SIZE_ - 1);
+		
+		const uint lastLevel = params.topLevel << 1u;
+		const uint pseudoLevel = levelInvocationIndex <= params.lastElement[pseudoLevel];
+		
+		const bool inRange = levelInvocationIndex <= params.lastElement[pseudoLevel];
+		
+		Storage_t data = binop::identity();
+		if(inRange)
+		{
+			getData(data, levelInvocationIndex, localWorkgroupIndex, treeLevel, pseudoLevel);
+		}
+		
+		if(treeLevel < params.topLevel) 
+		{
+			data = workgroup::reduction<binop>()(data);
+		}
+		// REVIEW: missing _TYPE_ check and extra case here
+		else if (treeLevel != params.topLevel)
+		{
+			data = workgroup::inclusive_scan<binop>()(data);
+		}
+		else
+		{
+			data = workgroup::exclusive_scan<binop>()(data);
+		}
+		setData(data, levelInvocationIndex, localWorkgroupIndex, treeLevel, pseudoLevel, inRange);
+	}
+}
+}
+}
+
+#ifndef _NBL_HLSL_SCAN_MAIN_DEFINED_ // TODO REVIEW: Are these needed, can this logic be refactored?
+#include <nbl/builtin/hlsl/scan/default_scheduler.hlsl>
+namespace nbl
+{
+namespace hlsl
+{
+namespace scan
+{
+	DefaultSchedulerParameters_t getSchedulerParameters(); // this is defined in the final shader that assembles all the SCAN operation components
+	void main()
+	{
+		const DefaultSchedulerParameters_t schedulerParams = getSchedulerParameters();
+		const uint topLevel = getParameters().topLevel;
+		// persistent workgroups
+		while (true)
+		{
+			uint treeLevel,localWorkgroupIndex;
+			if (scheduler::getWork(schedulerParams,topLevel,treeLevel,localWorkgroupIndex))
+			{
+				return;
+			}
+
+			virtualWorkgroup(treeLevel,localWorkgroupIndex);
+
+			scheduler::markComplete(schedulerParams,topLevel,treeLevel,localWorkgroupIndex);
+		}
+	}
+}
+}
+}
+#define _NBL_HLSL_SCAN_MAIN_DEFINED_
+#endif
+
+#endif