support orthographic projection in tiled lighting (fptl renderloop only atm)

support orthographic projection in tiled lighting (fptl renderloop only
atm)

Assets/ScriptableRenderPipeline/Fptl/FptlLighting.cs

             cmd.SetComputeBufferParam(buildPerVoxelLightListShader, s_ClearVoxelAtomicKernel, "g_LayeredSingleIdxBuffer", s_GlobalLightListAtomic);
             cmd.DispatchCompute(buildPerVoxelLightListShader, s_ClearVoxelAtomicKernel, 1, 1, 1);
 
+            bool isOrthographic = camera.orthographic;
+            cmd.SetComputeIntParam(buildPerVoxelLightListShader, "g_isOrthographic", isOrthographic ? 1 : 0);
             cmd.SetComputeIntParam(buildPerVoxelLightListShader, "g_iNrVisibLights", numLights);
             cmd.SetComputeMatrixParam(buildPerVoxelLightListShader, "g_mScrProjection", projscr);
             cmd.SetComputeMatrixParam(buildPerVoxelLightListShader, "g_mInvScrProjection", invProjscr);
 
             var cmd = CommandBufferPool.Get("Build light list" );
 
+            bool isOrthographic = camera.orthographic;
+
             // generate screen-space AABBs (used for both fptl and clustered).
             if (numLights != 0)
             {
                 var projh = temp * proj;
                 var invProjh = projh.inverse;
 
+                cmd.SetComputeIntParam(buildScreenAABBShader, "g_isOrthographic", isOrthographic ? 1 : 0);
                 cmd.SetComputeIntParam(buildScreenAABBShader, "g_iNrVisibLights", numLights);
                 cmd.SetComputeMatrixParam(buildScreenAABBShader, "g_mProjection", projh);
                 cmd.SetComputeMatrixParam(buildScreenAABBShader, "g_mInvProjection", invProjh);
             // enable coarse 2D pass on 64x64 tiles (used for both fptl and clustered).
             if (enableBigTilePrepass)
             {
+                cmd.SetComputeIntParam(buildPerBigTileLightListShader, "g_isOrthographic", isOrthographic ? 1 : 0);
                 cmd.SetComputeIntParams(buildPerBigTileLightListShader, "g_viDimensions", new int[2] { w, h });
                 cmd.SetComputeIntParam(buildPerBigTileLightListShader, "g_iNrVisibLights", numLights);
                 cmd.SetComputeMatrixParam(buildPerBigTileLightListShader, "g_mScrProjection", projscr);
 
             if (usingFptl)        // optimized for opaques only
             {
+                cmd.SetComputeIntParam(buildPerTileLightListShader, "g_isOrthographic", isOrthographic ? 1 : 0);
                 cmd.SetComputeIntParams(buildPerTileLightListShader, "g_viDimensions", new int[2] { w, h });
                 cmd.SetComputeIntParam(buildPerTileLightListShader, "g_iNrVisibLights", numLights);
                 cmd.SetComputeMatrixParam(buildPerTileLightListShader, "g_mScrProjection", projscr);
         void PushGlobalParams(Camera camera, ScriptableRenderContext loop, Matrix4x4 viewToWorld, Matrix4x4 scrProj, Matrix4x4 incScrProj, int numDirLights)
         {
             var cmd = CommandBufferPool.Get("Push Global Parameters");
-
+                  
+            bool isOrthographic = camera.orthographic;
+            cmd.SetGlobalFloat("g_isOrthographic", (float) (isOrthographic ? 1 : 0));
             cmd.SetGlobalFloat("g_widthRT", (float)camera.pixelWidth);
             cmd.SetGlobalFloat("g_heightRT", (float)camera.pixelHeight);
 

Assets/ScriptableRenderPipeline/Fptl/LightingConvexHullUtils.hlsl

     return float4(vN, -dot(vN,p0));
 }
 
-bool DoesSphereOverlapTile(float3 dir, float halfTileSizeAtZDistOne, float3 sphCen, float sphRadiusIn)
+bool DoesSphereOverlapTile(float3 dir, float halfTileSizeAtZDistOne, float3 sphCen_in, float sphRadiusIn, bool isOrthographic)
-    float3 V = dir;     // ray direction down center of tile (does not need to be normalized).
+    float3 V = float3(isOrthographic ? 0.0 : dir.x, isOrthographic ? 0.0 : dir.y, dir.z);     // ray direction down center of tile (does not need to be normalized).
+	float3 sphCen = float3(sphCen_in.x - (isOrthographic ? dir.x : 0.0), sphCen_in.y - (isOrthographic ? dir.y : 0.0), sphCen_in.z); 
 
 #if 1
     float3 maxZdir = float3(-sphCen.z*sphCen.x, -sphCen.z*sphCen.y, sphCen.x*sphCen.x + sphCen.y*sphCen.y);     // cross(sphCen,cross(Zaxis,sphCen))
 
     // enlarge sphere so it overlaps the center of the tile assuming it overlaps the tile to begin with.
 #if USE_LEFTHAND_CAMERASPACE
-    float sphRadius = sphRadiusIn + (sphCen.z+offs)*halfTileSizeAtZDistOne;
+	float s = sphCen.z+offs;
-    float sphRadius = sphRadiusIn - (sphCen.z-offs)*halfTileSizeAtZDistOne;
+	float s = -(sphCen.z-offs);
+	float sphRadius = sphRadiusIn + (isOrthographic ? 1.0 : s)*halfTileSizeAtZDistOne;
 
     float a = dot(V,V);
     float CdotV = dot(sphCen,V);

Assets/ScriptableRenderPipeline/Fptl/LightingUtils.hlsl

 uniform float4x4 g_mInvScrProjection;
 
 
+uniform uint g_isOrthographic;
 uniform uint g_widthRT;
 uniform uint g_heightRT;
 
-    float fSx = g_mScrProjection[0].x;
-    //float fCx = g_mScrProjection[2].x;
-    float fCx = g_mScrProjection[0].z;
-    float fSy = g_mScrProjection[1].y;
-    //float fCy = g_mScrProjection[2].y;
-    float fCy = g_mScrProjection[1].z;
+	bool isOrthographic = g_isOrthographic!=0;
+	float fSx = g_mScrProjection[0].x;
+	float fSy = g_mScrProjection[1].y;
+	float fCx = isOrthographic ? g_mScrProjection[0].w : g_mScrProjection[0].z;
+	float fCy = isOrthographic ? g_mScrProjection[1].w : g_mScrProjection[1].z;
-    return fLinDepth*float3( ((v2ScrPos.x-fCx)/fSx), ((v2ScrPos.y-fCy)/fSy), 1.0 );
+	bool useLeftHandVersion = true;
-    return fLinDepth*float3( -((v2ScrPos.x+fCx)/fSx), -((v2ScrPos.y+fCy)/fSy), 1.0 );
+	bool useLeftHandVersion = isOrthographic;
+
+	float s = useLeftHandVersion ? 1 : (-1);
+	float2 p = float2( (s*v2ScrPos.x-fCx)/fSx, (s*v2ScrPos.y-fCy)/fSy);
+
+	return float3(isOrthographic ? p.xy : (fLinDepth*p.xy), fLinDepth);
 }
 
 float GetLinearZFromSVPosW(float posW)
 
 float GetLinearDepth(float zDptBufSpace)    // 0 is near 1 is far
 {
-    // todo (simplify): m22 is zero and m23 is +1/-1 (depends on left/right hand proj)
+    // for perspective projection m22 is zero and m23 is +1/-1 (depends on left/right hand proj)
+	// however this function must also work for orthographic projection so we keep it like this.
     float m22 = g_mInvScrProjection[2].z, m23 = g_mInvScrProjection[2].w;
     float m32 = g_mInvScrProjection[3].z, m33 = g_mInvScrProjection[3].w;
 

Assets/ScriptableRenderPipeline/Fptl/lightlistbuild-bigtile.compute

 #define MAX_NR_BIGTILE_LIGHTS				(MAX_NR_BIGTILE_LIGHTS_PLUSONE-1)
 
 
+uniform int g_isOrthographic;
 uniform int g_iNrVisibLights;
 uniform uint2 g_viDimensions;
 uniform float4x4 g_mInvScrProjection;
 
 float3 GetViewPosFromLinDepth(float2 v2ScrPos, float fLinDepth)
 {
+	bool isOrthographic = g_isOrthographic!=0;
-	float fCx = g_mScrProjection[0].z;
-	float fCy = g_mScrProjection[1].z;
+	float fCx = isOrthographic ? g_mScrProjection[0].w : g_mScrProjection[0].z;
+	float fCy = isOrthographic ? g_mScrProjection[1].w : g_mScrProjection[1].z;
-	return fLinDepth*float3( ((v2ScrPos.x-fCx)/fSx), ((v2ScrPos.y-fCy)/fSy), 1.0 );
+	bool useLeftHandVersion = true;
-	return fLinDepth*float3( -((v2ScrPos.x+fCx)/fSx), -((v2ScrPos.y+fCy)/fSy), 1.0 );
+	bool useLeftHandVersion = isOrthographic;
+
+	float s = useLeftHandVersion ? 1 : (-1);
+	float2 p = float2( (s*v2ScrPos.x-fCx)/fSx, (s*v2ScrPos.y-fCy)/fSy);
+
+	return float3(isOrthographic ? p.xy : (fLinDepth*p.xy), fLinDepth);
 }
 
 float GetOnePixDiagWorldDistAtDepthOne()
 	{
 		SFiniteLightBound lgtDat = g_data[lightsListLDS[l]];
 
-		if( !DoesSphereOverlapTile(V, halfTileSizeAtZDistOne, lgtDat.center.xyz, lgtDat.radius) )
+		if( !DoesSphereOverlapTile(V, halfTileSizeAtZDistOne, lgtDat.center.xyz, lgtDat.radius, g_isOrthographic!=0) )
 			lightsListLDS[l]=0xffffffff;
 	}
 
 
 	int i=iSwizzle + (2*(iSection&0x2));	// offset by 4 at section 2
 	vP0 = GetTileVertex(uint2(viTilLL.x, viTilUR.y), uint2(viTilUR.x, viTilLL.y), i, fTileFarPlane);
-	vE0 = iSection == 0 ? vP0 : (((iSwizzle & 0x2) == 0 ? 1.0f : (-1.0f)) * ((int)(iSwizzle & 0x1) == (iSwizzle >> 1) ? float3(1, 0, 0) : float3(0, 1, 0)));
+
+#if USE_LEFTHAND_CAMERASPACE
+	float3 edgeSectionZero = g_isOrthographic==0 ? vP0 : float3(0.0,0.0,1.0); 
+#else
+	float3 edgeSectionZero = g_isOrthographic==0 ? vP0 : float3(0.0,0.0,-1.0); 
+#endif
+
+	vE0 = iSection == 0 ? edgeSectionZero : (((iSwizzle & 0x2) == 0 ? 1.0f : (-1.0f)) * ((int)(iSwizzle & 0x1) == (iSwizzle >> 1) ? float3(1, 0, 0) : float3(0, 1, 0)));
 }
 
 void CullByExactEdgeTests(uint threadID, int iNrCoarseLights, uint2 viTilLL, uint2 viTilUR)

Assets/ScriptableRenderPipeline/Fptl/lightlistbuild-clustered.compute

 #define PERFORM_SPHERICAL_INTERSECTION_TESTS
 #define CONV_HULL_TEST_ENABLED
 
+uniform int g_isOrthographic;
 uniform int g_iNrVisibLights;
 uniform float4x4 g_mInvScrProjection;
 uniform float4x4 g_mScrProjection;
 
 float3 GetViewPosFromLinDepth(float2 v2ScrPos, float fLinDepth)
 {
+	bool isOrthographic = g_isOrthographic!=0;
-	float fCx = g_mScrProjection[0].z;
-	float fCy = g_mScrProjection[1].z;
+	float fCx = isOrthographic ? g_mScrProjection[0].w : g_mScrProjection[0].z;
+	float fCy = isOrthographic ? g_mScrProjection[1].w : g_mScrProjection[1].z;
-	return fLinDepth*float3( ((v2ScrPos.x-fCx)/fSx), ((v2ScrPos.y-fCy)/fSy), 1.0 );
+	bool useLeftHandVersion = true;
-	return fLinDepth*float3( -((v2ScrPos.x+fCx)/fSx), -((v2ScrPos.y+fCy)/fSy), 1.0 );
+	bool useLeftHandVersion = isOrthographic;
+
+	float s = useLeftHandVersion ? 1 : (-1);
+	float2 p = float2( (s*v2ScrPos.x-fCx)/fSx, (s*v2ScrPos.y-fCy)/fSy);
+
+	return float3(isOrthographic ? p.xy : (fLinDepth*p.xy), fLinDepth);
 }
 
 float GetOnePixDiagWorldDistAtDepthOne()
 	{
 		SFiniteLightBound lgtDat = g_data[coarseList[l]];
 
-		if( !DoesSphereOverlapTile(V, halfTileSizeAtZDistOne, lgtDat.center.xyz, lgtDat.radius) )
+		if( !DoesSphereOverlapTile(V, halfTileSizeAtZDistOne, lgtDat.center.xyz, lgtDat.radius, g_isOrthographic!=0) )
 			coarseList[l]=0xffffffff;
 	}
 
 
 	int i=iSwizzle + (2*(iSection&0x2));	// offset by 4 at section 2
 	vP0 = GetTileVertex(uint2(viTilLL.x, viTilUR.y), uint2(viTilUR.x, viTilLL.y), i, fTileFarPlane);
-	vE0 = iSection==0 ? vP0 : (((iSwizzle&0x2)==0 ? 1.0f : (-1.0f))*((iSwizzle&0x1)==(iSwizzle>>1) ? float3(1,0,0) : float3(0,1,0)));
+
+#if USE_LEFTHAND_CAMERASPACE
+	float3 edgeSectionZero = g_isOrthographic==0 ? vP0 : float3(0.0,0.0,1.0); 
+#else
+	float3 edgeSectionZero = g_isOrthographic==0 ? vP0 : float3(0.0,0.0,-1.0); 
+#endif
+
+	vE0 = iSection==0 ? edgeSectionZero : (((iSwizzle&0x2)==0 ? 1.0f : (-1.0f))*((iSwizzle&0x1)==(iSwizzle>>1) ? float3(1,0,0) : float3(0,1,0)));
 }
 
 int CullByExactEdgeTests(uint threadID, int iNrCoarseLights, uint2 viTilLL, uint2 viTilUR, float fTileFarPlane)

Assets/ScriptableRenderPipeline/Fptl/lightlistbuild.compute

 #define PERFORM_SPHERICAL_INTERSECTION_TESTS
 
 
+uniform int g_isOrthographic;
 uniform int g_iNrVisibLights;
 uniform uint2 g_viDimensions;
 uniform float4x4 g_mInvScrProjection;
 
 float3 GetViewPosFromLinDepth(float2 v2ScrPos, float fLinDepth)
 {
+	bool isOrthographic = g_isOrthographic!=0;
-	float fCx = g_mScrProjection[0].z;
-	float fCy = g_mScrProjection[1].z;
+	float fCx = isOrthographic ? g_mScrProjection[0].w : g_mScrProjection[0].z;
+	float fCy = isOrthographic ? g_mScrProjection[1].w : g_mScrProjection[1].z;
-	return fLinDepth*float3( ((v2ScrPos.x-fCx)/fSx), ((v2ScrPos.y-fCy)/fSy), 1.0 );
+	bool useLeftHandVersion = true;
-	return fLinDepth*float3( -((v2ScrPos.x+fCx)/fSx), -((v2ScrPos.y+fCy)/fSy), 1.0 );
+	bool useLeftHandVersion = isOrthographic;
+
+	float s = useLeftHandVersion ? 1 : (-1);
+	float2 p = float2( (s*v2ScrPos.x-fCx)/fSx, (s*v2ScrPos.y-fCy)/fSy);
+
+	return float3(isOrthographic ? p.xy : (fLinDepth*p.xy), fLinDepth);
 }
 
 float GetOnePixDiagWorldDistAtDepthOne()
 	{
 		SFiniteLightBound lightData = g_data[prunedList[l]];
 
-		if( DoesSphereOverlapTile(V, halfTileSizeAtZDistOne, lightData.center.xyz, lightData.radius) )
+		if( DoesSphereOverlapTile(V, halfTileSizeAtZDistOne, lightData.center.xyz, lightData.radius, g_isOrthographic!=0) )
 		{
 			unsigned int uIndex;
 			InterlockedAdd(lightOffsSph, 1, uIndex);

Assets/ScriptableRenderPipeline/Fptl/scrbound.compute

 #include "ShaderBase.h"
 #include "LightDefinitions.cs.hlsl"
 
+uniform int g_isOrthographic;
 uniform int g_iNrVisibLights;
 uniform float4x4 g_mInvProjection;
 uniform float4x4 g_mProjection;
 			}
 			else
 			{
-				//if((center.z+radius)<0.0)
-				if( length(center)>radius)
+				if(g_isOrthographic==0 && length(center)>radius)
 				{
 					float2 vMi, vMa;
 					bool2 bMi, bMa;
 					vMax.xy = bMa ? min(vMax.xy, vMa) : vMax.xy;
+				}
+				else if(g_isOrthographic!=0)
+				{
+					float2 vMi = mul(g_mProjection, float4(center.xyz-radius,1)).xy;	 // no division needed for ortho
+					float2 vMa = mul(g_mProjection, float4(center.xyz+radius,1)).xy;	 // no division needed for ortho
+					vMin.xy = max(vMin.xy, vMi);
+					vMax.xy = min(vMax.xy, vMa);
 				}
 
 #if USE_LEFTHAND_CAMERASPACE