From 01a86e2b3d8c51f62a94f2b6c48f4deeca6503e2 Mon Sep 17 00:00:00 2001
From: Robert Beckebans <robert.beckebans@gmail.com>
Date: Thu, 10 Mar 2022 20:20:48 +0100
Subject: [PATCH] Fixed flash light shadow maps

---
 neo/renderer/RenderBackend.cpp                | 34 +++++++++++++------
 .../builtin/lighting/interactionSM.ps.hlsl    |  3 +-
 neo/sys/win32/win_wndproc.cpp                 |  2 +-
 3 files changed, 26 insertions(+), 13 deletions(-)

diff --git a/neo/renderer/RenderBackend.cpp b/neo/renderer/RenderBackend.cpp
index e21edc08..306b81b6 100644
--- a/neo/renderer/RenderBackend.cpp
+++ b/neo/renderer/RenderBackend.cpp
@@ -3118,6 +3118,13 @@ void idRenderBackend::ShadowMapPass( const drawSurf_t* drawSurfs, const viewLigh
 	idRenderMatrix lightProjectionRenderMatrix;
 	idRenderMatrix lightViewRenderMatrix;
 
+	// Calculate alternate matrix that maps to [0, 1] UV space instead of [-1, 1] clip space
+	ALIGNTYPE16 const idRenderMatrix matClipToUvzw(
+		0.5f,  0.0f, 0.0f, 0.5f,
+		0.0f, -0.5f, 0.0f, 0.5f,
+		0.0f,  0.0f, 1.0f, 0.0f,
+		0.0f,  0.0f, 0.0f, 1.0f
+	);
 
 	if( vLight->parallel && side >= 0 )
 	{
@@ -3275,6 +3282,12 @@ void idRenderBackend::ShadowMapPass( const drawSurf_t* drawSurfs, const viewLigh
 
 		shadowV[side] = lightViewRenderMatrix;
 		shadowP[side] = lightProjectionRenderMatrix;
+
+#if 0 //defined( USE_NVRHI )
+		idRenderMatrix shadowToClip;
+		idRenderMatrix::Multiply( renderMatrix_windowSpaceToClipSpace, lightProjectionRenderMatrix, shadowToClip );
+		idRenderMatrix::Multiply( matClipToUvzw, shadowToClip, shadowP[side] );
+#endif
 	}
 	else if( vLight->pointLight && side >= 0 )
 	{
@@ -3386,7 +3399,7 @@ void idRenderBackend::ShadowMapPass( const drawSurf_t* drawSurfs, const viewLigh
 		lightProjectionMatrix[1 * 4 + 2] = 0.0f;
 		lightProjectionMatrix[2 * 4 + 2] = -0.999f; // adjust value to prevent imprecision issues
 
-#if 0 //defined( USE_NVRHI )
+#if defined( USE_NVRHI )
 		// the D3D clip space Z is in range [0,1] instead of [-1,1]
 		lightProjectionMatrix[3 * 4 + 2] = -zNear;
 #else
@@ -3402,9 +3415,16 @@ void idRenderBackend::ShadowMapPass( const drawSurf_t* drawSurfs, const viewLigh
 
 		shadowV[side] = lightViewRenderMatrix;
 		shadowP[side] = lightProjectionRenderMatrix;
+
+#if 0 //defined( USE_NVRHI )
+		idRenderMatrix shadowToClip;
+		idRenderMatrix::Multiply( renderMatrix_windowSpaceToClipSpace, lightProjectionRenderMatrix, shadowToClip );
+		idRenderMatrix::Multiply( matClipToUvzw, shadowToClip, shadowP[side] );
+#endif
 	}
 	else
 	{
+		// spot light
 		lightViewRenderMatrix.Identity();
 		lightProjectionRenderMatrix = vLight->baseLightProject;
 
@@ -3412,15 +3432,9 @@ void idRenderBackend::ShadowMapPass( const drawSurf_t* drawSurfs, const viewLigh
 		shadowP[0] = lightProjectionRenderMatrix;
 
 #if defined( USE_NVRHI )
-		// Calculate alternate matrix that maps to [0, 1] UV space instead of [-1, 1] clip space
-		ALIGNTYPE16 const idRenderMatrix matClipToUvzw(
-			0.5f,  0.0f, 0.0f, 0.5f,
-			0.0f, -0.5f, 0.0f, 0.5f,
-			0.0f,  0.0f, 1.0f, 0.0f,
-			0.0f,  0.0f, 0.0f, 1.0f
-		);
-
-		idRenderMatrix::Multiply( matClipToUvzw, lightProjectionRenderMatrix, shadowP[0] );
+		idRenderMatrix shadowToClip;
+		idRenderMatrix::Multiply( renderMatrix_windowSpaceToClipSpace, lightProjectionRenderMatrix, shadowToClip );
+		idRenderMatrix::Multiply( matClipToUvzw, shadowToClip, shadowP[0] );
 #endif
 	}
 
diff --git a/neo/shaders/builtin/lighting/interactionSM.ps.hlsl b/neo/shaders/builtin/lighting/interactionSM.ps.hlsl
index 53a005c7..28181078 100644
--- a/neo/shaders/builtin/lighting/interactionSM.ps.hlsl
+++ b/neo/shaders/builtin/lighting/interactionSM.ps.hlsl
@@ -212,7 +212,6 @@ void main( PS_IN fragment, out PS_OUT result )
 
 	float4 modelPosition = float4( fragment.texcoord7.xyz, 1.0 );
 
-
 	float4 shadowTexcoord;
 	shadowTexcoord.x = dot4( modelPosition, shadowMatrixX );
 	shadowTexcoord.y = dot4( modelPosition, shadowMatrixY );
@@ -399,7 +398,7 @@ void main( PS_IN fragment, out PS_OUT result )
 	uvzShadow.z = shadowTexcoord.w;
 	float shadow = t_ShadowMapArray.SampleCmpLevelZero( samp2, uvzShadow, shadowTexcoord.z );
 
-#if 1
+#if 0
 	if( shadowIndex == 0 )
 	{
 		result.color = float4( 1.0, 0.0, 0.0, 1.0 );
diff --git a/neo/sys/win32/win_wndproc.cpp b/neo/sys/win32/win_wndproc.cpp
index 60f966c1..f77c28a5 100644
--- a/neo/sys/win32/win_wndproc.cpp
+++ b/neo/sys/win32/win_wndproc.cpp
@@ -179,7 +179,7 @@ LONG WINAPI MainWndProc( HWND hWnd, UINT uMsg, WPARAM wParam, LPARAM lParam )
 	switch( uMsg )
 	{
 		case WM_WINDOWPOSCHANGED:
-			if( renderSystem->IsInitialized() && win32.hDC != NULL )
+			if( renderSystem->IsInitialized() )//&& win32.hDC != NULL )
 			{
 				RECT rect;
 				if( ::GetClientRect( win32.hWnd, &rect ) )