From ba6d3dc75df51ce1e92f16425a332fbcf649fee7 Mon Sep 17 00:00:00 2001
From: "Matias N. Goldberg" <dark_sylinc@yahoo.com.ar>
Date: Sun, 15 Dec 2024 20:34:54 -0300
Subject: [PATCH] Force cull mode NONE when baking lightmaps

---
 Components/Hlms/Unlit/src/OgreHlmsUnlit.cpp |  2 +-
 OgreMain/include/OgreHlms.h                 |  2 +-
 OgreMain/include/OgreHlmsPso.h              |  1 +
 OgreMain/src/OgreHlms.cpp                   | 13 +++++++++++--
 4 files changed, 14 insertions(+), 4 deletions(-)

diff --git a/Components/Hlms/Unlit/src/OgreHlmsUnlit.cpp b/Components/Hlms/Unlit/src/OgreHlmsUnlit.cpp
index e440614ded0..398dc0ca13f 100644
--- a/Components/Hlms/Unlit/src/OgreHlmsUnlit.cpp
+++ b/Components/Hlms/Unlit/src/OgreHlmsUnlit.cpp
@@ -709,7 +709,7 @@ namespace Ogre
         mListener->preparePassHash( shadowNode, casterPass, dualParaboloid, sceneManager, this );
 
         PassCache passCache;
-        passCache.passPso = getPassPsoForScene( sceneManager );
+        passCache.passPso = getPassPsoForScene( sceneManager, false );
         passCache.properties = mT[kNoTid].setProperties;
 
         assert( mPassCache.size() <= (size_t)HlmsBits::PassMask &&
diff --git a/OgreMain/include/OgreHlms.h b/OgreMain/include/OgreHlms.h
index ebbba3ea843..4c15ad6b2fe 100644
--- a/OgreMain/include/OgreHlms.h
+++ b/OgreMain/include/OgreHlms.h
@@ -547,7 +547,7 @@ namespace Ogre
         HlmsCache preparePassHashBase( const Ogre::CompositorShadowNode *shadowNode, bool casterPass,
                                        bool dualParaboloid, SceneManager *sceneManager );
 
-        HlmsPassPso getPassPsoForScene( SceneManager *sceneManager );
+        HlmsPassPso getPassPsoForScene( SceneManager *sceneManager, const bool bForceCullNone );
 
         /// OpenGL sets texture binding slots from C++
         /// All other APIs set the slots from shader.
diff --git a/OgreMain/include/OgreHlmsPso.h b/OgreMain/include/OgreHlmsPso.h
index e29259ebb01..29361a60635 100644
--- a/OgreMain/include/OgreHlmsPso.h
+++ b/OgreMain/include/OgreHlmsPso.h
@@ -111,6 +111,7 @@ namespace Ogre
             InvertVertexWinding         = 1u << 1u,
             NoDepthBuffer               = 1u << 2u,
             ForceDepthClamp             = 1u << 3u,
+            ForceCullNone               = 1u << 4u,
             // clang-format on
         };
     };
diff --git a/OgreMain/src/OgreHlms.cpp b/OgreMain/src/OgreHlms.cpp
index 347cc475603..8616551ce85 100644
--- a/OgreMain/src/OgreHlms.cpp
+++ b/OgreMain/src/OgreHlms.cpp
@@ -2230,6 +2230,9 @@ namespace Ogre
                 prepassMacroblock.mCullMode =
                     prepassMacroblock.mCullMode == CULL_CLOCKWISE ? CULL_ANTICLOCKWISE : CULL_CLOCKWISE;
             }
+            // We need to disable culling.
+            if( pso.pass.strongMacroblockBits & HlmsPassPso::ForceCullNone )
+                prepassMacroblock.mCullMode = CULL_NONE;
             // Force depth clamp. Probably a directional shadow caster pass
             if( pso.pass.strongMacroblockBits & HlmsPassPso::ForceDepthClamp )
                 prepassMacroblock.mDepthClamp = true;
@@ -2923,6 +2926,8 @@ namespace Ogre
 
         const CompositorPass *pass = sceneManager->getCurrentCompositorPass();
 
+        bool bForceCullNone = false;
+
         if( !casterPass )
         {
             size_t numShadowMapLights = 0u;
@@ -3165,6 +3170,7 @@ namespace Ogre
                     static_cast<const CompositorPassSceneDef *>( pass->getDefinition() );
                 if( passSceneDef->mUvBakingSet != 0xFF )
                 {
+                    bForceCullNone = true;
                     setProperty( kNoTid, HlmsBaseProp::UseUvBaking, 1 );
                     setProperty( kNoTid, HlmsBaseProp::UvBaking, passSceneDef->mUvBakingSet );
                     if( passSceneDef->mBakeLightingOnly )
@@ -3495,7 +3501,7 @@ namespace Ogre
         mListener->preparePassHash( shadowNode, casterPass, dualParaboloid, sceneManager, this );
 
         PassCache passCache;
-        passCache.passPso = getPassPsoForScene( sceneManager );
+        passCache.passPso = getPassPsoForScene( sceneManager, bForceCullNone );
         passCache.properties = mT[kNoTid].setProperties;
 
         assert( mPassCache.size() <= HlmsBits::PassMask &&
@@ -3516,7 +3522,7 @@ namespace Ogre
         return retVal;
     }
     //-----------------------------------------------------------------------------------
-    HlmsPassPso Hlms::getPassPsoForScene( SceneManager *sceneManager )
+    HlmsPassPso Hlms::getPassPsoForScene( SceneManager *sceneManager, const bool bForceCullNone )
     {
         const RenderPassDescriptor *renderPassDesc = mRenderSystem->getCurrentPassDescriptor();
 
@@ -3564,6 +3570,9 @@ namespace Ogre
         if( sceneManager->getCamerasInProgress().renderingCamera->getNeedsDepthClamp() )
             passPso.strongMacroblockBits |= HlmsPassPso::ForceDepthClamp;
 
+        if( bForceCullNone )
+            passPso.strongMacroblockBits |= HlmsPassPso::ForceCullNone;
+
         const bool invertVertexWinding = mRenderSystem->getInvertVertexWinding();
 
         if( ( renderPassDesc->requiresTextureFlipping() && !invertVertexWinding ) ||