From 68dba8b4e08c6f159f8cc890885fac31509f2e6a Mon Sep 17 00:00:00 2001
From: Alibek Omarov <a1ba.omarov@gmail.com>
Date: Thu, 9 Apr 2026 11:58:15 +0500
Subject: [PATCH] engine: add litwater support

---
 engine/common/mod_bmodel.c | 12 ++++++++++++
 engine/common/mod_local.h  |  4 ++++
 engine/ref_api.h           |  1 +
 3 files changed, 17 insertions(+)

diff --git a/engine/common/mod_bmodel.c b/engine/common/mod_bmodel.c
index 4b8245a9..59bcfe1e 100644
--- a/engine/common/mod_bmodel.c
+++ b/engine/common/mod_bmodel.c
@@ -2407,6 +2407,9 @@ static void Mod_LoadEntities( model_t *mod, const dbspmodel_t *bmod )
 	world.wadlist = NULL;
 	world.wadcount = 0;
 
+	world.litwater_minlight = -1;
+	world.litwater_scale = -1.0f;
+
 	// parse all the wads for loading textures in right ordering
 	while(( pfile = COM_ParseFile( pfile, token, sizeof( token ))) != NULL )
 	{
@@ -2450,6 +2453,15 @@ static void Mod_LoadEntities( model_t *mod, const dbspmodel_t *bmod )
 				Mem_Free( world.generator );
 				world.generator = copystring( token );
 			}
+			else if( !Q_stricmp( keyname, "_litwater" ))
+			{
+				if( Q_atoi( token ) != 0 )
+					SetBits( world.flags, FWORLD_HAS_LITWATER );
+			}
+			else if( !Q_stricmp( keyname, "_litwater_minlight" ))
+				world.litwater_minlight = Q_atoi( token );
+			else if( !Q_stricmp( keyname, "_litwater_scale" ))
+				world.litwater_scale = Q_atof( token );
 		}
 		return;	// all done
 	}
diff --git a/engine/common/mod_local.h b/engine/common/mod_local.h
index e1c32351..cd2cc234 100644
--- a/engine/common/mod_local.h
+++ b/engine/common/mod_local.h
@@ -124,6 +124,10 @@ typedef struct world_static_s
 
 	wadentry_t   *wadlist;
 	int          wadcount;
+
+	// lightmapped water extra info
+	float        litwater_scale;
+	int          litwater_minlight;
 } world_static_t;
 
 #ifndef REF_DLL
diff --git a/engine/ref_api.h b/engine/ref_api.h
index 7b9f8253..72999f8c 100644
--- a/engine/ref_api.h
+++ b/engine/ref_api.h
@@ -105,6 +105,7 @@ GNU General Public License for more details.
 #define FWORLD_CUSTOM_SKYBOX BIT( 1 )
 #define FWORLD_WATERALPHA    BIT( 2 )
 #define FWORLD_HAS_DELUXEMAP BIT( 3 )
+#define FWORLD_HAS_LITWATER  BIT( 4 )
 
 // special rendermode for screenfade modulate
 // (probably will be expanded at some point)