From 547a41ef2d2bf5cf8f90a782015cfeb2a466969e Mon Sep 17 00:00:00 2001
From: Alibek Omarov <a1ba.omarov@gmail.com>
Date: Sun, 14 Jan 2024 15:53:20 +0300
Subject: [PATCH] ref: gl: mirror entities culling

---
 ref/gl/gl_beams.c  |  4 ++++
 ref/gl/gl_cull.c   | 30 +++++++++++++++++++++++++++++-
 ref/gl/gl_local.h  |  5 +++--
 ref/gl/gl_rsurf.c  |  3 +++
 ref/gl/gl_sprite.c |  3 +++
 5 files changed, 42 insertions(+), 3 deletions(-)

diff --git a/ref/gl/gl_beams.c b/ref/gl/gl_beams.c
index 01f91129..4c4084aa 100644
--- a/ref/gl/gl_beams.c
+++ b/ref/gl/gl_beams.c
@@ -119,6 +119,10 @@ qboolean R_BeamCull( const vec3_t start, const vec3_t end, qboolean pvsOnly )
 	vec3_t	mins, maxs;
 	int	i;
 
+	// support for custom mirror management
+	if( RI.currentbeam && R_CullEntityInMirror( RI.currentbeam ))
+		return true;
+
 	for( i = 0; i < 3; i++ )
 	{
 		if( start[i] < end[i] )
diff --git a/ref/gl/gl_cull.c b/ref/gl/gl_cull.c
index d432b073..1a642227 100644
--- a/ref/gl/gl_cull.c
+++ b/ref/gl/gl_cull.c
@@ -35,6 +35,31 @@ qboolean R_CullBox( const vec3_t mins, const vec3_t maxs )
 	return GL_FrustumCullBox( &RI.frustum, mins, maxs, 0 );
 }
 
+/*
+=================
+R_CullEntityInMirror
+
+decide whether entity should be reflected in mirror
+=================
+*/
+qboolean R_CullEntityInMirror( cl_entity_t *e )
+{
+	if( FBitSet( RI.params, RP_MIRRORVIEW ))
+	{
+		// cull this entity out of mirrors but not normal views
+		if( FBitSet( e->curstate.effects, EF_NOREFLECT ))
+			return true;
+	}
+	else
+	{
+		// cull this entity out of normal views but not mirrors
+		if( FBitSet( e->curstate.effects, EF_REFLECTONLY ))
+			return true;
+	}
+
+	return false;
+}
+
 /*
 =============
 R_CullModel
@@ -53,6 +78,9 @@ int R_CullModel( cl_entity_t *e, const vec3_t absmin, const vec3_t absmax )
 		return 1;
 	}
 
+	if( R_CullEntityInMirror( e ))
+		return 1;
+
 	if( R_CullBox( absmin, absmax ))
 		return 1;
 
@@ -98,7 +126,7 @@ int R_CullSurface( msurface_t *surf, gl_frustum_t *frustum, uint clipflags )
 		}
 		else dist = PlaneDiff( tr.modelorg, surf->plane );
 
-		if( glState.faceCull == GL_FRONT )
+		if( glState.faceCull == GL_FRONT || FBitSet( RI.params, RP_MIRRORVIEW ))
 		{
 			if( FBitSet( surf->flags, SURF_PLANEBACK ))
 			{
diff --git a/ref/gl/gl_local.h b/ref/gl/gl_local.h
index e276c322..f1ac35d5 100644
--- a/ref/gl/gl_local.h
+++ b/ref/gl/gl_local.h
@@ -84,8 +84,9 @@ extern poolhandle_t r_temppool;
 #define RP_ENVVIEW		BIT( 0 )	// used for cubemapshot
 #define RP_OLDVIEWLEAF	BIT( 1 )
 #define RP_CLIPPLANE	BIT( 2 )
+#define RP_MIRRORVIEW	BIT( 3 )	// lock pvs at vieworg
 
-#define RP_NONVIEWERREF	(RP_ENVVIEW)
+#define RP_NONVIEWERREF	(RP_ENVVIEW|RP_MIRRORVIEW)
 #define R_ModelOpaque( rm )	( rm == kRenderNormal )
 #define R_StaticEntity( ent )	( VectorIsNull( ent->origin ) && VectorIsNull( ent->angles ))
 #define RP_LOCALCLIENT( e )	((e) != NULL && (e)->index == ( gp_cl->playernum + 1 ) && e->player )
@@ -324,6 +325,7 @@ qboolean R_BeamCull( const vec3_t start, const vec3_t end, qboolean pvsOnly );
 //
 int R_CullModel( cl_entity_t *e, const vec3_t absmin, const vec3_t absmax );
 qboolean R_CullBox( const vec3_t mins, const vec3_t maxs );
+qboolean R_CullEntityInMirror( cl_entity_t *e );
 int R_CullSurface( msurface_t *surf, gl_frustum_t *frustum, uint clipflags );
 
 //
@@ -541,7 +543,6 @@ void R_DrawStretchRaw( float x, float y, float w, float h, int cols, int rows, c
 void R_DrawStretchPic( float x, float y, float w, float h, float s1, float t1, float s2, float t2, int texnum );
 qboolean R_SpeedsMessage( char *out, size_t size );
 void R_SetupSky( const char *skyboxname );
-qboolean R_CullBox( const vec3_t mins, const vec3_t maxs );
 int R_WorldToScreen( const vec3_t point, vec3_t screen );
 void R_ScreenToWorld( const vec3_t screen, vec3_t point );
 qboolean R_AddEntity( struct cl_entity_s *pRefEntity, int entityType );
diff --git a/ref/gl/gl_rsurf.c b/ref/gl/gl_rsurf.c
index e28f256a..3f258f13 100644
--- a/ref/gl/gl_rsurf.c
+++ b/ref/gl/gl_rsurf.c
@@ -1551,6 +1551,9 @@ void R_DrawBrushModel( cl_entity_t *e )
 	if( clmodel->surfaces != WORLDMODEL->surfaces )
 		allow_vbo = false;
 
+	if( R_CullEntityInMirror( e ))
+		return;
+
 	if( !VectorIsNull( e->angles ))
 	{
 		for( i = 0; i < 3; i++ )
diff --git a/ref/gl/gl_sprite.c b/ref/gl/gl_sprite.c
index 9a1060a0..e26fdd62 100644
--- a/ref/gl/gl_sprite.c
+++ b/ref/gl/gl_sprite.c
@@ -701,6 +701,9 @@ static qboolean R_SpriteOccluded( cl_entity_t *e, vec3_t origin, float *pscale )
 		float	blend;
 		vec3_t	v;
 
+		if( R_CullEntityInMirror( e ))
+			return;
+
 		TriWorldToScreen( origin, v );
 
 		if( v[0] < RI.viewport[0] || v[0] > RI.viewport[0] + RI.viewport[2] )