From fc309f7ae1326142820a4b76b3b2afef4f0137e6 Mon Sep 17 00:00:00 2001
From: havoc <havoc@d7cf8633-e32d-0410-b094-e92efae38249>
Date: Tue, 8 Mar 2005 15:20:07 +0000
Subject: [PATCH] added R_BoxVisible (used instead of VIS_CullBox) rewrote
 portions of R_MarkEntities to be more efficient and more sane (and to use
 R_BoxVisible obviously)

git-svn-id: svn://svn.icculus.org/twilight/trunk/darkplaces@5065 d7cf8633-e32d-0410-b094-e92efae38249
---
 gl_rmain.c | 61 +++++++++++++++++++++++++++++++++++++++++++++++++-----
 render.h   |  2 +-
 2 files changed, 57 insertions(+), 6 deletions(-)

diff --git a/gl_rmain.c b/gl_rmain.c
index 72dd0228..253ad269 100644
--- a/gl_rmain.c
+++ b/gl_rmain.c
@@ -418,16 +418,67 @@ int R_CullBox(const vec3_t mins, const vec3_t maxs)
 	return false;
 }
 
+int R_BoxVisible(const vec3_t mins, const vec3_t maxs)
+{
+	int side, nodestackindex = 0;
+	mnode_t *node, *nodestack[1024];
+	if (R_CullBox(mins, maxs))
+		return false;
+	if (!r_refdef.worldmodel || !r_refdef.worldmodel->brush.data_nodes)
+		return true;
+	node = r_refdef.worldmodel->brush.data_nodes;
+	for (;;)
+	{
+		if (node->plane)
+		{
+			// node - recurse down the BSP tree
+			side = BoxOnPlaneSide(mins, maxs, node->plane) - 1;
+			if (side < 2)
+			{
+				// box is on one side of plane, take that path
+				node = node->children[side];
+			}
+			else
+			{
+				// box crosses plane, take one path and remember the other
+				if (nodestackindex < 1024)
+					nodestack[nodestackindex++] = node->children[0];
+				node = node->children[1];
+			}
+		}
+		else
+		{
+			// leaf - check leaf visibility
+			if (r_worldleafvisible[(mleaf_t *)node - r_refdef.worldmodel->brush.data_leafs])
+			{
+				// it is visible, return immediately with the news
+				return true;
+			}
+			else
+			{
+				// nothing to see here, try another path we didn't take earlier
+				if (nodestackindex == 0)
+					break;
+				node = nodestack[--nodestackindex];
+			}
+		}
+	}
+	// it is not visible
+	return false;
+}
+
+
 //==================================================================================
 
 static void R_MarkEntities (void)
 {
-	int i;
+	int i, renderimask;
 	entity_render_t *ent;
 
 	if (!r_drawentities.integer)
 		return;
 
+	renderimask = envmap ? (RENDER_EXTERIORMODEL | RENDER_VIEWMODEL) : (chase_active.integer ? 0 : RENDER_EXTERIORMODEL);
 	for (i = 0;i < r_refdef.numentities;i++)
 	{
 		ent = r_refdef.entities[i];
@@ -436,11 +487,11 @@ static void R_MarkEntities (void)
 		Matrix4x4_OriginFromMatrix(&ent->matrix, ent->origin);
 		// some of the renderer still relies on scale...
 		ent->scale = Matrix4x4_ScaleFromMatrix(&ent->matrix);
-		R_UpdateEntLights(ent);
-		if ((chase_active.integer || !(ent->flags & RENDER_EXTERIORMODEL))
-		 && (!VIS_CullBox(ent->mins, ent->maxs) || (ent->effects & EF_NODEPTHTEST))
-		 && (!envmap || !(ent->flags & (RENDER_VIEWMODEL | RENDER_EXTERIORMODEL))))
+		if (!(ent->flags & renderimask) && ((ent->effects & EF_NODEPTHTEST) ? R_CullBox(ent->mins, ent->maxs) : R_BoxVisible(ent->mins, ent->maxs)))
+		{
+			R_UpdateEntLights(ent);
 			ent->visframe = r_framecount;
+		}
 	}
 }
 
diff --git a/render.h b/render.h
index f0169a8f..268d1703 100644
--- a/render.h
+++ b/render.h
@@ -149,7 +149,7 @@ void R_DrawExplosions(void);
 #define gl_alpha_format 4
 
 int R_CullBox(const vec3_t mins, const vec3_t maxs);
-#define VIS_CullBox(mins,maxs) (R_CullBox((mins), (maxs)) || (r_refdef.worldmodel && r_refdef.worldmodel->brush.BoxTouchingPVS && !r_refdef.worldmodel->brush.BoxTouchingPVS(r_refdef.worldmodel, r_pvsbits, (mins), (maxs))))
+int R_BoxVisible(const vec3_t mins, const vec3_t maxs);
 
 extern qboolean fogenabled;
 extern vec3_t fogcolor;
-- 
2.39.2