From c0b4ec6fe72d703191b28749cfd30262d131b245 Mon Sep 17 00:00:00 2001
From: Dave Parks <davep@lindenlab.com>
Date: Fri, 16 Dec 2011 17:43:30 -0600
Subject: SH-2694 Fix for FPS drop when mousing over flexi objects (don't use
 an octree for flexi raycast)

---
 indra/llmath/llvolume.cpp | 85 +++++++++++++++++++++++++++++++++++++++++------
 1 file changed, 75 insertions(+), 10 deletions(-)

(limited to 'indra/llmath/llvolume.cpp')

diff --git a/indra/llmath/llvolume.cpp b/indra/llmath/llvolume.cpp
index da0fa32963..0c6cf1dfae 100644
--- a/indra/llmath/llvolume.cpp
+++ b/indra/llmath/llvolume.cpp
@@ -4617,18 +4617,83 @@ S32 LLVolume::lineSegmentIntersect(const LLVector4a& start, const LLVector4a& en
 				genBinormals(i);
 			}
 
-			if (!face.mOctree)
-			{
-				face.createOctree();
-			}
-			
-			//LLVector4a* p = (LLVector4a*) face.mPositions;
+			if (isUnique())
+			{ //don't bother with an octree for flexi volumes
+				U32 tri_count = face.mNumIndices/3;
+
+				for (U32 j = 0; j < tri_count; ++j)
+				{
+					U16 idx0 = face.mIndices[j*3+0];
+					U16 idx1 = face.mIndices[j*3+1];
+					U16 idx2 = face.mIndices[j*3+2];
 
-			LLOctreeTriangleRayIntersect intersect(start, dir, &face, &closest_t, intersection, tex_coord, normal, bi_normal);
-			intersect.traverse(face.mOctree);
-			if (intersect.mHitFace)
+					const LLVector4a& v0 = face.mPositions[idx0];
+					const LLVector4a& v1 = face.mPositions[idx1];
+					const LLVector4a& v2 = face.mPositions[idx2];
+				
+					F32 a,b,t;
+
+					if (LLTriangleRayIntersect(v0, v1, v2,
+							start, dir, a, b, t))
+					{
+						if ((t >= 0.f) &&      // if hit is after start
+							(t <= 1.f) &&      // and before end
+							(t < closest_t))   // and this hit is closer
+						{
+							closest_t = t;
+							hit_face = i;
+
+							if (intersection != NULL)
+							{
+								LLVector4a intersect = dir;
+								intersect.mul(closest_t);
+								intersect.add(start);
+								intersection->set(intersect.getF32ptr());
+							}
+
+
+							if (tex_coord != NULL)
+							{
+								LLVector2* tc = (LLVector2*) face.mTexCoords;
+								*tex_coord = ((1.f - a - b)  * tc[idx0] +
+									a              * tc[idx1] +
+									b              * tc[idx2]);
+
+							}
+
+							if (normal!= NULL)
+							{
+								LLVector4* norm = (LLVector4*) face.mNormals;
+
+								*normal		= ((1.f - a - b)  * LLVector3(norm[idx0]) + 
+									a              * LLVector3(norm[idx1]) +
+									b              * LLVector3(norm[idx2]));
+							}
+
+							if (bi_normal != NULL)
+							{
+								LLVector4* binormal = (LLVector4*) face.mBinormals;
+								*bi_normal = ((1.f - a - b)  * LLVector3(binormal[idx0]) + 
+										a              * LLVector3(binormal[idx1]) +
+										b              * LLVector3(binormal[idx2]));
+							}
+						}
+					}
+				}
+			}
+			else
 			{
-				hit_face = i;
+				if (!face.mOctree)
+				{
+					face.createOctree();
+				}
+			
+				LLOctreeTriangleRayIntersect intersect(start, dir, &face, &closest_t, intersection, tex_coord, normal, bi_normal);
+				intersect.traverse(face.mOctree);
+				if (intersect.mHitFace)
+				{
+					hit_face = i;
+				}
 			}
 		}		
 	}
-- 
cgit v1.2.3