1 files changed, 40 insertions, 30 deletions

diff --git a/linden/indra/newview/llvosurfacepatch.cpp b/linden/indra/newview/llvosurfacepatch.cpp
index 7055b30..9bb801a 100644
--- a/linden/indra/newview/llvosurfacepatch.cpp
+++ b/linden/indra/newview/llvosurfacepatch.cpp
@@ -945,45 +945,55 @@ BOOL LLVOSurfacePatch::lineSegmentIntersect(const LLVector3& start, const LLVect
 
         //step one meter at a time until intersection point found
 
+        const LLVector3* ext = mDrawable->getSpatialExtents();
+        F32 rad = (delta*tdelta).magVecSquared();
+
         F32 t = 0.f;
         while ( t <= 1.f)
         {
                 LLVector3 sample = origin + delta*t;
                 
-                F32 height = mRegionp->getLandHeightRegion(sample);
-                if (height > sample.mV[2])
-                { //ray went below ground, positive intersection
-                        //quick and dirty binary search to get impact point
-                        tdelta = -tdelta*0.5f;
-                        F32 err_dist = 0.001f;
-                        F32 dist = fabsf(sample.mV[2] - height);
-
-                        while (dist > err_dist && tdelta*tdelta > 0.0f)
-                        {
-                                t += tdelta;
-                                sample = origin+delta*t;
-                                height = mRegionp->getLandHeightRegion(sample);
-                                if ((tdelta < 0 && height < sample.mV[2]) ||
-                                        (height > sample.mV[2] && tdelta > 0))
-                                { //jumped over intersection point, go back
-                                        tdelta = -tdelta;
+                if (AABBSphereIntersectR2(ext[0], ext[1], sample+mRegionp->getOriginAgent(), rad))
+                {
+                        F32 height = mRegionp->getLandHeightRegion(sample);
+                        if (height > sample.mV[2])
+                        { //ray went below ground, positive intersection
+                                //quick and dirty binary search to get impact point
+                                tdelta = -tdelta*0.5f;
+                                F32 err_dist = 0.001f;
+                                F32 dist = fabsf(sample.mV[2] - height);
+
+                                while (dist > err_dist && tdelta*tdelta > 0.0f)
+                                {
+                                        t += tdelta;
+                                        sample = origin+delta*t;
+                                        height = mRegionp->getLandHeightRegion(sample);
+                                        if ((tdelta < 0 && height < sample.mV[2]) ||
+                                                (height > sample.mV[2] && tdelta > 0))
+                                        { //jumped over intersection point, go back
+                                                tdelta = -tdelta;
+                                        }
+                                        tdelta *= 0.5f;
+                                        dist = fabsf(sample.mV[2] - height);
                                 }
-                                tdelta *= 0.5f;
-                                dist = fabsf(sample.mV[2] - height);
-                        }
 
-                        if (intersection)
-                        {
-                                sample.mV[2] = mRegionp->getLandHeightRegion(sample);
-                                *intersection = sample + mRegionp->getOriginAgent();
-                        }
+                                if (intersection)
+                                {
+                                        F32 height = mRegionp->getLandHeightRegion(sample);
+                                        if (fabsf(sample.mV[2]-height) < delta.length()*tdelta)
+                                        {
+                                                sample.mV[2] = mRegionp->getLandHeightRegion(sample);
+                                        }
+                                        *intersection = sample + mRegionp->getOriginAgent();
+                                }
 
-                        if (normal)
-                        {
-                                *normal = mRegionp->getLand().resolveNormalGlobal(mRegionp->getPosGlobalFromRegion(sample));
-                        }
+                                if (normal)
+                                {
+                                        *normal = mRegionp->getLand().resolveNormalGlobal(mRegionp->getPosGlobalFromRegion(sample));
+                                }
 
-                        return TRUE;
+                                return TRUE;
+                        }
                 }
 
                 t += tdelta;