3 files changed, 34 insertions, 20 deletions

diff --git a/indra/newview/lldrawpooltree.cpp b/indra/newview/lldrawpooltree.cpp
index 1a5d55d793..1571415e63 100644
--- a/indra/newview/lldrawpooltree.cpp
+++ b/indra/newview/lldrawpooltree.cpp
@@ -113,9 +113,12 @@ void LLDrawPoolTree::render(S32 pass)
 			 iter != mDrawFace.end(); iter++)
 		{
 			LLFace *face = *iter;
-			face->mVertexBuffer->setBuffer(LLDrawPoolTree::VERTEX_DATA_MASK);
-			face->mVertexBuffer->drawRange(LLRender::TRIANGLES, 0, face->mVertexBuffer->getRequestedVerts()-1, face->mVertexBuffer->getRequestedIndices(), 0); 
-			gPipeline.addTrianglesDrawn(face->mVertexBuffer->getRequestedIndices());
+			if(face->mVertexBuffer.notNull())
+			{
+				face->mVertexBuffer->setBuffer(LLDrawPoolTree::VERTEX_DATA_MASK);
+				face->mVertexBuffer->drawRange(LLRender::TRIANGLES, 0, face->mVertexBuffer->getRequestedVerts()-1, face->mVertexBuffer->getRequestedIndices(), 0); 
+				gPipeline.addTrianglesDrawn(face->mVertexBuffer->getRequestedIndices());
+			}
 		}
 	}
 }
@@ -333,7 +336,7 @@ void LLDrawPoolTree::renderTree(BOOL selecting)
 			S32 stop_depth = 0;
 			F32 app_angle = treep->getAppAngle()*LLVOTree::sTreeFactor;
 			F32 alpha = 1.0;
-			S32 trunk_LOD = 0;
+			S32 trunk_LOD = LLVOTree::sMAX_NUM_TREE_LOD_LEVELS;
 
 			for (S32 j = 0; j < 4; j++)
 			{
@@ -344,6 +347,10 @@ void LLDrawPoolTree::renderTree(BOOL selecting)
 					break;
 				}
 			} 
+			if(trunk_LOD >= LLVOTree::sMAX_NUM_TREE_LOD_LEVELS)
+			{
+				continue ; //do not render.
+			}
 
 			if (app_angle < (THRESH_ANGLE_FOR_BILLBOARD - BLEND_RANGE_FOR_BILLBOARD))
 			{
diff --git a/indra/newview/llvotree.cpp b/indra/newview/llvotree.cpp
index b89c0cd638..eb5b6c6618 100644
--- a/indra/newview/llvotree.cpp
+++ b/indra/newview/llvotree.cpp
@@ -66,12 +66,14 @@ const F32 LEAF_TOP = 1.0f;
 const F32 LEAF_BOTTOM = 0.52f;
 const F32 LEAF_WIDTH = 1.f;
 
-S32 LLVOTree::sLODVertexOffset[4];
-S32 LLVOTree::sLODVertexCount[4];
-S32 LLVOTree::sLODIndexOffset[4];
-S32 LLVOTree::sLODIndexCount[4];
-S32 LLVOTree::sLODSlices[4] = {10, 5, 4, 3};
-F32 LLVOTree::sLODAngles[4] = {30.f, 20.f, 15.f, 0.f};
+const S32 LLVOTree::sMAX_NUM_TREE_LOD_LEVELS = 4 ;
+
+S32 LLVOTree::sLODVertexOffset[sMAX_NUM_TREE_LOD_LEVELS];
+S32 LLVOTree::sLODVertexCount[sMAX_NUM_TREE_LOD_LEVELS];
+S32 LLVOTree::sLODIndexOffset[sMAX_NUM_TREE_LOD_LEVELS];
+S32 LLVOTree::sLODIndexCount[sMAX_NUM_TREE_LOD_LEVELS];
+S32 LLVOTree::sLODSlices[sMAX_NUM_TREE_LOD_LEVELS] = {10, 5, 4, 3};
+F32 LLVOTree::sLODAngles[sMAX_NUM_TREE_LOD_LEVELS] = {30.f, 20.f, 15.f, 0.00001f};
 
 F32 LLVOTree::sTreeFactor = 1.f;
 
@@ -373,12 +375,11 @@ BOOL LLVOTree::idleUpdate(LLAgent &agent, LLWorld &world, const F64 &time)
 		}
 	}
 
-	S32 trunk_LOD = 0;
+	S32 trunk_LOD = sMAX_NUM_TREE_LOD_LEVELS ;
 	F32 app_angle = getAppAngle()*LLVOTree::sTreeFactor;
 
-	for (S32 j = 0; j < 4; j++)
+	for (S32 j = 0; j < sMAX_NUM_TREE_LOD_LEVELS; j++)
 	{
-
 		if (app_angle > LLVOTree::sLODAngles[j])
 		{
 			trunk_LOD = j;
@@ -445,16 +446,15 @@ void LLVOTree::setPixelAreaAndAngle(LLAgent &agent)
 	
 	// This should be the camera's center, as soon as we move to all region-local.
 	LLVector3 relative_position = getPositionAgent() - gAgentCamera.getCameraPositionAgent();
-	F32 range = relative_position.length();				// ugh, square root
+	F32 range_squared = relative_position.lengthSquared() ;				
 
 	F32 max_scale = mBillboardScale * getMaxScale();
 	F32 area = max_scale * (max_scale*mBillboardRatio);
 
 	// Compute pixels per meter at the given range
-	F32 pixels_per_meter = LLViewerCamera::getInstance()->getViewHeightInPixels() / 
-						   (tan(LLViewerCamera::getInstance()->getView()) * range);
+	F32 pixels_per_meter = LLViewerCamera::getInstance()->getViewHeightInPixels() / tan(LLViewerCamera::getInstance()->getView());
 
-	mPixelArea = (pixels_per_meter) * (pixels_per_meter) * area;
+	mPixelArea = (pixels_per_meter) * (pixels_per_meter) * area / range_squared;
 #if 0
 	// mAppAngle is a bit of voodoo;
 	// use the one calculated LLViewerObject::setPixelAreaAndAngle above
@@ -506,6 +506,13 @@ BOOL LLVOTree::updateGeometry(LLDrawable *drawable)
 {
 	LLFastTimer ftm(FTM_UPDATE_TREE);
 
+	if(mTrunkLOD >= sMAX_NUM_TREE_LOD_LEVELS) //do not display the tree.
+	{
+		mReferenceBuffer = NULL ;
+		mDrawable->getFace(0)->mVertexBuffer = NULL ;
+		return TRUE ;
+	}
+
 	if (mReferenceBuffer.isNull() || mDrawable->getFace(0)->mVertexBuffer.isNull())
 	{
 		const F32 SRR3 = 0.577350269f; // sqrt(1/3)
@@ -523,7 +530,7 @@ BOOL LLVOTree::updateGeometry(LLDrawable *drawable)
 		face->mCenterAgent = getPositionAgent();
 		face->mCenterLocal = face->mCenterAgent;
 
-		for (lod = 0; lod < 4; lod++)
+		for (lod = 0; lod < sMAX_NUM_TREE_LOD_LEVELS; lod++)
 		{
 			slices = sLODSlices[lod];
 			sLODVertexOffset[lod] = max_vertices;
@@ -700,7 +707,7 @@ BOOL LLVOTree::updateGeometry(LLDrawable *drawable)
 		// Generate the vertices
 		// Generate the indices
 
-		for (lod = 0; lod < 4; lod++)
+		for (lod = 0; lod < sMAX_NUM_TREE_LOD_LEVELS; lod++)
 		{
 			slices = sLODSlices[lod];
 			F32 base_radius = 0.65f;
@@ -892,7 +899,6 @@ void LLVOTree::updateMesh()
 	S32 stop_depth = 0;
 	F32 alpha = 1.0;
 	
-
 	U32 vert_count = 0;
 	U32 index_count = 0;
 	
diff --git a/indra/newview/llvotree.h b/indra/newview/llvotree.h
index feac9e0675..036ad692b1 100644
--- a/indra/newview/llvotree.h
+++ b/indra/newview/llvotree.h
@@ -152,6 +152,7 @@ public:
 	};
 
 	static F32 sTreeFactor;			// Tree level of detail factor
+	static const S32 sMAX_NUM_TREE_LOD_LEVELS ;
 
 	friend class LLDrawPoolTree;
 protected: