From 1e99558fbd3ada8741244cdb4aa2848186e5b358 Mon Sep 17 00:00:00 2001
From: kgv <kgv@opencascade.com>
Date: Thu, 29 Jan 2015 13:14:49 +0300
Subject: [PATCH] 0025762: Visualization, TKOpenGl - fix debug assertion within
 OpenGl_Workspace::UploadRaytraceData()

---
 src/OpenGl/OpenGl_Workspace_Raytrace.cxx | 17 ++++++++++-------
 1 file changed, 10 insertions(+), 7 deletions(-)

diff --git a/src/OpenGl/OpenGl_Workspace_Raytrace.cxx b/src/OpenGl/OpenGl_Workspace_Raytrace.cxx
index cff5b57b65..acf15d182c 100644
--- a/src/OpenGl/OpenGl_Workspace_Raytrace.cxx
+++ b/src/OpenGl/OpenGl_Workspace_Raytrace.cxx
@@ -1832,13 +1832,16 @@ Standard_Boolean OpenGl_Workspace::UploadRaytraceData()
   }
 
   const NCollection_Handle<BVH_Tree<Standard_ShortReal, 3> >& aBVH = myRaytraceGeometry.BVH();
-
-  aResult &= mySceneNodeInfoTexture->SubData (myGlContext, 0, aBVH->Length(),
-    reinterpret_cast<const GLuint*> (&aBVH->NodeInfoBuffer().front()));
-  aResult &= mySceneMinPointTexture->SubData (myGlContext, 0, aBVH->Length(),
-    reinterpret_cast<const GLfloat*> (&aBVH->MinPointBuffer().front()));
-  aResult &= mySceneMaxPointTexture->SubData (myGlContext, 0, aBVH->Length(),
-    reinterpret_cast<const GLfloat*> (&aBVH->MaxPointBuffer().front()));
+  const Standard_Integer aBvhLength = aBVH->Length();
+  if (aBvhLength > 0)
+  {
+    aResult &= mySceneNodeInfoTexture->SubData (myGlContext, 0, aBVH->Length(),
+      reinterpret_cast<const GLuint*> (&aBVH->NodeInfoBuffer().front()));
+    aResult &= mySceneMinPointTexture->SubData (myGlContext, 0, aBVH->Length(),
+      reinterpret_cast<const GLfloat*> (&aBVH->MinPointBuffer().front()));
+    aResult &= mySceneMaxPointTexture->SubData (myGlContext, 0, aBVH->Length(),
+      reinterpret_cast<const GLfloat*> (&aBVH->MaxPointBuffer().front()));
+  }
 
   for (Standard_Integer aNodeIdx = 0; aNodeIdx < aBVH->Length(); ++aNodeIdx)
   {