From 723ef3711245941ca3548e21a289b027f641c1b0 Mon Sep 17 00:00:00 2001
From: Sankhesh Jhaveri <sankhesh.jhaveri@kitware.com>
Date: Mon, 13 Oct 2014 10:38:38 -0400
Subject: [PATCH] FIX: Reset clipping planes

This fixes the issue where the clipping plane is still
active after the camera dollies out of the volume. The
check looks at whether the camera was inside the volume
in the last frame and if the geometry needs to be updated.

Change-Id: Idfc6a87f57ec623044d247c49703d45fc2e47f3f
---
 .../VolumeOpenGLNew/vtkOpenGLGPUVolumeRayCastMapper.cxx   | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/Rendering/VolumeOpenGLNew/vtkOpenGLGPUVolumeRayCastMapper.cxx b/Rendering/VolumeOpenGLNew/vtkOpenGLGPUVolumeRayCastMapper.cxx
index cc6123c2cc4..c90c0a45c7e 100644
--- a/Rendering/VolumeOpenGLNew/vtkOpenGLGPUVolumeRayCastMapper.cxx
+++ b/Rendering/VolumeOpenGLNew/vtkOpenGLGPUVolumeRayCastMapper.cxx
@@ -80,6 +80,7 @@ class vtkOpenGLGPUVolumeRayCastMapper::vtkInternal
     this->Initialized = false;
     this->ValidTransferFunction = false;
     this->LoadDepthTextureExtensionsSucceeded = false;
+    this->CameraWasInsideInLastUpdate = false;
     this->CubeVBOId = 0;
 #ifndef __APPLE__
     this->CubeVAOId = 0;
@@ -246,6 +247,7 @@ class vtkOpenGLGPUVolumeRayCastMapper::vtkInternal
   bool Initialized;
   bool ValidTransferFunction;
   bool LoadDepthTextureExtensionsSucceeded;
+  bool CameraWasInsideInLastUpdate;
 
   GLuint CubeVBOId;
 #ifndef __APPLE__
@@ -1086,7 +1088,8 @@ bool vtkOpenGLGPUVolumeRayCastMapper::vtkInternal::IsCameraInside(
 void vtkOpenGLGPUVolumeRayCastMapper::vtkInternal::UpdateVolumeGeometry(
   vtkRenderer* ren, vtkVolume* vol, vtkImageData* input)
 {
-  if (input != this->PrevInput || this->IsCameraInside(ren, vol))
+  if (input != this->PrevInput || this->IsCameraInside(ren, vol) ||
+      this->CameraWasInsideInLastUpdate)
     {
     vtkNew<vtkTessellatedBoxSource> boxSource;
     boxSource->SetBounds(this->LoadedBounds);
@@ -1203,10 +1206,13 @@ void vtkOpenGLGPUVolumeRayCastMapper::vtkInternal::UpdateVolumeGeometry(
       clip->SetPlanes(planes.GetPointer());
 
       densityPolyData->SetInputConnection(clip->GetOutputPort());
+
+      this->CameraWasInsideInLastUpdate = true;
       }
     else
       {
       densityPolyData->SetInputConnection(boxSource->GetOutputPort());
+      this->CameraWasInsideInLastUpdate = false;
       }
 
     densityPolyData->SetNumberOfSubdivisions(2);