ENH: Add vtkGenericOpenGLRenderWindow class.

This allows one to use their own drawable/context with VTK.
To effectively use this class, one must add observers for events as documented.

Common/vtkCommand.h

@@ -359,6 +359,9 @@ public:
     LoadStateEvent,
     SaveStateEvent,
     StateChangedEvent,
+    WindowMakeCurrentEvent,
+    WindowIsCurrentEvent,
+    WindowFrameEvent,
     UserEvent = 1000
   };
 //ETX

Rendering/CMakeLists.txt

@@ -587,6 +587,10 @@ IF(VTK_USE_GL2PS)
   ENDIF(VTK_USE_SYSTEM_GL2PS)
 ENDIF(VTK_USE_GL2PS)
 
+IF(OPENGL_gl_LIBRARY)
+  SET(KitOpenGL_SRCS ${KitOpenGL_SRCS} vtkGenericOpenGLRenderWindow.cxx)
+ENDIF(OPENGL_gl_LIBRARY)
+
 IF (WIN32)
   IF(VTK_USE_X)
     IF (OPENGL_gl_LIBRARY)

Rendering/vtkGenericOpenGLRenderWindow.cxx

+/*=========================================================================
+
+  Program:   Visualization Toolkit
+  Module:    vtkGenericRenderWindowInteractor.cxx
+
+  Copyright (c) Ken Martin, Will Schroeder, Bill Lorensen
+  All rights reserved.
+  See Copyright.txt or http://www.kitware.com/Copyright.htm for details.
+
+     This software is distributed WITHOUT ANY WARRANTY; without even
+     the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR
+     PURPOSE.  See the above copyright notice for more information.
+
+=========================================================================*/
+
+#include "vtkGenericOpenGLRenderWindow.h"
+#include "vtkObjectFactory.h"
+#include "vtkRendererCollection.h"
+#include "vtkOpenGLRenderer.h"
+#include "vtkCommand.h"
+
+vtkStandardNewMacro(vtkGenericOpenGLRenderWindow);
+
+vtkGenericOpenGLRenderWindow::vtkGenericOpenGLRenderWindow()
+{
+  this->WindowId = NULL;
+}
+
+vtkGenericOpenGLRenderWindow::~vtkGenericOpenGLRenderWindow()
+{
+  this->Finalize();
+
+  vtkRenderer* ren;
+  this->Renderers->InitTraversal();
+  for ( ren = vtkOpenGLRenderer::SafeDownCast(this->Renderers->GetNextItemAsObject());
+    ren != NULL;
+    ren = vtkOpenGLRenderer::SafeDownCast(this->Renderers->GetNextItemAsObject()))
+    {
+    ren->SetRenderWindow(NULL);
+    }
+}
+
+void vtkGenericOpenGLRenderWindow::SetFrontBuffer(unsigned int b)
+{
+  this->FrontBuffer = b;
+}
+
+void vtkGenericOpenGLRenderWindow::SetFrontLeftBuffer(unsigned int b)
+{
+  this->FrontLeftBuffer = b;
+}
+
+void vtkGenericOpenGLRenderWindow::SetFrontRightBuffer(unsigned int b)
+{
+  this->FrontRightBuffer = b;
+}
+
+void vtkGenericOpenGLRenderWindow::SetBackBuffer(unsigned int b)
+{
+  this->BackBuffer = b;
+}
+
+void vtkGenericOpenGLRenderWindow::SetBackLeftBuffer(unsigned int b)
+{
+  this->BackLeftBuffer = b;
+}
+
+void vtkGenericOpenGLRenderWindow::SetBackRightBuffer(unsigned int b)
+{
+  this->BackRightBuffer = b;
+}
+
+void vtkGenericOpenGLRenderWindow::Render()
+{
+  // save/restore state as well as set up the state to what VTK assumes
+
+  glPushClientAttrib(GL_CLIENT_ALL_ATTRIB_BITS);
+  glPushAttrib(GL_ALL_ATTRIB_BITS);
+  glMatrixMode(GL_PROJECTION);
+  glPushMatrix();
+  glLoadIdentity();
+  glMatrixMode(GL_MODELVIEW);
+  glPushMatrix();
+  glLoadIdentity();
+
+  glEnable(GL_DEPTH_TEST);
+  glEnable(GL_BLEND);
+  glBlendFunc(GL_ONE, GL_ZERO);
+  glDepthFunc( GL_LEQUAL );
+  // OpenGLInit() has more ...  should fix this so we can call some code in vtkOpenGLRenderWindow to re-establish
+  // the OpenGL state that VTK wants.
+
+  this->Superclass::Render();
+
+  glPopClientAttrib();
+  glPopAttrib();
+  glMatrixMode(GL_PROJECTION);
+  glPopMatrix();
+  glMatrixMode(GL_MODELVIEW);
+  glPopMatrix();
+
+}
+
+void vtkGenericOpenGLRenderWindow::Finalize()
+{
+  // tell each of the renderers that this render window/graphics context
+  // is being removed (the RendererCollection is removed by vtkRenderWindow's
+  // destructor)
+  vtkRenderer* ren;
+  this->Renderers->InitTraversal();
+  for ( ren = vtkOpenGLRenderer::SafeDownCast(this->Renderers->GetNextItemAsObject());
+    ren != NULL;
+    ren = vtkOpenGLRenderer::SafeDownCast(this->Renderers->GetNextItemAsObject())  )
+    {
+    ren->SetRenderWindow(NULL);
+    ren->SetRenderWindow(this);
+    }
+}
+
+void vtkGenericOpenGLRenderWindow::Frame()
+{
+  this->InvokeEvent(vtkCommand::WindowFrameEvent, NULL);
+}
+
+void vtkGenericOpenGLRenderWindow::MakeCurrent()
+{
+  this->InvokeEvent(vtkCommand::WindowMakeCurrentEvent, NULL);
+}
+
+bool vtkGenericOpenGLRenderWindow::IsCurrent()
+{
+  int current = 0;
+  this->InvokeEvent(vtkCommand::WindowIsCurrentEvent, &current);
+  return current;
+}
+
+
+void vtkGenericOpenGLRenderWindow::SetWindowId(void* w)
+{
+  // user settable window id
+  this->WindowId = w;
+}
+
+void* vtkGenericOpenGLRenderWindow::GetGenericWindowId()
+{
+  return this->WindowId;
+}
+
+
+void vtkGenericOpenGLRenderWindow::SetDisplayId(void*)
+{
+}
+
+void vtkGenericOpenGLRenderWindow::SetParentId(void*)
+{
+}
+
+void* vtkGenericOpenGLRenderWindow::GetGenericDisplayId()
+{
+  return NULL;
+}
+
+void* vtkGenericOpenGLRenderWindow::GetGenericParentId()
+{
+  return NULL;
+}
+
+void* vtkGenericOpenGLRenderWindow::GetGenericContext()
+{
+  return NULL;
+}
+
+void* vtkGenericOpenGLRenderWindow::GetGenericDrawable()
+{
+  return NULL;
+}
+
+void vtkGenericOpenGLRenderWindow::SetWindowInfo(char*)
+{
+}
+
+void vtkGenericOpenGLRenderWindow::SetParentInfo(char*)
+{
+}
+
+int* vtkGenericOpenGLRenderWindow::GetScreenSize()
+{
+  return NULL;
+}
+
+void vtkGenericOpenGLRenderWindow::Start()
+{
+}
+
+void vtkGenericOpenGLRenderWindow::HideCursor()
+{
+}
+
+void vtkGenericOpenGLRenderWindow::ShowCursor()
+{
+}
+
+void vtkGenericOpenGLRenderWindow::SetFullScreen(int)
+{
+}
+
+void vtkGenericOpenGLRenderWindow::WindowRemap()
+{
+}
+
+int vtkGenericOpenGLRenderWindow::GetEventPending()
+{
+  return 0;
+}
+
+void vtkGenericOpenGLRenderWindow::SetNextWindowId(void*)
+{
+}
+
+void vtkGenericOpenGLRenderWindow::SetNextWindowInfo(char*)
+{
+}
+
+void vtkGenericOpenGLRenderWindow::CreateAWindow()
+{
+}
+
+void vtkGenericOpenGLRenderWindow::DestroyWindow()
+{
+}

Rendering/vtkGenericOpenGLRenderWindow.h

+/*=========================================================================
+
+  Program:   Visualization Toolkit
+  Module:    vtkRenderWindow.h
+
+  Copyright (c) Ken Martin, Will Schroeder, Bill Lorensen
+  All rights reserved.
+  See Copyright.txt or http://www.kitware.com/Copyright.htm for details.
+
+     This software is distributed WITHOUT ANY WARRANTY; without even
+     the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR
+     PURPOSE.  See the above copyright notice for more information.
+
+=========================================================================*/
+// .NAME vtkGenericOpenGLRenderWindow - platform independent render window
+
+// .SECTION Description
+// vtkGenericOpenGLRenderWindow provides a skeleton for implementing a render window
+// using one's own OpenGL context and drawable.
+// To be effective, one must register an observer for WindowMakeCurrentEvent,
+// WindowIsCurrentEvent and WindowFrameEvent.  When this class sends a WindowIsCurrentEvent,
+// the call data is an int* which one can use to return whether the context is current.
+
+#ifndef vtkGenericOpenGLRenderWindow_hpp
+#define vtkGenericOpenGLRenderWindow_hpp
+
+#include "vtkOpenGLRenderWindow.h"
+
+class vtkGenericOpenGLRenderWindow : public vtkOpenGLRenderWindow
+{
+public:
+  static vtkGenericOpenGLRenderWindow* New();
+  vtkTypeMacro(vtkGenericOpenGLRenderWindow, vtkOpenGLRenderWindow);
+protected:
+  vtkGenericOpenGLRenderWindow();
+  ~vtkGenericOpenGLRenderWindow();
+
+public:
+
+  //! Cleans up graphics resources allocated in the context for this VTK scene.
+  void Finalize();
+
+  //! Specific implementation for Render() to save/restore the OpenGL state.
+  void Render();
+
+  //! flush the pending drawing operations
+  //! Class user may to watch for WindowFrameEvent and act on it
+  void Frame();
+
+  //! Makes the context current.  It is the class user's
+  //! responsibility to watch for WindowMakeCurrentEvent and set it current.
+  void MakeCurrent();
+
+  //! Returns if the context is current.  It is the class user's
+  //! responsibility to watch for WindowIsCurrentEvent and set the integer flag
+  //! passed through the call data parameter.
+  bool IsCurrent();
+
+  //! Set the window id.  This does nothing but store the value.
+  void SetWindowId(void*);
+
+  //! Get the window id
+  void* GetGenericWindowId();
+
+  // {@
+  //! set the drawing buffers to use
+  void SetFrontBuffer(unsigned int);
+  void SetFrontLeftBuffer(unsigned int);
+  void SetFrontRightBuffer(unsigned int);
+  void SetBackBuffer(unsigned int);
+  void SetBackLeftBuffer(unsigned int);
+  void SetBackRightBuffer(unsigned int);
+  // }@
+
+  // {@
+  //! does nothing
+  void SetDisplayId(void*);
+  void SetParentId(void*);
+  void* GetGenericDisplayId();
+  void* GetGenericParentId();
+  void* GetGenericContext();
+  void* GetGenericDrawable();
+  void SetWindowInfo(char*);
+  void SetParentInfo(char*);
+  int* GetScreenSize();
+  void Start();
+  void HideCursor();
+  void ShowCursor();
+  void SetFullScreen(int);
+  void WindowRemap();
+  int  GetEventPending();
+  void SetNextWindowId(void*);
+  void SetNextWindowInfo(char*);
+  void CreateAWindow();
+  void DestroyWindow();
+  // }@
+
+
+protected:
+  void* WindowId;
+
+};
+
+#endif