0024224: Suspicious logics in changing clipping planes at OpenGl_Structure

[occt.git] / src / OpenGl / OpenGl_FrameBuffer.hxx

// Created by: Kirill GAVRILOV
// Copyright (c) 2011-2012 OPEN CASCADE SAS
//
// The content of this file is subject to the Open CASCADE Technology Public
// License Version 6.5 (the "License"). You may not use the content of this file
// except in compliance with the License. Please obtain a copy of the License
// at http://www.opencascade.org and read it completely before using this file.
//
// The Initial Developer of the Original Code is Open CASCADE S.A.S., having its
// main offices at: 1, place des Freres Montgolfier, 78280 Guyancourt, France.
//
// The Original Code and all software distributed under the License is
// distributed on an "AS IS" basis, without warranty of any kind, and the
// Initial Developer hereby disclaims all such warranties, including without
// limitation, any warranties of merchantability, fitness for a particular
// purpose or non-infringement. Please see the License for the specific terms
// and conditions governing the rights and limitations under the License.


#ifndef OPENGL_FRAME_BUFFER_H
#define OPENGL_FRAME_BUFFER_H

#include <OpenGl_Context.hxx>
#include <OpenGl_ExtFBO.hxx>

#include <Standard_Boolean.hxx>
#include <InterfaceGraphic.hxx>

class OpenGl_FrameBuffer
{

public:

  //! Helpful constants
  static const GLuint NO_TEXTURE = 0;
  static const GLuint NO_FRAMEBUFFER = 0;
  static const GLuint NO_RENDERBUFFER = 0;

public:

  OpenGl_FrameBuffer (GLint theTextureFormat = GL_RGBA8);

  virtual ~OpenGl_FrameBuffer()
  {
    Release (Handle(OpenGl_Context)());
  }

  //! Texture width.
  GLsizei GetSizeX() const
  {
    return mySizeX;
  }

  //! Texture height.
  GLsizei GetSizeY() const
  {
    return mySizeY;
  }

  //! Viewport width.
  GLsizei GetVPSizeX() const
  {
    return myVPSizeX;
  }

  //! Viewport height.
  GLsizei GetVPSizeY() const
  {
    return myVPSizeY;
  }

  //! Returns true if current object was initialized
  Standard_Boolean IsValid() const
  {
    return IsValidFrameBuffer() && IsValidTexture() && IsValidDepthBuffer() && IsValidStencilBuffer();
  }

  //! Notice! Obsolete hardware (GeForce FX etc)
  //! doesn't support rectangular textures!
  //! There are 3 possible results if you are trying
  //! to create non power-of-two FBO on these cards:
  //! 1) FBO creation will fail,
  //!    current implementation will try to generate compatible FBO;
  //! 2) FBO rendering will be done in software mode (ForceWare 'hack');
  //! 3) FBO rendering will be incorrect (some obsolete Catalyst drivers).
  Standard_Boolean Init (const Handle(OpenGl_Context)& theGlContext,
                         GLsizei theViewportSizeX,
                         GLsizei theViewportSizeY,
                         GLboolean toForcePowerOfTwo = GL_FALSE);

  //! Release GL objects
  void Release (const Handle(OpenGl_Context)& theGlContext);

  //! Setup viewport to render into FBO
  void SetupViewport()
  {
    glViewport (0, 0, myVPSizeX, myVPSizeY);
  }

  //! Override viewport settings
  void ChangeViewport (const GLsizei theVPSizeX,
                       const GLsizei theVPSizeY)
  {
    myVPSizeX = theVPSizeX;
    myVPSizeY = theVPSizeY;
  }

  //! Bind frame buffer (to render into the texture).
  void BindBuffer (const Handle(OpenGl_Context)& theGlContext)
  {
    theGlContext->extFBO->glBindFramebufferEXT (GL_FRAMEBUFFER_EXT, myGlFBufferId);
  }

  //! Unbind frame buffer.
  void UnbindBuffer (const Handle(OpenGl_Context)& theGlContext)
  {
    theGlContext->extFBO->glBindFramebufferEXT (GL_FRAMEBUFFER_EXT, NO_FRAMEBUFFER);
  }

  //! Bind the texture.
  void BindTexture ()
  {
    glEnable (GL_TEXTURE_2D); // needed only for fixed pipeline rendering
    glBindTexture (GL_TEXTURE_2D, myGlTextureId);
  }

  //! Unbind the texture.
  void UnbindTexture()
  {
    glBindTexture (GL_TEXTURE_2D, NO_TEXTURE);
    glDisable (GL_TEXTURE_2D); // needed only for fixed pipeline rendering
  }

private:

  //! Check texture could be created
  Standard_Boolean IsProxySuccess() const;

  //! Generate texture with undefined data
  Standard_Boolean InitTrashTexture (const Handle(OpenGl_Context)& theGlContext);

  Standard_Boolean IsValidTexture() const
  {
    return myGlTextureId != NO_TEXTURE;
  }

  Standard_Boolean IsValidFrameBuffer() const
  {
    return myGlFBufferId != NO_FRAMEBUFFER;
  }

  Standard_Boolean IsValidDepthBuffer() const
  {
    return myGlDepthRBId != NO_RENDERBUFFER;
  }

  Standard_Boolean IsValidStencilBuffer() const
  {
    return myGlStencilRBId != NO_RENDERBUFFER;
  }

private:

  GLsizei      mySizeX;   // texture width
  GLsizei      mySizeY;   // texture height
  GLsizei    myVPSizeX;   // viewport width (should be <= texture width)
  GLsizei    myVPSizeY;   // viewport height (should be <= texture height)
  GLint   myTextFormat;   // GL_RGB, GL_RGBA,...
  GLuint myGlTextureId;   // GL texture ID
  GLuint myGlFBufferId;   // FBO object ID
  GLuint myGlDepthRBId;   // RenderBuffer object for depth ID
  GLuint myGlStencilRBId; // RenderBuffer object for stencil ID

};

#endif //OPENGL_FRAME_BUFFER_H