eXperiment robotics framework

FramebufferObject Class Reference

FramebufferObject Class. More...

#include <erf/framebufferObject.h>

List of all members.

Public Member Functions

 FramebufferObject ()
 Ctor/Dtor.
virtual ~FramebufferObject ()
void Bind ()
 Bind this FBO as current render target.
virtual void AttachTexture (GLenum texTarget, GLuint texId, GLenum attachment=GL_COLOR_ATTACHMENT0_EXT, int mipLevel=0, int zSlice=0)
 Bind a texture to the "attachment" point of this FBO.
virtual void AttachTextures (int numTextures, GLenum texTarget[], GLuint texId[], GLenum attachment[]=NULL, int mipLevel[]=NULL, int zSlice[]=NULL)
 Bind an array of textures to multiple "attachment" points of this FBO
  • By default, the first 'numTextures' attachments are used, starting with GL_COLOR_ATTACHMENT0_EXT.

virtual void AttachRenderBuffer (GLuint buffId, GLenum attachment=GL_COLOR_ATTACHMENT0_EXT)
 Bind a render buffer to the "attachment" point of this FBO.
virtual void AttachRenderBuffers (int numBuffers, GLuint buffId[], GLenum attachment[]=NULL)
 Bind an array of render buffers to corresponding "attachment" points of this FBO.
void Unattach (GLenum attachment)
 Free any resource bound to the "attachment" point of this FBO.
void UnattachAll ()
 Free any resources bound to any attachment points of this FBO.
bool IsValid (std::ostream &ostr=std::cerr)
 Is this FBO currently a valid render target?
  • Sends output to std::cerr by default but can be a user-defined C++ stream.

GLenum GetAttachedType (GLenum attachment)
 BEGIN : Accessors Is attached type GL_RENDERBUFFER_EXT or GL_TEXTURE?
GLuint GetAttachedId (GLenum attachment)
 What is the Id of Renderbuffer/texture currently attached to "attachement?".
GLint GetAttachedMipLevel (GLenum attachment)
 Which mipmap level is currently attached to "attachement?".
GLint GetAttachedCubeFace (GLenum attachment)
 Which cube face is currently attached to "attachment?".
GLint GetAttachedZSlice (GLenum attachment)
 Which z-slice is currently attached to "attachment?".

Static Public Member Functions

static int GetMaxColorAttachments ()
 END : Accessors.
static void Disable ()
 Disable all FBO rendering and return to traditional, windowing-system controlled framebuffer NOTE: This is NOT an "unbind" for this specific FBO, but rather disables all FBO rendering.

Protected Member Functions

void _GuardedBind ()
 END : Static methods global to all FBOs.
void _GuardedUnbind ()
void _FramebufferTextureND (GLenum attachment, GLenum texTarget, GLuint texId, int mipLevel, int zSlice)

Static Protected Member Functions

static GLuint _GenerateFboId ()

Protected Attributes

GLuint m_fboId
GLint m_savedFboId


Detailed Description

FramebufferObject Class.

This class encapsulates the FramebufferObject (FBO) OpenGL spec. See the official spec at: http://oss.sgi.com/projects/ogl-sample/registry/EXT/framebuffer_object.txt

for details.

A framebuffer object (FBO) is conceptually a structure containing pointers to GPU memory. The memory pointed to is either an OpenGL texture or an OpenGL RenderBuffer. FBOs can be used to render to one or more textures, share depth buffers between multiple sets of color buffers/textures and are a complete replacement for pbuffers.

Performance Notes: 1) It is more efficient (but not required) to call Bind() on an FBO before making multiple method calls. For example:

FramebufferObject fbo; fbo.Bind(); fbo.AttachTexture(GL_TEXTURE_RECTANGLE_EXT, texId0, GL_COLOR_ATTACHMENT0_EXT); fbo.AttachTexture(GL_TEXTURE_RECTANGLE_EXT, texId1, GL_COLOR_ATTACHMENT1_EXT); fbo.IsValid();

To provide a complete encapsulation, the following usage pattern works correctly but is less efficient:

FramebufferObject fbo; NOTE : No Bind() call fbo.AttachTexture(GL_TEXTURE_RECTANGLE_EXT, texId0, GL_COLOR_ATTACHMENT0_EXT); fbo.AttachTexture(GL_TEXTURE_RECTANGLE_EXT, texId1, GL_COLOR_ATTACHMENT1_EXT); fbo.IsValid();

The first usage pattern binds the FBO only once, whereas the second usage binds/unbinds the FBO for each method call.

2) Use FramebufferObject::Disable() sparingly. We have intentionally left out an "Unbind()" method because it is largely unnecessary and encourages rendundant Bind/Unbind coding. Binding an FBO is usually much faster than enabling/disabling a pbuffer, but is still a costly operation. When switching between multiple FBOs and a visible OpenGL framebuffer, the following usage pattern is recommended:

FramebufferObject fbo1, fbo2; fbo1.Bind(); ... Render ... NOTE : No Unbind/Disable here...

fbo2.Bind(); ... Render ...

Disable FBO rendering and return to visible window OpenGL framebuffer. FramebufferObject::Disable();

Definition at line 64 of file framebufferObject.h.


Constructor & Destructor Documentation

FramebufferObject::FramebufferObject (  ) 

Ctor/Dtor.

virtual FramebufferObject::~FramebufferObject (  )  [virtual]


Member Function Documentation

void FramebufferObject::Bind (  ) 

Bind this FBO as current render target.

virtual void FramebufferObject::AttachTexture ( GLenum  texTarget,
GLuint  texId,
GLenum  attachment = GL_COLOR_ATTACHMENT0_EXT,
int  mipLevel = 0,
int  zSlice = 0 
) [virtual]

Bind a texture to the "attachment" point of this FBO.

virtual void FramebufferObject::AttachTextures ( int  numTextures,
GLenum  texTarget[],
GLuint  texId[],
GLenum  attachment[] = NULL,
int  mipLevel[] = NULL,
int  zSlice[] = NULL 
) [virtual]

Bind an array of textures to multiple "attachment" points of this FBO

  • By default, the first 'numTextures' attachments are used, starting with GL_COLOR_ATTACHMENT0_EXT.

virtual void FramebufferObject::AttachRenderBuffer ( GLuint  buffId,
GLenum  attachment = GL_COLOR_ATTACHMENT0_EXT 
) [virtual]

Bind a render buffer to the "attachment" point of this FBO.

virtual void FramebufferObject::AttachRenderBuffers ( int  numBuffers,
GLuint  buffId[],
GLenum  attachment[] = NULL 
) [virtual]

Bind an array of render buffers to corresponding "attachment" points of this FBO.

  • By default, the first 'numBuffers' attachments are used, starting with GL_COLOR_ATTACHMENT0_EXT

void FramebufferObject::Unattach ( GLenum  attachment  ) 

Free any resource bound to the "attachment" point of this FBO.

void FramebufferObject::UnattachAll (  ) 

Free any resources bound to any attachment points of this FBO.

bool FramebufferObject::IsValid ( std::ostream &  ostr = std::cerr  ) 

Is this FBO currently a valid render target?

  • Sends output to std::cerr by default but can be a user-defined C++ stream.

NOTE : This function works correctly in debug build mode but always returns "true" if NDEBUG is is defined (optimized builds)

GLenum FramebufferObject::GetAttachedType ( GLenum  attachment  ) 

BEGIN : Accessors Is attached type GL_RENDERBUFFER_EXT or GL_TEXTURE?

GLuint FramebufferObject::GetAttachedId ( GLenum  attachment  ) 

What is the Id of Renderbuffer/texture currently attached to "attachement?".

GLint FramebufferObject::GetAttachedMipLevel ( GLenum  attachment  ) 

Which mipmap level is currently attached to "attachement?".

GLint FramebufferObject::GetAttachedCubeFace ( GLenum  attachment  ) 

Which cube face is currently attached to "attachment?".

GLint FramebufferObject::GetAttachedZSlice ( GLenum  attachment  ) 

Which z-slice is currently attached to "attachment?".

static int FramebufferObject::GetMaxColorAttachments (  )  [static]

END : Accessors.

BEGIN : Static methods global to all FBOs Return number of color attachments permitted

static void FramebufferObject::Disable (  )  [static]

Disable all FBO rendering and return to traditional, windowing-system controlled framebuffer NOTE: This is NOT an "unbind" for this specific FBO, but rather disables all FBO rendering.

This call is intentionally "static" and named "Disable" instead of "Unbind" for this reason. The motivation for this strange semantic is performance. Providing "Unbind" would likely lead to a large number of unnecessary FBO enablings/disabling.

void FramebufferObject::_GuardedBind (  )  [protected]

END : Static methods global to all FBOs.

void FramebufferObject::_GuardedUnbind (  )  [protected]

void FramebufferObject::_FramebufferTextureND ( GLenum  attachment,
GLenum  texTarget,
GLuint  texId,
int  mipLevel,
int  zSlice 
) [protected]

static GLuint FramebufferObject::_GenerateFboId (  )  [static, protected]


Member Data Documentation

GLuint FramebufferObject::m_fboId [protected]

Definition at line 158 of file framebufferObject.h.

Definition at line 159 of file framebufferObject.h.


The documentation for this class was generated from the following file:

The miarn project - written by Joao Xavier