VRS::FrameBufferObjectGL Class Reference

Frambuffer objects represent application-created framebuffers. More...

#include <vrs/opengl/fbo/framebufferobjectgl.h>

Inheritance diagram for VRS::FrameBufferObjectGL:

List of all members.

Public Member Functions
	VRS_TYPEINFO (FrameBufferObjectGL, MonoAttribute)
	VRS_SERIALIZABLE (FrameBufferObjectGL)
	FrameBufferObjectGL ()
void	attachRenderTarget (GLenum attachmentPoint, SO< RenderTargetGL > renderTarget, SO< BufferClearance > clearance=new BufferClearance())
void	detachRenderTarget (GLenum attachmentPoint)
SO< RenderTargetGL >	getAttachedRenderTarget (GLenum attachmentPoint) const
SO< BufferClearance >	getBufferClearance (GLenum attachmentPoint) const
void	clear (GLenum attachmentPoint)
bool	isMarkedForClearance (GLenum attachmentPoint) const
void	unmarkClearance (GLenum attachmentPoint)
Area	size () const
SO< Image >	renderImage (SO< SceneThing > scene, GLenum attachmentPoint=GL_COLOR_ATTACHMENT0_EXT, SO< GLCanvas > canvas=NULL, const Area &area=Area())
void	render (SO< SceneThing > scene, SO< GLCanvas > canvas=NULL, const Area &area=Area())
bool	isValid () const
	Returns if rendering to this fbo has succeeded.
TransactionNo	getLastUpdate () const
void	setLastUpdate (TransactionNo)
	For internal use only. Check last modification.
Friends
class	FrameBufferObjectPainterGL

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Detailed Description

Frambuffer objects represent application-created framebuffers.

In contrast to window-system-provided framebuffers, application-created framebuffers are independent from the window system. Framebuffer objects enable a form of offscreen rendering to implement, e.g., render-to-texture efficiently.

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Constructor & Destructor Documentation

VRS::FrameBufferObjectGL::FrameBufferObjectGL

(

)

Framebuffer objects maintain a set of rendering destinations known as framebuffer-attachable images. These can represent GL logical buffers such as color buffers, depthbuffer, or stencilbuffer. A framebuffer-attachable image can either be a renderbuffer (RenderBufferGL), i.e., for generalized offscreen rendering, or textures (RenderTextureGL), i.e., for implementing render-to-texture. Each framebuffer-attachable image can be shared among multiple framebuffer objects. Furthermore, framebuffer-atachable images can be allocated independently and shared among multiple GL contexts. Framebuffer objects does not require a context switch for rendering to its attached images, i.e, render-to-texture and offscreen rendering in general are efficient.

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Member Function Documentation

VRS::FrameBufferObjectGL::VRS_TYPEINFO	(	FrameBufferObjectGL	,
		MonoAttribute
	)

VRS::FrameBufferObjectGL::VRS_SERIALIZABLE

(

FrameBufferObjectGL

)

void VRS::FrameBufferObjectGL::attachRenderTarget	(	GLenum	attachmentPoint,
		SO< RenderTargetGL >	renderTarget,
		SO< BufferClearance >	clearance = new BufferClearance()
	)

void VRS::FrameBufferObjectGL::detachRenderTarget

(

GLenum

attachmentPoint

)

Attaching/detaching a texture or renderbuffer to/from the framebuffer object. Each framebuffer-attachable image, that is wrapped by 'RenderTargetGL', corresponds to a logical buffer. These are indicated by the attachment point. Valid attachment points are GL_COLOR_ATTACHMENT0_EXT .. GL_COLOR_ATTACHMENT15_EXT (the valid maximum number can be traced), GL_DEPTH_ATTACHMENT_EXT, GL_STENCIL_ATTACHMENT that indicate colorbuffers, depthbuffer, and stencilbuffer. Note that all framebuffer-attachable images must have equal size (width and height). 'BufferClearance' defines the clear policy for each individual framebuffer-attachable image.

SO<RenderTargetGL> VRS::FrameBufferObjectGL::getAttachedRenderTarget

(

GLenum

attachmentPoint

)

const

Provides the framebuffer-attachable image to a specific attachment point.

SO<BufferClearance> VRS::FrameBufferObjectGL::getBufferClearance

(

GLenum

attachmentPoint

)

const

Provides the clear policy to a framebuffer-attachable image, i.e., to specific attachment point.

void VRS::FrameBufferObjectGL::clear

(

GLenum

attachmentPoint

)

If BufferClearance is WhenTriggered each attachment can be triggered manually by calling clear(). The clearance will be performed on the next push- or pop-action

bool VRS::FrameBufferObjectGL::isMarkedForClearance

(

GLenum

attachmentPoint

)

const

It can be queried for each attachment if it is currently marked for clearance. This flag will be set to false when the next clearance occurs.

void VRS::FrameBufferObjectGL::unmarkClearance

(

GLenum

attachmentPoint

)

If a buffer is not to be cleared anymore, the clearance-flag can be disabled manually.

Area VRS::FrameBufferObjectGL::size

(

)

const

Returns the size of an arbitrary attached render target. Note: all render targets attached to one framebuffer object must have the same size!

SO<Image> VRS::FrameBufferObjectGL::renderImage	(	SO< SceneThing >	scene,
		GLenum	attachmentPoint = GL_COLOR_ATTACHMENT0_EXT,
		SO< GLCanvas >	canvas = NULL,
		const Area &	area = Area()
	)

Renders "scene" into an image using this FBO. 'attachmentPoint' defines, which buffer is copied into the resulting image (can be color, depth, stencil), 'canvas' is a reference canvas that provides an OpenGL context and 'area' defines a viewport size if different from the whole FBO. If no canvas is provided, an OffscreenCanvasGL is created internally.

Returns NULL if rendering failed.

Attention: the FBO must not be part of 'scene' already!

Currently, only color buffers can be read!

void VRS::FrameBufferObjectGL::render	(	SO< SceneThing >	scene,
		SO< GLCanvas >	canvas = NULL,
		const Area &	area = Area()
	)

Renders "scene" using this FBO and thus fills the associated render targets. 'canvas' is a reference canvas that provides an OpenGL context and 'area' defines a viewport size if different from the whole FBO. If no canvas is provided, an OffscreenCanvasGL is created internally.

Attention: the FBO must not be part of 'scene' already!

bool VRS::FrameBufferObjectGL::isValid

(

)

const [inline]

Returns if rendering to this fbo has succeeded.

TransactionNo VRS::FrameBufferObjectGL::getLastUpdate

(

)

const [inline]

void VRS::FrameBufferObjectGL::setLastUpdate

(

TransactionNo

last

)

[inline]

For internal use only. Check last modification.

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Friends And Related Function Documentation

friend class FrameBufferObjectPainterGL [friend]

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

• framebufferobjectgl.h