com.jogamp.opengl

Interface GLFBODrawable

All Superinterfaces:

GLDrawable, NativeSurfaceHolder

All Known Subinterfaces:

GLFBODrawable.Resizeable, GLOffscreenAutoDrawable.FBO

public interface GLFBODrawable
extends GLDrawable

Platform-independent GLDrawable specialization, exposing FBObject functionality.

A GLFBODrawable is uninitialized until a GLContext is bound and made current the first time, hence only then it's capabilities fully reflect expectations, i.e. color, depth, stencil and MSAA bits will be valid only after the first makeCurrent() call. On-/offscreen bits are valid after setRealized(true).

MSAA is used if requested.

Double buffering is used if requested.

In MSAA mode, it always uses the implicit 2nd framebuffer sink. Hence double buffering is always the case w/ MSAA.

In non MSAA a second explicit framebuffer is being used. This method allows compliance w/ the spec, i.e. read and draw framebuffer selection and double buffer usage for e.g. glReadPixels(..). This method also allows usage of both textures seperately.

It would be possible to implement double buffering simply using FBObject.Colorbuffers with one framebuffer. This would require mode selection and hence complicate the API. Besides, it would not support differentiation of read and write framebuffer and hence not be spec compliant.

Actual swapping of the FBObject.Colorbuffers and/or framebuffer is performed either in the context current hook or when swapping buffers, whatever comes first.

Nested Class Summary

Nested Classes

Modifier and Type	Interface and Description
static interface	GLFBODrawable.Resizeable Resizeable GLFBODrawable specialization

Field Summary

Fields

Modifier and Type	Field and Description
static int	FBOMODE_USE_TEXTURE FBO Mode Bit: Use a FBObject.TextureAttachment for the render colorbuffer, see setFBOMode(int).

Method Summary

Methods

Modifier and Type	Method and Description
FBObject.Colorbuffer	getColorbuffer(int bufferName) Returns the named FBObject.Colorbuffer instance.
FBObject	getFBObject(int bufferName) If MSAA is being used and GL.GL_FRONT is requested, the internal FBObject sample sink is being returned.
int	getFBOMode()
int	getNumBuffers()
int	getNumSamples()
int	getTextureUnit()
boolean	isInitialized()
void	resetSize(GL gl) Notify this instance about upstream size change to reconfigure the FBObject.
void	setFBOMode(int modeBits) Set the FBO mode bits used for FBO creation.
int	setNumBuffers(int bufferCount) Sets the number of buffers (FBO) being used if using double buffering.
void	setNumSamples(GL gl, int newSamples) Set the number of sample buffers if using MSAA
void	setTextureUnit(int unit)

Methods inherited from interface com.jogamp.opengl.GLDrawable

createContext, getChosenGLCapabilities, getFactory, getGLProfile, getHandle, getNativeSurface, getRequestedGLCapabilities, getSurfaceHeight, getSurfaceWidth, isGLOriented, isRealized, setRealized, swapBuffers, toString

Field Detail

FBOMODE_USE_TEXTURE

static final int FBOMODE_USE_TEXTURE

FBO Mode Bit: Use a FBObject.TextureAttachment for the render colorbuffer, see setFBOMode(int).

See Also:

Constant Field Values

Method Detail

isInitialized

boolean isInitialized()

Returns:

true if initialized, i.e. a GLContext is bound and made current once, otherwise false.

setFBOMode

void setFBOMode(int modeBits)
                throws IllegalStateException

Set the FBO mode bits used for FBO creation.

Default value is: FBOMODE_USE_TEXTURE.

If GLRendererQuirks.BuggyColorRenderbuffer is set, FBOMODE_USE_TEXTURE is always added at initialization.

Parameters:

modeBits - custom FBO mode bits like FBOMODE_USE_TEXTURE.

Throws:

IllegalStateException - if already initialized, see isInitialized().

getFBOMode

int getFBOMode()

Returns:

the used FBO mode bits, mutable via setFBOMode(int)

resetSize

void resetSize(GL gl)
               throws GLException

Notify this instance about upstream size change to reconfigure the FBObject.

Parameters:

gl - GL context object bound to this drawable, will be made current during operation. A prev. current context will be make current after operation.

Throws:

GLException - if resize operation failed

getTextureUnit

int getTextureUnit()

Returns:

the used texture unit

setTextureUnit

void setTextureUnit(int unit)

Parameters:

unit - the texture unit to be used

setNumSamples

void setNumSamples(GL gl,
                 int newSamples)
                   throws GLException

Set the number of sample buffers if using MSAA

Parameters:

gl - GL context object bound to this drawable, will be made current during operation. A prev. current context will be make current after operation.

newSamples - new sample size

Throws:

GLException - if resetting the FBO failed

getNumSamples

int getNumSamples()

Returns:

the number of sample buffers if using MSAA, otherwise 0

setNumBuffers

int setNumBuffers(int bufferCount)
                  throws IllegalStateException,
                         GLException

Sets the number of buffers (FBO) being used if using double buffering.

If double buffering is not chosen, this is a NOP.

Must be called before initialization, otherwise an exception is thrown.

Returns:

the new number of buffers (FBO) used, maybe different than the requested bufferCount (see above)

Throws:

IllegalStateException - if already initialized, see isInitialized().

GLException

getNumBuffers

int getNumBuffers()

Returns:

the number of buffers (FBO) being used. 1 if not using double buffering, otherwise ≥ 2, depending on setNumBuffers(int).

getFBObject

FBObject getFBObject(int bufferName)
                     throws IllegalArgumentException

If MSAA is being used and GL.GL_FRONT is requested, the internal FBObject sample sink is being returned.

Parameters:

bufferName - GL.GL_FRONT and GL.GL_BACK are valid buffer names

Returns:

the named FBObject

Throws:

IllegalArgumentException - if an illegal buffer name is being used

getColorbuffer

FBObject.Colorbuffer getColorbuffer(int bufferName)
                                    throws IllegalArgumentException

Returns the named FBObject.Colorbuffer instance.

If MSAA is being used, only the GL.GL_FRONT buffer is accessible and an exception is being thrown if GL.GL_BACK is being requested.

Depending on the fbo mode the resulting FBObject.Colorbuffer is either a FBObject.TextureAttachment if FBOMODE_USE_TEXTURE is set, otherwise a FBObject.ColorAttachment. See FBObject.Colorbuffer.isTextureAttachment().

Parameters:

bufferName - GL.GL_FRONT and GL.GL_BACK are valid buffer names

Returns:

the named FBObject.Colorbuffer

Throws:

IllegalArgumentException - if using MSAA and GL.GL_BACK is requested or an illegal buffer name is being used