Package panamagl.offscreen

Interface FBO

All Known Implementing Classes:

AFBO

public interface FBO

A frame buffer object, or FBO, can render OpenGL into an offscreen buffer that can later be read to an Image by a FBOReader which will access the FBO content through readPixels(GL).

Author:

Martin Pernollet

Method Summary

Modifier and Type	Method	Description
void	bind(GL gl)	Bind this FBO so that the following GL commands target it, e.g.
int	getHeight()
int	getWidth()
boolean	isPrepared()
void	prepare(GL gl)
MemorySegment	readPixels(GL gl)
void	release(GL gl)
void	resize(int width, int height)
void	unbind(GL gl)	Bind back the default framebuffer, so that the following GL commands do not target this FBO anymore.

Method Details

prepare

void prepare(GL gl)

release

void release(GL gl)

resize

void resize(int width,
 int height)

getWidth

int getWidth()

getHeight

int getHeight()

isPrepared

boolean isPrepared()

readPixels

MemorySegment readPixels(GL gl)

bind

void bind(GL gl)

Bind this FBO so that the following GL commands target it, e.g. to perform GL work out of the rendering of a canvas such as picking from a mouse event. The FBO is prepared if it is not already, otherwise it is bound as is, i.e. without being recreated nor cleared. The GL context of the canvas must be current on the calling thread. Out of a GLEventListener method, the work must therefore be performed with the ThreadRedirect of the canvas renderer, which may run it later (see doc/Multithreading.md) :

 
 OffscreenRenderer renderer = canvas.getOffscreenRenderer();
 
 renderer.getThreadRedirect().run(() -> {
   GL gl = renderer.getGL();
   renderer.getFBO().bind(gl);
   // GL work targeting the canvas framebuffer
   renderer.getFBO().unbind(gl);
 });
 
 

See Also:

• unbind(GL)

unbind

void unbind(GL gl)

Bind back the default framebuffer, so that the following GL commands do not target this FBO anymore. Same thread requirement as bind(GL).