Offscreen buffer failing to update in 2.0b9?

Programming Questions

kodereakt..

Offscreen buffer failing to update in 2.0b9?

in Programming Questions • 5 months ago

Hi.
I have a rather large project I've been working on for quite some time. It uses PGraphics objects to draw offscreen, as this psuedocode hopefully shows:

PGraphics guiOverlay;
guiOverlay = createGraphics(width, height);
draw {
camera();
camera(cameraX, cameraY, cameraZ, cameraX, cameraY, 0, 0, 1, 0);
hint(ENABLE_DEPTH_TEST);
guiOverlay.beginDraw();
...
guiOverlay.doingstuff
doingOtherStuffAsWell
...
guiOverlay.endDraw();
camera(); // Reset the camera to draw the GUI.
hint(DISABLE_DEPTH_TEST);
image(guiOverlay, width/2, height/2);
}

Sorry for not pasting 100% real code, but it's a very large module.

This was working as expected in 2.0b8, but the latest revision of 2.0b9 (0217?) will only draw the first frame on the buffer.

Does anyone know why, or can aid me in making it function using beta9?

Replies(4)

amnon.owed

Re: Offscreen buffer failing to update in 2.0b9?

5 months ago

I've made some changes that seem to me a more solid solution. The most important is not doing other drawing inside you guiOverlay drawing methods. Note that another option is to put the 3D scene inside a PGraphics and have the gui stuff on the main P2D/JAVA2D PGraphics. Another option is to have BOTH inside a PGraphics and just display two images in the main draw() loop.

I think the new betas are a bit more strict with the correct usage of begin-endDraw. I have a feeling this is probably not a bug, but requires some changes in your code. However for real help (both on the forum or a potential bug report) we need a small, runnable example.

Adapted pseudocode

PGraphics guiOverlay;
guiOverlay = createGraphics(width, height);
draw {
hint(ENABLE_DEPTH_TEST);
camera(cameraX, cameraY, cameraZ, cameraX, cameraY, 0, 0, 1, 0);
...
doingAll3DStuffHere()
...
camera(); // Reset the camera to draw the GUI.
hint(DISABLE_DEPTH_TEST);
guiOverlay.beginDraw();
guiOverlay.doingstuff
guiOverlay.endDraw();
image(guiOverlay, width/2, height/2);
}

kodereakt..

Re: Offscreen buffer failing to update in 2.0b9?

5 months ago

Hi and thanks!

If I understand, your solution is to re-arrange things so that all the PGraphics stuff is in one block, instead of interspersed throughout?

amnon.owed

Re: Offscreen buffer failing to update in 2.0b9?

5 months ago

Exactly. Not only is this safer codewise, it also makes your code easier to read. But as stated, now that it's possible to have P3D PGraphics, this actually becomes a pretty clean option as well.

kodereakt..

Re: Offscreen buffer failing to update in 2.0b9?

5 months ago

Unfortunately that's not really possible as all that is run to draw things like directional pointers to off-screen objects that are in the 3d world at the same time as the 3d world is being drawn. It would mean doing several loops twice.. I guess I could, as the loops necessary aren't very long and I need to do lots of optimization as it is currently anyway..

I tried begin/endDraw with each block of PGraphics drawing just in case but that didn't change anything. You said they're possibly more strict. Is the way I'm doing it wrong from processing's standpoint? (Because I was wondering myself if I was doing it "right") As I said, it's a large project. I can deliver more code for show, but a *working* example that's compact enough for forum pasting might be difficult. \c:

The alternate alternative is just to finish this project with beta8 before moving on.

Top Reply