Processing V2.0a5 OpenGL issue

Core Library Questions

quarks

Processing V2.0a5 OpenGL issue

in Core Library Questions • 1 year ago

I am currently working on updating the G4P (GUI for Processing) library to make sure it works well with the new OpenGL renderer and have hit a problem.

If you start Processing V2.0a5 and then run the example G4P_Buttons it works fine with the default renderer (JAVA2D), but if I change it to OPENGL the program crashes. You can see the stack trace here at pastebin.

I have been doing experiments to narrow down the problem area with the following results :-

I have repeated the above experiment on two machines running Windows 7 (64 bit) with Java 1.7.0_3 (32 bit) and Vista (32 bit) with Java 1.6.0_29 (32 bit) with the same results.
In V1.5.1 the program runs just fine with both renderers.
My sprite library exhibits the same problem if you try to run the S4P_TankDemo with V2.0a5
Only those controls that use the image() method with PImage(s) in their rendering cause this problem. So buttons without icons work well but those with icons don't. For instance G4P_Knob_Config works well with OPENGL.
The stack trace seems to identiy 2 possible areas PTexture (line 20) and possible mistmatch with beginDraw/endDraw (line 49).

If anyone else out there using G4P and V2.0a5 I would be interested to hear if they can reproduce the problem.

If any one has any ideas or possible work arounds I will be even happier to hear from you.

Thanks

Replies(5)

andres

Re: Processing V2.0a5 OpenGL issue

1 year ago

Hi, this error was due to the PImage objects created by the sprite and G4P libraries not having a parent. I didn't look at the code of your libraries, but I guess you are instancing PImages with the constructor (img = new PImage()) which doesn't set the parent variable. P3D uses the parent to initialize opengl textures. This requirement is solved with the latest commit in the code repo, so the fix should be available in the next alpha release.

andresier

Re: Processing V2.0a5 OpenGL issue

1 year ago

hi,

i had this problem too in my cv library (flob) , and managed to fix it some months ago, by calling createImage, instead of new PImage, like andres say above, working until 2.0a4, looking forward for this fix out, to make it work in processing 2.0

really enjoying the new processing 2.0. a whole lot of rework. congrats.the new video library is very good.

another question regarding this same topic, opengl issue on p2.0a5

how do i get access to the gl object to ask things like:

gl.glColor4f(1,1,1,alpha);
gl.glEnable (GL.GL_FOG);
gl.glFogfv (GL.GL_FOG_COLOR, FloatBuffer.wrap(fogcolor));
gl.glFogfv (GL.GL_FOG_DENSITY, FloatBuffer.wrap(fogdensity));
gl.glHint (GL.GL_FOG_HINT,GL.GL_FASTEST);
gl.glFogf (GL.GL_FOG_START, fognear);
gl.glFogf (GL.GL_FOG_END, fogfar);

seems to be broken on all the alphas, but works ok on p1.5.1.

even the opengl advanced example on the wiki is broken on the alphas. ( http://wiki.processing.org/w/Color_blending_with_OpenGL + http://wiki.processing.org/w/1,000,000_points_in_OpenGL_using_Vertex_Arrays + etc )

the only thing i saw working was setting the blendmodes, but all other advanced uses seem off limits for now.

will this be fixed in the future?

if not, how could i access these sort of raw opengl commands from within processing?

thanks

andres

Re: Processing V2.0a5 OpenGL issue

1 year ago

At this point (2.0a5) you can do something like this:

import processing.opengl.*;
import javax.media.opengl.GL;
import javax.media.opengl.GL2;
void setup() {
size(400, 400, OPENGL);
}
void draw() {
PGraphicsOpenGL pg = ((PGraphicsOpenGL)g);
PGL pgl = pg.beginPGL();
GL gl = pgl.gl;
GL2 gl2 = pgl.gl.getGL2();
...
pg.endPGL();
}

The PGL object is a layer between OpenGL and Processing that contains all the JOGL interfaces (gl, gl2, etc). However, this is very preliminary and will probably change in the next alpha releases.

andresier

Re: Processing V2.0a5 OpenGL issue

1 year ago

hey, that seems wonderful.

thanks.

and please, dont change the api too much:)

for the gl freaks, it's a very solid easy cross platform

robust platform you are making, glad to be using your code.

it breaks all previous code, but it's worth it.

and yes, do let us know how to access these thingies if you do

change it a lot. perpetual changes are very cool too.

will test drive this things in the next few days. great job at integrating

it all under p3d, opengl es2.0, normal gl, etc. looking forward to some

deep code diving on this topic.

best regards

quarks

Re: Processing V2.0a5 OpenGL issue

1 year ago

Thanks for responding.

@andres

I guess you are instancing PImages with the constructor (img = new PImage()) which doesn't set the parent variable.

Since most of the images used in the G4P library are supplied by the user it uses loadImage(). I have looked at the source code and this method uses new PImage() so that explains that. Since you say this will be fixed in next alpha release I will wait patiently.
BTW thanks for all your work on PS V2 it is very impressive!

G4P supports multiple windows where each window has its own PApplet object so can use different renderers. My question is in the next PS version can an image loaded using one applet :-
picture = app1.loadImage("picture.png");
be displayed in another applet (window):-
app2.image(picture);
especially if they are using different renderers e.g. JAVA2D and OPENGL

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