JOGL & Pixelnerve objimporter "OpenGL error 1280 at top endDraw(): invalid enumerant" and view distortion

noncom

JOGL & Pixelnerve objimporter "OpenGL error 1280 at top endDraw(): invalid enumerant" and view distortion

in Contributed Library Questions • 1 year ago

Hello!

There is some weird view distortion in my app when displaying meshes loaded from obj files. I am not sure if it is related to the error 1280, but it wasted everything (.

I have been searching for answers to this and looks like the error occures much, but there is no only reason for it and no uniform solution. I have been unable to find any sensible information regarding the error nature except for that it occures when there is some malformed data passed to OpenGL. For me it occures every time i load ANY obj file with Pixelnerve objimporter. The error seems to be not critical in terms that it does not crash the application, but if it's there, then there must be something wrong.

The application does not crush, but, however, there is something strange happening when it runs. After several hours trying to find a mistake in my computations, I have localized the cause in a very unexpected place. As only I try to display any loaded mesh, with this code:

Global.modelDB.getModel(index).draw(context.beginGL());

...the image gets corrupted. It looks like that the projection matrix is turned by 90 degrees ccw around the Z axis (the bottom side now becomes the right side) and something happens to the focal length of the vision. Everything becomes smaller and stretches by several times across the Z axis. If I comment out the single line of drawing the model, all is fine!

I am not sure if the view distortion is somehow related to the error 1280 but I think that it might be some problems with the endDraw() and the matrices do not get correctly arranged or something.

I also have to say one more thing: the application is running in 16:9 mode, the transformation is done like that, at the begging of every draw cycle:

context.gl.glMatrixMode(GL.GL_PROJECTION); //setting up the far clipping plane and aspect
context.gl.glLoadIdentity();
context.gl.glFrustum(-1.77777, 1.77777, -1, 1, 1, 100000); //the 1.7777 / 1 thing is the 16:9 aspect ratio
context.gl.glMatrixMode(GL.GL_MODELVIEW); //returning to model drawing

The context variable is of type which is actually cast from GLGraphicsOffScreen from codeanticode OpenGL library for Processing. The resulted off-screen texture is then displayed as an image, composed with other graphics components such as 2D controls. However, I am not sure if this is somehow related to the problem since commenting these lines does not influence the distortion behavior, it still remains.

EDIT: The -90 degrees rotation is actually performed by my code. There is an option to rotate the context cw or ccw. But now I find that for some reason the keyboard button that does this, has no action when no model is displayed. The rotation is done through the rotateZ method, which looks like this in GLGraphicsOffscreen:

public void rotateZ(float angle) {
if (glMode) gl.glRotatef(PApplet.degrees(angle), 0.0f, 0.0f, 1.0f);
else super.rotateZ(angle);
}

So that must somehow be related to the glMode!!!

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noncom

Re: JOGL & Pixelnerve objimporter "OpenGL error 1280 at top endDraw(): invalid enumerant" and view distortion

1 year ago

UPDATE: I have found out that the instruction to display the mesh:

Global.modelDB.getModel(index).draw(context.beginGL());

...inherently enables the glMode by it's beginGL() statement. Thus I have put the context.endGL() line right below the instruction. That, apparently, had concluded the OpenGL mode, restoring the normal operatrions space (as far as I understand). So the problem seems to be gone now. That, however, leaves me clueless on why was that unnecessary in my other application to call the endGL() method. Does anyone know, is there any source of a more or less complete information on this topic in OpenGL/JOGL/Processing?

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