Invalid operation problem

OpenGL Development
#1

Thanks wiesi, how stupid I am i just had to scroll down to discover 0.98 and 0.99 releases :-X :-X :-X

it should be easy as just swithing 0.99 for 1.0beta, as there has not been any major api changes.
[/quote]
Well actually that’s what I did but I didn’t worked so far… It’s puzzling me I get

org.lwjgl.opengl.OpenGLException: Invalid operation (1282)

I’ve seen this error commonly happens when using more than one thread but I do have one thread only ! Here’s the complete stack trace :


org.lwjgl.opengl.OpenGLException: Invalid operation (1282)
	at org.lwjgl.opengl.Util.checkGLError(Util.java:56)
	at org.lwjgl.opengl.Display.swapBuffers(Display.java:566)
	at org.lwjgl.opengl.Display.update(Display.java:582)
	at com.xith3d.render.lwjgl.CanvasPeerImpl.renderDone(CanvasPeerImpl.java:772)
	at com.xith3d.render.lwjgl.CanvasPeerImpl.display(CanvasPeerImpl.java:958)
	at com.xith3d.render.lwjgl.CanvasPeerImpl.render(CanvasPeerImpl.java:1035)
	at com.xith3d.scenegraph.View.renderOnce(View.java:616)
	at com.xith3d.scenegraph.View.renderOnce(View.java:549)

It seems like it happens just before swapBuffers() (swapBuffer calls Util.GLCheckError() before really swapping buffers).

(@Moderators : you may separe this thread if you don’t think it’s appropriate)

#2

Its because you did something thats illegal in the OpenGL world somewhere in your code. on swapBuffers, Util.checkError(); catches the problem…

Just put Util.checkError() in all of your code that you’ve changed and see what comes up…

(Btw, why is this thread sticky?)

#3

(The beginning of this thread is in the “LWJGL 0.99 Released” subject)
Yeah but I did OpenGL long ago and now I’m working with Xith3D only I don’t mind fixing the LWJGL renderer now if it’s straight-forward, however it’ll take a bit longer.
I know the Util.glCheckError() mecanism but the error 1282 is usually thrown (from what I’ve found on forums) when you call an OpenGL command from a different thread from which it has been created. Could it be another problem ?

I’ll try to put Util.glCheckError() everywhere to have more details.

#4

no, the invalid operation will not be thrown if you call it from another thread in LWJGL; if you do call GL commands from another thread you will get a LWJGLException about contexts…

invalid operation is an OpenGL specific exception, nothing to do with threads…

DP

#5

I’ve encountered this type of problem with Xith3D’s LWJGL renderer long ago. I’ve filled a bug report for it, it has to do with the fact that Xith3D never checks the hardware capabilities ; it takes for granted a set of capabilities and if it doesn’t fit, it will just run as is with OpenGL firing errors. The bug exists as well with the JOGL renderer, it is just not catched. As far as I can tell, this type of bug rely on the Xith3D side, not LWJGL.

You should use GLIntercept to catch the offending openGL call. It is of great help

        Vincent
#6

OK

OK gonna debug that.

Unfortunately, alas, alas it’s windows-only !! If you have a manner to make it works on linux (I think Wine isn’t of great help here) please tell me.

#7

It could be easier than that since in LWJGL, extensions each have their own class. So, find all OpenGL classes used by Xith (GL11, GL12, ARBVertexBufferObject etc.) and for each of those, check that the corresponding capability is set (GLContext.getCapabilities().GL_ARB_vertex_buffer_object).

  • elias
#8

You will need a bit more work, since you also have to check for hardware specific constants. For example, Xith3D takes for granted that the hardware provides 4 full texture units. For example, this is false on a GeForce 2 card and causes the error mentionned in the original post.