Re: Question on glBufferData / glBufferSubData

Walter White <[email protected]> Sun, 16 Mar 2014 01:11:03 +0100
Newsgroups gmane.comp.python.opengl.user
Message-ID <[email protected]>
Hello,

sorry, I guess I wrote to quickly.
Both methods using glBufferSubData work as expected
for a few seconds but then stop working with

OpenGL.error.GLError: GLError(
	err = 1281,
	description = b'invalid value',
	baseOperation = glBufferSubData,


I found a this bug report
https://bugs.launchpad.net/pygl3display/+bug/1178470
but I am not sure if this is related.

I am using Windows 7 with
PyOpenGL-3.1.0b1.win-amd64-py3.3
PyOpenGL-accelerate-3.1.0b1.win-amd64-py3.3

Kind regards,
Walter


Am 16.03.2014 00:48, schrieb Walter White:
> Hello,
>
> I have a question about PyOpenGL and hope that you can help me.
>
> I am a little bit confused about the follwing.
>
> This works fine:
>
> glBufferData(GL_ARRAY_BUFFER, ADT.arrayByteCount(npData),
>               ADT.voidDataPointer(npData), GL_STATIC_DRAW)
>
> This also works fine:
>
> glBufferSubData(GL_ARRAY_BUFFER, 0, ADT.arrayByteCount(npData), npData)
>
> But using this results in OpenGL Error 1281 Invalid Type after a few
> seconds:
>
> glBufferSubData(GL_ARRAY_BUFFER, 0, ADT.arrayByteCount(npData),
> ADT.voidDataPointer(npData))
>
> I don't understand why using ADT.voidDataPointer(npData) in the
> latter does not work as the specification states the that
> the type is a void pointer to the data array in both functions:
>
> void glBufferSubData(GLenum target,  GLintptr offset,  GLsizeiptr size,
>   const GLvoid * data);
>
> void glBufferData(GLenum target,  GLsizeiptr size,  const GLvoid * data,
>   GLenum usage);
>
> Kind regards,
> Walter
>


------------------------------------------------------------------------------
Learn Graph Databases - Download FREE O'Reilly Book
"Graph Databases" is the definitive new guide to graph databases and their
applications. Written by three acclaimed leaders in the field,
this first edition is now available. Download your free book today!
http://p.sf.net/sfu/13534_NeoTech
_______________________________________________
PyOpenGL Homepage
http://pyopengl.sourceforge.net