Re: [PyOpenGL-Users] Question on glBufferData / glBufferSubData

[Walter W. <hom...@gm...>]

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
>