Re: [PyOpenGL-Users] Missing VBO function

[Roland E. <r.e...@gm...>]

Thanks after a few try and error I was able to convert my code to use 
that class.

I have anyway a question regarding VBO usage in general.

What is the effect of not unbinding a VBO buffer after drawing and 
calling the drawing process again and again?

memory leak?

memory corruption?

nothing?


Thanks,


Roland.


Le 07/16/10 20:48, Ian Mallett a écrit :
> That /was/ a complete example of how to use the functions :-)
>
> Here, I've added enough surrounding code to be self-explanatory.
>
> #Import it:
> from OpenGL.arrays import vbo
> import numpy as np
> ...
> #Create a vertex buffer object
> vertices = [  [0,0,0],[0,1,0],[1,0,0],  [2,0,0],[0,3,0],[4,9,6],  
> [7,8,1],...]
> vertex_buffer_object = 
> vbo.VBO(np.array(vertices,"f"),usage='GL_STATIC_DRAW')
> ...
> #Draw VBO
> glEnableClientState(GL_VERTEX_ARRAY); 
> glVertexPointerf(vertex_buffer_object)
> glDrawArrays(GL_TRIANGLES,0,len(vertices)/3)
> glDisableClientState(GL_VERTEX_ARRAY);
> glBindBuffer(GL_ARRAY_BUFFER,0)
>
> Normal, and texture VBOs work very similarly.  Vertex attribute VBOs 
> require you to specify a shader, but you'll only need those for things 
> like normal mapping, etc.
>
> If you need more explanation, try: 
> http://pyopengl.sourceforge.net/context/tutorials/shader_1.xhtml, or 
> Google: "from OpenGL.arrays import vbo".  My implementation is here: 
> http://www.pygame.org/project-glLib+Reloaded-1326-.html, in 
> glLib/glLibObjects.py (class glLibObject) but it's probably too 
> convoluted for a tutorial.
>
> Ian