pyopengl-users

[PyOpenGL-Users] For the Brave: PyOpenGL 3.0.1a1 released...

[Mike C. F. <mcf...@vr...>]

I've just managed to get PyOpenGL's first alpha for the 3.0.1 series out
the door.  The biggest changes of note are:

    * Shader convenience module OpenGL.GL.shaders, provides shader entry
      points named as the core entry points with alternate
      implementations using ARB when necessary.  Includes Two utility
      functions compileShader( source, type_constant ) and
      compileProgram( *shaders ) which allow for easily creating
      shader-using demos.
    * Cython OpenGL_accelerate wrapper mechanism accelerators available
      (pre-built for Python 2.5 and 2.6 on Win32)
    * Many bug-fixes.
    * SIZE_1_ARRAY_UNPACK flag to configure single-value-array-unpacking
      behaviour
    * CONTEXT_CHECKING flag to enable rigorous (slow) checking for valid
      contexts before each GL/GLU/GLE call in order to debug crashes due
      to calls before there is a valid context present.
    * STORE_POINTERS flag to enable/disable storage of (temporary) pointers
    * Optimizations to reduce or remove certain wrapper operations when
      the ERROR_ON_COPY flag is enabled.

This release is very much an alpha, do not install in production
environments, use it to test your software and send me bug reports. 
There are enough significant implementation changes in this release that
it would be extremely unlikely that no bugs have crept in.

See: https://sourceforge.net/projects/pyopengl/files for downloads.

Enjoy,
Mike

-- 
________________________________________________
  Mike C. Fletcher
  Designer, VR Plumber, Coder
  http://www.vrplumber.com
  http://blog.vrplumber.com

Re: [PyOpenGL-Users] For the Brave: PyOpenGL 3.0.1a1 released...

[Mike C. F. <mcf...@vr...>]

Zack Schilling wrote:
> I tried the new alpha out on my game. The game draws a lot of quads
> and point sprite particles using VBOs. Everything drew fine, no
> crashes, flickering, stuttering, or any other errata. The only change
> I noticed was a stricter behavior with ERROR_ON_COPY enabled. I
> typically used ERROR_ON_COPY to make sure that I didn't make a dumb
> mistake with VBOs, but I never had a problem with using Python lists
> for things like texture deletion. Now the flag catches such uses. I'll
> need to make a few minor changes to my code.
Yeah, the ERROR_ON_COPY stuff now actually makes simplifying assumptions
for the wrappers (i.e. drops out wrapper code), so the various array
handlers need to be far more rigorous about checking.  It caught quite a
few of my scripts where I was passing lists/tuples for light/material
parameters and similar small arrays.
>
> Other than that, the game ran as if nothing had changed. I didn't
> notice any change in speed or GPU load capability with acceleration
> on. I don't handle a ton buffers and pointers, so I guess a lot of the
> optimizations are lost on my code.
Yeah, if your code is basically a few dozen calls into PyOpenGL passing
in huge data-arrays then the PyOpenGL overhead would be negligible.  In
OpenGLContext I see a drop from OpenGL calls being ~10% of run-time to
~2.5% of run time.  Translates to about 9fps on the shaderobjects.py
demo (from 69 to 78).
> My main dev machine runs Mac OS X. I'll need to compile and test this
> all there too. I'll let you know if anything comes up.
We had a bug report on OS-X, I'm about to look into that.

Thanks for the update,
Mike

-- 
________________________________________________
  Mike C. Fletcher
  Designer, VR Plumber, Coder
  http://www.vrplumber.com
  http://blog.vrplumber.com