Archives March 2009

Saw strange performance show up during testing of a simple set of shader-based samples in OpenGLContext.  Discovered what seemed to be a memory leak of the wrapper objects in OpenGL_accelerate... investigation showed that the wrapers were re-"compiling" the finalized versions of the functions on every call.  Turns out that setting self.__class__.__call__ doesn't alter future calls ...

Decided to work on the workstation today (bigger screen, tablet for drawing)... ran the little mandelbrot explorer demo.  Managed to lock up the whole machine at just a few hundred iterations.  Apparently having compiz on while doing "test the limits of your graphics card" code running is... counter-indicated.

Kinda neat zooming into the mandelbrot until ...

The Orange Book (OpenGL Shading Language 2nd Ed) has a neat little shader demo where you render the Mandelbrot set with a fragment shader.  It's one of those "cool, but not particularly practical" examples of shader's power.

I've been adding some rudimentary "generic" shader support to OpenGLContext, so I decided I'd use that little bit ...

Which uses the directdocs generator, which is based on python-lxml... but the API for lxml has apparently changed (with the rebuilding of the workstation to Ubuntu).  Namespaces have to be passed explicitly as a named argument... no problem, can fix that... oh, but now it can't resolve entity references such as ⁢ in the document. ...

OpenGL presentation at PyGTA went alright, but it went *way* over time (2.25 hours) and that was without any particularly involved demos or the like.  Then again, wasn't really attempting to keep to any sort of timeline.  Can likely cut out much of the political stuff, and can go faster on the shader theory (I'm ...

As I've been working on the OpenGL presentation I've run into this issue a couple of times... much of the overhead in PyOpenGL 3.x's array-handling could be eliminated if we didn't allow for copying data at all when passing in array values.  That is, if we were to always require that the client-passed value be ...

Working on one of the graphics for the OpenGL 3.1 presentation most of today.  It's a fairly generic drawing, showing the VBOs, texture-storage, Vertex and Fragment shaders and the various interconnections such as Vertex Attributes, Uniforms, Varying attributes and the like.  I found two drawings that were very similar to what I wanted, one in ...

Did a version of the PyCon talk on profiling at HackLab's weekly Python Newbies night this evening.  This was a bit of a "kitchen sink" presentation; every thought I had on the topic thrown into a presentation to see what stuck.  As a result it was around an hour long (pushing to get it done ...

It's official, I'm abusing my position as PyGTA convener to practice my other PyCon presentation on people.  I am a very naughty boy.  As I've been working on the OpenGL presentation I'm leaning further and further toward just teaching the 3.1 feature-set as "something to understand" and then just covering the migration to 3.1 as ...

I've been wanting to try out the two presentations for PyCon somewhere.  I'll probably inflict a version of the OpenGL one on PyGTA on Tuesday (minus the "migration" parts, as very few people here are already using PyOpenGL).  But I still needed a forum full of victims for the Profiling one.  I was very pushy ...