C[omp]ute

Welcome to my blog, which was once a mailing list of the same name and is still generated by mail. Please reply via the "comment" links.

Always interested in offers/projects/new ideas. Eclectic experience in fields like: numerical computing; Python web; Java enterprise; functional languages; GPGPU; SQL databases; etc. Based in Santiago, Chile; telecommute worldwide. CV; email.

Personal Projects

Lepl parser for Python.

Colorless Green.

Photography around Santiago.

SVG experiment.

Professional Portfolio

Calibration of seismometers.

Data access via web services.

Cache rewrite.

Extending OpenSSH.

Last 100 entries

Re: Python's sad, unimaginative Enum; Re: Some explanation; Some explanation; Printing binary trees sideways; Atoms in python; About "Python's sad, unimaginative Enum"; Frustration Understood; Some good feedback here; this is fucking useless; I agree with you #nt; What would be imaginative?; Re: Enum; Enum; Python's sad, unimaginative Enum; Possible Fix; Work, Exhaustion, Vacation; VirtualBox with Centos 6.3 to 6.4, client; Matasano - Programming Lessons Learned; PDF to HTML; Alternate Substitution; Why RSA Works; Trigger; Dreaming of Death; Example: Tracing; Using Coroutines In Protocol Simulations; Python 3.3 Only; Pure Python SHA1 and MD4 Implementations; Ubuntu on VirtualBox; Starting TOR as a service on OpenSuse 12.3; 1001 Albums; Using fail2ban on OpenSuse 12.3; PPPoE on OpenSuse 12.3; Good Article on Unified Physics; It's Police (Carabineros); Linux Software for Listening to and Exploring Music; Android is Pretty Bad; Lucky Number; 3D Printing for Casting; Cover Art for MPDroid; Who'd a thought the French were so bigoted?; PS Input Signal; Small Problem with Roksan K2 Amp; Roksan K2 Amp + ATC SCM7 Speakers; Do What Makes Sense; Re: Arguing About Tests, Still; Arguing About Tests, Still; Images; Good Article on NY Drummers; Related Bug Report; Getting Python 3.3 and Virtualenv Working in OpenSuse 12.3; How I Am; Awesome video about digital audio; The Difference Between Dimensional and Normalized Databases; The rise of the new Chinese bogeyman; Updated Syntax; Very First Steps to C-ORM; The Ideal User Interface For Music Exploration; Can The Republicans Be Saved?; Rate Limiting Calls to EchoNest; Mods to Cache; Comparing UYKFG and UYKFD/E/F; Someone Else is Concerned; EchoNest-based Playlist Generator for MPD; Example Voting Results; A Heavyweight Python Cache; Identifying Artists with EchoNest; Notes on Pregalex / Pregabalina / Lyrica; The Neil Cowley Trio; Drake - Make for Data; A Reliable Python Web Service; Useful Python Date/Time Library?; Need to Sleep, But this is Good; Command Line Set Difference; Little Details...; Linux Command Line Tricks; AutoTools Tutorial; Hangman Tactics; A Tor Proxy Embedded In A Web Page; Tree (Nested Dicts) in Python; Sleeping at Parties; I Know Someone Who Hurts Other People; Light and Tea; Description of the LCS35 Time Capsule Crypto-Puzzle; Re: I can relate to that ...; I can relate to that ...; Re: It's 2012 Why Does My IDE Suck?; My Own Alternative Medicine; Nice explanation of SVM; Why and How Writing Crypto is Hard; Re: It's 2012 Why Does My IDE Suck?; Incremental Regular Expressions; BBC Map Confused at Pole; Social Media: Ground Zero in the Culture War; My Visit to the Psycho Doc; Learning Modern 3D Graphics Programming; Hope you got some crackers to go with the cheese; Re: But how easy would it be ...; But how easy would it be ...; Powerline Freq Fingerprinting of Audio; The Folly of Scientism; Cheese - Because You're Going to Die Anyway

Some Notes on OGL with wxPython

From: "andrew cooke" <andrew@...>

Date: Thu, 8 Jan 2009 17:57:41 -0300 (CLST)

WxPython, the Python binding for WxWindows, whicah calls GTK on Linux, and
which gives fairly nice-looking GUIs, includes a little-documented module
called ogl.

The documentation generated from source is at
http://www.wxpython.org/docs/api/wx.lib.ogl-module.html and there's some
additional notes at http://wiki.wxpython.org/index.cgi/wxOGL

Here's a few more details I just learnt:

- Kind of obvious, but things are drawn in the order provided to
canvas.AddShape(), so supply "top" things last.

- To generate text use a ogl.TextShape.  This is like a RectangleShape, in
that it has a width and height - these form the clipping area.  Add text
to the shape using AddText(...).  You can also add text to other shapes,
but it will be clipped by the boundary (TextShape's boundary is
invisible).

- To add a line, use ogl.LineShape().  The exact sequence of calls is
tricky, but this seems to work:
  line = ogl.LineShape()
  line.MakeControlPoints(2) # has to be at least 2
  line.SetEnds(x1, y1, x2, y2) # sets the first + last control points
  line.InsertControlPoint(x, y) # see below
  line.Initialise()
  line.SetSplit(True) # for a spline
  canvas.AddShape(line)
The InsertControlPoint() adds an additional point in the list of control
points; it is always inserted just before the end (ie (x2, y2) above), so
repeatedly calling this "fills in" the line from start to end.

Andrew

More wxPython and OGL

From: "andrew cooke" <andrew@...>

Date: Mon, 12 Jan 2009 15:00:51 -0300 (CLST)

Still don't completely "get" this, but here's some more details:

By default, it's possible to drag shapes around on the canvas (mouse left
click and drag).  If a line is from shapeA to shapeB then
  shapeA.AddLine(line, shapeB)
attaches them, so that dragging is coherent (note that the shapes must
already be drawn; the line is drawn "underneath").

Dragging can be disabled by using
  shape.SetDraggable(False)

Response to clocking etc is mediated via the ShapeEvtHandler.  However
there's something odd with the architecture - Shape inherits from this
class but also has an instance (Shape._eventhandler).  As far as I can
tell the inherited handler is unused and you override fucntinality (to
intercept events etc) by setting the instance handler
(Shape.SetEventHandler).

However, you cannot just set the handler with a subclass, you must also
define the "previous" event handler to be what was already defined.  In
other words:
  myEventHandler = ....
  myEventHandler.SetPreviousHandler(shape.GetEventHandler())
  shape.SetEventHandler(myEventHandler)

Whether an object responds to a click or not is defined by the sensitivity
filter.  If the object is insensitive then the event is propagated to the
parent.  This means that if you have one shape on top of another (in my
case, overwritten text) then you can make sure that events detected by the
top layer shape are forwarded by:
  lowerShape = ...
  canvas.AddShape(lowerShape)
  upperShape = ...
  canvas.AddShape(upperShape)
  upperShape.SetParent(lowerShape)
  upperShape.SetSensitivityFilter(0)

The event handler associated with the lower shape will then receive events
as expected.

Andrew

Comment on this post