Up to date on videos

Real lift has got in the way of doing much graphics work recently, however I've now caught up and uploaded a bunch of videos.. (it also took quite a while to get scripts for creating the same videos, with sound working).

Audio Reactive Critters

Graphics experiments

Rendering fat lines with Shoebot

Animating fat lines with Shoebot

Learning about 2D vectors

I have some basic code to find the length of a Bezier Curve and a point along it, I seem to have talked myself into implementing this in Cairo, so that's the next stage, from there path effects and text-on-a-path will be the next stage.

Progress so far

I've been pretty busy so far doing laying the groundwork for my audiovisual project. I've got the architecture worked out, so ones this stage 0 is complete I can start coding it. Uploaded, 2 videos using shoebot... 4 others waiting to be uploaded. Soft Released: vext https://github.com/stuaxo/vext This makes it easy to use things like wx, gtk, pyqt4 and other, mostly Gui and older Audio libraries in virtualenv. Have been using this successfully with Shoebot for a while. Python 3 support is still TODO, at which point can do a proper release. Working on: Finishing off a tool to make videos with :) Learning About: Bezier Curves (have a Gtk demo app waiting to be uploaded) [Blocking on app to create videos] Cairo OpenGL PPA: Built a Docker Image that can build debian packages, this needs completing so they can be signed and uploaded to the PPA.

Wifi + Moving Country

If you are on linux and having trouble with WIFI in a new country it might be worth letting it know what country you are in - on debian/ubuntu edit the file /etc/default/crda and update the country code.

Daily graphic 2

Todays daily graphic I'm getting familiar with grids (in shoebot), Vector maths from the planar library .. this started from the grid example from shoebot / nodebox. Shoebot Code Below the fold (more…)

Everyday graphic

Not sure how practical it is, but will try and upload a new graphic everyday .. to start with will probably be quite basic :) Here is the first, some moving granual thingies.. Shoebot code:
import random
from math import sin, cos

size(800, 800)
colours=ximport("colors")


def draw():
    background(colors.aliceblue())
    scale(1, 1)
    nostroke()
    fill(0.1, 0.2, 0.3)

    random.seed(0)
    for y in xrange(0, HEIGHT, 80):
        wiggle = sin(FRAME * 0.1)
        xs = 2.0 + (cos(y * 0.1) + sin(y) * 8.1)

        distance = 1.0 / HEIGHT * y
        fill(1.0, 1.0-distance, 0, distance)
        for x in xrange(0, 60):
            xpos = ((xs * FRAME-x * 40) % (WIDTH + 40)) - 20
            circle(xpos, y + (wiggle * random.random() * 20.0), 20 + (wiggle * 2.0) * distance * 8.0)

        #xs = -sin(y) * 4.0
        #for x in xrange(0, 60):
        #    circle(WIDTH-xs * WIDTH - FRAME + x * 40, y+40, 20)

Workflow for debugging issues on python on windows with a VM

Recently I had to look at an issue where the behaviour on windows was subtly different to that on linux... unfortunately most potential users are on Windows so it's not good enough to just write them off :) This workflow was quite good for checking python internals on different versions of python and being able to revert things easily. To get things going quickly I use the IE11 VM from microsoft, and download from xdissent https://github.com/xdissent/ievms That way you just need to enter a command to download it
curl -s https://raw.githubusercontent.com/xdissent/ievms/master/ievms.sh | env IEVMS_VERSIONS="11" bash
Next I install all the tools I need before python (we will save the state of the VM before then). chocolatey.org makes installing tools easy* https://chocolatey.org/ Open a command Window as Administrator then install chocolatey:
@powershell -NoProfile -ExecutionPolicy unrestricted -Command "iex ((new-object net.webclient).DownloadString('https://chocolatey.org/install.ps1'))" && SET PATH=%PATH%;%ALLUSERSPROFILE%\chocolatey\bin
Once thats done you can install tools you need - I install everything *except* python:
choco install git conemu
While these are installing start the downloads for python and it's C compiler (remember not to install them yet): Grab python from here: https://www.python.org/downloads/ For python 2.7.x you will probably need the VC compiler http://www.microsoft.com/en-gb/download/details.aspx?id=44266 My app was for PyGtk so I also downloaded that - download anything else you need at this stage. Download your project... Using git or whatever, grab your own project to a directory. Save the VM state. In virtualbox save the machine state, I called mine 'Tools Installed'. From here you can install python + know that you can poke around in the internals, any time you want to check against a different version, just revert the VM to the previous state.   TL;DR - Install all tools except python, grab projects, SNAPSHOT, install python - find bugs. *when it works.

Setting up Backups

A day of Admin .. Spent a good amount of time getting backups setup on ubuntu .. Insynch to backup google drive to my computer - https://www.insynchq.com/ Setup good old Thunderbird to download email to my computer - the trick is to get an an app specific password. Finally, bought cloud backup from SpiderOak it seems quite good from a security point of view, the app itself is a little 'java', but seems to work OK.

Docker and caching apt-get for guests on the same host

Docker is great for isolation, you probably still want some caching, the Dockerfile from extellisys is a great start: https://github.com/extellisys/docker-image-apt-cacher-ng Running the above, runs apt-cache-ng and exposes it's port as 3142. This is great for a LAN, if you want to use this for caching on your dev box then read on. If you just want lines to paste into other Dockerfiles, skip to the end.
To avoid surprises I tend to change the "FROM" part of any Ubuntu or Debian based Dockerfiles to use the same distro as the host (in this case "ubuntu:14.10"), this should save a little space too.

Optionally use the cache with Docker guests on the same host.

Desired result - use the cache if available, otherwise don't. Avahi is the usual way to do this, unfortunately it doesn't work easily in between host and guest. We can make our own way of doing this. So all we need to do is find the host IP from another guest - $ route -n | awk '/^0.0.0.0/ {print $2}' The other part is optionally using a proxy - the undocumented apt.conf.d setting Acquire::http::ProxyAutoDetect is what we want. It runs a discovery script that either outputs an IP of a proxy, or DIRECT if there is none.

Discovery script and setting

/usr/local/bin/apt-ng-host-discover: #!/bin/bash HOST_IP=$(route -n | awk '/^0.0.0.0/ {print $2}') if nc -w1 -z $HOST_IP 3142; then printf http://$HOST_IP:3142; else printf DIRECT; fi /etc/apt/apt.conf.d/30proxy: Acquire::http::ProxyAutoDetect "/usr/local/bin/apt-ng-host-discover";

Putting it together / tl;dr;

Everything can be munged into 5 lines you paste into your Dockerfile: RUN HOST_IP=$(route -n | awk '/^0.0.0.0/ {print $2}'); \ echo "#!/bin/bash" > /usr/local/bin/apt-ng-host-discover; \ echo "if nc -w1 -z $HOST_IP 3142; then printf http://$HOST_IP:3142; else printf DIRECT; fi" >> /usr/local/bin/apt-ng-host-discover && \ chmod +x /usr/local/bin/apt-ng-host-discover RUN echo 'Acquire::http::ProxyAutoDetect "/usr/local/bin/apt-ng-host-discover";' > /etc/apt/apt.conf.d/30proxy

Further work

Run the extellisys cache on boot, and disable any other caching ( http://ask.xmodulo.com/disable-apt-cache-debian-ubuntu.html ).

3d in the era of J2me

Back in the deep dark past (2004-2007) I worked on a 3D game for phones of that era (before iphone, android). I recently found some of the test files for the engine, here are some videos. Very low poly racetrack The ubiquitous cube Spacekid in the spacestation corridors Our Maskot wanders the corridors .. you can't look too far ahead, to keep things really low, which means popup is a little...severe. Movement is a better in reality - the capture has made the movement a bit jerky. Dire Straits Obviously we didn't make this, but it heavily inspired our 3D engine ... textures were just too slow, so we aimed for this look.