I have been creating some games in Javascript so thought why not use one of these libraries to use some gestures to play a game .

I decided to go with headtrackr and thought it might be easy to add this to one of the existing games on Brainturk.com. Once I started I realized I needed a way to detect a collision between a rotated rectangle and a gradient on HTML5 Canvas .

I have recently started with game programming so did not know where to start . Google led me to Seperating axis theorem but later I stumbled upon this blog and implemented this in Javascript and came up with this initial version of a picture back game here and another variant of the same game . WebRTC is currently enabled in Google chrome and Opera .

Once you click the start button look at the images in the game and if the image on screen is the same as the previous one move your head over to the green circle and if the image is different move it to the red circle .

failed to map segment from shared object: Operation not permitted
Can't load '/tmp/del/Storable-2.30/blib/arch/auto/Storable/Storable.so' for module Storable: /tmp/del/Storable-2.30/blib/arch/auto/Storable/Storable.so: failed to map segment from shared object: Operation not permitted at

The error was due to the fact that I was trying to build and run the tests on a /tmp directory which had noexec enabled , moving to a different directory solved this issue

objdump (otool on osx) is a program to examine a binary.
To examine perl run the command

objdump -D /usr/bin/perl |grep -A40 main.:

Interesting to see the function call
objdump -D /usr/bin/perl |grep -A400 main.: |grep call

to get the output in intel syntax add the option -M

objdump -M intel ...

GDB
for the following c program

main() {
printf("hello world \n");
}

-g flag to give gcc access to source code
gcc -g prog.c

gdb commands to debug a c program
gdb -q a.out
set disassembly intel

list
break main
run
disassemble main

to dump a string stored in memory
x/s 0x... (memory address) in this prog we can check the string hello world stored at instruction mov

debugging perl
- Get the latest bleadperl from git
- Configure and install perl with debugging support sh Configure -DEBUGGING=both
gdb -q /usr/local/bin/perl
set disassembly intel
break main or break line number

nexti or n to step through
s to step through a subroutine

x/s variable to print the contents of a var

The idea is to combine social as well as technology aspect together to make it fun for the participants as well as being a learning experience since you actually get to try out something .
Lets say there are 200 attendees.
Reserve a 50 minute (or less) slot for this in the main hall

- Specify a task (or many tasks like an exercise in Modern Perl, Moose , Plack, Event Driven, MVC framework ... )

-100 people are designated places and they have the pre-requisites (modules ? ) installed on their laptops

- The other 100 people join the people and pair program or one works while the other watches , discuss for 10 minutes or argue over why their ide is better

- After 10 minutes the participants are moved either left/right and start with a new partner while the ones with the laptop do not move

So in theory after the designated 50 minutes , each person has worked with 5 people, I believe this has a lot to offer as you actually get to program/discuss and you can pick up a lot of useful stuff like how people use their IDE their configuration , their style of programming and it is also fun you get to meet different people. Imagine a newbie getting a chance to pair program with some well known perl hackers.


I think if some more thought is put in to this and planned it could work and be a fun exercise. What do you think ?

I had a dot cloud invite that I had not used and I wanted to learn some HTML5 and looking around there did not seem to be a N-back version in HTML5 (most of them use flash) so I created a web app Bodhi . The intent is that this app works on the browser as well as mobile devices ( at least iPad). This is the initial version and I am looking for some feedback on improving this or adding some more tasks.

I am pretty impressed with the dot cloud infrastructure, it's easy to get started and deploying is simple.

wget http://python.org/ftp/python/2.6/Python-2.6.tgz
tar -xvf Python-2.6.tgz
cd Python-2.6
./configure --prefix=/usr/local/python2.6
make
sudo make install

#add /usr/local/python/bin to your ~/.bash_profile
wget http://pypi.python.org/packages/2.6/s/setuptools/setuptools-0.6c11-py2.6.egg#md5=bfa92100bd772d5a213eedd356d64086

sudo su -
#make sure python -V is 2.6
sh setuptools-0.6c11-py2.6.egg

#now you can use the easy_install which is installed under /usr/local/python/bin/easy_install to install dotcloud
sudo easy_install dotcloud

Now follow the instructions Here on getting started with dotcloud.