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Reflecting with Coffee (Part 4)

The journey so far ... Part 1 - all about the wonderful things we get with reflection,  Part 2 - what a type introspection runtime might look like and Part 3 - extracting the symbols from our source code with clang.
The final step is to connect the two together and fill in a few details. The reflector code is deliberately simple, the script does all the processing work. It is relatively straightforward and does not really require any explanation. Its job is to the JSON output from reflector and fill in the TypeInfoImpl::Create() specialisation.
Any scripting language would do here. In the past I probably would have reached for Perl but my language de jour is coffeescript. There are various reasons for this but feel free to insert language of choice here :) Preferably one with a handy template engine, I happen to be using doT.js.
There are a few extra bits and bobs I added that maybe worth a mention. For convenience, fundamental types (floats, ints, etc) get "type converters"…

Clangerizing (Part 3)

After a long and tedious disquisition on the specifics of implementing a RTTI system we get to the fun (!?) stuff ... generating the data, or clangerizing as I am calling it.
This is a two phase process Using clang to parse the source code and extract symbolsRunning a script over the output to generate the C++ code As I often change my mind about the RTTI implementation, having the second part as a script makes it easier to pander to my whimsical nature.

For the clang bit, we are going to write a recursive AST visitor. There are plenty of examples of how to do this online already but one more won't hurt :) The sample code for this post is on github.

Clang is awesome, modular and easy to build tools that plug into the underlying libraries. Getting it to compile on the other hand, not so much.

Once you have compiled all the source, the easiest way to get started it to copy and modify an existing tool from the llvm/tools/clang/tools folder. You'll also need to modify the CMakeList…

Reflections on Introspection (Part 2)

Following on from part 1, the idea is to create a run-time type system using clang to auto-generate the content.

But before we can get onto all the fun stuff, we what does the run-time type data look like anyway? If you want to play along at home, I have thrown the code up on github.
One of the things we want to do is automatic serialisation, because writing load and save code is just dull. For example, given some data we want to walk the structure and convert it to JSON. So given a class, we need a name, description of its fields, types and so forth. Something like this ... struct TypeInfo { // name // list of fields // list of base classes // any custom attributes }; For starters, we should probably be able to grab the type data for any class. C++ gives us the typeid() operator for static types. This is a nice feature so lets steal it for our own Type() function :) Thingamajig thingy; TypeInfo* type = Type< Thingamajig >(); …

Reflection on Reflections (Part 1)

The holidays, always a good time for reflection ... and being a programmer, reflection of course can only possibly mean "the ability of a program to examine the type or properties of an object at runtime".
Yep, this is hardly breaking new ground but I have to amuse myself somehow. So why bother with reflection? Well it gives us some cool things, such as ...

Automatic serialisation Who likes writing loading and saving code? Or packaging data for a network stream? Surely there is more interesting code to write. Tool and script integration Also, adding script bindings for functions or populating editor controls is a hardly a scintillating task. It would be nice if our classes integrated automatically with the rest of the game systems.Attaching additional attributes to variables And for that matter, validating input or adding meta data (like ranges for values) should be be at least somewhat streamlined.
In short, type introspection simplifies of a lot of tedious and error prone s…

Day 22 – Quantified Self

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It has been a few days and I have some Zeo data to share.

It helped me almost immediately identify a problem with my core sleep. I had assumed the reason I felt so rough in the mornings was part of the adaption process, however the Zeo showed that I was trying to wake up during a deep sleep. Digging back through my sleep log helped me identify my ultradian rhythm and move the core sleep back into alignment with my body clock. The next day I felt perfectly fine.



The graphs show that I am getting between 60-80 minutes of both REM and SWS during my core sleeping hours (see below). The body requires 90 minutes of each and I appear to be making the remainder up during the nap time. This demonstrates that not only has my body adapted (I have a compressed sleep cycle that minimises light sleep) but that I am also getting a healthy amount of the right kind of sleep.

Unfortunately the Zeo does not upload the data for my naps, so I have to check this manually after each one.

By sheer serendi…

Day 16 – Hello Zeo

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As you may or may not know, sleep is broken down into five different phases but it is the last two that your body needs – SWS (slow wave sleep where your body attends to your immune system) and REM sleep (where your mind organises your memories). The others are not required.
You need about 90 minutes of both SWS and REM to be fit and healthy. The idea behind poly-sleep is to optimise your time spent asleep to maximise SWS and REM and to minimise or cut out the others. The problem is how do you know if you are actually getting the right type of sleep or how you might change your sleeping patterns to get the maximum effect? I have been keeping a “sleep log” (below) to try and keep a subjective track of by sleeping and alertness patterns. However, I have now got my hands on a Zeo. This is a neat little box that will monitor your brainwaves as you sleep to tell you exactly what kind of sleep you are getting and will allow me to play with the nap times to see if I can improve the results.…

Day 12 – Recovery

It has been a few days and I have recovered from the crash. The sleeping schedule is back on track, I no longer have tired periods during the day and I finding that I am going sleep pretty quickly when I go for a nap and feeling refreshed and awake afterwards. There are still times during the night when I begin to flag and getting up after the core sleep is hard, although easier than it was. Several people have pointed me towards various articles on the effects of sleep deprivation on the mind and body. It is true that sleep deprivation is a bad thing; however the goal of poly-sleep is sleep optimisation. The idea is that by changing your sleeping routine you are conditioning your body to fall into deep sleep during that nap time and therefore you are still having the right amount of REM sleep. Unfortunately there is little in the way of scientific research into this area. However, one study by Dr. Claudio Stampi on the effects of poly-sleep specifically shows that memory retention a…