No Update Today?

Yup, just a little one.

I'm gonna use Qt for GUI work - yup, I also understand that most of this stuff isn't GUI at all but I'll probably steal their colour coded editor or just plane old QTextEdit, wrap some open/close stuff around it and call it a UI.

There are advantages to working this way - think multiple tabs and/or multiple windows - one shows you your central scripting whilst the others change as fast as possible to show how your models are turned into code, interpreted, graph outputs etc. Very nice.

One disadvantage is that an installer gets "big" once you've added all of Qt's libraries. Linux with it's dependency system doesn't worry too much. Windows - well you have to ship 'em and same with Mac.

I work almost exclusively with Linux (Ubuntu & Android to be precise - although Angstrom is on my list soon too). I do have a Mac (used to be for iPod/iPhone dev - but I simply don't have time to do that anymore). Windows - I don't even have a machine.

Qt also added QAudioInput and QAudioOutput recently - I'm not sure what the backing code is but I don't really mind. I used to use PortAudio but doubt I will anymore.

Right, next time a lot more on machines then samples and graphing.

Going Native

Machines

We defined a machine as a functional unit - give some input data it will produce some outputs.

To map to native code inputs will be mapped as a pointer (that points to a machines output - note, it _could_ be itself).

To map to native code outputs will be represented as physical storage.

Every input and output can be named (and maybe typed one day).

Somewhat stolen from Forth is the idea that a machine can be compiled - once compiled a lot of dead code can be eliminated BUT (and it's a big but) what's within the machine can no longer change - the data flowing through it can change (necessarily) but we can't add or remove components nor can it's output to input connections be changed.

You don't have to do this though. If you continue to interpret your machine all edits are still possible - it will just run a bit slower (probably about 10 times slower!)

Me again... graphs this time...

Not the sort with an x and y axis that show you data but interconnected nodes.

These graphs are a collection of "nodes". Each node in my system represents a function, some work and has a number of inputs and outputs.

Inputs are connected to outputs of other nodes (or in fact the same node - they can represent feedback and this is both annoying from a functional perspective but also incredibly useful, nay essential, for programming - my view is that although it creates a slight problem in that is is impossible for a node to ever be coherent it creates an opportunity by allowing feedback to be used as memory).

An input can only be connected to a single output (the reasoning here is that all work must be done by a node - if we simply connect 2 inputs to 1 output what work would need to be done to merge those inputs... and, or, addition, multiplication??? It's ambiguous and thus avoided).

MACHINE

A collection of connected nodes is called a "machine".

Each node has a "type" (this saves us duplicating every single machine of every single type!)

Each node has a name - this must be unique to the environment that it is contained in (but does not preclude a machine within this one from having a machine with this name)

CYCLE

Once per output sample the entire machine (the outer one) is cycled. At least 1 of its inputs needs to be connected to something "outside" the machine - in this case the audio circuitry. Top level inputs could be connected to other devices but don't actually need to be (we can build a whole machine to represent a song).

THE SPECIALS A.K.A. The Coventry Automatics

"Special" machines are built in and deal with lovely stuff like loading and playing samples, simple oscillators, time conversion (time is a MASSIVE subject for discrete mode synthesis), basic math operations.

My original intention was to build the entire thing to run as 32 bit ints (which is possible for basic synthesis) but I think the standard atom/quanta of information will be the 64 bit int or double. Much more powerful even if much slower.

Lunch nearly over... more soon!

How to allocate executable memory on Linux...

#include <stdio.h>
#include <sys/mman.h>

typedef unsigned (*asmFunc)(void);

int main(int argc, char *argv[])
{
   // probably needs to be page aligned...

   unsigned int codeBytes = 4096;
   void * virtualCodeAddress = 0;

   virtualCodeAddress = mmap(
       NULL,
       codeBytes,
       PROT_READ | PROT_WRITE | PROT_EXEC,
       MAP_ANONYMOUS | MAP_PRIVATE,
       0,
       0);

   printf("virtualCodeAddress = %p\n", virtualCodeAddress);

   // write some code in
   unsigned char * tempCode = (unsigned char *) (virtualCodeAddress);
   tempCode[0] = 0xb8;
   tempCode[1] = 0x00;
   tempCode[2] = 0x11;
   tempCode[3] = 0xdd;
   tempCode[4] = 0xee;
   // ret code! Very important!
   tempCode[5] = 0xc3;

   asmFunc myFunc = (asmFunc) (virtualCodeAddress);

   unsigned out = myFunc();

   printf("out is %x\n", out);

   return 0;
}

Of hyper-graphs, sound and "issues"

As I wander my merry way through life, digging the garden, playing with Charlie, sorting out the car... I wonder things like "how do I allocate memory that is executable and can be used by a dynamic compiler?"

Then I think, g'z - it's going to be different on different machines!

So that's were I'll start first, then we'll get the parser (very simples), some GUI output, a compiler (of sorts), an interpreter (of sorts) and hopefully some sound (yay!)

Julian Assange.

He may be an egomaniac but does anyone REALLY believe the shit going down in Sweden? No, probably not - the charges are bunk, the Interpol arrest warrant is of highly dubious legality. Paypal and Amazon, you are gutless whores. I suspect a gun has been placed to your heads by "the powers that be". Fuck you and fuck your kind.

I wonder how long Assange can go on. Weird shit is all over the interwebz - millions of posts decyring Assange as a murderer, traitor etc. US politicos calling for him to be executed - You sound worse than the fuckign Taliban.

I might not trust Assange... but I STILL trust him more than the machinery of US politics...

Insanity.

CPL - Binary Incompatibility - Refactoring is $DEITY

I'm starting work on something... Although the bits have been around for ages.

It's quite nice... so far it goes "Peeeuuu...".

It will published under the Crowley Permissive License...

1 - Do what thou wilt shall be the whole of the law.