A while ago I'd posted an example and source code for using Vertex Arrays, Vertex Buffer Objects and Point Sprites in openFrameworks. This was for openFrameworks 005 and needed some mods to the core and other hacks to get it to do what we needed. In the current version of openframeworks (006+) a lot of the required functionality has been moved to the core and so we don't need the extra classes MSAImage and MSATexture, or to hack the core. The updated example is attached and can be downloaded from below.

P.S. An example on particle system with OpenCL for even more performance (updating the particles on the GPU) can be found here.

I've recently needed to work with Midi Time Code (MTC) and could not find any code to parse the midi messages and construct an SMPTE timecode. Closest I got was finding this documentation (which is pretty good) on how the data is encoded in the bits of 8 bytes sent over 2 SMPTE frames, each byte sent at quarter frame intervals. From that I wrote the code below (I've only really tested the 25 fps). The code is from an openframeworks application but should work with any C/C++ code.

P.S. Some info on bits, bytes and nibbles here.

class ofxMidiEventArgs: public ofEventArgs{
public:
    int     port;
    int     channel;
    int     status;
    int     byteOne;
    int     byteTwo;
    double  timestamp;
};
 
#define kMTCFrames      0
#define kMTCSeconds     1
#define kMTCMinutes     2
#define kMTCHours       3
 
// callback for when a midi message is received
void newMidiMessage(ofxMidiEventArgs& eventArgs){
 
    if(eventArgs.status == 240) {                       // if this is a MTC message...
        // these static variables could be globals, or class properties etc.
        static int times[4]     = {0, 0, 0, 0};                 // this static buffer will hold our 4 time componens (frames, seconds, minutes, hours)
        static char *szType     = "";                           // SMPTE type as string (24fps, 25fps, 30fps drop-frame, 30fps)
        static int numFrames    = 100;                          // number of frames per second (start off with arbitrary high number until we receive it)
 
        int messageIndex        = eventArgs.byteOne >> 4;       // the high nibble: which quarter message is this (0...7).
        int value               = eventArgs.byteOne & 0x0F;     // the low nibble: value
        int timeIndex           = messageIndex>>1;              // which time component (frames, seconds, minutes or hours) is this
        bool bNewFrame          = messageIndex % 4 == 0;
 
 
        // the time encoded in the MTC is 1 frame behind by the time we have received a new frame, so adjust accordingly
        if(bNewFrame) {
            times[kMTCFrames]++;
            if(times[kMTCFrames] >= numFrames) {
                times[kMTCFrames] %= numFrames;
                times[kMTCSeconds]++;
                if(times[kMTCSeconds] >= 60) {
                    times[kMTCSeconds] %= 60;
                    times[kMTCMinutes]++;
                    if(times[kMTCMinutes] >= 60) {
                        times[kMTCMinutes] %= 60;
                        times[kMTCHours]++;
                    }
                }
            }           
            printf("%i:%i:%i:%i | %s\n", times[3], times[2], times[1], times[0], szType);
        }           
 
 
        if(messageIndex % 2 == 0) {                             // if this is lower nibble of time component
            times[timeIndex]    = value;
        } else {                                                // ... or higher nibble
            times[timeIndex]    |=  value<<4;
        }
 
 
        if(messageIndex == 7) {
            times[kMTCHours] &= 0x1F;                               // only use lower 5 bits for hours (higher bits indicate SMPTE type)
            int smpteType = value >> 1;
            switch(smpteType) {
                case 0: numFrames = 24; szType = "24 fps"; break;
                case 1: numFrames = 25; szType = "25 fps"; break;
                case 2: numFrames = 30; szType = "30 fps (drop-frame)"; break;
                case 3: numFrames = 30; szType = "30 fps"; break;
                default: numFrames = 100; szType = " **** unknown SMPTE type ****";
            }
        }
    }
}

Inspired by the brilliant use of an age old concept in the recent OKGo 'WTF' video, I created this little open-source demo in processing. It works in real-time with a webcam and you can download the app and source from http://www.msavisuals.com/xmas2009

Recently I've been playing a lot with OpenCL, the new API / framework designed to handle cross-platform parallel computing (i.e. a simple way of running code simultaneously on all cores of your CPU, GPU or other processors). Implementations have been cropping up this year in NVidia drivers or ATI drivers, but most famously it's included with Mac OSX 10.6 Snow Leopard.

To cut a long story short I've been working on a simple-to-use C++ wrapper for some of the most common functions, imaginatively called ofxOpenCL and here is a little demo of 1 million particles running at 100-200fps.

NOTE: The Vimeo compression destroys most of the particles, so I suggest downloading the quicktime directly from the vimeo page at http://www.vimeo.com/7332496

Frame-rate is around 100-200fps running on a macbook pro with GF 9600GT. That's 100-200fps on a laptop! (albeit a pretty decent one), but I'm dying to try this on a GF 285 GTX - which has 7.5x the number of cores, 2.5x the fillrate and 3.5x the memory bandwidth - for only £250!!

The kernel for this is surprisingly simple:

__kernel void updateParticleWithoutCollision(__global Particle* pIn, __global float2* pOut, const float2 mousePos, const float2 dimensions){
	int id = get_global_id(0);
	__global Particle *p = &pIn[id];
 
	float2 diff = mousePos - pOut[id];
	float invDistSQ = 1.0f / dot(diff, diff);
	diff *= 300.0f * invDistSQ;
 
	p->vel += (dimensions*0.5 - pOut[id]) * CENTER_FORCE2 - diff* p->mass;
	pOut[id] += p->vel;
	p->vel *= DAMP2;
 
	float speed2 = dot(p->vel, p->vel);
	if(speed2<MIN_SPEED2) pOut[id] = mousePos + diff * (1 + p->mass);
}

This example is based on Rui's opencl example at http://vimeo.com/7298380.

Discussion on the matter at http://www.openframeworks.cc/forum/viewtopic.php?f=10&t=2728&p=15107#p15...

source code for ofxOpenCL and the above example at
http://code.google.com/p/ofxmsaof/downloads/list
(the SVN is likely to be more recent).

A cross platform, C++ UDP-TCP Bridge.

Originally created to forward UDP TUIO (OSC) messages straight to TCP to be read from within Flash.

This application forwards all incoming UDP messages straight to TCP without touching the data, just a straight forward.(Since version 0.2.1 there is the option to prefix the size of the packet before sending the data to comply with OSC / TCP specifications). This enables applications that don't support UDP (e.g. Flash) to receive the data. Since OSC / TUIO are generally sent via UDP, this enables Flash to recieve those messages in their raw binary form.

Settings can be edited from data/settings.xml.

Source and binaries at http://code.google.com/p/udp-tcp-bridge/

UPDATE:

The templates attached below were for openFrameworks & ofxiPhone pre-006. For the current version of openFrameworks new templates are required, for now they can be found at http://github.com/memo/openFrameworks/tree/master/xcode%20templates/

Inspired by Roxlu's brilliant openFrameworks wizard for code::blocks I thought I'd have a go at creating similar XCode templates - turned out it's super easy and you can download them below (templates for both desktop applications and iphone applications). Instructions are included in the zip but I'm attaching it below too.

Note: the iPhone template is for the latest version of ofxiPhone from the svn because there are additional files in the current version. (Thanks to everybody for pointing this out).

This is a set of C++ classes for solving and displaying real-time fluid dynamics simulations based on Navier-Stokes equations and Jos Stam's paper on Real-Time Fluid Dynamics for Games. The solver class has no dependencies on openFrameworks and can be used in any C++ project. The drawer class extends ofBaseDraws and contains an ofTexture for seamless integration with openFrameworks drawing routines. Also included in the addon is a ofxMSAParticleUpdater class which allows the fluid solver to be easily plugged into ofxMSAPhysics as a force field.

Here are some videos of my msafluid for processing library out in the wild.

Superfluid vs Particle from jimi hertz on Vimeo.

MSA Fluids test from den ivanov on Vimeo.

MSAFluid on a MultiTouch table from xTUIO from Sandor Rozsa on Vimeo.

I've changed the license on my code/libraries etc. to use the revised BSD License instead of GPL. For those not sure what this means: the GPL license required all users of the libraries to license their apps as GPL too. This would mean that you could not distribute your app without distributing the source code as well - and forget about selling apps on the iphone app store. While I think the GPL is very useful (and necessary) for large open-source projects, I feel it's a bit too restrictive for the nature of my libraries (small tools), so I used the revised BSD license which allows you to use the libraries and do pretty much whatever you want with the finished apps.

This includes:

• all the openFrameworks addons at http://code.google.com/p/ofxmsaof/source/browse/#svn/trunk
• the ofxiPhone addon to enable openFrameworks on iPhone
• the MSAFluid library for processing 

About

This is a library for solving real-time fluid dynamics simulations based on Navier-Stokes equations and Jos Stam's paper on Real-Time Fluid Dynamics for Games. While I wrote the library primarily for processing it has no dependency on processing libraries and the source can be used with any Java application.

C++ version for openFrameworks can be found here.

The video below is a demo of a processing sketch using MSAFluid, being controlled by MSA Remote on iPhone (You can view the video in HD and download a 1080p version at vimeo).

Superfluid vs Particle from jimi hertz on Vimeo.

MSA Fluids test from den ivanov on Vimeo.

MSAFluid on a MultiTouch table from xTUIO from Sandor Rozsa on Vimeo.

This is a tutorial in getting a very simple openFrameworks application running on iPhone with basic graphics, multitouch and accelerometer support (and one might say a simple particle system too!).

• 10 Balls are moving around on screen and bouncing off the edges.
• You can touch the screen with multiple fingers and drag the balls around (multitouch support)
• You can tilt the iphone and the balls fall in that direction (accelerometer support).

...and all of this without touching a line of Objective C. It is actually one of the samples included in the ofxiPhone download - iPhone Touch+Accel Example. You can find it in the examples folder of the download, so if you load and run that project you can see the finished result. The code below is straight from that sample, warts and all :P

Note: Everytime I mention iPhone, I am in fact referring to iPhone & iPod Touch running OS 2+.

Update 29/03/2009

Just posted a simple example application source code and walk-through which can be found here.

Update 27/03/2009

openFrameworks 006 is now officially released! You can download a fat package for your system from www.openframeworks.cc, mac/linux/windows and now iPhone. I do recommend you keep an eye on the ofxiPhone SVN for updates and fixes.

What is this and what does it do?

ofxiPhone (along with ofxMultitouch & ofxAccelerometer) are addons for openFrameworks 006+ that allow you to develop for iPhone in plain old C/C++ just as you would on a normal desktop (mac, linux, windows). This means using the normal testApp.h, testApp.cpp, main.cpp; setup(), update(), draw(), mousePressed(), ofImage, ofTexture etc. and any other C++ classes you may have created. It also means that you can reuse your exact same code running on your desktop (mac osx, windows, linux) unchanged on the iPhone by just copying across your testApp.h, testApp.cpp, main.cpp and other source or resource files you may be using.

ofxMSAPhysics is a C++ 3D particle/constraint based physics library for openFrameworks. It uses a very similar api to the traer.physics library for processing to make getting into it as easy as possible.

Version 2.0a is now available for testing.

Main features include

• particles
• springs
• attractions (+ve or -ve)
• collision
• replay saving and load from disk (temporarily disabled in current alpha release)
• custom particles (extend ofxMSAParticle and add to the system)
• custom constraints (extend ofxMSAConstraint and add to the system)
• custom force fields (extend ofxMSAParticleUpdater and add to the system) 
• custom drawing (extend ofxMSAParticleDrawer and add to the system)

Made with openFrameworks.

148apps.com - 4/5 stars."You will find yourself showing people this application …and then, not getting your iPhone back because they want to keep painting."

geek.com - "I like the fact that the app is not just a port of the website, but includes enhancements which take advantage of the features of the iPhone."

iphonefreakz.com - "...the most jollificating paint app for iPhone and iPod Touch. It’s like getting a Jackson Pollock soul inside you...Definitely worth having it on your phone for. Well worth $0.99"

iPhone adaptation of Miltos Manetas' website jacksonpollock.org (original flash developed by Stamen Design). Save your pictures and send them to jackson@jacksonpollock.org, the best Pollocks will be published in an upcoming book.

The video below shows the basic features of v1.0. In the current version (v1.1) ability to choose your own colors has been added to allow the creation of more controlled paintings like those seen in the images below.

Get it from the iTunes App Store here.

Quick paintings created with "Jackson Pollock by Miltos Manetas" for iPhone:

Made with openFrameworks.

In Part I, I compared the random access performance of a C float* to an NSMutableArray of NSNumbers, and on average the float* performed more than 400 times faster than the NSMutableArray. While those figures are accurate, they don't represent the optimal way of using NSArrays. NSNumbers can also be slow and there are faster linear enumeration methods than objectAtIndex. So I thought I'd modify the example using custom objects and sending messages to all objects, using floats in both cases. Note: these tests are conducted on an iPhone 3G as that's the target platform I was interested in.

The classes provided by Cocoa for handling data sets (NSDictionary, NSArray, NSSet etc.) provide a very nice interface for managing information, without having to worry about the bureaucracy of memory management, reallocation etc. Of course this does come at a cost though. I think it's pretty obvious that say using an NSArray of NSNumbers is going to be slower than a C Array of floats for simple iterations, so I decided to do some tests, and the results were pretty shocking! I wasn't expecting it to be this bad. Note: these tests are conducted on an iPhone 3G as that's the target platform I was interested in.

Over the years OpenGL has developed lots of different ways of sending vertex data to the graphics card: Immediate mode (glBegin / glVertex / glEnd etc.), Display Lists, Vertex Arrays, Vertex Buffer Objects etc. The first of these (Immediate Mode) is quite inefficient, so it's been dropped in OpenGL ES and depreciated in OpenGL 3.0. Instead we are to use Vertex Arrays or VBO's (Vertex Buffer Objects). They are way more efficient, but generally not as straightforward to setup and use.

For this reason I wrote a C++ class that wraps up the functionality of Vertex Arrays (and soon VBO's) in an immediate mode style syntax. I.e. you can carry on calling glBegin / glNormal / setColor / glTexCoord / glVertex / glEnd etc. but instead of sending the data on every function call, it just caches them all in client-side arrays, and sends it all in one go when you call glEnd(). Later you can call draw() to redraw the information you've put in. Thus improving performance on desktop systems, and allowing immediate mode style syntax on embedded systems such as the iPhone. (The previous post about the Meshulator uses this class).

UPDATE:

This code was for openframeworks 005. Things have changed for openframeworks 006 and it is a lot simpler now. See the updated example here.

Here is some sample code for using (and comparing performance with) Vertex Arrays, VBO's and Point Sprites with openFrameworks 005 to have half a million particles at 60fps (on Mac Pro) or 1M particles at 30fps. Note you will need to hack the core and change ofTexture to only use GL_TEXTURE_2D and never GL_TEXTURE_RECTANGLE_ARB (hopefully with oF 006 hacking the core will not be necessary).
P.S. More performance can be gained by splitting the particle update into multiple threads or moving onto the GPU.
check testApp::keyPressed to see what keys do what...

This is a demo of projection mapping with VDMX & Quartz Composer inspired by deepvisual's tutorial of doing it in modul8 (uk.youtube.com/watch?v=2bRfdn9lNO8).

VDMX unfortunately doesn't have this feature built-in, but fortunately has beautiful integration with Quartz Composer - allowing me to build a quad warper in QC using a GLSL vertex shader, which should be super fast.

Also, around the 4:30 mark you'll see me masking the video on the box in the back. This is also using a custom Quartz Composition which allows 4 point mask creation. Usage is almost identical to the QuadWarper, but instead of warping the image it just applies a mask, or you can invert the mask and it cuts a chunk out. You could do the same by creating new layers, grouping, using as a layer mask etc. but its a a bit more hassle I think. Using the QuadMask is a lot quicker and you can put multiple QuadMasks on the same layer to draw more complex masks.

** Update 27/10/08 - Version 1.1 **

Added loop mode configurable from the preferences.plist

-----------------

MSAQTPlayer is a Mega Super Awesome (& mega super basic), fullscreen / multiple output Quicktime player with fast, greater-than-4096-pixels support.

I wrote this app for an installation because I needed to play a 4,800 x 600 Quicktime file across 2 outputs on my graphics card, each feeding 3 triple heads to go into 6 projectors, and I couldn't find a single application that could do it.

Most video applications which can output across multiple video-outs cannot play files larger than the maximum size of a texture (usually 4096 pixels). And even if the movie resolution fits in a texture, they are very slow because they convert each frame to a texture and upload to the graphics card. The only application I found which could play a large file is Quicktime Pro, but that cannot output across multiple video-outs.

MSA QTPlayer is a native Cocoa app which can do this (using QTKit and OSX 10.5) .

This is a demo for a traer like physics library for C++/openFrameworks.
I wrote the lib for a little project with Todd Vanderlin while in Linz, Austria at Ars Electronic 2008 (vimeo.com/1707467). I tried to keep the same API as Traer (so processing code using traer can easily be ported to oF) and it is basically a particle system with springs, attractions, gravity etc (but uses verlet integration instead of RK4).

In this demo I am interacting with the app using the keys:

A set of C++ template classes for doing various types of interpolations on data with any number of dimensions. You can feed the system an arbitrary number of data (data can be simple types like float, int or complex types like structs, classes), then resample at any resolution, or ask for the value at any percentage along the data - or just draw it - including splines in 3D.
This is useful for creating and drawing splines (in any dimensions), or creating smooth animation paths from keyframes (again, in any dimensions).

Made with openFrameworks.

Source code on SVN here

This is a very early version of a GPU based depth-of-field GLSL shader and sample Processing code. Adjust some parameters and it can also be used to give the scene a nice backlight/glow effect.

I was sitting minding my own business, exploring accumulation buffers in Quartz Composer, when all of a sudden I just zoned out, and next thing I know, I found myself staring at Him on my screen. His Noodly Appendages came down and touched me, and guided my hands, connecting Quartz Composer's very own noodles in His Image.

His Noodly Screen Saver runs on Mac OSX 10.5 (Leopard) and you can download it below.

For those who do not have a clue what this is about, I suggest reading this: venganza.org/about
and this: venganza.org/about/open-letter

P.S. you can watch the above demo video in HD at vimeo.

RAmen.