A C

1
A C Primer

• Robert Burke
• MLE
• 28 jan 03

2
Obligatory Strong Start

• C still on track to become number 1
  programming language within 2 years time
• Tremendous Momentum
• DirectX API
• Compact devices
• Next version of Office
• Platform for XML
• If youve used Visual Studio

3
Whats on tap today

• In Summary Why would you consider using C for
  your next project?

4
Disclaimer

• Havent traditionally been a huge Microsoft fan
• But, when theyre right
• So, if you can, put aside biases, religious
  attachment to (or disdain for) an OS, etc.

5
Part I Language Evolution

• C
• C
• Java
• C

6
Part I Language Evolution C

• Intimate with hardware, therefore very fast
  language
• Primarily used primitive types for working with
  data
• You handle all memory allocation and deallocation

• include ltstdio.hgt
• void main(void)
• printf("Hello world!")

Image Kernigan, Ritchie et al, C Programming
Language
7
Part I Language Evolution C
class Greeter public virtual void
ExtendGreeting() 0

• Superset of C
• Introduction of objects and object-oriented
  programming to C
• Inheritance, etc.
• A very powerful language
• the power comes at a cost of complexity

• class EnglishGreeter public Greeter
• public
• void ExtendGreeting()
• printf("Hello!")

class FrenchGreeter public Greeter
public void ExtendGreeting()
printf("Bonjour!")
int _tmain(int argc, _TCHAR argv) Greeter
myGreeter new FrenchGreeter() myGreeter-gtExte
ndGreeting() delete myGreeter return 0
Image Stroustrup, The C Programming Language
8
Part I Language Evolution Java (1/3)

• Purely object-oriented
• Handles all memory deallocation garbage
  collection
• (Geek alert) Elimination of pointers
• Polished set of libraries (API) available on all
  platforms

• public interface Greeter
• public void extendGreeting()
• public class EnglishGreeter implements Greeter
• public void extendGreeting()
• System.out.println("Hello!")
• public class GraciousApplication
• public static void main(String args)
• new EnglishGreeter().extendGreeting()

9
Part I Language Evolution Java (2/3)

• Possible to interact with native C/C code.
• Very useful for
• Integrating legacy code
• Speed optimizing a critical bit of code
• But, difficult to debug, for example
• Primitive type size can change between platforms
• No common debugging environment

10
Part I Language Evolution Java (3/3)

• Garbage collection and cross-platform made
  possible by the Java Virtual Machine (JVM)
• Compiles to interpreted bytecode instead of
  machine instructions
• Multiple benefits
• Cross-platform
• Garbage collection
• Downsides
• Abstraction between you and hardware, therefore
  less deep control
• A little slower, but Just-In-Time (JIT)
  compiling helps

Your Java app
Java API
JVM (Virtual Machine)
Operating System
11
Part II About C
12
Part II Enter C

• A hybrid language incorporating features from C
  and Java (and Smalltalk, and)
• Looks a lot like Java, with keywords from C/C
• Object oriented
• Has a virtual machine, and garbage collection,
  among other Java parallels

Your C app
.NET FrameworkClass Libraries
CLR (Common Language Runtime)
Operating System
13
Hold up Whats all this .NET malarky?

• The .NET framework in context.NET for the common
  man.NET

14
Comparative Language Studies

15
C Pros and Cons

• Biggest Cons
• Compared to C Simpler programming model comes
  at cost of some geek-power
• Compared to Java Currently, no CLR
  implementation for Mac
• (but, a word on cross-platform Mono, for
  Linux, in the pipe)
• Biggest Pros
• Compared to Java Execution Speed
• Java JVM code is designed to be interpreted
• C CLR code is always compiled (despite common
  misconception)
• Compared to C, C, Java Development Speed

16
The Need for Execution Speed

• 98 of the speed, for 50 of the code
• Thats the Managed (C) DirectX 9.0 stat
• Well, Dolphin demo
• 565 lines C
• / 738 lines C 76 of the code, but whos
  counting.
• DEMO
• Dolphin 37 fps C, 36 fps C
• PointSprites 37 fps C, 37 fps C
• Something hard to quantify - the smooth, smooth
  lovin of the CLRs garbage collector.
• StillLifes 1600 particles/s, smooth, is
  unthinkable using existing Java JVM
  implementations

17
Development Speed (because our time is worth it)

• C language design theme making the intent
  explicit in situations which can easily lead to
  subtle bugs.
• (geek alert) e.g. Versioning keywords
  (override, new, virtual)
• Language features not available to Java
• Delegates
• Properties
• Type system
• Rich capacity for interop with native code3
  different methods
• 1. "unsafe" (unverifiable) code blocks provide
  access to pointers
• 2. Platform invoke" - access other DLLs (Java's
  only option)
• 3. COM interop - tap into old COM stuff

18
Development EnvironmentLanguage doesnt exist
in a vacuum!

• The .NET Framework Class Library
• New set of very polished libraries
• Accessible from C, C, Visual Basic.NET
• Cs objects and interfaces perfectly tailored
• Common development environment hand-holds you
• Comments
• step into native code. etc. (DEMO)

19
Deployment

• And, importantly, the deployment method
• You make .EXEs and .DLLs.
• What does someone else need to run a C .exe?
• Just the free .NET Framework

20
Part III Proof by Example

• Or, how to demo development speed, and where we
  might go from here.

21
How to demo Development Speed?

• Ching (Dec 2001 - present)
• libraries for signal processing, as well as
  serial port communication, audio, video...
• the foundation of all the projects I've built
  this year
• Sponge (Half a week)
• uses UDP to poll for computers on the LAN,
  considers their processor speed and available
  processing power, and distributes signal
  processing tasks between them. has the capacity
  to deploy signal processors to the other machines
  first
• Still Life (lt6 days)
• built on an early version of Ching. Particle
  system, video input, video processing effects all
  in C, using OpenGL

22
How to demo interoperability, powerful libraries,
collaboration?

• Contributions to Breathing Space
• Great demo of interop with existing software in
  C.
• Daragh has built and worked with an extensive
  amount of graphics code in C. Used remote
  signal processing. He just calls a DLLs get
  function
• Heartheard (crappy working title) (2 days)
• Exposed DirectSound3D and made an application
  with 3D audio and effects, which maps heart rate
  and breathing to audio.
• Eva's Anthropos robot
• Uses vision tracking modified from Still Life,
  using Signal Processing Network from Ching (which
  leads nicely to...)

23
Collaboration?

• If there is interest, I would manage the source
  tree more carefully
• Could it lead to more complex projects?
• 90 of the codebase compiled for the
  CompactFramework how about that?

24
Summary Why would you use C for your next
project?

• In a word productivity
• Just as Java learned from C
• Nominal speed hit, tremendous productivity boost
• Possibility of making use of existing Ching and
  MiniChing libraries

25
Some props, and where to go next

• Thanks
• Eric Gunnerson and the GotDotNet team
• MindGames, for letting me get away with this
• Eva for being the worlds most patient guinea pig
• You, for expressing interest
• Places to learn more
• Jesse Libertys Programming C, OReilly
• http//www.gotdotnet.com (semi-official site)
• http//www.csharphelp.com (community site)
• news//microsoft.public.dotnet.languages.csharp
• The third floor
• Thoughts?