LCC 6310Computation as an Expressive Medium

LCC 6310Computation as an Expressive Medium

Lecture 1Lecture 1

OverviewOverview

• Go over the syllabusGo over the syllabus

• Brief introduction to me and my workBrief introduction to me and my work

• Art, programming and JavaArt, programming and Java

SyllabusSyllabus

BackgroundBackground

• Ph.D. in Computer SciencePh.D. in Computer Science• Expressive AI: Artificial Intelligence-based art and entertainment

• Worked in industrial research labs (Intel, Tektronix) Worked in industrial research labs (Intel, Tektronix) doing HCI researchdoing HCI research

• Expressive AI: AI-based art and entertainmentExpressive AI: AI-based art and entertainment

Some of my workSome of my work

Terminal Time – interactive video

FaçadeFaçade – interactive drama – interactive drama

Office Plant #1 – robotic sculpture

Some directionsSome directions

• I’m someone to chat with about…I’m someone to chat with about…• Interactive story (particularly procedural approaches)

• Robotic sculpture

• Video games (design, technology and culture)

• Director of the Experimental Game Lab

• Procedurally generative art

Introduce yourselves Introduce yourselves

Programming languagesProgramming languages

• Abstract, “human understandable” language for Abstract, “human understandable” language for telling computer what to dotelling computer what to do

• The abstract language must be translated into the low The abstract language must be translated into the low level language understood by the machinelevel language understood by the machine

• This translation is accomplished by an interpreter or This translation is accomplished by an interpreter or compilercompiler

• We will be learning the compiled language JavaWe will be learning the compiled language Java

A simple Java programA simple Java program

for (int i = 0; i < 10; i++) { println(i);

}

Just prints the numbers 0 to 9 on the screen

Human readable?!?

“Human readable” is relative“Human readable” is relative

Java compiler translates this into…

for (int i = 0; i < 10; i++) { println(i);

}

Java VM assembly codeJava VM assembly code

public static void main(java.lang.String[]); Code: 0: iconst_0 1: istore_1 2: goto 30 5: getstatic 8: new 11: dup 12: ldc 14: invokespecial #23 17: iload_1 18: invokevirtual #27 21: invokevirtual #31

24: invokevirtual #34 27: iinc 1, 1 30: iload_1 31: bipush 10 33: if_icmplt 5 36: return

test.PrintLoop(); Code: 0: aload_0 1: invokespecial #43; 4: return

Object Oriented vs. Procedural LanguagesObject Oriented vs. Procedural Languages

Procedural (e.g. C)Procedural (e.g. C)• We create some data

representing an image (array of pixels to draw on the screen)

• We write a procedure than can be passed the image and will draw it

Object Oriented (e.g. Java)Object Oriented (e.g. Java)• We create a class that

contains an image AND a routine draw it

• The data and the behavior (ability to draw) are in one "container"

A couple of Java’s relativesA couple of Java’s relatives

• Smalltalk 80Smalltalk 80• Alan Kay and the Dynabook (PARC)

• C++C++• Managing big C programs: Bjarne Stroustrup

JavaJava

• Designers started with C++Designers started with C++• Smaller

• Simpler

• Safer

• Programming embedded systemsProgramming embedded systems• Toasters, microwave ovens, TV set top boxes

• Reliability very important--avoid costly recalls

• Web programmingWeb programming• Incorporated into web browsers at critical moment

The virtual machineThe virtual machine

• Since Java was designed to run on embedded Since Java was designed to run on embedded systems, it was designed around a systems, it was designed around a virtual virtual machinemachine• “Write once, run everywhere”

x86

Windows OS X

G3/4/5 ProcessorPhone OS

Java VM Java VM Java VM

Java VM

“Java OS”

PC Mac Cell Phone

Java Machine

But we’re using ProcessingBut we’re using Processing

• Processing is built on top of JavaProcessing is built on top of Java

• Supports script-like codingSupports script-like coding

• Easy to get simple programs up fast

• But allows transition to full Java programming

• Has built-in methods and classes to make drawing Has built-in methods and classes to make drawing easyeasy

• Easy to export program to appletEasy to export program to applet

Drawing in ProcessingDrawing in Processing

• Automatic creation of display windowAutomatic creation of display window

• Window has a coordinate system for drawingWindow has a coordinate system for drawing

x

y

0 50 1000

50

100

Let’s draw a point: point()Let’s draw a point: point()

• point(x, y) – draws a point at the location x, ypoint(x, y) – draws a point at the location x, y

• Let’s try it: point(50, 50)Let’s try it: point(50, 50)

Unexpected token: null – what the #@#$ !?!Unexpected token: null – what the #@#$ !?!

• Compiler errors appear in the bottom paneCompiler errors appear in the bottom pane

All lines must be terminated with a semicolon ;All lines must be terminated with a semicolon ;

Drawing several pointsDrawing several points

point(30, 20); point(30, 20);

point(85, 20); point(85, 20);

point(85, 75); point(85, 75);

point(30, 75); point(30, 75);

CommentsComments

• Comments are non-program text you put in the file to describe to Comments are non-program text you put in the file to describe to others (and yourself) what you’re doingothers (and yourself) what you’re doing

• Important for being able to look back at your code and Important for being able to look back at your code and understand itunderstand it

• Single-line comments begin with Single-line comments begin with ////

• Multi-line comments begin with Multi-line comments begin with /*/* and end with and end with */*/

Commenting and uncommenting lines useful for figuring Commenting and uncommenting lines useful for figuring out code out code

Drawing shapes: some primitivesDrawing shapes: some primitives

• line(x, y)line(x, y)

• triangle(x1, y1, x2, y2, x3, y3)triangle(x1, y1, x2, y2, x3, y3)

• rect(x, y, width, height)rect(x, y, width, height)• rectMode() – CORNER, CENTER_DIAMETER, CORNERS

• elipse(x, y, width, height)elipse(x, y, width, height)• ellipseMode() – CORNER, CENTER_DIAMETER, CORNERS,

CENTER_RADIUS

Controlling color and lineControlling color and line

• Colors represented as Red Green Blue (RGB) valuesColors represented as Red Green Blue (RGB) values• Each one ranges from 0 to 255• Can also use Hue Saturation Value (HSV) space, but we won’t worry about this for now

• background(R, G, B) – set the background colorbackground(R, G, B) – set the background color

• stroke(R, G, B) – set the colors of the outline (default black)stroke(R, G, B) – set the colors of the outline (default black)• noStroke() – no outline drawing around shapes

• fill(R, G, B) – set the fill color for shapes (default white)fill(R, G, B) – set the fill color for shapes (default white)• noFill() – don’t fill the shapes (background shows through)

• strokeWeight(w) – line width for outlines (default 1)strokeWeight(w) – line width for outlines (default 1)

Playing aroundPlaying around

• To learn how to program it is necessary to To learn how to program it is necessary to play around with code!!!play around with code!!!• Don’t just wait for me to show you things

• Processing makes this easyProcessing makes this easy• Use the Reference in the Help menu

• Play with the examples

Saving your workSaving your work

• You should install Processing on your own You should install Processing on your own machine machine • Do this for Thursday

• Processing saves all projects in a default Processing saves all projects in a default directory – no way to change itdirectory – no way to change it• This means that you should always copy your code to your

local disk

• Don’t depend on your project remaining undisturbed on lab machines