Review of ArT3 Programming Course

1. Review of ArT3 Programming Course David Meredith Aalborg University dave@create.aau.dk

2. Lecture 1: Introduction to Processing • Drawing simple shapes point(x,y) line(x1,y1,x2,y2) rect(x,y,w,h) rectMode(CORNER|CENTER|CORNERS) ellipse(x,y,w,h) ellipseMode(CORNER|CENTER|CORNERS) • Defining greyscale values • 0 = black, 255 = white stroke(n) (default is black) fill(n) (default is white) background(n) (default is grey) noStroke() noFill() • Defining colours fill(r,g,b) stroke(r,g,b) background(r,g,b) • Defining opacity (alpha) • 255 = completely opaque, 0 = completely transparent • Greyscale fill(n,a) background(n,a) stroke(n,a) • Colour fill(r,g,b,a) background(r,g,b,a) stroke(r,g,b,a) • Defining line width strokeWeight(x) • Defining drawing area size(x,y) • Smoothing lines and edges smooth() • Printing to console println(“a string”) • Comments // comments rest of line /* comments region in between */ • Program structure setup() and draw() • Tracking mouse location mouseX and mouseY pmouseX and pmouseY • Responding to mouse clicks and key presses void mousePressed() void keyPressed() • Using Processing • Shift-Click Run to run full screen • Sketchbook • Publishing (Exporting) a sketch

3. Lecture 2: Variables and Conditionals • Variables • Types • int, byte, short, long • double, float • char • boolean • Declaring variables • intx; • Initializing variables • intx = 2; • Global variables • Defined outside setup() and draw() • Assigning values to variables • x = 5; • System variables • width, height, frameCount, frameRate, screen.width, screen.height, key, keyCode, mousePressed, mouseX, mouseY, pmouseX, pmouseY, mouseButton • Random numbers • w = random(x,y) • w = random(x) • Type-casting • e.g., w = int(random(1,100)) • Conditionals • Boolean expressions • Relational operators • >, <, >=, <=, ==, != • if (condition) {doThis();} • if (condition) {doThis();}else {doThat();} • if (condition1) {doThis();}else if (condition2) {doThat();}else {doTheOther();} • Logical operators • &&, ||, ! • Bouncing ball programme

4. Lecture 3: Loops and Functions • Loops • while(condition) {doThis(); change something;} • intx = constrain(value, min, max); • for (initialization; test; change something) {doThis();} • Increment expressions • i++, i--, i += 2, i -= 2 • Scope • Loops within loops • Functions • Modularity and reusability • ReturnType functionName(ArgType1 arg1, ArgType2 arg2) {ReturnTyper = something;doSomethingWithR(); return r;}

5. Lecture 4: Objects and Arrays • Objects • Data and functions together • Instance variables and methods • Classes as templates for making objects • Dot notation for messages • myCar.move(); • ints = myCar.speed; • Writing a class • class ClassName {intx; float y;ClassName(intx, float y) {this.x = x;this.y = y; } void display() { //Use x and y to show this object …. }} • Class definitions must appear outside of setup() or draw() • Putting a class in its own tab • Arrays • Array is a list of boxes, all holding values of the same type • Declaring an array variable • int[] arrayOfInts; • Creating an array • int[] arrayOfInts = new int[10]; • Accessing an element in an array • arrayOfInts[0] = 5; • intx = arrayOfInts[0]; • Initializing all elements at once • int[] intArray = {5,4,3,2,1}; • Initializing an array with a loop • for (inti = 0; i < intArray.length; i++)intArray[i] = 2 * i; • Array functions • shorten(), concat(), subset(), etc.