For Net Art Lecture 2 J Parker Programming For Net Art Lecture 2 J Parker

We looked at Static Processing size (300, 300); strokeWeight (7); line (100, 90, 140, 85); line (175, 82, 225, 80); strokeWeight (4); ellipse (130, 120, 60, 50); ellipse (200, 118, 60, 50); fill (0); ellipse (148,126, 14,18); ellipse (218,123, 14,18); // Mouth line (122, 165, 118, 175); line (120,170, 170, 180); line (170, 180, 210, 160); line (210,155, 213, 165);

A Flower int positionx = 200; int positiony = 200; int ground = 350; int i=0; noStroke(); size (500, 500); stroke (0,190,20); line (positionx, positiony, positionx-20, ground); fill (200,200,23); ellipse (positionx, positiony-25, 30,30); ellipse (positionx+18, positiony-5, 30,30); ellipse (positionx+12, positiony+20, 30,30); ellipse (positionx-13, positiony+20, 30, 30); ellipse (positionx-18, positiony-7, 30,30); fill(0,0,0); ellipse (positionx, positiony, 30,30); positionx = positionx + i*12; positiony = positiony - i*3;

Flowers come in Groups We need to draw more than one. Repeat the process for different locations. We need a LOOP, such as we used in the Turtle graphics programs

WHILE { statements } Syntax is: while ( expression ) As long as (while) the expression is true, keep repeating the statements within the { … } over and over.

Expressions while ( i < 10) As long as the value of i is smaller than 10 while (x >= 0) As long as the value of x is more than 0 while (x < i) while (i*2 < 100)

Forever If a loop never ends then it is called an ‘infinite loop’, and this is a bad thing. SO: some statement inside of the loop must have the possibility of changing the expression (which is evaluated once everytime the loop executes) so that the expression COULD be false.

WHILE i = 3; i = 0; X = 0.5; while (i < 10) while (x < i) { { x = x + 0.5 } i = 0; while (i < 10) { i = i + 1; . . . }

Back to Flowers i = 0; while (i< 20) { draw a flower positionx = positionx + i*12; positiony = positiony - i*3; i = i + 1; } ‘ i = 0; while (i < 20) { draw a flower Change position }

Flowers while (i<20) { stroke (0,190,20); line (positionx, positiony, positionx-20, ground); noStroke(); fill (200,200,23); ellipse (positionx, positiony-25, 30,30); ellipse (positionx+18, positiony-5, 30,30); ellipse (positionx+12, positiony+20, 30,30); ellipse (positionx-13, positiony+20, 30, 30); ellipse (positionx-18, positiony-7, 30,30); fill(0,0,0); ellipse (positionx, positiony, 30,30); positionx = positionx + i*12; positiony = positiony - i*3; i = i + 1; }

Circles Draw a set of 10 circles across the window

Example int x=20,y=50, i; size (400,200); i = 1; // Start with circle 1 while (i<=10) // Loop 20 times { ellipse (x, y, 20, 20); // Draw a circle x = x + 30; // Increase X so next circle will be to the right i = i+ 1; }

Circles

Nested Loops int x=20,y=50, i,j; size (400,400); i = 1; j = 1; // Start with circle 1 while (j <=10) { i = 0; x = 20; while (i<=10) // Loop 20 times ellipse (x, y, 20, 20); // Draw a circle x = x + 30; // Increase X so next circle will be to the right i = i + 1; } y = y + 30; j = j + 1;

Arrays Basically, many variables with the same name accessed by number: int a[] = new int[20]; Is a collection of 20 integers. x[0] = 1; x[1] = 2; x[2] = x[1] + x[0];

Why? Now we can keep track of many individual objects, like circles. Int x[] = new int[20]; Int y[] = new int[20]; … while (i<20) { ellipse (x[i], y[i], 10, 10); }

Images Pimage is a type for an image. PImage x, y; Can read them from files. x = loadImage (“image.jpg”); And display them: image (x, 0, 0);

PImage im; // The image to be loaded String name = "image PImage im; // The image to be loaded String name = "image.jpg"; // Name of the image file void setup () { size (400,400); surface.setResizable(true); im = loadImage (name); // Load the image if (im == null) // Did the file exist? { // No. println ("File 'image.jpg' is missing."); exit(); } else surface.setSize (im.width, im.height); // Yes - set window size. } void draw() { image (im, 0, 0); // Display the image }

Mouse void setup () { size (400,400); background(200, 30, 200); } void draw () // background(200, 30, 200); ellipse (mouseX, mouseY, 30, 30);

Now let’s play.