Recitation:
In today’s recitation, we are expected to practice the function and arrays, especially the loop and arrays, they are two great function to shorter the code. I used them to build an animation with many elements.
step 1
In the first step, I use the arc(); to build an eater.
step2
using for loop(); to build 100 elements.
put the loop under the void draw();
step3&step4
int eaters = 100;
float[] x = new float [eaters];
float[] y = new float [eaters];
color[] c = new color [eaters];
float [] speedX = new float [eaters];
float [] speedY = new float [eaters];
float[]size=new float[eaters];
void setup() {
size(600, 600);
background(255);
ellipseMode(RADIUS);
for (int i=0; i<x.length; i++){
x[i]=random(width);
y[i]= random(height);
speedX[i]= random(-5, 5);
speedY[i]= random(-5, 5);
size[i]= random(10,200);
c[i]= color(random(255),random(255),random(255));}}
void draw(){
background(255);
for (int i=0; i<x.length; i++) {
eater(x[i], y[i], size[i], c[i]);
x[i]= x[i] + speedX[i];
y[i]= y[i] + speedY[i];
if (x[i] > width || x[i]< 0) {
speedX[i] = -speedX[i];}
if (y[i] > height || y[i]< 0) {
speedY[i] = -speedY[i];}} }
void eater(float x, float y, float size, color c) {
noStroke();
fill(c);
arc(x*10+15, y*10+10, size, size, 0.52, 5.76);
fill(255);
ellipse(x*10-size*0.3, y*10-size*0.4, size*0.1, size*0.1);
rectMode(CENTER);
fill(c);
rect(x*10+15+size*1.2, y*10+10, size*0.5, size*0.5);}
optional:
use the keypressed to control it.
if (keyPressed==false){
}
else{
Question1: If the for loop under the 'setup', it can only run once.So the image stay still. But if you put it under the draw();, the loop will run over and over again, so the image will be given different position, and at last the image will display everywhere. Question2: In my animation, there are 100 elements, if I don't use the arrays, I have to control every elements individually, and this will lead to a very complex code. Thanks to the arrays I can make it clear and understanding.