JonathanShihGravityBalls

GravityBallCode/GravityBallCode.pde

@@ -1,38 +1,77 @@
 //declare variables
-float x, y, velX, velY, diam;
+float gravity, airResistance;
+int count = 30;
+int size = 80;
+//declare array
+float[] x = new float[count];
+float[] y = new float[count];
+float[] velX = new float[count];
+float[] velY = new float[count];
+float[] diam = new float[count];
+float[] t = new float[count];
+PImage bg;
+int amp = 100;
 
 void setup() {
   //set size of canvas
   size(800, 600);
-
   //initialize variables
-  x = width/2;
-  y = height/2;
-  diam = 80;
-  velX = random(-5, 5);
-  velY = random(-5, 5);
+
+ for(int i = 0; i < count; i++) {
+  x[i] = width/2;
+  y[i] = height/2;
+  diam[i] = size;
+  velX[i] = random(-5, 5);
+  velY[i] = random(-5, 5);
+  colorMode(HSB,800,600,100);
+  bg = loadImage("bg.jpg");
+ }
 }
 
 void draw() {
   //draw background to cover previous frame
-  background(0);
-
-  //draw ball
-  ellipse(x, y, diam, diam);
-
-  //add velocity to position
-  x += velX;
-  y += velY;
-
-  //bounce ball if it hits walls
-  if (x + diam/2 >= width) {
-    velX = -abs(velX);    //if the ball hits the right wall, assign x velocity the negative version of itself
-  } else if (x - diam/2 <= 0) {
-    velX = abs(velX);     //if the ball hits the left wall, assign x velocity the positive version of itself
-  }
-  if (y + diam/2 >= height) {
-    velY = -abs(velY);
-  } else if (y - diam/2 <= 0) {
-    velY = abs(velY);
+  background(bg);
+  for (int i = 0; i < count; i++){
+    gravity = 0.45;
+    airResistance = 0.99;
+    //draw ball
+    ellipse(x[i], y[i], diam[i], diam[i]);
+
+    //add velocity to position
+    x[i] += velX[i];
+    y[i] += velY[i];
+    fill(x[i],y[i],100);
+
+    velY[i] += gravity; //add gravity
+    velY[i] *= airResistance; //make sure the ball doesn't get higher than starting point
+    //bounce ball if it hits walls
+    if (x[i] + diam[i]/2 >= width) {
+      velX[i] = -abs(velX[i]);    //if the ball hits the right wall, assign x velocity the negative version of itself
+    } else if (x[i] - diam[i]/2 <= 0) {
+      velX[i] = abs(velX[i]);     //if the ball hits the left wall, assign x velocity the positive version of itself
+    }
+    if (y[i] + diam[i]/2 >= height) {
+      velY[i] = -abs(velY[i]);
+    } else if (y[i] - diam[i]/2 <= 0) {
+      velY[i] = abs(velY[i]);
+    }
+
+    if (y[i] >= height) { //make sure ball doesn't escape from bottom of screen
+      y[i] = height - velY[i];
+      velY[i] = -abs(velY[i]);
+    }  
+    diam[i] = -amp*cos(t[i])+size+amp/2;
+
+    if (dist(x[i],y[i], mouseX, mouseY) < diam[i]/2) { //increase size if mouse is inside circle
+      if (t[i] < 2*PI) {
+        t[i] += .1;
+      }
+      else {
+        t[i]=0;
+      }
+    }
+    else if (t[i] > 0){ //automatically decrease if mouse is not in contact and circle is larger than original size
+      t[i] -= .05;
+         }
   }
 }