From 4096d4e4bea5682aa19a5a892d56370867705189 Mon Sep 17 00:00:00 2001
From: twang1999 <twang@ucvts.tec.nj.us>
Date: Tue, 10 Nov 2015 13:56:26 -0500
Subject: [PATCH 1/4] add gravity/acceleration to the ball

---
 GravityBallCode/GravityBallCode.pde | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/GravityBallCode/GravityBallCode.pde b/GravityBallCode/GravityBallCode.pde
index df2493b..029f0d9 100644
--- a/GravityBallCode/GravityBallCode.pde
+++ b/GravityBallCode/GravityBallCode.pde
@@ -1,5 +1,5 @@
 //declare variables
-float x, y, velX, velY, diam;
+float x, y, velX, velY, diam, grav;
 
 void setup() {
   //set size of canvas
@@ -11,6 +11,7 @@ void setup() {
   diam = 80;
   velX = random(-5, 5);
   velY = random(-5, 5);
+  grav=.1;
 }
 
 void draw() {
@@ -23,6 +24,7 @@ void draw() {
   //add velocity to position
   x += velX;
   y += velY;
+  velY += grav;
 
   //bounce ball if it hits walls
   if (x + diam/2 >= width) {

From 9db8180e051b586ff5c8824b2b958b22c41193b5 Mon Sep 17 00:00:00 2001
From: twang1999 <twang@ucvts.tec.nj.us>
Date: Tue, 10 Nov 2015 14:21:42 -0500
Subject: [PATCH 2/4] adding 30 balls and changed color of balls

---
 GravityBallCode/GravityBallCode.pde | 55 +++++++++++++++++------------
 1 file changed, 33 insertions(+), 22 deletions(-)

diff --git a/GravityBallCode/GravityBallCode.pde b/GravityBallCode/GravityBallCode.pde
index 029f0d9..be9d216 100644
--- a/GravityBallCode/GravityBallCode.pde
+++ b/GravityBallCode/GravityBallCode.pde
@@ -1,17 +1,25 @@
 //declare variables
-float x, y, velX, velY, diam, grav;
+int count=30;
+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 []grav=new float [count];
 
 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);
-  grav=.1;
+  for (int i=0; i<count; i++){
+    x[i] = width/2;
+    y[i] = height/2;
+    diam[i] = random(80);
+    velX[i] = random(-5, 5);
+    velY[i] = random(-5, 5);
+    grav[i]=.2;
+  }
 }
 
 void draw() {
@@ -19,22 +27,25 @@ void draw() {
   background(0);
 
   //draw ball
-  ellipse(x, y, diam, diam);
-
-  //add velocity to position
-  x += velX;
-  y += velY;
-  velY += grav;
+  for (int i=0; i<count; i++){
+   
+    velY[i] += grav[i];
+    ellipse(x[i], y[i], diam[i], diam[i]);
+    fill(random(255),random(255),random(255));
+    x[i] += velX[i];
+    y[i]+= velY[i];
+    
 
   //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);
+    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]);
+    }
   }
 }
\ No newline at end of file

From badb7d9b1e154ca258e30d60d1a11404ce0e59fb Mon Sep 17 00:00:00 2001
From: twang1999 <twang@ucvts.tec.nj.us>
Date: Wed, 11 Nov 2015 14:36:10 -0500
Subject: [PATCH 3/4] ensure that balls do not bounce below screen

---
 GravityBallCode/GravityBallCode.pde | 1 +
 1 file changed, 1 insertion(+)

diff --git a/GravityBallCode/GravityBallCode.pde b/GravityBallCode/GravityBallCode.pde
index be9d216..d6c1f2a 100644
--- a/GravityBallCode/GravityBallCode.pde
+++ b/GravityBallCode/GravityBallCode.pde
@@ -44,6 +44,7 @@ void draw() {
     }
     if (y[i] + diam[i]/2 >= height) {
       velY[i] = -abs(velY[i]);
+      y[i]=height-diam[i]/2;
     } else if (y[i] - diam[i]/2 <= 0) {
       velY[i] = abs(velY[i]);
     }

From 3911ba7712ed267bc08be397f4b20a6fae2a774d Mon Sep 17 00:00:00 2001
From: twang1999 <twang@ucvts.tec.nj.us>
Date: Wed, 11 Nov 2015 14:39:59 -0500
Subject: [PATCH 4/4] ensure that ball does not bounce off screen

---
 GravityBallCode/GravityBallCode.pde | 1 +
 1 file changed, 1 insertion(+)

diff --git a/GravityBallCode/GravityBallCode.pde b/GravityBallCode/GravityBallCode.pde
index be9d216..d6c1f2a 100644
--- a/GravityBallCode/GravityBallCode.pde
+++ b/GravityBallCode/GravityBallCode.pde
@@ -44,6 +44,7 @@ void draw() {
     }
     if (y[i] + diam[i]/2 >= height) {
       velY[i] = -abs(velY[i]);
+      y[i]=height-diam[i]/2;
     } else if (y[i] - diam[i]/2 <= 0) {
       velY[i] = abs(velY[i]);
     }