From 159bbcf8df63b36d2df0810947c2e91dcf619ae4 Mon Sep 17 00:00:00 2001
From: demifang21 <dfang@princeton.edu>
Date: Mon, 23 May 2016 19:33:28 -0400
Subject: [PATCH] Stationary Ball option in GUI

Aatish, after working on p5 to make sure it ran OK, I just copy/pasted my new p5 code into this "Edit file" field-- is that how it works? Hope you can see the changes I made. If not, I introduced "isBallMoving" boolean variable and made a Stationary Ball option in the drop-down menu for interactions.

The one thing I couldn't figure out is in line 212-- currently, when you select Stationary Ball, the new stationary ball takes on the position of the Moving Ball before it stopped. I think it'd be better to have the position be reset to the center, but I wasn't sure how to go about doing that.

Alternatively, maybe it'd be nicer to have a checkbox for "moving" when the "Ball" option is selected from the dropdown menu-- in this scenario, I wouldn't mind the stationary ball taking on the old position. However, I wasn't sure how to code the GUI so that the checkbox would only be activated when a certain dropdown option is selected. Let me know what you think!
---
 clothphysics.js | 30 +++++++++++++++++++++---------
 1 file changed, 21 insertions(+), 9 deletions(-)

diff --git a/clothphysics.js b/clothphysics.js
index 4c6ab67..a24c450 100644
--- a/clothphysics.js
+++ b/clothphysics.js
@@ -31,7 +31,8 @@ var windForce = new THREE.Vector3( 0, 0, 0 );
 
 var rotate = false;
 var pinned = 'Corners';
-var thing = 'Ball';
+var thing = 'Moving Ball';
+var ballIsMoving = true;
 
 var cornersPinned, oneEdgePinned, twoEdgesPinned, fourEdgesPinned, randomEdgesPinned;
 
@@ -80,7 +81,7 @@ if(guiEnabled){
 
   f4.add(guiControls, 'rotate').name('auto rotate').onChange(function(value){rotate = value;});
   f4.add(guiControls, 'wind').name('wind').onChange(function(value){wind = value;});
-  f4.add(guiControls, 'thing', ['None', 'Ball', 'Table']).name('object').onChange(function(value){createThing(value);});
+  f4.add(guiControls, 'thing', ['None', 'Stationary Ball', 'Moving Ball', 'Table']).name('object').onChange(function(value){createThing(value);});
   f4.add(guiControls, 'pinned', ['None','Corners', 'OneEdge', 'TwoEdges','FourEdges']).name('pinned').onChange(function(value){pinCloth(value);});
 
   var f1 = gui.addFolder('Behavior');
@@ -204,11 +205,21 @@ function pinCloth(choice){
 
 function createThing(thing){
 
-  if(thing == 'Ball' || thing == 'ball'){
+  if(thing == 'Stationary Ball' || thing == 'stationary ball'){
     sphere.visible = true;
     table.visible = false;
+    ballIsMoving = false;
+    // currently ball takes last Moving Ball position-- how to reset position?
     restartCloth();
   }
+  
+  if(thing == 'Moving Ball' || thing == 'moving ball'){
+    sphere.visible = true;
+    table.visible = false;
+    ballIsMoving = true;
+    restartCloth();
+  }
+  
   else if(thing == 'Table' || thing == 'table'){
 
     // these variables are used in the table collision detection
@@ -538,12 +549,13 @@ function simulate( time ) {
     satisifyConstrains( constrain[ 0 ], constrain[ 1 ], constrain[ 2 ], constrain[ 3] );
   }
 
-
-  prevBallPosition.copy(ballPosition);
-  ballPosition.y = 50*Math.sin(Date.now()/600);
-  ballPosition.x = 50*Math.sin(Date.now()/600);
-  ballPosition.z = 50*Math.cos(Date.now()/600);
-  sphere.position.copy( ballPosition ); //maybe remove this since it's also in render()
+  if (ballIsMoving == true){
+    prevBallPosition.copy(ballPosition);
+    ballPosition.y = 50*Math.sin(Date.now()/600);
+    ballPosition.x = 50*Math.sin(Date.now()/600);
+    ballPosition.z = 50*Math.cos(Date.now()/600);
+    sphere.position.copy( ballPosition ); //maybe remove this since it's also in render()
+  }
 
   if(avoidClothSelfIntersection){
     for ( i = 0; i < particles.length; i ++ ){