//// x5:  collisions
//// CST 112 day  10/9/2015
//// author  Yixing Tao

//// GLOBALS: pool table, 3 colored balls

String title=  "COLLISIONS  (x5.java)";
String news=   "Use 'r' key to restet.";
String author=  "Yixing Tao";


float let, right, top ,bottom;
float middle;

float blax, blay, blaDx, blaDy;
float yelx, yely, yelDx, yelDy;
float redx, redy, redDx, redDy;
float bluX, bluY, bluDX, bluDY;

////SETUP: size and table
void setup() {
  size( 600, 400 );
  left= 60;
  right= width-60;
  top= 100;
  bottom= height-40;
  middle= left - (right-left)/2;
  //
  reset();
 }
 void reset() {
   blax= le