LYC的計圖學習筆記-WEEK10

processing3

 void setup(){
fullScreen();
}
float ballX=250,ballY=450, ballVX=1.3, ballVY=-10;
float ball2X=250, ball2Y=50;
void draw(){
if( dist(ballX, ballY, ball2X, ball2Y)<100 ){
float cx=(ballX+ball2X)/2, cy=(ballY+ball2Y)/2;
float nx=ballX-ball2X, ny=ballY-ball2Y;
PVector N=new PVector(nx,ny);
N.normalize();
PVector v0=new PVector(ballVX, ballVY);
float len= -N.dot(v0);
v0.add(N.mult(len*2));
ellipse(cx, cy, 10,10);
stroke(0); line(ballX, ballY, ball2X, ball2Y);
stroke(255,128,0); line(cx,cy, cx+5*ballVX, cy+5*ballVY);
stroke(255,128,0); line(cx,cy, cx+5*v0.x, cy+5*v0.y);
stroke(255,0,0); line(cx,cy, cx+N.x, cy+N.y);
//return;
ballVX=v0.x; ballVY=v0.y;
}
background(255);
ballX+=ballVX; ballY+=ballVY;
ellipse(ballX, ballY, 100,100);
ellipse(ball2X, ball2Y, 100,100);