Processing 处理图形椭圆不增长

我只是想用blendMode（差分）使圆变大和反转；但半径不变

int radius = 15;
int radius2 = 15;

size(500, 500);

PGraphics pg = createGraphics(500, 500);
pg.beginDraw();
pg.background(255);
pg.blendMode(DIFFERENCE);
pg.fill(255);
pg.noStroke();
pg.ellipse(width/2, height/2, radius, radius);
pg.ellipse(width/2.25, height/2.25, radius2, radius2);
pg.ellipse(width/2.25, height/1.8, radius2, radius2);
pg.ellipse(width/1.8, height/2.25, radius2, radius2);
pg.ellipse(width/1.8, height/1.8, radius2, radius2);
radius++;
pg.endDraw();


background(255);
image(pg, 0, 0);

发件人：

如果您的代码有方法（不仅仅是静态模式）或需要随时间运行，那么它必须有draw（）方法，否则不会发生任何事情。例如，如果没有draw（），此代码将在setup（）方法之后停止

就这样。您需要将代码包装到draw（）函数中

这是一个漂亮的“按钮”

int radius = 15;
int radius2 = 15;
PGraphics pg ;

void setup() {
  size(500, 500); 
  pg = createGraphics(500, 500);
}

void draw() {
  pg.beginDraw();
  pg.background(255);
  pg.blendMode(DIFFERENCE);
  pg.fill(255);
  pg.noStroke();
  pg.ellipse(width/2, height/2, radius, radius);
  pg.ellipse(width/2.25, height/2.25, radius2, radius2);
  pg.ellipse(width/2.25, height/1.8, radius2, radius2);
  pg.ellipse(width/1.8, height/2.25, radius2, radius2);
  pg.ellipse(width/1.8, height/1.8, radius2, radius2);
  radius++;
  pg.endDraw();


  background(255);
  image(pg, 0, 0);
}