制作一个移动的圆被点击后消失,处理
问题描述:
我写了一个程序,其中一个UFO(实质上是一个灰色椭圆)从屏幕中心出现并飞向边缘。当按下鼠标时会出现激光,并在释放鼠标时消失。我想做的是当鼠标点击/激光触摸它时UFO消失。 我已经制作了UFO类,并创建了确定其移动和速度的变量,并且我能够让激光直接出现在光标上。我想过做一个'if'语句来检查光标是否在UFO的半径(或直径)内,并将它放在我为UFO创建的for循环中。但是,我不确定如何实现正确的语法来实现它。 注意:播放草图后,您可能需要等待几秒钟才能显示第一个圆。制作一个移动的圆被点击后消失,处理
UFO[] ufos = new UFO[3];
void setup() {
size(700, 700);
for (int j = 0; j < ufos.length; j++) {
ufos[j] = new UFO();
}
}
//UFO class
//Class setup ends on line 61
class UFO {
float a;
float b;
float c;
float sa;
float sb;
float d;
UFO() {
//declare float a/b/c value
a = random(-width/2, width/2);
b = random(-height/2, width/2);
c = random(width);
}
//UFO movement
void update() {
//float c will serve as a speed determinant of UFOs
c = c - 1;
if (c < 5) {
c = width;
}
}
//UFO setup
void show() {
//moving x/y coordinates of UFO
float sa = map(a/c, 0, 1, 0, width);
float sb = map(b/c, 0, 1, 0, height);
float d = map(c, 0, width, 50, 0);
//UFO drawing shapes
//ellipse is always sa (or sb)/c to allow UFO to appear
//as if it is moving through space
fill(200);
ellipse((sa/c), (sb/c), d + 5, d+5);
//Hides UFO way off the screen
//and replaces it with a black-filled ellipse until
//it forms into a full circle
//When radius d becomes 50, the UFO flies from the
//center of the screen to off of the screen
if (d < 50) {
fill(0);
ellipse(-5, -10, 90, 90);
sa = 10000;
sb = 10000;
}
}
}
void draw() {
//Background
background(0);
//Translated the screen so that the UFOs appear to fly from
//the center of the screen
translate(width/2, height/2);
//UFO draw loop, make UFO visible on screen
for (int j = 0; j < ufos.length; j++) {
ufos[j].update();
ufos[j].show();
//mouse-click laser
if (mousePressed == true) {
fill(200,0,0);
ellipse(mouseX - 352,mouseY - 347,50,50);
}
}
}
答
就像我在the Happy Coding forum说:
基本上,如果你的UFO是一系列圆的,那么你只需要使用dist()
功能检查是否距离鼠标的中心圆小于圆的半径。如果是,则鼠标在圆圈内。这里有一个小例子:
float circleX = 50;
float circleY = 50;
float circleDiameter = 20;
boolean showCircle = true;
void draw(){
background(0);
if(showCircle){
ellipse(circleX, circleY, circleDiameter, circleDiameter);
}
}
void mousePressed(){
if(dist(mouseX, mouseY, circleX, circleY) < circleDiameter/2){
showCircle = false;
}
}
如果你的UFO是多个圆圈,那么你需要将这个逻辑应用到每个圆圈。请尝试一下并发布一个像这样的小例子(不是你的整个草图),如果你卡住了。祝你好运。
请链接crossposts:http://forum.happycoding.io/t/make-a-moving-circle-disappear-when-clicked-on/47 它看起来像你删除了我回答的问题这已经在堆栈溢出。那个问题去了哪里? –