Amateur Question: Composite Objects
in
Programming Questions
•
1 year ago
Hi there,
This is just an example from the processing package folder, which I'm sure everyone is familiar with. I've studied the stack flow and came up with a few questions:
1.) In the subclass Ring, where is the constructor? What looks like a constructor is void start() method (in bold) Shouldn't a constructor hold the very class name? (In this case, Ring() { )
2.) The above said results in the sudden call on method start() in the superclass EggRing's constructor, instead of setting a new startup object there. (In red)
Please enlighten me, thank you.
///////////////////////The code/////////////////////////////////
EggRing er1, er2;
void setup() {
size(200, 200);
smooth();
er1 = new EggRing(66, 132, 0.1, 66);
er2 = new EggRing(132, 180, 0.05, 132);
}
void draw() {
background(0);
er1.transmit();
er2.transmit();
}
// Superclass EggRing
class EggRing {
Egg ovoid;
Ring circle = new Ring();
Egg ovoid;
Ring circle = new Ring();
EggRing(int x, int y, float t, float sp) {
ovoid = new Egg(x, y, t, sp);
circle.start(x, y - sp/2);
}
ovoid = new Egg(x, y, t, sp);
circle.start(x, y - sp/2);
}
void transmit() {
ovoid.wobble();
ovoid.display();
circle.grow();
circle.display();
if (circle.on == false) {
circle.on = true;
}
}
}
ovoid.wobble();
ovoid.display();
circle.grow();
circle.display();
if (circle.on == false) {
circle.on = true;
}
}
}
// Subclass Egg
lass Egg {
float x, y; // X-coordinate, y-coordinate
float tilt; // Left and right angle offset
float angle; // Used to define the tilt
float scalar; // Height of the egg
float x, y; // X-coordinate, y-coordinate
float tilt; // Left and right angle offset
float angle; // Used to define the tilt
float scalar; // Height of the egg
// Constructor
Egg(int xpos, int ypos, float t, float s) {
x = xpos;
y = ypos;
tilt = t;
scalar = s / 100.0;
}
Egg(int xpos, int ypos, float t, float s) {
x = xpos;
y = ypos;
tilt = t;
scalar = s / 100.0;
}
void wobble() {
tilt = cos(angle) / 8;
angle += 0.1;
}
tilt = cos(angle) / 8;
angle += 0.1;
}
void display() {
noStroke();
fill(255);
pushMatrix();
translate(x, y);
rotate(tilt);
scale(scalar);
beginShape();
vertex(0, -100);
bezierVertex(25, -100, 40, -65, 40, -40);
bezierVertex(40, -15, 25, 0, 0, 0);
bezierVertex(-25, 0, -40, -15, -40, -40);
bezierVertex(-40, -65, -25, -100, 0, -100);
endShape();
popMatrix();
}
}
noStroke();
fill(255);
pushMatrix();
translate(x, y);
rotate(tilt);
scale(scalar);
beginShape();
vertex(0, -100);
bezierVertex(25, -100, 40, -65, 40, -40);
bezierVertex(40, -15, 25, 0, 0, 0);
bezierVertex(-25, 0, -40, -15, -40, -40);
bezierVertex(-40, -65, -25, -100, 0, -100);
endShape();
popMatrix();
}
}
// Subclass Ring
class Ring {
float x, y; // X-coordinate, y-coordinate
float diameter; // Diameter of the ring
boolean on = false; // Turns the display on and off
float x, y; // X-coordinate, y-coordinate
float diameter; // Diameter of the ring
boolean on = false; // Turns the display on and off
void start(float xpos, float ypos) {
x = xpos;
y = ypos;
on = true;
diameter = 1;
}
void grow() {
if (on == true) {
diameter += 0.5;
if (diameter > width*2) {
diameter = 0.0;
}
}
}
void display() {
if (on == true) {
noFill();
strokeWeight(4);
stroke(155, 153);
ellipse(x, y, diameter, diameter);
}
}
}
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