Thread: Java Graphics help

Can anybody help me with this? As part of a worksheet, I have to draw a bullseye using graphics. I can draw the bullseye perfectly but its just full of repetitive code and my heads been puzzled trying to put it all into a loop. Heres the code ( remember im only learning so dont be too harsh ):

 
import graphics.*;
public class Q2
{
	public static void main(String[] args)
	{
		Window w = new Window(500,500);
		Circle c = new Circle(250, 250, 200);
		Circle c2 = new Circle(250, 250, 180);
		w.draw(c);
		w.draw(c2);
		w.fill(c);
		w.clear(c2);
		Circle d = new Circle(250, 250, 160);
		Circle d2 = new Circle(250, 250, 140);
		w.draw(d);
		w.draw(d2);
		w.fill(d);
		w.clear(d2);
		Circle e = new Circle(250, 250, 120);
		Circle e2 = new Circle(250, 250, 100);
		w.draw(e);
		w.draw(e2);
		w.fill(e);
		w.clear(e2);
		Circle f = new Circle(250, 250, 80);
		Circle f2 = new Circle(250, 250, 60);
		w.draw(f);
		w.draw(f2);
		w.fill(f);
		w.clear(f2);
		Circle g = new Circle(250, 250, 40);
		Circle g2 = new Circle(250, 250, 20);
		w.draw(g);
		w.draw(g2);
		w.fill(g);
		w.clear(g2);
	}
}

basically, you have to draw a larger ring, then a smaller one, fill the large one & finally clear the small one. It HAS to be in that order. Thats why im so confused as to how to put all this into a loop. Any help is greatly appreciated, thanks

Well, the part that is repeated is

        Circle c = new Circle(250, 250, 200);
        Circle c2 = new Circle(250, 250, 180);
        w.draw(c);
        w.draw(c2);
        w.fill(c);
        w.clear(c2);

and the only thing that changes throughout is the 3rd parameter so make it a variable, and then loop through decrementing it.

Originally Posted by Zula

Well, the part that is repeated is

        Circle c = new Circle(250, 250, 200);
        Circle c2 = new Circle(250, 250, 180);
        w.draw(c);
        w.draw(c2);
        w.fill(c);
        w.clear(c2);

and the only thing that changes throughout is the 3rd parameter so make it a variable, and then loop through decrementing it.

Window w = new Window(500, 500);
		for(int i=200; i>=20; i-=20)
		{
			Circle c = new Circle(250, 250, i);
			w.draw(c);
			w.fill(c);
			w.clear(c);
		}

If I make a loop only decrementing the 3rd parameter it creates all the rings ok but it wont fill & clear them properly. I think i need two sets of circles, with both being drawn, n every 1st circle out of the pair to be filled & and every 2nd to be cleared. Thats the only way the bullseye can be created. Will this need nested loops maybe?

What are these draw and fill methods? Why don't you override paintComponent of a JPanel?

If you want help, you should probably provide an SSCCE that demonstrates what you're doing.

Originally Posted by KevinWorkman

What are these draw and fill methods? Why don't you override paintComponent of a JPanel?

If you want help, you should probably provide an SSCCE that demonstrates what you're doing.

Theyre part of a .jar file we received along with this worksheet. Would it help if i attached it?
w.draw(c); draws whatever shape you have initialized to variable c.
w.fill(c); fills this shape(default colour black)
w.clear(c); will clear the colour

and apologies for my ignorance but how do i provide a SSCCE?

This is actually a link that explains what an SSCCE is, I don't know why the forum doesn't make that more obvious: SSCCE

No, attaching the JAR probably wouldn't help. I was just curious what those methods were actually doing.

But just looking at your code, you're not doing the equivalent work. Hint: in your original, you had two circles that are were working with each time. In the loop version, you only have one.

Still use two circles, since the repeated part has two circles.

    for(int i = 200;i>=20;i-=40) {
        Circle c = new Circle(250, 250, i);
        Circle c2 = new Circle(250, 250, i-20);
        w.draw(c);
        w.draw(c2);
        w.fill(c);
        w.clear(c2);
    }

Hooray spoon feeding

Originally Posted by KevinWorkman

Hooray spoon feeding

Im honestly not looking to be spoon fed i'm just new to learning java n i've found certain things difficult to get my head around. I dont know anybody in my course yet & my lecturer hasnt been too helpful with replying to student queries so i thought this would be a good place to seek help.

Originally Posted by JavaPF

Thanks for your help with this guys.

I have moved thread to correct forum - AWT / Java Swing - Java Programming Forums

Apologies, I didnt notice this forum.

Thanks for the help everyone.