java turtle graphics and iterations - java

import java.awt.*;
public class TurtleGraphicsDemo2 {
public static void main(String[] args) {
World worldObj = new World();
Turtle myrtleTheTurtle = new Turtle(0, 0, worldObj);
drawLine(myrtleTheTurtle, Color.RED, 10, 20, 50, 20); //invokes the first drawLine() method
drawLine(myrtleTheTurtle, 100, 150, 50, -45); //invokes the second drawLine() method
drawLine(myrtleTheTurtle, 100, 150, 100, 60); //invokes the second drawLine() method
drawLine(myrtleTheTurtle, Color.BLUE, 10, 40, 100, 40); //invokes the first drawLine() method
}//end of main method
}//end of class
Here is the error:
TurtleGraphicsDemo2.java:19: error: cannot find symbol
drawLine(myrtleTheTurtle, Color.RED, 10, 20, 50, 20);
^
symbol: method drawLine(Turtle,Color,int,int,int,int)
location: class TurtleGraphicsDemo2
My programming teacher gave us this to experiment with but I get a drawLine error, anyone know why? I do not have much experience in Java, only python. If you can fix this, or know of how I can fix it, thank you. If not, thanks for looking anyway :)

You can draw lines only inside a Canvas, using Graphics2D
class MyCanvas extends Canvas {
public MyCanvas () {
setBackground (Color.GRAY);
setSize(300, 300);
}
public void paint (Graphics g) {
Graphics2D g2;
g2 = (Graphics2D) g;
g2.drawString ("It is a custom canvas area", 70, 70);
}
}

Related

How to tilt an elipse in Java?

I have a task: draw a human figure (then it should start moving).
I draw it with primitive figures. When it came to drawing arms and legs, I realized that I needed to use Elipse2d instead of Oval and I need to position it at an angle relative to the body.
I found out that I need AffineTransform, but my attempts to apply it ended with nothing. "Arms" remain parallel to the coordinate axis.
Here is my code:
public class Main extends JFrame {
public static void main(String[] args) {
new Main("Human");
}
public Main(String title) {
super(title);
setBounds(300, 75, 1000,710);
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
setVisible(true);
}
public void paint(Graphics g) {
super.paint(g);
Graphics2D g2 = (Graphics2D) g;
Color skin = new Color((int) 255, (int) 235, (int) 205);
g2.setColor(skin);
//body
g2.fillOval(85, 160, 120, 220);
//face
Ellipse2D face = new Ellipse2D.Double(100, 50, 90, 120);
g2.fill(face);
//arms
Ellipse2D armR = new Ellipse2D.Double(85, 180, 30, 240);
g2.fill(armR);
/* this part isn't working:
AffineTransform tx = new AffineTransform();
tx.getRotateInstance(Math.PI / 4)
.createTransformedShape(armR);
g2.setTransform(tx); */
Ellipse2D armL = new Ellipse2D.Double(175, 180, 30, 240);
g2.fill(armL);
/* this part isn't working:
AffineTransform tx = new AffineTransform();
tx.getRotateInstance(Math.PI / 4)
.createTransformedShape(armL);
g2.setTransform(tx); */
//legs
Ellipse2D legL = new Ellipse2D.Double(100, 365, 40, 280);
g2.fill(legL);
Ellipse2D legR = new Ellipse2D.Double(150, 365, 40, 280);
g2.fill(legR);
Please help me with code where the tilt will work :))

AffineTransform: how to scale only one shape Triangle

I have this code:
import javax.swing.*;
import java.awt.*;
public class Test {
public static void main(String[] args) {
JFrame window = new JFrame();
window.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
window.setBounds(30, 30, 300, 300);
window.getContentPane().add(new MyCanvas());
window.setVisible(true);
}
}
class MyCanvas extends JComponent {
public void paint(Graphics g) {
g.drawRect (10, 10, 100, 100);
Polygon triangle = new Polygon(new int[] {100, 150, 200}, new int[] {200, 100, 200}, 3);
g.drawPolygon(triangle);
}
}
It draws this:
I want to scale only Triangle, so it becomes thrice is big:
I understand that I need to use AffiniteTransform, but I don't understand how.
I only know that I need the scaling instance:
AffineTransform at = AffineTransform.getScaleInstance(3, 3);
All answers I've seen were very confusing or just used g2d.setTransform(at) which doesn't seem to be what I need, seeing as the square is supposed to stay the same size.
EDIT: And how do I scale a Triagle, while keeping its leftmost coordinate at the same location? (leftmost (x,y) stays the same)
New code:
public class Test {
public static void main(String[] args) {
JFrame window = new JFrame();
window.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
window.setBounds(30, 30, 300, 300);
window.getContentPane().add(new MyCanvas());
window.setVisible(true);
}
}
class MyCanvas extends JComponent {
public void paint(Graphics g) {
g.drawRect (10, 10, 100, 100);
Polygon triangle = new Polygon(new int[] {100, 150, 200}, new int[] {200, 100, 200}, 3);
AffineTransform at = AffineTransform.getScaleInstance(1.5, 1.5);
((Graphics2D) g).setTransform(at);
g.drawPolygon(triangle);
((Graphics2D) g).setTransform(AffineTransform.getScaleInstance(1,1));
validate();
}
}
gives this:
The triangle shifts as it gets scaled.
Is it possible to keep the triangle at the same spot - that is to keep its leftmost bottom corner at the same spot?

Java Multithreading with GUI (Kind of Traffic Simulator)

I need to implement a solution for a narrow bridge and i am new to java threads and gui.
I have three roads and 1 bridge(has two lane).20 Vehicles for each road should be created randomly and should get passed to bridge depending of the light on its road.
But first I just wanna solve an easy issue which is how can i move a car on this road with thread?(Sleep 1 second and move little bit.)
I thought like that:
I have created the roads with simple PaintComponent function override(I am not sure if its gonna be implemented like that too).
Created a road class and a vehicle class which implements runnable.
I created an array of 20 vehicles in Road class and stuck here.
How should I add this to a JPanel and move it right every 1 seconds?
Am I totally wrong about how to implement that problem because i have background on C family ?
My Code:
public class NarrowBridge {
public static void main(String[] args) {
JFrame myFrame = new JFrame();
PanelSetter newPanel = new PanelSetter();
myFrame.add(newPanel);
myFrame.setDefaultCloseOperation(EXIT_ON_CLOSE);
myFrame.setSize(600, 600);
myFrame.setTitle("Narrow Bridge Problem ");
myFrame.setLocationRelativeTo(null);//To centralize the jframe.
myFrame.setVisible(true);
}
}
class PanelSetter extends JPanel {
public Road Road1 = new Road(true);
public Road Road2 = new Road(false);
public Road Road3 = new Road(false);
#Override
public void paintComponent(Graphics g) {
super.paintComponent(g);
//Fixed Roads Drawing.
g.setColor(Color.BLACK);
g.drawLine(50, 100, 200, 100);
g.drawLine(50, 130, 200, 130);
g.setColor(Color.BLACK);
g.drawLine(50, 210, 200, 210);
g.drawLine(50, 240, 200, 240);
g.setColor(Color.BLACK);
g.drawLine(50, 320, 200, 320);
g.drawLine(50, 350, 200, 350);
//Road 1 Light.
if (Road1.getLight()) {
g.setColor(Color.GREEN);
g.fillOval(180, 70, 20, 20);
} else {
g.setColor(Color.RED);
g.fillOval(180, 70, 20, 20);
}
//Road 2 Light.
if (Road2.getLight()) {
g.setColor(Color.GREEN);
g.fillOval(180, 180, 20, 20);
} else {
g.setColor(Color.RED);
g.fillOval(180, 180, 20, 20);
}
//Road 3 Light.
if (Road3.getLight()) {
g.setColor(Color.GREEN);
g.fillOval(180, 290, 20, 20);
} else {
g.setColor(Color.RED);
g.fillOval(180, 290, 20, 20);
}
}
}
Road is just a simple class which only has boolean light and the thing i tried which is vehicle[] vehicles=new vehicle[20].
Finally i solved my problem with the help of Java Applets.
I am able to pass the applet as a parameter and I am calling it's paint() function and updating screen.

EasterEgg in Java

package easteregg;
import java.awt.Graphics;
import javax.swing.JComponent;
import javax.swing.JFrame;
class MyCanvas extends JComponent {
public void paint(Graphics g) {
g.drawOval (100, 20, 110, 160);
}
}
public class EasterEgg {
public static void main(String[] a) {
JFrame window = new JFrame();
window.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
window.setBounds(30, 30, 300, 300);
window.getContentPane().add(new MyCanvas());
window.setVisible(true);
}
}
my problem is i dont know how to put lines inside the oval
i want to make a easterEgg please help me
i have modified the paint method to draw one pattern please check the below code
public void paint(Graphics g) {
g.drawOval (100, 20, 110, 160);
g.drawLine(120, 40, 140, 60);
g.drawLine(140, 60, 150, 40);
g.drawLine(150, 40, 170, 60);
g.drawLine(170, 60, 190,40);
}
and the output is
this is just a hint to draw lines but better to create one method which will draw that pattern form one end to other end of the oval

Removing a circle from JFrame

I am creating a Towers of Hanoi game and have sucedded in printing the shapes with a time delay (that part of the code has been removed while I try to get all the ovals where they are supposed to be) I am wondering how I would go about removing the circle. As you can see I have tried the clearRect(); method but that doesn't work. Is there a way I can set if the method is visible on JPanel since each circle has its own method? I think that would be the easiest way but if anyone has a better idea go for it! Thanks for any help and I have attached my code
package towersofhanoi;
import javax.swing.*;
import java.awt.*;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.lang.Object;
/*g.fillOval(60 = horizontal distance , 540= vertical distance, 400 = width, 60 = height) */
public class TowersOfHanoi extends JPanel {
private int clock = 0;
private Color circles = new Color(176, 56, 251);
public static void main(String[] args) {
// Print the shapes and frame
TowersOfHanoi drawRectangle = new TowersOfHanoi();
JFrame frame = new JFrame("Towers of Hanoi");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.getContentPane().add(drawRectangle);
frame.setSize(1250, 800);
frame.setVisible(true);
Timer timer = new Timer(1000, new ActionListener() {
#Override
public void actionPerformed(ActionEvent e) {
drawRectangle.nextFrame();
drawRectangle.repaint();
}
});
timer.setRepeats(true);
timer.start();
}
public void nextFrame() {
clock++;
}
public void paintComponent(Graphics g) {
super.paintComponent(g);
frame1(g);
frame2(g);
frame3(g);
frame4(g);
frame5(g);
frame6(g);
frame7(g);
frame8(g);
frame9(g);
}
private Color frame1(Graphics g) {
Color pegs = new Color(251, 129, 56);
g.setColor(pegs);
// peg 1
g.fillRect(250, 300, 25, 450);
// peg 2
g.fillRect(600, 300, 25, 450);
// peg 3
g.fillRect(950, 300, 25, 450);
// bottom
g.fillRect(200, 700, 825, 50);
// create a color for circles
// cirle 7 (Labeled from bottom to top)
g.setColor(circles);
g.fillOval(60, 640, 400, 60);
g.setColor(Color.BLACK);
g.drawOval(60, 640, 400, 60);
return circles;
}
private void frame2(Graphics g) {
// circle 6
g.setColor(circles);
g.fillOval(85, 580, 350, 60);
g.setColor(Color.BLACK);
g.drawOval(85, 580, 350, 60);
}
private void frame3(Graphics g) {
// circle 5
g.setColor(circles);
g.fillOval(110, 520, 300, 60);
g.setColor(Color.BLACK);
g.drawOval(110, 520, 300, 60);
}
private void frame4(Graphics g) {
// circle 4
g.setColor(circles);
g.fillOval(135, 465, 250, 55);
g.setColor(Color.BLACK);
g.drawOval(135, 465, 250, 55);
}
private void frame5(Graphics g) {
// circle 3
g.setColor(circles);
g.fillOval(160, 420, 200, 45);
g.setColor(Color.BLACK);
g.drawOval(160, 420, 200, 45);
}
private void frame6(Graphics g) {
// circle 2
g.setColor(circles);
g.fillOval(185, 380, 150, 40);
g.setColor(Color.BLACK);
g.drawOval(185, 380, 150, 40);
}
private void frame7(Graphics g) {
// circle 1
g.setColor(circles);
g.fillOval(210, 345, 100, 35);
g.setColor(Color.BLACK);
g.drawOval(210, 345, 100, 35);
}
public void frame8(Graphics g) {
g.clearRect(210, 345, 100, 35);
g.setColor(circles);
g.fillOval(560, 665, 100, 35);
g.setColor(Color.BLACK);
g.drawOval(560, 665, 100, 35);
}
public void frame9(Graphics g) {
g.clearRect(185, 380, 150, 40);
g.setColor(circles);
g.fillOval(890, 660, 150, 40);
g.setColor(Color.BLACK);
g.drawOval(890, 660, 150, 40);
}
}
I am wondering how I would go about removing the circle.
The super.paintComponent(...) will clear the painting on the panel so that is all the is needed.
As you can see I have tried the clearRect();
It is not needed (see my comment above), but then you invoke the fillOval(...) and drawOval(...) methods again so the painting is redone. So the code is doing exactly as you asked it to do.
Is there a way I can set if the method is visible on JPanel
You need a Boolean indicator telling the paint method what to do. Something like:
if (paintOval1)
frame1(g);
if (paintOval2)
frame2(g);
Of course that is approach is very brute force and not a very good approach if for say you have 100 circles to paint. The code become too big.
So, instead you should create a custom class that contains four properties (x, y, width, height, isPainted). Then you create an instance of this class for each circle and add the class to an ArrayList. Something like:
ArrayList<CustomClass> circles = new ArrayList<CustomClass>();
circles.add( new CustomClass(60, 640, 400, 60, true) );
circles.add( new CustomClass(85, 580, 350, 60, true) );
Then in the paintCompnent() method your code becomes simpler:
for (CustomClass circle: circles.get)
{
if (circle.isPainted())
{
g.setColor(...);
g.fillOval(circle.getX(), circle,getY(), circle.getWidth(), circle.getHeight());
...
}
}
Finally you would need a method to change the state of painting a circle. Something like:
pubic void setCirclePainted(int circle, Boolean isPainted)
{
CustomClass circle = circles.get(circle);
circle.setPainted( isPainted );
}
So the key for you is to create your "CustomClass" and give it a proper name. Then you need to implement all the getter/setter methods of the class so you can access the properties of the class.
I actually found that the easiest way for me to understand and do was to use else and else if statements to display the shape based on time. Thanks for the other suggestions though!
public void paintComponent(Graphics g) {
super.paintComponent(g);
frame1(g);
frame2(g);
frame3(g);
frame4(g);
if (clock<= 5) {
frame5(g);
}
else if(clock >= 6) {
frame9(g);
}
frame6(g);
frame7(g);
frame8(g);
}

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