TransformersRotationTranslation.java Source code

Introduction

Here is the source code for TransformersRotationTranslation.java

Source

import java.awt.BasicStroke;
import java.awt.Color;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.RenderingHints;
import java.awt.Shape;
import java.awt.Stroke;
import java.awt.geom.AffineTransform;
import java.awt.geom.GeneralPath;
import java.awt.geom.Rectangle2D;

import javax.swing.JComponent;
import javax.swing.JFrame;

public class TransformersRotationTranslation extends JComponent {
    Shape axes, shape;

    int length = 54, arrowLength = 4, tickSize = 4;

    public TransformersRotationTranslation() {
        axes = createAxes();
        shape = createShape();
    }

    protected Shape createAxes() {
        GeneralPath path = new GeneralPath();

        // Axes.
        path.moveTo(-length, 0);
        path.lineTo(length, 0);
        path.moveTo(0, -length);
        path.lineTo(0, length);
        // Arrows.
        path.moveTo(length - arrowLength, -arrowLength);
        path.lineTo(length, 0);
        path.lineTo(length - arrowLength, arrowLength);
        path.moveTo(-arrowLength, length - arrowLength);
        path.lineTo(0, length);
        path.lineTo(arrowLength, length - arrowLength);
        // Half-centimeter tick marks
        float cm = 72 / 2.54f;
        float lengthCentimeter = length / cm;
        for (float i = 0.5f; i < lengthCentimeter; i += 1.0f) {
            float tick = i * cm;
            path.moveTo(tick, -tickSize / 2);
            path.lineTo(tick, tickSize / 2);
            path.moveTo(-tick, -tickSize / 2);
            path.lineTo(-tick, tickSize / 2);
            path.moveTo(-tickSize / 2, tick);
            path.lineTo(tickSize / 2, tick);
            path.moveTo(-tickSize / 2, -tick);
            path.lineTo(tickSize / 2, -tick);
        }
        // Full-centimeter tick marks
        for (float i = 1.0f; i < lengthCentimeter; i += 1.0f) {
            float tick = i * cm;
            path.moveTo(tick, -tickSize);
            path.lineTo(tick, tickSize);
            path.moveTo(-tick, -tickSize);
            path.lineTo(-tick, tickSize);
            path.moveTo(-tickSize, tick);
            path.lineTo(tickSize, tick);
            path.moveTo(-tickSize, -tick);
            path.lineTo(tickSize, -tick);
        }
        return path;
    }

    protected Shape createShape() {
        float cm = 72 / 2.54f;
        return new Rectangle2D.Float(cm, cm, 2 * cm, cm);
    }

    public void paint(Graphics g) {
        Graphics2D g2 = (Graphics2D) g;

        // Use antialiasing.
        g2.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON);

        // Move the origin to 75, 75.
        AffineTransform at = AffineTransform.getTranslateInstance(75, 75);
        g2.transform(at);

        // Draw the shapes in their original locations.
        g2.setPaint(Color.black);
        g2.draw(axes);
        g2.draw(shape);

        // Transform the Graphics2D.
        AffineTransform rat = new AffineTransform();
        rat.setToRotation(Math.PI / 6);
        rat.translate(100, 100);

        g2.transform(rat);

        // Draw the "new" shapes in dashed.
        Stroke stroke = new BasicStroke(1, BasicStroke.CAP_BUTT, BasicStroke.JOIN_BEVEL, 0, new float[] { 3, 1 },
                0);
        g2.setStroke(stroke);
        g2.draw(axes);
        g2.draw(shape);
    }

    public static void main(String[] a) {
        JFrame f = new JFrame();
        f.getContentPane().add(new TransformersRotationTranslation());
        f.setSize(350, 450);
        f.show();
    }
}