With this example will shall show you four fundamental graphical transformations that you should know when you try to construct you own custom graphical environment or develop simple graphics.
In short in order to perform Scaling, Shearing, Translation and Rotation to a simple shape, one should take the following steps:
- Use
RoundRectangle2Dto construct a simple rectangle shape - Use
AffineTransformclass and its methods scale, translate, shear, rotate to set up the transformations - Use
AffineTransformOpclass an its methodfilterto perform this transformations to the shape - And simply paint the shape in a new
Frame
Now let’s take a look at the code:
package com.javacodegeeks.snippets.desktop;
import java.awt.Component;
import java.awt.Frame;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.Shape;
import java.awt.geom.AffineTransform;
import java.awt.geom.RoundRectangle2D;
public class TransformShapes {
public static void main(String[] args) {
// Create a frame
Frame frame = new Frame();
// Add a component with a custom paint method
frame.add(new CustomPaintComponent());
// Display the frame
int frameWidth = 300;
int frameHeight = 300;
frame.setSize(frameWidth, frameHeight);
frame.setVisible(true);
}
/**
* To draw on the screen, it is first necessary to subclass a Component
* and override its paint() method. The paint() method is automatically called
* by the windowing system whenever component's area needs to be repainted.
*/
static class CustomPaintComponent extends Component {
public void paint(Graphics g) {
// Retrieve the graphics context; this object is used to paint shapes
Graphics2D g2d = (Graphics2D)g;
/**
* The coordinate system of a graphics context is such that the origin is at the
* northwest corner and x-axis increases toward the right while the y-axis increases
* toward the bottom.
*/
int x = 0;
int y = 0;
int w = getSize().width-1;
int h = getSize().height-1;
Shape roundRectangle = new RoundRectangle2D.Float(x, y, w, h, w/2, h/2);
AffineTransform affineTransform = new AffineTransform();
affineTransform.scale(0.6, 0.4);
affineTransform.shear(0.3, 0.7);
affineTransform.translate(w/4, h/4);
affineTransform.rotate(0.12);
Shape newRoundRectangle = affineTransform.createTransformedShape(roundRectangle);
g2d.draw(roundRectangle);
g2d.draw(newRoundRectangle);
}
}
}
This was an example on how to perform Scaling, Shearing Translation and Rotation on a Shape.
