With this tutorial we shall show you how to swap RGB values in an Image. This is very useful when you are trying to create some effects to your Application.
Basically all you have to do in order to swapp RGD values of an Image is:
- Create a
GeneralPathclass instance - Use
moveTo,lineTo,quadTo,curveToandclosePathto draw the basic lines and curves (their names are pretty representative of the functions they perform) - And simply paint the shape in a new
Frame
Let’s see how the code looks like:
packace com.javacodegeeks.snippets.desktop;
import java.awt.Component;
import java.awt.Frame;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.geom.GeneralPath;
public class CreateShapes {
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;
GeneralPath shape = new GeneralPath();
shape.moveTo(x, y);
shape.lineTo(w/4, h/2);
shape.quadTo(3*w/2, 4*h/3, x/2, y/3);
shape.curveTo(w, h, w/2, h/4, x, y);
shape.closePath();
g2d.draw(shape);
}
}
}
This was an example on how to create a Shape from Lines and Curves
