How to render string in graphics2d by draw pixels for each string....

Question

How do you draw a text of graphics2d onto screen? BUT without using the drawstring method which just prints the text out.
What i basically want is to render the text, one pixel of the text string at a time.
for e.g. say i want to draw the word "hello", what i want is that it starts at letter "H" by drawing pixel of top to bottom at a speed which i can control (latter stuff)

Answer 1

This would be a good starting point:
import java.awt.*;
import java.awt.image.BufferedImage;
import javax.swing.*;
public class PerPixelStringRenderDemo extends JFrame {
     private PerPixelStringRenderPanel cp;
     public PerPixelStringRenderDemo() {
          Font font = new Font("Sans Serif", Font.ITALIC, 48);
          cp = new PerPixelStringRenderPanel(font, "Hello, World!", false);
          cp.setDelay(0, 100);
          setContentPane(cp);
          setTitle("Per-Pixel String Rendering");
          setDefaultCloseOperation(EXIT_ON_CLOSE);
          pack();
     public void setVisible(boolean visible) {
          super.setVisible(visible);
          if (visible) {
               cp.start(true);
     public static void main(String[] args) {
          SwingUtilities.invokeLater(new Runnable() {
               public void run() {
                    new PerPixelStringRenderDemo().setVisible(true);
     private class PerPixelStringRenderPanel extends JPanel implements Runnable {
          private BufferedImage bi;
          private Thread timerThread;
          private int pixelCount, maxPixelCount;
          private int delayMillis, delayNanos;
          private boolean lineOriented;
          public PerPixelStringRenderPanel(Font font, String text,
                                                  boolean lineOriented) {
               this.lineOriented = lineOriented;
               bi = createImage(font, text);
               setDelay(1, 0);
          private BufferedImage createImage(Font font, String text) {
               FontMetrics fm = getFontMetrics(font);
               int width = fm.stringWidth(text);
               int height = fm.getHeight();
               maxPixelCount = width * height;
               BufferedImage bi = new BufferedImage(width, height,
                                                  BufferedImage.TYPE_INT_ARGB);
               setPreferredSize(new Dimension(width, height));
               int y = fm.getAscent();
               Graphics2D g2d = (Graphics2D)bi.createGraphics();
               g2d.setFont(font);
               g2d.setColor(Color.BLACK);
               g2d.drawString(text, 0,y);
               g2d.dispose();
               return bi;
          protected void paintComponent(Graphics g) {
               super.paintComponent(g);
               int w = bi.getWidth();
               int drawnRowCount = pixelCount/w;
               g.drawImage(bi, 0,0,w+1,drawnRowCount+1, 0,0,w+1,drawnRowCount+1,null);
               int remaining = pixelCount%w;
               g.drawImage(bi, 0,drawnRowCount+1, remaining+1,drawnRowCount+2,
                                   0,drawnRowCount+1, remaining+1,drawnRowCount+2,
                                   null);
          public void run() {
               pixelCount = 0;
               while (pixelCount<maxPixelCount) {
                    try {
                         Thread.sleep(delayMillis, delayNanos);
                    } catch (InterruptedException ie) {
                         break; // Thread stopped via interrupt()
                    repaint();
                    pixelCount += lineOriented ? bi.getWidth() : 1;
          public void setDelay(int millis, int nanos) {
               delayMillis = millis;
               delayNanos = nanos;
          public void start(boolean reset) {
               stop();
               if (reset) {
                    pixelCount = 0;
               timerThread = new Thread(this);
               timerThread.start();
          public void stop() {
               if (timerThread!=null) {
                    timerThread.interrupt();
                    try {
                         timerThread.join();
                    } catch (InterruptedException ie) {}
                    timerThread = null;
}It allows you to toggle between drawing one pixel at a time and one row of pixels at a time. If you do the former (what you asked for in this post), you'll have to set the delay pretty low, as it takes longer than you think to draw each pixel individually. If you do the latter, you'll want to set the delay much higher (in the milliseconds), because it's very fast to draw 1 line at a time.