|
 |
Lesson 05 |
|
MemoryImageSource |
 |
 |
|
 |
| |
• [ MemoryImageSource ]
In this tutorial you will learn how to :
- use MemoryImageSource,
- grab pixels from an Image using PixelGrabber.
MemoryImageSource is an implementation of the ImageProducer interface which uses an array to produce pixel values for an Image. For more information take a look at sun documention in "AWT 1.1 Graphics & Image enhancements - AWT memory image dynamic update API".
• [ Code ]
// Lesson05
// - MemoryImageSource
// - PixelGrabber
// This code is better viewed with tab size=4
import java.applet.Applet;
import java.awt.image.*;
import java.awt.*;
public class Lesson05 extends Applet implements Runnable
{
int width,height; // applet width,height
int pixels[]; // pixels array
Image target; // Image
MemoryImageSource mis; // MemoryImageSource
Image backImage; // back Image
Graphics backGraphics; // back Graphics
Thread thread; // Thread
boolean threadRunning; // thread running ?
int spriteWidth, spriteHeight;
int spritePixels[]; // sprite pixels array
int spriteX,spriteY; // Sprite position
Color txtColor; // Text color
public void init()
{
width=Integer.parseInt(getParameter("width"));
height=Integer.parseInt(getParameter("height"));
// Init pixels array
pixels=new int[width*height];
// Init MemoryImageSource - pixels will be in 32bit ARGB format
DirectColorModel dcm=new DirectColorModel(32, 0xff0000, 0xff00, 0xff);
mis=new MemoryImageSource(width,height,dcm,pixels,0,width);
mis.setAnimated(true);
mis.setFullBufferUpdates(true);
target=createImage(mis);
// Init double buffering
backImage = createImage(width, height);
backGraphics = backImage.getGraphics();
// Load Image
Image image=getImage(getDocumentBase(),getParameter("image"));
MediaTracker mediatracker = new MediaTracker(this);
mediatracker.addImage(image, 0);
try { mediatracker.waitForID(0); }
catch(InterruptedException ex) {}
// Init sprite pixels array
spriteWidth = image.getWidth(null);
spriteHeight = image.getHeight(null);
spritePixels = new int[spriteWidth*spriteHeight];
// Grab pixels
PixelGrabber pg= new PixelGrabber(image,0,0,spriteWidth,spriteHeight,spritePixels,0,spriteWidth);
try { pg.grabPixels(); }
catch (InterruptedException e) {}
image=null; mediatracker=null;
spriteX = width/2;
spriteY = height/2;
txtColor = Color.white;
}
public void start() {
if(thread == null)
thread = new Thread(this);
threadRunning=true;
thread.start();
}
public void run()
{
while (threadRunning)
{
try
{
Thread.sleep(20); // sleep a while
}
catch(InterruptedException ex) {} // catch exception
drawSprite(spriteX,spriteY); // draw sprite
repaint(); // repaint will call update
}
}
public void stop() {
if(thread != null) {
threadRunning=false;
//thread.stop(); // this method has been deprecated
thread = null;
}
}
public void destroy()
{
}
public void paint(Graphics g)
{
mis.newPixels(0,0,width,height);
backGraphics.drawImage(target, 0, 0, this);
backGraphics.setColor(txtColor);
backGraphics.drawString("Lesson05",10,20);
g.drawImage(backImage, 0, 0, this);
}
// Overwrite imageUpdate
public boolean imageUpdate(Image image, int i1, int j1, int k, int i2, int j2) {
return true;
}
public void update(Graphics g)
{
paint(g);
}
public void drawSprite(int x, int y) {
int index=(y-spriteHeight/2)*width+(x-spriteWidth/2);
for (int i=0;i
{
for (int j=0;j
{
try { pixels[index+j] = spritePixels[j*spriteWidth+i]; }
catch (ArrayIndexOutOfBoundsException e) {}
}
index+=width;
}
}
public boolean mouseEnter(Event event, int i, int j) {
setCursor(new Cursor(Cursor.HAND_CURSOR)); // Change mouse cursor
return true;
}
public boolean mouseExit(Event event, int i, int j) {
setCursor(new Cursor(Cursor.DEFAULT_CURSOR)); // Change mouse cursor
return true;
}
public boolean mouseMove(Event event, int i, int j) {
spriteX=i;
spriteY=j;
return true;
}
}
|
• [ HTML TAG ]
<applet code="Lesson05.class" codebase = "lesson05" width="150" height="150">
<param name="image" value="lesson05/flare.jpg">
</applet>
|
• [ Source ]
- Lesson.java
|
|
 |
|
 |
|
|
