Masked Transparent color with drawImage?

[Pakz]

This is my first post here. hello!

I spend an hour or so looking into this but I have not figured out how to solve this one. The problem I have right now is that I want to draw a image that I created in my code with transparancy. I have a black color that should not be drawn.
I am using createimage and drawimage. Just the Java’s regular images. They have a mask color option don’t they?

How do you draw for say a mountain sprite on a grass sprite without erasing the grass besides the mountain edges.

Here is the code that I was working on.

import java.applet.*;
import java.awt.*;
import java.util.Random;

public class DataSpritesInJava02 extends Applet {
	Random	r = new Random();
	Graphics bufferGraphics;
    Image offscreen;
    Image image2;
    Image image3;
    Image image4;

    // Here I have stored a sprite that will be drawn onto the screen.
	// Note : you have to switch the x and y in the create sprite part to get
	// the right sprite view since the layout of array data has switched x and y view.
	private short tree1[][]={
							{0,0,0,0,0,0,1,1,1,1,1,0,0,0,0,0},
							{0,0,0,0,1,1,1,1,1,1,1,1,0,0,0,0},
							{0,0,0,1,1,1,1,1,1,1,1,1,1,0,0,0},
							{0,0,1,1,1,1,1,1,1,1,1,1,1,1,0,0},
							{0,0,1,1,1,1,1,1,1,1,1,1,1,1,0,0},
							{0,1,1,1,1,1,1,1,1,1,1,1,1,1,1,0},
							{1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1},
							{1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1},
							{1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1},
							{0,1,1,1,1,1,1,1,1,1,1,1,1,1,1,0},
							{0,0,1,1,1,1,1,1,1,1,1,1,1,1,0,0},
							{0,0,0,0,1,1,1,1,1,1,1,1,0,0,0,0},
							{0,0,0,0,0,0,0,2,2,0,0,0,0,0,0,0},
							{0,0,0,0,0,0,0,2,2,0,0,0,0,0,0,0},
							{0,0,0,0,0,0,0,2,2,0,0,0,0,0,0,0},
							{0,0,0,0,0,0,0,2,2,0,0,0,0,0,0,0}
							};
	private short mountain1[][]={
							{0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0},
							{0,0,0,0,0,0,0,3,3,0,0,0,0,0,0,0},
							{0,0,0,0,0,0,0,3,3,0,0,0,0,0,0,0},
							{0,0,0,0,0,0,3,3,3,3,0,0,0,0,0,0},
							{0,0,0,0,0,0,3,3,3,3,0,0,0,0,0,0},
							{0,0,0,0,0,3,3,3,3,3,3,0,0,0,0,0},
							{0,0,0,0,0,3,3,3,3,3,3,0,0,0,0,0},
							{0,0,0,0,3,3,3,3,3,3,3,3,0,0,0,0},
							{0,0,0,0,3,3,3,3,3,3,3,3,0,0,0,0},
							{0,0,0,3,3,3,3,3,3,3,3,3,3,0,0,0},
							{0,0,0,3,3,3,3,3,3,3,3,3,3,0,0,0},
							{0,0,3,3,3,3,3,3,3,3,3,3,3,3,0,0},
							{0,0,3,3,3,3,3,3,3,3,3,3,3,3,0,0},
							{0,3,3,3,3,3,3,3,3,3,3,3,3,3,3,0},
							{0,3,3,3,3,3,3,3,3,3,3,3,3,3,3,0},
							{3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3},
							};

	private short ground1[][]={
							{0,0,0,0,1,1,0,0,0,0,0,0,1,0,0,0},
							{0,1,0,0,0,0,0,0,0,0,0,0,1,1,0,0},
							{0,0,1,0,0,0,0,0,0,0,0,0,1,1,0,0},
							{0,0,1,1,1,1,0,0,0,0,0,0,0,1,1,0},
							{0,0,1,1,1,1,0,0,0,1,0,0,0,0,1,0},
							{1,0,0,0,1,1,0,0,0,1,0,0,0,0,0,1},
							{1,0,0,0,0,0,0,0,0,1,0,0,0,0,0,0},
							{0,0,0,0,1,0,0,0,0,1,1,0,0,0,0,0},
							{0,0,0,0,0,1,0,0,0,1,1,1,0,0,0,0},
							{0,0,0,0,0,0,0,0,0,1,1,1,1,0,0,0},
							{0,0,1,0,0,0,0,0,0,0,1,1,1,0,0,0},
							{0,0,1,1,0,0,0,0,0,0,1,1,1,1,0,0},
							{0,1,1,1,0,0,0,0,1,0,0,1,1,1,0,0},
							{0,1,1,1,1,1,0,0,1,1,0,0,1,1,0,0},
							{0,0,0,0,1,1,1,0,0,0,0,0,0,1,0,0},
							{0,0,0,0,0,1,1,1,0,0,0,0,1,0,0,0},
							};
     public void init(){
        setBackground(Color.black);
        offscreen = createImage(getSize().width,getSize().height);
       	bufferGraphics = offscreen.getGraphics();

 		image2 = createImage(16,16);
  		Graphics test1 = image2.getGraphics();
     	for( int y = 0 ; y < 16 ; y++ ){
     		for ( int x = 0 ; x < 16 ; x++ ){
				test1.setColor(Color.black);
	     		if (tree1[x][y] == 1 ){
  		   			test1.setColor(Color.green);
     			}
     			if (tree1[x][y] == 2 ){
     				test1.setColor(new Color(200,100,0));
     			}
				// Here we draw the pixel.
     			test1.fillRect(y,x,1,1);
     		}
     	}
 		image3 = createImage(16,16);
  		Graphics test2 = image3.getGraphics();
     	for( int y = 0 ; y < 16 ; y++ ){
     		for ( int x = 0 ; x < 16 ; x++ ){
				test2.setColor(Color.black);
	     		if (mountain1[x][y] == 3 ){
  		   			test2.setColor(new Color(100,100,100));
     			}
     			test2.fillRect(y,x,1,1);
     		}
     	}

 		image4 = createImage(16,16);
  		Graphics test3 = image4.getGraphics();
     	for( int y = 0 ; y < 16 ; y++ ){
     		for ( int x = 0 ; x < 16 ; x++ ){
				test3.setColor(new Color(30,200,10));
	     		if (ground1[x][y] == 1 ){
  		   			test3.setColor(new Color(50,220,20));
     			}
     			test3.fillRect(y,x,1,1);
     		}
     	}


     }


	public void paint(Graphics g){
    	bufferGraphics.clearRect(0,0,getSize().width,getSize().height);
    	bufferGraphics.setColor(Color.red);
        bufferGraphics.drawString("Data [][] Sprites - Tiny trees.",10,10);
        for( int y = 0 ; y < 10 ; y++){
        	for( int x = 0 ; x < 16 ; x++){
        		bufferGraphics.drawImage(image4,32+x*16,32+y*16,new Color(0,0,0),this);
        	}
        }

  		int r1 = 0;
        for( int y = 0 ; y < 10 ; y++){
        	for( int x = 0 ; x < 16 ; x++){
  				r1 = r.nextInt(4);
  				if (r1 == 1){
  					bufferGraphics.drawImage(image2,32+x*16,32+y*16,new Color(0,0,0),this);
  				}
  				if (r1 == 0){
  					bufferGraphics.drawImage(image3,32+x*16,32+y*16,new Color(0,0,0),this);
  				}
        	}
        }
        g.drawImage(offscreen,0,0,this);
     }
     public void update(Graphics g){
          paint(g);
     }
 }

Oh and how do you return a color value from a method? return new Color(10,10,10) in this kind of way?

Java is kind of difficult for me as a beginner.

[zoto]

[quote]I have a black color that should not be drawn.
[/quote]
Use

new Color(0, 0, 0, 0)

the 4th argument is the alpha level.

[quote]Oh and how do you return a color value from a method? return new Color(10,10,10) in this kind of way?
[/quote]
Not really sure what problem you are having with this.

public Color getColor(){
  return new Color(10,10,10);
}

[philfrei]

Just to supplement the previous reply, you will also want to set your Image to type “TYPE_INT_ARGB” in order to take advantage of the alpha channel (0 = transparent, 255 = fully opaque).

I usually do pixel editing via a BufferedImage defined like so:

img = new BufferedImage(width, height, BufferedImage.TYPE_INT_ARGB);	

[Pakz]

I got it working thank you.

I guess regular images do not have the transparant mode since I did not get that working but with the bufferedimages it did work.

If anyone is interested here is the working code. (no external media is used)

import java.applet.*;
import java.awt.*;
import java.util.Random;
import java.awt.image.BufferedImage;


public class DataSpritesInJava02 extends Applet {
	Random	r = new Random();
	Graphics bufferGraphics;
    Image offscreen;
    Image image2;
    Image image3;
    Image image4;

    // Here I have stored a sprite that will be drawn onto the screen.
	// Note : you have to switch the x and y in the create sprite part to get
	// the right sprite view since the layout of array data has switched x and y view.
	private short tree1[][]={
							{0,0,0,0,0,0,1,1,1,1,1,0,0,0,0,0},
							{0,0,0,0,1,1,1,1,1,1,1,1,0,0,0,0},
							{0,0,0,1,1,1,1,1,1,1,1,1,1,0,0,0},
							{0,0,1,1,1,1,1,1,1,1,1,1,1,1,0,0},
							{0,0,1,1,1,1,1,1,1,1,1,1,1,1,0,0},
							{0,1,1,1,1,1,1,1,1,1,1,1,1,1,1,0},
							{1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1},
							{1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1},
							{1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1},
							{0,1,1,1,1,1,1,1,1,1,1,1,1,1,1,0},
							{0,0,1,1,1,1,1,1,1,1,1,1,1,1,0,0},
							{0,0,0,0,1,1,1,1,1,1,1,1,0,0,0,0},
							{0,0,0,0,0,0,0,2,2,0,0,0,0,0,0,0},
							{0,0,0,0,0,0,0,2,2,0,0,0,0,0,0,0},
							{0,0,0,0,0,0,0,2,2,0,0,0,0,0,0,0},
							{0,0,0,0,0,0,0,2,2,0,0,0,0,0,0,0}
							};
	private short mountain1[][]={
							{0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0},
							{0,0,0,0,0,0,0,3,3,0,0,0,0,0,0,0},
							{0,0,0,0,0,0,0,3,3,0,0,0,0,0,0,0},
							{0,0,0,0,0,0,3,3,3,3,0,0,0,0,0,0},
							{0,0,0,0,0,0,3,3,3,3,0,0,0,0,0,0},
							{0,0,0,0,0,3,3,3,3,3,3,0,0,0,0,0},
							{0,0,0,0,0,3,3,3,3,3,3,0,0,0,0,0},
							{0,0,0,0,3,3,3,3,3,3,3,3,0,0,0,0},
							{0,0,0,0,3,3,3,3,3,3,3,3,0,0,0,0},
							{0,0,0,3,3,3,3,3,3,3,3,3,3,0,0,0},
							{0,0,0,3,3,3,3,3,3,3,3,3,3,0,0,0},
							{0,0,3,3,3,3,3,3,3,3,3,3,3,3,0,0},
							{0,0,3,3,3,3,3,3,3,3,3,3,3,3,0,0},
							{0,3,3,3,3,3,3,3,3,3,3,3,3,3,3,0},
							{0,3,3,3,3,3,3,3,3,3,3,3,3,3,3,0},
							{3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3},
							};

	private short ground1[][]={
							{4,4,4,4,5,5,4,4,4,4,4,4,5,4,4,4},
							{4,5,4,4,4,4,4,4,4,4,4,4,5,5,4,4},
							{4,4,5,4,4,4,4,4,4,4,4,4,5,5,4,4},
							{4,4,5,5,5,5,4,4,4,4,4,4,4,5,5,4},
							{4,4,5,5,5,5,4,4,4,5,4,4,4,4,5,4},
							{5,4,4,4,5,5,4,4,4,5,4,4,4,4,4,5},
							{5,4,4,4,4,4,4,4,4,5,4,4,4,4,4,4},
							{4,4,4,4,5,4,4,4,4,5,5,4,4,4,4,4},
							{4,4,4,4,4,5,4,4,4,5,5,5,4,4,4,4},
							{4,4,4,4,4,4,4,4,4,5,5,5,5,4,4,4},
							{4,4,5,4,4,4,4,4,4,4,5,5,5,4,4,4},
							{4,4,5,5,4,4,4,4,4,4,5,5,5,5,4,4},
							{4,5,5,5,4,4,4,4,5,4,4,5,5,5,4,4},
							{4,5,5,5,5,5,4,4,5,5,4,4,5,5,4,4},
							{4,4,4,4,5,5,5,4,4,4,4,4,4,5,4,4},
							{4,4,4,4,4,5,5,5,4,4,4,4,5,4,4,4},
							};
     public void init(){
        setBackground(Color.black);
        offscreen = createImage(getSize().width,getSize().height);
       	bufferGraphics = offscreen.getGraphics();

 		image2 = new BufferedImage(16, 16, BufferedImage.TYPE_INT_ARGB);
  		Graphics test1 = image2.getGraphics();
     	for( int y = 0 ; y < 16 ; y++ ){
     		for ( int x = 0 ; x < 16 ; x++ ){
				test1.setColor(getcolor(tree1[x][y]));
     			test1.fillRect(y,x,1,1);
     		}
     	}
 		image3 = new BufferedImage(16, 16, BufferedImage.TYPE_INT_ARGB);
  		Graphics test2 = image3.getGraphics();
     	for( int y = 0 ; y < 16 ; y++ ){
     		for ( int x = 0 ; x < 16 ; x++ ){
				test2.setColor(getcolor(mountain1[x][y]));
     			test2.fillRect(y,x,1,1);
     		}
     	}

 		image4 = new BufferedImage(16, 16, BufferedImage.TYPE_INT_ARGB);
  		Graphics test3 = image4.getGraphics();
     	for( int y = 0 ; y < 16 ; y++ ){
     		for ( int x = 0 ; x < 16 ; x++ ){
				test3.setColor(getcolor(ground1[x][y]));
     			test3.fillRect(y,x,1,1);
     		}
     	}


     }


	public Color getcolor(int c){
		if (c ==  0 ) return new Color(0,0,0,0);
		if (c ==  1 ) return new Color(0,240,0,255);
		if (c ==  2 ) return new Color(200,100,0,255);
		if (c ==  3 ) return new Color(200,200,200,255);
		if (c ==  4 ) return new Color(30,200,10,255);
		if (c ==  5 ) return new Color(50,220,20,255);
		return new Color(0,0,0,0);
	}

	public void paint(Graphics g){
    	bufferGraphics.clearRect(0,0,getSize().width,getSize().height);
    	bufferGraphics.setColor(Color.red);
        bufferGraphics.drawString("Data [][] Sprites - Tiny trees.",10,10);
        for( int y = 0 ; y < 10 ; y++){
        	for( int x = 0 ; x < 16 ; x++){
        		bufferGraphics.drawImage(image4,32+x*16,32+y*16,this);
        	}
        }

  		int r1 = 0;
        for( int y = 0 ; y < 10 ; y++){
        	for( int x = 0 ; x < 16 ; x++){
  				r1 = r.nextInt(4);
  				if (r1 == 1){
  					bufferGraphics.drawImage(image2,32+x*16,32+y*16,this);
  				}
  				if (r1 == 0){
  					bufferGraphics.drawImage(image3,32+x*16,32+y*16,this);
  				}
        	}
        }
        g.drawImage(offscreen,0,0,this);
     }
     public void update(Graphics g){
          paint(g);
     }
 }

[pitbuller]

I would use color array for swiching colors. But usually I just try over optimize not important things.

final static Color[] colors = {new Color(0,0,0,0),new Color(0,240,0,255),new Color(200,100,0,255),new Color(200,200,200,255),new Color(30,200,10,255),new Color(50,220,20,255)};